From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62BFDC6FA99 for ; Fri, 24 Feb 2023 07:28:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229789AbjBXH2A (ORCPT ); Fri, 24 Feb 2023 02:28:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbjBXH1z (ORCPT ); Fri, 24 Feb 2023 02:27:55 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2AC91EBDF; Thu, 23 Feb 2023 23:27:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223646; x=1708759646; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=4bpIJXn+Cqwm7qv6s3tf9xXrKBIQ0tJR6b3uTXiGGZk=; b=mQVj+Agy8UqmTAVhyCXCy+j1egXSUIKmp8HJRNvT3usuwVmsXQNlqEfM 3VrvOo6FcJlM7cinR16lFGi9f9cDQJcisnGofqA2VLjYtjYXPliRs4bSj hk96IDFNhj3GLJhV9zd+9x0tm+jnDaYsWimzJSfKrdRTllvX48w+6t2US OpcuW3VmF+YC3IljwpuAUlAZ5OiVaMDr72zv6oValYjwNpfoGedEl41DP Y5jcVdNO4i0VowY55+rhBghkcUcvUM086DhPRfcCRfqaDXpEpGGYig1N5 8unIHt0of2ZwHwSWc9KoCALtuMw21WCm2fw+JXBp67XnrJbWWUxnIX8Up w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835919" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835919" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639188" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639188" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:19 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 01/32] x86/traps: let common_interrupt() handle IRQ_MOVE_CLEANUP_VECTOR Date: Thu, 23 Feb 2023 23:01:14 -0800 Message-Id: <20230224070145.3572-2-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" IRQ_MOVE_CLEANUP_VECTOR is the only one of the system IRQ vectors that is *below* FIRST_SYSTEM_VECTOR. It is a slow path, so just push it into common_interrupt() just before the spurious interrupt handling. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/kernel/irq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 766ffe3ba313..7e125fff45ab 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -248,6 +248,10 @@ DEFINE_IDTENTRY_IRQ(common_interrupt) desc =3D __this_cpu_read(vector_irq[vector]); if (likely(!IS_ERR_OR_NULL(desc))) { handle_irq(desc, regs); +#ifdef CONFIG_SMP + } else if (vector =3D=3D IRQ_MOVE_CLEANUP_VECTOR) { + sysvec_irq_move_cleanup(regs); +#endif } else { ack_APIC_irq(); =20 --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB0D8C64ED8 for ; Fri, 24 Feb 2023 07:28:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229741AbjBXH2E (ORCPT ); Fri, 24 Feb 2023 02:28:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229584AbjBXH14 (ORCPT ); Fri, 24 Feb 2023 02:27:56 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CD8FE61F09; Thu, 23 Feb 2023 23:27:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223647; x=1708759647; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=+07M/jdcAjybRtq6S8stNipvXlQHUYZnJXtua9YtTGQ=; b=aTijHxt1BoIvKF5T0ICNILy6br2ACYKALfq181Oosialks8/dP0wMHpQ u4+o5/dOs5Z8yR7xip/+a9r7tZ/O7mnfJjymbIH/UhkTC7q6bzz9P0Wg2 lLZfXzZ///2HHWh3u6FDQQMLBv0L9i+0K/nA+LDdLY+gaph6Fwg2qBfSS GbPUysCNqAOlpfpBxy9+Jthi3JGrZeFHAvRUqOk0eo5+SSb7h+Mk76q6v R050RhaC45LTb2VpFkago9RwOGzvDLp72sQzMNnZmvkbcMzfOUYuRueZp BAJAtt8lVcEhFOym8UJj/ptvrwzAtGTlMxHONX1+vR5tfU+h3fnVcemNh A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835928" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835928" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:20 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639191" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639191" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:20 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 02/32] x86/traps: add a system interrupt table for system interrupt dispatch Date: Thu, 23 Feb 2023 23:01:15 -0800 Message-Id: <20230224070145.3572-3-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Upon receiving an external interrupt, KVM VMX reinjects it through calling the interrupt handler in its IDT descriptor on the current kernel stack, which essentially uses the IDT as an interrupt dispatch table. However the IDT is one of the lowest level critical data structures between a x86 CPU and the Linux kernel, we should avoid using it *directly* whenever possible, espeically in a software defined manner. On x86, external interrupts are divided into the following groups 1) system interrupts 2) external device interrupts With the IDT, system interrupts are dispatched through the IDT directly, while external device interrupts are all routed to the external interrupt dispatch function common_interrupt(), which dispatches external device interrupts through a per-CPU external interrupt dispatch table vector_irq. To eliminate dispatching external interrupts through the IDT, add a system interrupt handler table for dispatching a system interrupt to its corresponding handler directly. Thus a software based dispatch function will be: void external_interrupt(struct pt_regs *regs, u8 vector) { if (is_system_interrupt(vector)) system_interrupt_handlers[vector_to_sysvec(vector)](regs); else /* external device interrupt */ common_interrupt(regs, vector); } What's more, with the Intel FRED (Flexible Return and Event Delivery) architecture, IDT, the hardware based event dispatch table, is gone, and the Linux kernel needs to dispatch events to their handlers with vector to handler mappings, the dispatch function external_interrupt() is also needed. Signed-off-by: H. Peter Anvin (Intel) Co-developed-by: Xin Li Signed-off-by: Xin Li --- arch/x86/include/asm/idtentry.h | 64 +++++++++++++++++++++++++++------ arch/x86/include/asm/traps.h | 7 ++++ arch/x86/kernel/traps.c | 40 +++++++++++++++++++++ 3 files changed, 100 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentr= y.h index 72184b0b2219..381bc2b8c1c2 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -167,17 +167,22 @@ __visible noinstr void func(struct pt_regs *regs, uns= igned long error_code) =20 /** * DECLARE_IDTENTRY_IRQ - Declare functions for device interrupt IDT entry - * points (common/spurious) + * points (common/spurious) and their corresponding + * software based dispatch handlers in the non-noinstr + * text section * @vector: Vector number (ignored for C) * @func: Function name of the entry point * - * Maps to DECLARE_IDTENTRY_ERRORCODE() + * Maps to DECLARE_IDTENTRY_ERRORCODE(), plus a dispatch function prototype */ #define DECLARE_IDTENTRY_IRQ(vector, func) \ - DECLARE_IDTENTRY_ERRORCODE(vector, func) + DECLARE_IDTENTRY_ERRORCODE(vector, func); \ + void dispatch_##func(struct pt_regs *regs, unsigned long error_code) =20 /** * DEFINE_IDTENTRY_IRQ - Emit code for device interrupt IDT entry points + * and their corresponding software based dispatch + * handlers in the non-noinstr text section * @func: Function name of the entry point * * The vector number is pushed by the low level entry stub and handed @@ -187,6 +192,9 @@ __visible noinstr void func(struct pt_regs *regs, unsig= ned long error_code) * irq_enter/exit_rcu() are invoked before the function body and the * KVM L1D flush request is set. Stack switching to the interrupt stack * has to be done in the function body if necessary. + * + * dispatch_func() is a software based dispatch handler in the non-noinstr + * text section. */ #define DEFINE_IDTENTRY_IRQ(func) \ static void __##func(struct pt_regs *regs, u32 vector); \ @@ -204,31 +212,48 @@ __visible noinstr void func(struct pt_regs *regs, \ irqentry_exit(regs, state); \ } \ \ +void dispatch_##func(struct pt_regs *regs, unsigned long error_code) \ +{ \ + u32 vector =3D (u32)(u8)error_code; \ + \ + kvm_set_cpu_l1tf_flush_l1d(); \ + run_irq_on_irqstack_cond(__##func, regs, vector); \ +} \ + \ static noinline void __##func(struct pt_regs *regs, u32 vector) =20 /** * DECLARE_IDTENTRY_SYSVEC - Declare functions for system vector entry poi= nts + * and their corresponding software based dispatch + * handlers in the non-noinstr text section * @vector: Vector number (ignored for C) * @func: Function name of the entry point * - * Declares three functions: + * Declares four functions: * - The ASM entry point: asm_##func * - The XEN PV trap entry point: xen_##func (maybe unused) * - The C handler called from the ASM entry point + * - The C handler used in the system interrupt handler table * - * Maps to DECLARE_IDTENTRY(). + * Maps to DECLARE_IDTENTRY(), plus a dispatch table function prototype */ #define DECLARE_IDTENTRY_SYSVEC(vector, func) \ - DECLARE_IDTENTRY(vector, func) + DECLARE_IDTENTRY(vector, func); \ + void dispatch_table_##func(struct pt_regs *regs) =20 /** * DEFINE_IDTENTRY_SYSVEC - Emit code for system vector IDT entry points + * and their corresponding software based dispatch + * handlers in the non-noinstr text section * @func: Function name of the entry point * * irqentry_enter/exit() and irq_enter/exit_rcu() are invoked before the * function body. KVM L1D flush request is set. * - * Runs the function on the interrupt stack if the entry hit kernel mode + * Runs the function on the interrupt stack if the entry hit kernel mode. + * + * dispatch_table_func() is used in the system interrupt handler table for + * system interrupts dispatching. */ #define DEFINE_IDTENTRY_SYSVEC(func) \ static void __##func(struct pt_regs *regs); \ @@ -244,11 +269,19 @@ __visible noinstr void func(struct pt_regs *regs) \ irqentry_exit(regs, state); \ } \ \ +void dispatch_table_##func(struct pt_regs *regs) \ +{ \ + kvm_set_cpu_l1tf_flush_l1d(); \ + run_sysvec_on_irqstack_cond(__##func, regs); \ +} \ + \ static noinline void __##func(struct pt_regs *regs) =20 /** * DEFINE_IDTENTRY_SYSVEC_SIMPLE - Emit code for simple system vector IDT - * entry points + * entry points and their corresponding + * software based dispatch handlers in + * the non-noinstr text section * @func: Function name of the entry point * * Runs the function on the interrupted stack. No switch to IRQ stack and @@ -256,6 +289,9 @@ static noinline void __##func(struct pt_regs *regs) * * Only use for 'empty' vectors like reschedule IPI and KVM posted * interrupt vectors. + * + * dispatch_table_func() is used in the system interrupt handler table for + * system interrupts dispatching. */ #define DEFINE_IDTENTRY_SYSVEC_SIMPLE(func) \ static __always_inline void __##func(struct pt_regs *regs); \ @@ -273,6 +309,14 @@ __visible noinstr void func(struct pt_regs *regs) \ irqentry_exit(regs, state); \ } \ \ +void dispatch_table_##func(struct pt_regs *regs) \ +{ \ + __irq_enter_raw(); \ + kvm_set_cpu_l1tf_flush_l1d(); \ + __##func (regs); \ + __irq_exit_raw(); \ +} \ + \ static __always_inline void __##func(struct pt_regs *regs) =20 /** @@ -638,9 +682,7 @@ DECLARE_IDTENTRY(X86_TRAP_VE, exc_virtualization_excep= tion); =20 /* Device interrupts common/spurious */ DECLARE_IDTENTRY_IRQ(X86_TRAP_OTHER, common_interrupt); -#ifdef CONFIG_X86_LOCAL_APIC DECLARE_IDTENTRY_IRQ(X86_TRAP_OTHER, spurious_interrupt); -#endif =20 /* System vector entry points */ #ifdef CONFIG_X86_LOCAL_APIC @@ -651,7 +693,7 @@ DECLARE_IDTENTRY_SYSVEC(X86_PLATFORM_IPI_VECTOR, sysvec= _x86_platform_ipi); #endif =20 #ifdef CONFIG_SMP -DECLARE_IDTENTRY(RESCHEDULE_VECTOR, sysvec_reschedule_ipi); +DECLARE_IDTENTRY_SYSVEC(RESCHEDULE_VECTOR, sysvec_reschedule_ipi); DECLARE_IDTENTRY_SYSVEC(IRQ_MOVE_CLEANUP_VECTOR, sysvec_irq_move_cleanup); DECLARE_IDTENTRY_SYSVEC(REBOOT_VECTOR, sysvec_reboot); DECLARE_IDTENTRY_SYSVEC(CALL_FUNCTION_SINGLE_VECTOR, sysvec_call_function_= single); diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 47ecfff2c83d..28c8ba5fd81c 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -47,4 +47,11 @@ void __noreturn handle_stack_overflow(struct pt_regs *re= gs, struct stack_info *info); #endif =20 +/* + * How system interrupt handlers are called. + */ +#define DECLARE_SYSTEM_INTERRUPT_HANDLER(f) \ + void f (struct pt_regs *regs) +typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler)); + #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index d317dc3d06a3..e4bdebdf05dd 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1451,6 +1451,46 @@ DEFINE_IDTENTRY_SW(iret_error) } #endif =20 +#define SYSV(x,y) [(x) - FIRST_SYSTEM_VECTOR] =3D y + +static system_interrupt_handler system_interrupt_handlers[NR_SYSTEM_VECTOR= S] =3D { +#ifdef CONFIG_SMP + SYSV(RESCHEDULE_VECTOR, dispatch_table_sysvec_reschedule_ipi), + SYSV(CALL_FUNCTION_VECTOR, dispatch_table_sysvec_call_function), + SYSV(CALL_FUNCTION_SINGLE_VECTOR, dispatch_table_sysvec_call_function_sin= gle), + SYSV(REBOOT_VECTOR, dispatch_table_sysvec_reboot), +#endif + +#ifdef CONFIG_X86_THERMAL_VECTOR + SYSV(THERMAL_APIC_VECTOR, dispatch_table_sysvec_thermal), +#endif + +#ifdef CONFIG_X86_MCE_THRESHOLD + SYSV(THRESHOLD_APIC_VECTOR, dispatch_table_sysvec_threshold), +#endif + +#ifdef CONFIG_X86_MCE_AMD + SYSV(DEFERRED_ERROR_VECTOR, dispatch_table_sysvec_deferred_error), +#endif + +#ifdef CONFIG_X86_LOCAL_APIC + SYSV(LOCAL_TIMER_VECTOR, dispatch_table_sysvec_apic_timer_interrupt), + SYSV(X86_PLATFORM_IPI_VECTOR, dispatch_table_sysvec_x86_platform_ipi), +# ifdef CONFIG_HAVE_KVM + SYSV(POSTED_INTR_VECTOR, dispatch_table_sysvec_kvm_posted_intr_ipi), + SYSV(POSTED_INTR_WAKEUP_VECTOR, dispatch_table_sysvec_kvm_posted_intr_wa= keup_ipi), + SYSV(POSTED_INTR_NESTED_VECTOR, dispatch_table_sysvec_kvm_posted_intr_ne= sted_ipi), +# endif +# ifdef CONFIG_IRQ_WORK + SYSV(IRQ_WORK_VECTOR, dispatch_table_sysvec_irq_work), +# endif + SYSV(SPURIOUS_APIC_VECTOR, dispatch_table_sysvec_spurious_apic_interrupt= ), + SYSV(ERROR_APIC_VECTOR, dispatch_table_sysvec_error_interrupt), +#endif +}; + +#undef SYSV + void __init trap_init(void) { /* Init cpu_entry_area before IST entries are set up */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9421C61DA3 for ; Fri, 24 Feb 2023 07:28:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229656AbjBXH2G (ORCPT ); Fri, 24 Feb 2023 02:28:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229672AbjBXH15 (ORCPT ); Fri, 24 Feb 2023 02:27:57 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9D49628DF; Thu, 23 Feb 2023 23:27:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; 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([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:20 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 03/32] x86/traps: add install_system_interrupt_handler() Date: Thu, 23 Feb 2023 23:01:16 -0800 Message-Id: <20230224070145.3572-4-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some kernel components install system interrupt handlers into the IDT, and we need to do the same for system_interrupt_handlers. A new function install_system_interrupt_handler() is added to install a system interrupt handler into both the IDT and system_interrupt_handlers. Signed-off-by: Xin Li --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/kernel/cpu/acrn.c | 7 +++++-- arch/x86/kernel/cpu/mshyperv.c | 22 ++++++++++++++-------- arch/x86/kernel/kvm.c | 4 +++- arch/x86/kernel/traps.c | 8 ++++++++ drivers/xen/events/events_base.c | 5 ++++- 6 files changed, 36 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 28c8ba5fd81c..46f5e4e2a346 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -41,6 +41,8 @@ void math_emulate(struct math_emu_info *); =20 bool fault_in_kernel_space(unsigned long address); =20 +void install_system_interrupt_handler(unsigned int n, const void *asm_addr= , const void *addr); + #ifdef CONFIG_VMAP_STACK void __noreturn handle_stack_overflow(struct pt_regs *regs, unsigned long fault_address, diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c index 485441b7f030..9351bf183a9e 100644 --- a/arch/x86/kernel/cpu/acrn.c +++ b/arch/x86/kernel/cpu/acrn.c @@ -18,6 +18,7 @@ #include #include #include +#include =20 static u32 __init acrn_detect(void) { @@ -26,8 +27,10 @@ static u32 __init acrn_detect(void) =20 static void __init acrn_init_platform(void) { - /* Setup the IDT for ACRN hypervisor callback */ - alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback); + /* Install system interrupt handler for ACRN hypervisor callback */ + install_system_interrupt_handler(HYPERVISOR_CALLBACK_VECTOR, + asm_sysvec_acrn_hv_callback, + sysvec_acrn_hv_callback); =20 x86_platform.calibrate_tsc =3D acrn_get_tsc_khz; x86_platform.calibrate_cpu =3D acrn_get_tsc_khz; diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 46668e255421..d61d9353a234 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -415,19 +416,24 @@ static void __init ms_hyperv_init_platform(void) */ x86_platform.apic_post_init =3D hyperv_init; hyperv_setup_mmu_ops(); - /* Setup the IDT for hypervisor callback */ - alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_hyperv_callback); =20 - /* Setup the IDT for reenlightenment notifications */ + /* Install system interrupt handler for hypervisor callback */ + install_system_interrupt_handler(HYPERVISOR_CALLBACK_VECTOR, + asm_sysvec_hyperv_callback, + sysvec_hyperv_callback); + + /* Install system interrupt handler for reenlightenment notifications */ if (ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT) { - alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR, - asm_sysvec_hyperv_reenlightenment); + install_system_interrupt_handler(HYPERV_REENLIGHTENMENT_VECTOR, + asm_sysvec_hyperv_reenlightenment, + sysvec_hyperv_reenlightenment); } =20 - /* Setup the IDT for stimer0 */ + /* Install system interrupt handler for stimer0 */ if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) { - alloc_intr_gate(HYPERV_STIMER0_VECTOR, - asm_sysvec_hyperv_stimer0); + install_system_interrupt_handler(HYPERV_STIMER0_VECTOR, + asm_sysvec_hyperv_stimer0, + sysvec_hyperv_stimer0); } =20 # ifdef CONFIG_SMP diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 1cceac5984da..5c684df6de7a 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -829,7 +829,9 @@ static void __init kvm_guest_init(void) =20 if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) { static_branch_enable(&kvm_async_pf_enabled); - alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_kvm_asyncpf_inter= rupt); + install_system_interrupt_handler(HYPERVISOR_CALLBACK_VECTOR, + asm_sysvec_kvm_asyncpf_interrupt, + sysvec_kvm_asyncpf_interrupt); } =20 #ifdef CONFIG_SMP diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index e4bdebdf05dd..c0f7666140da 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1491,6 +1491,14 @@ static system_interrupt_handler system_interrupt_han= dlers[NR_SYSTEM_VECTORS] =3D { =20 #undef SYSV =20 +void __init install_system_interrupt_handler(unsigned int n, const void *a= sm_addr, const void *addr) +{ + BUG_ON(n < FIRST_SYSTEM_VECTOR); + + system_interrupt_handlers[n - FIRST_SYSTEM_VECTOR] =3D (system_interrupt_= handler)addr; + alloc_intr_gate(n, asm_addr); +} + void __init trap_init(void) { /* Init cpu_entry_area before IST entries are set up */ diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_b= ase.c index c443f04aaad7..1a9eaf417acc 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #endif @@ -2246,7 +2247,9 @@ static __init void xen_alloc_callback_vector(void) return; =20 pr_info("Xen HVM callback vector for event delivery is enabled\n"); - alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_xen_hvm_callback); + install_system_interrupt_handler(HYPERVISOR_CALLBACK_VECTOR, + asm_sysvec_xen_hvm_callback, + sysvec_xen_hvm_callback); } #else void xen_setup_callback_vector(void) {} --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EC61C61DA3 for ; Fri, 24 Feb 2023 07:28:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229823AbjBXH2K (ORCPT ); Fri, 24 Feb 2023 02:28:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229712AbjBXH15 (ORCPT ); Fri, 24 Feb 2023 02:27:57 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24F9F63DD1; 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([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:20 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 04/32] x86/traps: add external_interrupt() to dispatch external interrupts Date: Thu, 23 Feb 2023 23:01:17 -0800 Message-Id: <20230224070145.3572-5-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add external_interrupt() to dispatch external interrupts to their handlers. If an external interrupt is a system interrupt, dipatch it through system_interrupt_handler_table, otherwise call into dispatch_common_interrupt(). Signed-off-by: H. Peter Anvin (Intel) Co-developed-by: Xin Li Signed-off-by: Xin Li --- arch/x86/kernel/traps.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c0f7666140da..31ad645be2fb 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1499,6 +1499,47 @@ void __init install_system_interrupt_handler(unsigne= d int n, const void *asm_add alloc_intr_gate(n, asm_addr); } =20 +#ifndef CONFIG_X86_LOCAL_APIC +/* + * Used when local APIC is not compiled into the kernel, but + * external_interrupt() needs dispatch_spurious_interrupt(). + */ +DEFINE_IDTENTRY_IRQ(spurious_interrupt) +{ + pr_info("Spurious interrupt (vector 0x%x) on CPU#%d, should never happen.= \n", + vector, smp_processor_id()); +} +#endif + +/* + * External interrupt dispatch function. + * + * Until/unless dispatch_common_interrupt() can be taught to deal with the + * special system vectors, split the dispatch. + * + * Note: dispatch_common_interrupt() already deals with IRQ_MOVE_CLEANUP_V= ECTOR. + */ +int external_interrupt(struct pt_regs *regs, unsigned int vector) +{ + unsigned int sysvec =3D vector - FIRST_SYSTEM_VECTOR; + + if (vector < FIRST_EXTERNAL_VECTOR) { + pr_err("invalid external interrupt vector %d\n", vector); + return -EINVAL; + } + + if (sysvec < NR_SYSTEM_VECTORS) { + if (system_interrupt_handlers[sysvec]) + system_interrupt_handlers[sysvec](regs); + else + dispatch_spurious_interrupt(regs, vector); + } else { + dispatch_common_interrupt(regs, vector); + } + + return 0; +} + void __init trap_init(void) { /* Init cpu_entry_area before IST entries are set up */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B266C61DA3 for ; Fri, 24 Feb 2023 07:28:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229874AbjBXH2R (ORCPT ); Fri, 24 Feb 2023 02:28:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229785AbjBXH2A (ORCPT ); Fri, 24 Feb 2023 02:28:00 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0475865AD; Thu, 23 Feb 2023 23:27:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223675; x=1708759675; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5ojl4mrz7EluvMPfPkXTnSlfudBddxu4Pmb5fcSRBp4=; b=Tp63Vz3gpKZhF217zJNL3ZZ6XzIRQ0GD+MZOhoYw0XZIPXlNh/vdLLjP wf1M4gksykRmZ/m0jCBV6r4RJfCyOybh1ap6/I85Rtp6NOYZU2vq75+LF yPTfBbkM7PbpztJyyHMck0kbE6jp/AzswcQ6GajRpS5pf0H19QPMT2ETD EPuw9uBJj5sfv4jv/n8+6v5liiJDTpTlBmZs/bPhNzGlv4l7Z/HnlnotQ HKQMRr3xraXQC0nEDio/o7+kyeR4ywSy1wCXY4XsbkJTQWml6hTfYnEpa gHP+k1ed3AFa1y6RqncyA5IWkq+j+mo1NKzeO+h9lnqwmw/Ju1gb2ufsH g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835959" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835959" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639200" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639200" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:20 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 05/32] x86/traps: export external_interrupt() for VMX IRQ reinjection Date: Thu, 23 Feb 2023 23:01:18 -0800 Message-Id: <20230224070145.3572-6-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To eliminate dispatching IRQ through the IDT, export external_interrupt() for VMX IRQ reinjection. Signed-off-by: Xin Li --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/kernel/traps.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 46f5e4e2a346..da4c21ed68b4 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -56,4 +56,6 @@ void __noreturn handle_stack_overflow(struct pt_regs *reg= s, void f (struct pt_regs *regs) typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler)); =20 +int external_interrupt(struct pt_regs *regs, unsigned int vector); + #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 31ad645be2fb..cebba1f49e19 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1540,6 +1540,20 @@ int external_interrupt(struct pt_regs *regs, unsigne= d int vector) return 0; } =20 +#if IS_ENABLED(CONFIG_KVM_INTEL) +/* + * KVM VMX reinjects IRQ on its current stack, it's a sync call + * thus the values in the pt_regs structure are not used in + * executing IRQ handlers, except cs.RPL and flags.IF, which + * are both always 0 in the VMX IRQ reinjection context. + * + * However, the pt_regs structure is sometimes used in stack + * dump, e.g., show_regs(). So let the caller, i.e., KVM VMX + * decide how to initialize the input pt_regs structure. + */ +EXPORT_SYMBOL_GPL(external_interrupt); +#endif + void __init trap_init(void) { /* Init cpu_entry_area before IST entries are set up */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 964F2C61DA3 for ; Fri, 24 Feb 2023 07:28:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229922AbjBXH2W (ORCPT ); Fri, 24 Feb 2023 02:28:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229606AbjBXH2A (ORCPT ); Fri, 24 Feb 2023 02:28:00 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35C9F7EC3; Thu, 23 Feb 2023 23:27:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223675; x=1708759675; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uSGLCwu5a/GZ7qpPDjOQ37bzlx0va0P3TMBnImGGqAs=; b=j7ypfV3L9YakMAbe2khYbWNuRTfmlVZB427LsGB6fCJncJjUsKISBeHW j69OLXhRY/Mrmo4bKoUgMCiJPQFgozD5oQeSIgMNGqRLBPQtgll4AlJFK P9ORwpktcjkl8cOqzSSBaydm6tttKWRYonUlm4vR/j7bEjeZgnNpomQmj +h1/zcdKyqjIMzpaNDjobVqd/ge9UEeqCNjp87U5T6ou5Y2CwDe3OTZ0f hguTGGI7vcdxsL12vEflZo9uBF22IthZUaGKId/YLWjis8SwAsyV+oi3v mmZUNTtvjtiudUpzYBZ3jjbllp83miPiGY9cokdg8J30233trLmieEZC3 Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835967" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835967" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639203" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639203" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:20 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 06/32] x86/cpufeature: add the cpu feature bit for FRED Date: Thu, 23 Feb 2023 23:01:19 -0800 Message-Id: <20230224070145.3572-7-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add the CPU feature bit for FRED (Flexible Return and Event Delivery). The Intel flexible return and event delivery (FRED) architecture defines si= mple new transitions that change privilege level (ring transitions). The FRED architecture was designed with the following goals: 1) Improve overall performance and response time by replacing event delivery through the interrupt descriptor table (IDT event delivery) and event retur= n by the IRET instruction with lower latency transitions. 2) Improve software robustness by ensuring that event delivery establishes = the full supervisor context and that event return establishes the full user con= text. The new transitions defined by the FRED architecture are FRED event deliver= y and, for returning from events, two FRED return instructions. FRED event deliver= y can effect a transition from ring 3 to ring 0, but it is used also to deliver e= vents incident to ring 0. One FRED instruction (ERETU) effects a return from ring= 0 to ring 3, while the other (ERETS) returns while remaining in ring 0. Search for the latest FRED spec in most search engines with this search pat= tern: site:intel.com FRED (flexible return and event delivery) specification Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/cpufeatures.h | 1 + tools/arch/x86/include/asm/cpufeatures.h | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpuf= eatures.h index fdb8e09234ba..ef6e638fa300 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -315,6 +315,7 @@ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instruction= s */ #define X86_FEATURE_CMPCCXADD (12*32+ 7) /* "" CMPccXADD instruc= tions */ #define X86_FEATURE_ARCH_PERFMON_EXT (12*32+ 8) /* "" Intel Architectural = PerfMon Extension */ +#define X86_FEATURE_FRED (12*32+17) /* Flexible Return and Event Delivery= */ #define X86_FEATURE_LKGS (12*32+18) /* "" Load "kernel" (userspace) GS */ #define X86_FEATURE_AMX_FP16 (12*32+21) /* "" AMX fp16 Support */ #define X86_FEATURE_AVX_IFMA (12*32+23) /* "" Support for VPMAD= D52[H,L]UQ */ diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/incl= ude/asm/cpufeatures.h index b70111a75688..b2218a7a0927 100644 --- a/tools/arch/x86/include/asm/cpufeatures.h +++ b/tools/arch/x86/include/asm/cpufeatures.h @@ -312,6 +312,7 @@ #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instruction= s */ #define X86_FEATURE_CMPCCXADD (12*32+ 7) /* "" CMPccXADD instruc= tions */ +#define X86_FEATURE_FRED (12*32+17) /* Flexible Return and Event Delivery= */ #define X86_FEATURE_LKGS (12*32+18) /* "" Load "kernel" (userspace) GS */ #define X86_FEATURE_AMX_FP16 (12*32+21) /* "" AMX fp16 Support */ #define X86_FEATURE_AVX_IFMA (12*32+23) /* "" Support for VPMAD= D52[H,L]UQ */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F268FC64ED8 for ; Fri, 24 Feb 2023 07:28:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229935AbjBXH2Y (ORCPT ); Fri, 24 Feb 2023 02:28:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbjBXH2B (ORCPT ); Fri, 24 Feb 2023 02:28:01 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DB4D113E3; Thu, 23 Feb 2023 23:27:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223677; x=1708759677; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=HXuHZjSMZ3B1Hok/xgWVtrid7iYmCcbq68b8/8447FE=; b=MpsOjrq+JZpY1cnCfRFzAqh/nUgIf163T+J9c66cloPsvYLecUyvmOJ9 46a3uRTREIaEhg9/14dq63Tk3wkT4u+rcH6epKiRWhq75UZvcpJdOiPNM 2gJz6ACWhxf4Jo62/BBlhjKuRhv2Hs+ALWMFevSAJwE9bifIJ2j/equKB AnhxY5NIYpirZzBaF1dsqkyjM0X+PBHisMtdOl1ZH2RPZBzylfeev7jo5 n1PeNei6EkGgh4Wi9XoH2uNPDDDoItEr+SvUi9ZQora13hezmLhZXYKA5 2OVHl3C6x1G7C27And5N332vwdhnkYDQTHvsN/sYYqYvc3zSjZOfYqxNZ A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835978" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835978" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639206" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639206" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:21 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 07/32] x86/opcode: add ERETU, ERETS instructions to x86-opcode-map Date: Thu, 23 Feb 2023 23:01:20 -0800 Message-Id: <20230224070145.3572-8-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add the instruction opcodes used by FRED: ERETU, ERETS. Opcode number is per public FRED draft spec v3.0. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/lib/x86-opcode-map.txt | 2 +- tools/arch/x86/lib/x86-opcode-map.txt | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.= txt index 5168ee0360b2..7a269e269dc0 100644 --- a/arch/x86/lib/x86-opcode-map.txt +++ b/arch/x86/lib/x86-opcode-map.txt @@ -1052,7 +1052,7 @@ EndTable =20 GrpTable: Grp7 0: SGDT Ms | VMCALL (001),(11B) | VMLAUNCH (010),(11B) | VMRESUME (011),(1= 1B) | VMXOFF (100),(11B) | PCONFIG (101),(11B) | ENCLV (000),(11B) -1: SIDT Ms | MONITOR (000),(11B) | MWAIT (001),(11B) | CLAC (010),(11B) | = STAC (011),(11B) | ENCLS (111),(11B) +1: SIDT Ms | MONITOR (000),(11B) | MWAIT (001),(11B) | CLAC (010),(11B) | = STAC (011),(11B) | ENCLS (111),(11B) | ERETU (F3),(010),(11B) | ERETS (F2),= (010),(11B) 2: LGDT Ms | XGETBV (000),(11B) | XSETBV (001),(11B) | VMFUNC (100),(11B) = | XEND (101)(11B) | XTEST (110)(11B) | ENCLU (111),(11B) 3: LIDT Ms 4: SMSW Mw/Rv diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86= -opcode-map.txt index 5168ee0360b2..7a269e269dc0 100644 --- a/tools/arch/x86/lib/x86-opcode-map.txt +++ b/tools/arch/x86/lib/x86-opcode-map.txt @@ -1052,7 +1052,7 @@ EndTable =20 GrpTable: Grp7 0: SGDT Ms | VMCALL (001),(11B) | VMLAUNCH (010),(11B) | VMRESUME (011),(1= 1B) | VMXOFF (100),(11B) | PCONFIG (101),(11B) | ENCLV (000),(11B) -1: SIDT Ms | MONITOR (000),(11B) | MWAIT (001),(11B) | CLAC (010),(11B) | = STAC (011),(11B) | ENCLS (111),(11B) +1: SIDT Ms | MONITOR (000),(11B) | MWAIT (001),(11B) | CLAC (010),(11B) | = STAC (011),(11B) | ENCLS (111),(11B) | ERETU (F3),(010),(11B) | ERETS (F2),= (010),(11B) 2: LGDT Ms | XGETBV (000),(11B) | XSETBV (001),(11B) | VMFUNC (100),(11B) = | XEND (101)(11B) | XTEST (110)(11B) | ENCLU (111),(11B) 3: LIDT Ms 4: SMSW Mw/Rv --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26EC8C678DB for ; Fri, 24 Feb 2023 07:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229491AbjBXH2T (ORCPT ); Fri, 24 Feb 2023 02:28:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229787AbjBXH2A (ORCPT ); Fri, 24 Feb 2023 02:28:00 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E28CFA; Thu, 23 Feb 2023 23:27:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223676; x=1708759676; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LPt5KI78RHrT+nU0CTWy5sIjKcY7qI5WuuF75Mzk9KE=; b=FOyHO+P+PgPhBp3/aZD05bBqV/hH+KXihA3COHmVpGY9xw9ObdVydZ2O 10f6gA2Y4+mDdBUgXWJzpzfkLSNupnveg7fQLsZLCjSzyLLO6WyLT7se2 5syE29CqD2wFXT3F6vrggGC9Hz1GUFczSpD+wr2VkHkwneHfAHH4M4uuz +vsL7YCT2BkiWl2pTP4tdRMP8zFt9hf2+JAad6rEyvI7IPXNPd8+s7uWO C5TJSnW/581PizhovqFoNldH0VPzZ+9/abYD7vTapfEVE07hmMTOFNXic 85S/ET/L85s+GPk0rvXjQeEiMkWxbkZM5aDwf5ScmBnigsVTqmEs6TkdG w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835980" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835980" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639210" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639210" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:21 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 08/32] x86/objtool: teach objtool about ERETU and ERETS Date: Thu, 23 Feb 2023 23:01:21 -0800 Message-Id: <20230224070145.3572-9-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Update the objtool decoder to know about the ERETU and ERETS instructions (type INSN_CONTEXT_SWITCH.) Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- tools/objtool/arch/x86/decode.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decod= e.c index e7b030f7e2a5..735c909540b5 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -509,12 +509,22 @@ int arch_decode_instruction(struct objtool_file *file= , const struct section *sec case 0x0f: =20 if (op2 =3D=3D 0x01) { - - if (modrm =3D=3D 0xca) - *type =3D INSN_CLAC; - else if (modrm =3D=3D 0xcb) - *type =3D INSN_STAC; - + switch (insn_last_prefix_id(&insn)) { + case INAT_PFX_REPE: + case INAT_PFX_REPNE: + if (modrm =3D=3D 0xca) { + /* eretu/erets */ + *type =3D INSN_CONTEXT_SWITCH; + } + break; + default: + if (modrm =3D=3D 0xca) { + *type =3D INSN_CLAC; + } else if (modrm =3D=3D 0xcb) { + *type =3D INSN_STAC; + } + break; + } } else if (op2 >=3D 0x80 && op2 <=3D 0x8f) { =20 *type =3D INSN_JUMP_CONDITIONAL; --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 496CDC6FA99 for ; Fri, 24 Feb 2023 07:28:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229946AbjBXH22 (ORCPT ); Fri, 24 Feb 2023 02:28:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229723AbjBXH2B (ORCPT ); Fri, 24 Feb 2023 02:28:01 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39B0415557; Thu, 23 Feb 2023 23:27:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223678; x=1708759678; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=+NHRufqx3uD2JDcRRkT2OSWUCnw5FRpH1XcQKduLdUk=; b=RWE/jgop6PK+myh+sc+KbWayTeRsrt7ahNHsRduhhV6CsZO1/Ue0WoSF v+F+ePZQDSi6n9J4OPKWKrvG69ecxMRbNG5AWjSS0qReIlvOzTq968A0/ 3+eHNSk0jTmrTzm0aKfiEU85MWWEWcRR0/GL5NmUHiZ4GpsnciRJNBBN+ XH3KjvRrYeLvHd1He0AqIdxfJZIZAQQKZ9yy1ABppaznTzEPCjl34KRle 106joPE1JhYmvWlSNH8JsIn7G+7SbqIPWbWdi6IDPntaG8fUUs5+ZFkK/ MYI0ZRhdK4pwhuRA7VY9J1QTTc9ppL4NYRROaDh0u244tRLjncAR9yIcn g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835987" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835987" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639213" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639213" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:21 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 09/32] x86/cpu: add X86_CR4_FRED macro Date: Thu, 23 Feb 2023 23:01:22 -0800 Message-Id: <20230224070145.3572-10-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add X86_CR4_FRED macro for the FRED bit in %cr4. This bit should be a pinned bit, not to be changed after initialization. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/uapi/asm/processor-flags.h | 2 ++ arch/x86/kernel/cpu/common.c | 11 ++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include= /uapi/asm/processor-flags.h index c47cc7f2feeb..a90933f1ff41 100644 --- a/arch/x86/include/uapi/asm/processor-flags.h +++ b/arch/x86/include/uapi/asm/processor-flags.h @@ -132,6 +132,8 @@ #define X86_CR4_PKE _BITUL(X86_CR4_PKE_BIT) #define X86_CR4_CET_BIT 23 /* enable Control-flow Enforcement Technology = */ #define X86_CR4_CET _BITUL(X86_CR4_CET_BIT) +#define X86_CR4_FRED_BIT 32 /* enable FRED kernel entry */ +#define X86_CR4_FRED _BITULL(X86_CR4_FRED_BIT) =20 /* * x86-64 Task Priority Register, CR8 diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 831a1a07d357..21237cb0aa93 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -412,10 +412,15 @@ static __always_inline void setup_umip(struct cpuinfo= _x86 *c) cr4_clear_bits(X86_CR4_UMIP); } =20 -/* These bits should not change their value after CPU init is finished. */ +/* + * These bits should not change their value after CPU init is finished. + * The explicit cast to unsigned long suppresses a warning on i386 for + * x86-64 only feature bits >=3D 32. + */ static const unsigned long cr4_pinned_mask =3D - X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | - X86_CR4_FSGSBASE | X86_CR4_CET; + (unsigned long) + (X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP | + X86_CR4_FSGSBASE | X86_CR4_CET | X86_CR4_FRED); static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning); static unsigned long cr4_pinned_bits __ro_after_init; =20 --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EAF5C677F1 for ; Fri, 24 Feb 2023 07:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229618AbjBXH2b (ORCPT ); Fri, 24 Feb 2023 02:28:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229813AbjBXH2E (ORCPT ); Fri, 24 Feb 2023 02:28:04 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 391EC3645D; Thu, 23 Feb 2023 23:28:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223680; x=1708759680; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6QHPRwIE+z7Ui/OjlYLx1iEgisWIGhf7tIyqWsGywtA=; b=efReIt8PnRFBlQAJYL6d92TBIB8Bjkk+RTq6qYDgQYvn2dem5csZP2IB WX+J3o160kZ/30Yeuh20iN7Wzn0Nn3pEbvF4B6Evq0NVZbndX6b/+Fp/D 9D8oltpXJAckmEDwBU90+fzx7uUnWC3CELgIGQPo3qyxmtd7qs+G13BhJ p2kghDwSXpM1iQ/p4zU+IxVb/gQ+OzHjzwIf9KrVenSMtHPWokyfkc9gB S9tUFE1nDsKySCzrew3hkWqI41VsYrr89NlvM+y88vfbYbR4ewMMxu9Pi t5VMgxYSM0DCDx5gsKuXT3gHZXHTq8/L43ilO5snUnyARwchI/tSNJ3P8 A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334835992" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334835992" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639216" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639216" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:21 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 10/32] x86/fred: add Kconfig option for FRED (CONFIG_X86_FRED) Date: Thu, 23 Feb 2023 23:01:23 -0800 Message-Id: <20230224070145.3572-11-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add the configuration option CONFIG_X86_FRED to enable FRED. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/Kconfig | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a825bf031f49..da62178bb246 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -500,6 +500,15 @@ config X86_CPU_RESCTRL =20 Say N if unsure. =20 +config X86_FRED + bool "Flexible Return and Event Delivery" + depends on X86_64 + help + When enabled, try to use Flexible Return and Event Delivery + instead of the legacy SYSCALL/SYSENTER/IDT architecture for + ring transitions and exception/interrupt handling if the + system supports. + if X86_32 config X86_BIGSMP bool "Support for big SMP systems with more than 8 CPUs" --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98CDAC64ED8 for ; Fri, 24 Feb 2023 07:28:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229966AbjBXH2e (ORCPT ); Fri, 24 Feb 2023 02:28:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjBXH2M (ORCPT ); Fri, 24 Feb 2023 02:28:12 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8890B36FF2; Thu, 23 Feb 2023 23:28:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223680; x=1708759680; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=CV81LNEfI5DBj7B7dwsrQlKANaQmTPQxLP8wnGG3SkY=; b=agcKIy8Sl8mC/QF6Trf1fSSSy2DlpGqKlqUnXgH8Vv8K8O/0JcH7ukrU LHa3LKNYqzJI2vMvgXjg2oOfbTdh90dJ4ufH8DvEpW0DsJdg/E77Ffwbs +VuoBDhTGhyHInY/MTPX2L+//LaD2In3fGLCEdxevMQMHMsndCap60dkY kar8WDwjp3YKuMI2PQoFy7KMSLDREgnD7AOMUNiy6zElWgUIoE3kEQNa7 m4AcKDNcTUXVji7CpHkVLYsswM92U0m3ylyvp67RfkKwEZfEQs27cbI2P 3+vh306TlNY3ZL7frA9Zyr4WxrO9w+56xk1/vxIvQQrScWJcn9d6weLA7 w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836002" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836002" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639219" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639219" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:21 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 11/32] x86/fred: if CONFIG_X86_FRED is disabled, disable FRED support Date: Thu, 23 Feb 2023 23:01:24 -0800 Message-Id: <20230224070145.3572-12-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add CONFIG_X86_FRED to to make cpu_feature_enabled() work correctly with FRED. Originally-by: Megha Dey Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/disabled-features.h | 8 +++++++- tools/arch/x86/include/asm/disabled-features.h | 8 +++++++- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/as= m/disabled-features.h index 5dfa4fb76f4b..56838de9cb23 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -99,6 +99,12 @@ # define DISABLE_TDX_GUEST (1 << (X86_FEATURE_TDX_GUEST & 31)) #endif =20 +#ifdef CONFIG_X86_FRED +# define DISABLE_FRED 0 +#else +# define DISABLE_FRED (1 << (X86_FEATURE_FRED & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -115,7 +121,7 @@ #define DISABLED_MASK10 0 #define DISABLED_MASK11 (DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET| \ DISABLE_CALL_DEPTH_TRACKING) -#define DISABLED_MASK12 0 +#define DISABLED_MASK12 (DISABLE_FRED) #define DISABLED_MASK13 0 #define DISABLED_MASK14 0 #define DISABLED_MASK15 0 diff --git a/tools/arch/x86/include/asm/disabled-features.h b/tools/arch/x8= 6/include/asm/disabled-features.h index c44b56f7ffba..2d3ec539dcc7 100644 --- a/tools/arch/x86/include/asm/disabled-features.h +++ b/tools/arch/x86/include/asm/disabled-features.h @@ -99,6 +99,12 @@ # define DISABLE_TDX_GUEST (1 << (X86_FEATURE_TDX_GUEST & 31)) #endif =20 +#ifdef CONFIG_X86_FRED +# define DISABLE_FRED 0 +#else +# define DISABLE_FRED (1 << (X86_FEATURE_FRED & 31)) +#endif + /* * Make sure to add features to the correct mask */ @@ -115,7 +121,7 @@ #define DISABLED_MASK10 0 #define DISABLED_MASK11 (DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET| \ DISABLE_CALL_DEPTH_TRACKING) -#define DISABLED_MASK12 0 +#define DISABLED_MASK12 (DISABLE_FRED) #define DISABLED_MASK13 0 #define DISABLED_MASK14 0 #define DISABLED_MASK15 0 --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C381C677F1 for ; Fri, 24 Feb 2023 07:28:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229987AbjBXH2k (ORCPT ); Fri, 24 Feb 2023 02:28:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229780AbjBXH2P (ORCPT ); Fri, 24 Feb 2023 02:28:15 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5978438017; Thu, 23 Feb 2023 23:28:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223681; x=1708759681; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EBPvYb+gJfY5lBKAurDpvp1Pyt5VBU6XG/KB8jZzGbc=; b=VQK15ErGdmMiHujHAsXNoFGznpQIvOquNQXWO4VN6IONs7l2UJ1tz+oU HajXgcNZrnKY2NGOIQ0kitfdzHQwb0uGpXYGRE/B8UWusKzucQrxZPy3w kCtNfqL2ah2w7i+/h8fF5mRMlyRrQcyba5sbpHwv+2V7he7Q2x8qjYrYP V18ArbCSAD7W7VB/FnFdAPt9EkV7Zr8r2N5L8xpNSWQdS/RxYH42elT9E qGBTgcYDQ5z3TtW1IvXC7tEtCnhEmINWfnEXItc02UKcqSxPGKttSQdbS BNZmpCT9jTbH4b87bOD6O0QbyHHc26Gfdo2a1pDKDtoSBBygdq9VeJNcp A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836020" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836020" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639222" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639222" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 12/32] x86/cpu: add MSR numbers for FRED configuration Date: Thu, 23 Feb 2023 23:01:25 -0800 Message-Id: <20230224070145.3572-13-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add MSR numbers for the FRED configuration registers. Originally-by: Megha Dey Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/msr-index.h | 13 ++++++++++++- tools/arch/x86/include/asm/msr-index.h | 13 ++++++++++++- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-in= dex.h index ad35355ee43e..87db728f8bbc 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -36,8 +36,19 @@ #define EFER_FFXSR (1<<_EFER_FFXSR) #define EFER_AUTOIBRS (1<<_EFER_AUTOIBRS) =20 -/* Intel MSRs. Some also available on other CPUs */ +/* FRED MSRs */ +#define MSR_IA32_FRED_RSP0 0x1cc /* Level 0 stack pointer */ +#define MSR_IA32_FRED_RSP1 0x1cd /* Level 1 stack pointer */ +#define MSR_IA32_FRED_RSP2 0x1ce /* Level 2 stack pointer */ +#define MSR_IA32_FRED_RSP3 0x1cf /* Level 3 stack pointer */ +#define MSR_IA32_FRED_STKLVLS 0x1d0 /* Exception stack levels */ +#define MSR_IA32_FRED_SSP0 MSR_IA32_PL0_SSP /* Level 0 shadow stack pointe= r */ +#define MSR_IA32_FRED_SSP1 0x1d1 /* Level 1 shadow stack pointer */ +#define MSR_IA32_FRED_SSP2 0x1d2 /* Level 2 shadow stack pointer */ +#define MSR_IA32_FRED_SSP3 0x1d3 /* Level 3 shadow stack pointer */ +#define MSR_IA32_FRED_CONFIG 0x1d4 /* Entrypoint and interrupt stack level= */ =20 +/* Intel MSRs. Some also available on other CPUs */ #define MSR_TEST_CTRL 0x00000033 #define MSR_TEST_CTRL_SPLIT_LOCK_DETECT_BIT 29 #define MSR_TEST_CTRL_SPLIT_LOCK_DETECT BIT(MSR_TEST_CTRL_SPLIT_LOCK_DETE= CT_BIT) diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/includ= e/asm/msr-index.h index 37ff47552bcb..0ade66db3627 100644 --- a/tools/arch/x86/include/asm/msr-index.h +++ b/tools/arch/x86/include/asm/msr-index.h @@ -34,8 +34,19 @@ #define EFER_LMSLE (1<<_EFER_LMSLE) #define EFER_FFXSR (1<<_EFER_FFXSR) =20 -/* Intel MSRs. Some also available on other CPUs */ +/* FRED MSRs */ +#define MSR_IA32_FRED_RSP0 0x1cc /* Level 0 stack pointer */ +#define MSR_IA32_FRED_RSP1 0x1cd /* Level 1 stack pointer */ +#define MSR_IA32_FRED_RSP2 0x1ce /* Level 2 stack pointer */ +#define MSR_IA32_FRED_RSP3 0x1cf /* Level 3 stack pointer */ +#define MSR_IA32_FRED_STKLVLS 0x1d0 /* Exception stack levels */ +#define MSR_IA32_FRED_SSP0 MSR_IA32_PL0_SSP /* Level 0 shadow stack pointe= r */ +#define MSR_IA32_FRED_SSP1 0x1d1 /* Level 1 shadow stack pointer */ +#define MSR_IA32_FRED_SSP2 0x1d2 /* Level 2 shadow stack pointer */ +#define MSR_IA32_FRED_SSP3 0x1d3 /* Level 3 shadow stack pointer */ +#define MSR_IA32_FRED_CONFIG 0x1d4 /* Entrypoint and interrupt stack level= */ =20 +/* Intel MSRs. Some also available on other CPUs */ #define MSR_TEST_CTRL 0x00000033 #define MSR_TEST_CTRL_SPLIT_LOCK_DETECT_BIT 29 #define MSR_TEST_CTRL_SPLIT_LOCK_DETECT BIT(MSR_TEST_CTRL_SPLIT_LOCK_DETE= CT_BIT) --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EA68C678DB for ; Fri, 24 Feb 2023 07:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229980AbjBXH2g (ORCPT ); Fri, 24 Feb 2023 02:28:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229778AbjBXH2M (ORCPT ); Fri, 24 Feb 2023 02:28:12 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0550F16ADA; Thu, 23 Feb 2023 23:28:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223681; x=1708759681; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=UOsdS7+owJQ73WNU9ofGpL7BxDN6CoX4IXCHRYhbv+k=; b=ZscckcB8j2PIEaJNbM/mcGDM19ZsA5TiJglT7i0/OXPGx/krEz8XArZ/ xbRCUmi9yg5INoFaey7BtKPgMm7b9pYVp3vF+yxJ1eAWkjoewdoMBtmPb xXRa7lqXA7VtHcdUK5Io9pjim3xiJxz/MqJFbJXoOk4UTZVl6JiUchAUV WOLRHWVwscxIeW5GQxv3BV4/MbnUn/K/DMThnxYi2RNkzfvAG5Yk7DBS4 C2feV79OVNw2DVm1RZtlVJct5kvRAt7tA5L1NC7rCbjkaMWZkwo7gFzoC J9ouVlabage/DLXKbuDlMgjs6+szWlbcYoG0NNoBk/oZMruFgY+DC9jff g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836024" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836024" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639225" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639225" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 13/32] x86/fred: header file for event types Date: Thu, 23 Feb 2023 23:01:26 -0800 Message-Id: <20230224070145.3572-14-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" FRED inherits the Intel VT-x enhancement of classified events with a two-level event dispatch logic. The first-level dispatch is on the event type, not the event vector as used in the IDT architecture. This also means that vectors in different event types are orthogonal, e.g., vectors 0x10-0x1f become available as hardware interrupts. Add a header file for event types, and also use it in . Suggested-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/event-type.h | 17 +++++++++++++++++ arch/x86/include/asm/vmx.h | 17 +++++++++-------- 2 files changed, 26 insertions(+), 8 deletions(-) create mode 100644 arch/x86/include/asm/event-type.h diff --git a/arch/x86/include/asm/event-type.h b/arch/x86/include/asm/event= -type.h new file mode 100644 index 000000000000..fedaa0e492c5 --- /dev/null +++ b/arch/x86/include/asm/event-type.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_EVENT_TYPE_H +#define _ASM_X86_EVENT_TYPE_H + +/* + * Event type codes: these are the same that are used by VTx. + */ +#define EVENT_TYPE_HWINT 0 /* Maskable external interrupt */ +#define EVENT_TYPE_RESERVED 1 +#define EVENT_TYPE_NMI 2 /* Non-maskable interrupt */ +#define EVENT_TYPE_HWFAULT 3 /* Hardware exceptions (e.g., page fault) */ +#define EVENT_TYPE_SWINT 4 /* Software interrupt (INT n) */ +#define EVENT_TYPE_PRIVSW 5 /* INT1 (ICEBP) */ +#define EVENT_TYPE_SWFAULT 6 /* Software exception (INT3 or INTO) */ +#define EVENT_TYPE_OTHER 7 /* FRED: SYSCALL/SYSENTER */ + +#endif diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h index 498dc600bd5c..8d9b8b0d8e56 100644 --- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -15,6 +15,7 @@ #include #include #include +#include #include =20 #define VMCS_CONTROL_BIT(x) BIT(VMX_FEATURE_##x & 0x1f) @@ -372,14 +373,14 @@ enum vmcs_field { #define VECTORING_INFO_DELIVER_CODE_MASK INTR_INFO_DELIVER_CODE_MASK #define VECTORING_INFO_VALID_MASK INTR_INFO_VALID_MASK =20 -#define INTR_TYPE_EXT_INTR (0 << 8) /* external interrupt */ -#define INTR_TYPE_RESERVED (1 << 8) /* reserved */ -#define INTR_TYPE_NMI_INTR (2 << 8) /* NMI */ -#define INTR_TYPE_HARD_EXCEPTION (3 << 8) /* processor exception */ -#define INTR_TYPE_SOFT_INTR (4 << 8) /* software interrupt */ -#define INTR_TYPE_PRIV_SW_EXCEPTION (5 << 8) /* ICE breakpoint - undocumen= ted */ -#define INTR_TYPE_SOFT_EXCEPTION (6 << 8) /* software exception */ -#define INTR_TYPE_OTHER_EVENT (7 << 8) /* other event */ +#define INTR_TYPE_EXT_INTR (EVENT_TYPE_HWINT << 8) /* external interrupt= */ +#define INTR_TYPE_RESERVED (EVENT_TYPE_RESERVED << 8) /* reserved */ +#define INTR_TYPE_NMI_INTR (EVENT_TYPE_NMI << 8) /* NMI */ +#define INTR_TYPE_HARD_EXCEPTION (EVENT_TYPE_HWFAULT << 8) /* processor ex= ception */ +#define INTR_TYPE_SOFT_INTR (EVENT_TYPE_SWINT << 8) /* software interrup= t */ +#define INTR_TYPE_PRIV_SW_EXCEPTION (EVENT_TYPE_PRIVSW << 8) /* ICE breakp= oint - undocumented */ +#define INTR_TYPE_SOFT_EXCEPTION (EVENT_TYPE_SWFAULT << 8) /* software exc= eption */ +#define INTR_TYPE_OTHER_EVENT (EVENT_TYPE_OTHER << 8) /* other event */ =20 /* GUEST_INTERRUPTIBILITY_INFO flags. */ #define GUEST_INTR_STATE_STI 0x00000001 --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41AFEC61DA3 for ; Fri, 24 Feb 2023 07:28:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229993AbjBXH2l (ORCPT ); Fri, 24 Feb 2023 02:28:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229832AbjBXH2P (ORCPT ); Fri, 24 Feb 2023 02:28:15 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E433439B8C; Thu, 23 Feb 2023 23:28:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223681; x=1708759681; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tgdMYcOakRl86nvaaJrJKyKhhcEE7k0v0Jtz0oYjgp0=; b=iaOLLL5CMtrEjpVGli29hO2Rz0UEz5Jljwt75jT6hOTm1IjzH5pAsG0l uOiVsG+ndzJpdB9g11gKIfFqOvY7D+mI6APxVw1lZhJ7RSeZznMKmKbHN J65CgN/T1R3DD/ie40S8ofYwlEsVpMj90YEHCQSnp36IhALJ+hwbcNs++ 0QX2CJx68UA6ENlCXLJNZyZavYqqNAXQNg+GvxOLZ9V//g1QvF6eJIaV5 AXYGbXOHjDKjIsdIrNtfDgdLbpHpFjgJgTxlcK1n571uq05dqftba7DpQ JlUhZZZXSW8M7EdOoynWfbKNTBTOJ2284pA+zhFYaiHHqnYUvuvlLHv0s A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836026" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836026" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:22 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639228" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639228" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 14/32] x86/fred: header file with FRED definitions Date: Thu, 23 Feb 2023 23:01:27 -0800 Message-Id: <20230224070145.3572-15-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add a header file for FRED prototypes and definitions. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 101 ++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 arch/x86/include/asm/fred.h diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h new file mode 100644 index 000000000000..f4de2cdd1c7f --- /dev/null +++ b/arch/x86/include/asm/fred.h @@ -0,0 +1,101 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/x86/include/asm/fred.h + * + * Macros for Flexible Return and Event Delivery (FRED) + */ + +#ifndef ASM_X86_FRED_H +#define ASM_X86_FRED_H + +#ifdef CONFIG_X86_FRED + +#include +#include + +/* + * FRED return instructions + * + * Replace with "ERETS"/"ERETU" once binutils support FRED return instruct= ions. + * The binutils version supporting FRED instructions is still TBD, and will + * update once we have it. + */ +#define ERETS _ASM_BYTES(0xf2,0x0f,0x01,0xca) +#define ERETU _ASM_BYTES(0xf3,0x0f,0x01,0xca) + +/* + * Event stack level macro for the FRED_STKLVLS MSR. + * Usage example: FRED_STKLVL(X86_TRAP_DF, 3) + * Multiple values can be ORd together. + */ +#define FRED_STKLVL(v,l) (_AT(unsigned long, l) << (2*(v))) + +/* FRED_CONFIG MSR */ +#define FRED_CONFIG_CSL_MASK 0x3 +#define FRED_CONFIG_SHADOW_STACK_SPACE _BITUL(3) +#define FRED_CONFIG_REDZONE(b) __ALIGN_KERNEL_MASK((b), _UL(0x3f)) +#define FRED_CONFIG_INT_STKLVL(l) (_AT(unsigned long, l) << 9) +#define FRED_CONFIG_ENTRYPOINT(p) _AT(unsigned long, (p)) + +/* FRED event type and vector bit width and counts */ +#define FRED_EVENT_TYPE_BITS 3 /* only 3 bits used in FRED 3.0 */ +#define FRED_EVENT_TYPE_COUNT _BITUL(FRED_EVENT_TYPE_BITS) +#define FRED_EVENT_VECTOR_BITS 8 +#define FRED_EVENT_VECTOR_COUNT _BITUL(FRED_EVENT_VECTOR_BITS) + +/* FRED EVENT_TYPE_OTHER vector numbers */ +#define FRED_SYSCALL 1 +#define FRED_SYSENTER 2 + +/* Flags above the CS selector (regs->csl) */ +#define FRED_CSL_ENABLE_NMI _BITUL(28) +#define FRED_CSL_ALLOW_SINGLE_STEP _BITUL(25) +#define FRED_CSL_INTERRUPT_SHADOW _BITUL(24) + +#ifndef __ASSEMBLY__ + +#include +#include + +/* FRED stack frame information */ +struct fred_info { + unsigned long edata; /* Event data: CR2, DR6, ... */ + unsigned long resv; +}; + +/* Full format of the FRED stack frame */ +struct fred_frame { + struct pt_regs regs; + struct fred_info info; +}; + +/* Getting the FRED frame information from a pt_regs pointer */ +static __always_inline struct fred_info *fred_info(struct pt_regs *regs) +{ + return &container_of(regs, struct fred_frame, regs)->info; +} + +static __always_inline unsigned long fred_event_data(struct pt_regs *regs) +{ + return fred_info(regs)->edata; +} + +/* + * How FRED event handlers are called. + * + * FRED event delivery establishes the full supervisor context + * by pushing everything related to the event being delivered + * to the FRED stack frame, e.g., the faulting linear address + * of a #PF is pushed as event data of the FRED #PF stack frame. + * Thus a struct pt_regs has everything needed and it's the only + * input parameter required for a FRED event handler. + */ +#define DECLARE_FRED_HANDLER(f) void f (struct pt_regs *regs) +#define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) +typedef DECLARE_FRED_HANDLER((*fred_handler)); + +#endif /* __ASSEMBLY__ */ + +#endif /* CONFIG_X86_FRED */ + +#endif /* ASM_X86_FRED_H */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D8BEC61DA3 for ; Fri, 24 Feb 2023 07:28:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230002AbjBXH2o (ORCPT ); Fri, 24 Feb 2023 02:28:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229846AbjBXH2Q (ORCPT ); Fri, 24 Feb 2023 02:28:16 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5653B3B0ED; Thu, 23 Feb 2023 23:28:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; 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([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 15/32] x86/fred: make unions for the cs and ss fields in struct pt_regs Date: Thu, 23 Feb 2023 23:01:28 -0800 Message-Id: <20230224070145.3572-16-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Make the cs and ss fields in struct pt_regs unions between the actual selector and the unsigned long stack slot. FRED uses this space to store additional flags. The printk changes are simply due to the cs and ss fields changed to unsigned short from unsigned long. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/entry/vsyscall/vsyscall_64.c | 2 +- arch/x86/include/asm/ptrace.h | 36 ++++++++++++++++++++++++--- arch/x86/kernel/process_64.c | 2 +- 3 files changed, 34 insertions(+), 6 deletions(-) diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscal= l/vsyscall_64.c index 4af81df133ee..6349c818d20a 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -76,7 +76,7 @@ static void warn_bad_vsyscall(const char *level, struct p= t_regs *regs, if (!show_unhandled_signals) return; =20 - printk_ratelimited("%s%s[%d] %s ip:%lx cs:%lx sp:%lx ax:%lx si:%lx di:%lx= \n", + printk_ratelimited("%s%s[%d] %s ip:%lx cs:%x sp:%lx ax:%lx si:%lx di:%lx\= n", level, current->comm, task_pid_nr(current), message, regs->ip, regs->cs, regs->sp, regs->ax, regs->si, regs->di); diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index f4db78b09c8f..341e44847cc1 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -82,13 +82,41 @@ struct pt_regs { * On hw interrupt, it's IRQ number: */ unsigned long orig_ax; -/* Return frame for iretq */ + + /* Return frame for iretq/eretu/erets */ unsigned long ip; - unsigned long cs; + union { + unsigned long csl; /* CS + any fields above it */ + struct __attribute__((__packed__)) { + unsigned short cs; /* CS selector proper */ + unsigned int current_stack_level: 2; + unsigned int __csl_resv1 : 6; + unsigned int interrupt_shadowed : 1; + unsigned int software_initiated : 1; + unsigned int __csl_resv2 : 2; + unsigned int nmi : 1; + unsigned int __csl_resv3 : 3; + unsigned int __csl_resv4 : 32; + }; + }; unsigned long flags; unsigned long sp; - unsigned long ss; -/* top of stack page */ + union { + unsigned long ssl; /* SS + any fields above it */ + struct __attribute__((__packed__)) { + unsigned short ss; /* SS selector proper */ + unsigned int __ssl_resv1: 16; + unsigned int vector : 8; + unsigned int __ssl_resv2: 8; + unsigned int type : 4; + unsigned int __ssl_resv3: 4; + unsigned int enclv : 1; + unsigned int long_mode : 1; + unsigned int nested : 1; + unsigned int __ssl_resv4: 1; + unsigned int instr_len : 4; + }; + }; }; =20 #endif /* !__i386__ */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 4e34b3b68ebd..57de166dc61c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -116,7 +116,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_m= ode mode, =20 printk("%sFS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", log_lvl, fs, fsindex, gs, gsindex, shadowgs); - printk("%sCS: %04lx DS: %04x ES: %04x CR0: %016lx\n", + printk("%sCS: %04x DS: %04x ES: %04x CR0: %016lx\n", log_lvl, regs->cs, ds, es, cr0); printk("%sCR2: %016lx CR3: %016lx CR4: %016lx\n", log_lvl, cr2, cr3, cr4); --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E56CC61DA3 for ; Fri, 24 Feb 2023 07:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230009AbjBXH2s (ORCPT ); Fri, 24 Feb 2023 02:28:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbjBXH2Q (ORCPT ); Fri, 24 Feb 2023 02:28:16 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D82813B871; Thu, 23 Feb 2023 23:28:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223683; x=1708759683; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DOSNEZFexx6rcKjeivP+6dofAP4lFXi0PU4el7mRCPw=; b=cfayCtg/qSSK8qR2tmbmLSZdnapv4PghcHymXEGt2ERLGQZbVfY6nRwF uQxz3S3s5jJZ+ATZyUCY0Pzw7oGa6FUUowmRcz3m6Tg0xk5i5ZQ0DXIRm vf9is//wXFbDAX7wF7wqVI8Az9z8RapbnA174u0pvYtea79w9JVpw/79A 9TzWPajLTykCmN9Prxc8q7zqC+U1IkhWT3DodbVqbFeTx/0Ay8JFOa7NM Dv8Y99ygPCKX0lddpGsMTujx85GdQH/G/KP6cPN1lJMXjhlw/ku8dI0TE lGrr56uYRktdoyEG4SgvDy7p59fvhOE4NbSifyBCDTXmVTF26Wi/G5/Hd A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836049" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836049" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639237" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639237" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 16/32] x86/fred: reserve space for the FRED stack frame Date: Thu, 23 Feb 2023 23:01:29 -0800 Message-Id: <20230224070145.3572-17-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" When using FRED, reserve space at the top of the stack frame, just like i386 does. A future version of FRED might have dynamic frame sizes, though, in which case it might be necessary to make TOP_OF_KERNEL_STACK_PADDING a variable instead of a constant. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/thread_info.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thre= ad_info.h index f1cccba52eb9..998483078d5f 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -31,7 +31,9 @@ * In vm86 mode, the hardware frame is much longer still, so add 16 * bytes to make room for the real-mode segments. * - * x86_64 has a fixed-length stack frame. + * x86-64 has a fixed-length stack frame, but it depends on whether + * or not FRED is enabled. Future versions of FRED might make this + * dynamic, but for now it is always 2 words longer. */ #ifdef CONFIG_X86_32 # ifdef CONFIG_VM86 @@ -39,8 +41,12 @@ # else # define TOP_OF_KERNEL_STACK_PADDING 8 # endif -#else -# define TOP_OF_KERNEL_STACK_PADDING 0 +#else /* x86-64 */ +# ifdef CONFIG_X86_FRED +# define TOP_OF_KERNEL_STACK_PADDING (2*8) +# else +# define TOP_OF_KERNEL_STACK_PADDING 0 +# endif #endif =20 /* --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80887C64ED8 for ; Fri, 24 Feb 2023 07:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229785AbjBXH2v (ORCPT ); Fri, 24 Feb 2023 02:28:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229862AbjBXH2Q (ORCPT ); Fri, 24 Feb 2023 02:28:16 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08DAD3BD99; Thu, 23 Feb 2023 23:28:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223684; x=1708759684; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LJAXoIH5EY7acqY4mtQFvimkQPN5qKlFIb9dyMRhzXM=; b=JALtesKalKiWS8Um/rnVqxvJwn6iKwexl0KWvppcuoKq39bBspCUB3ZI M/UWFkVd5/vI3IkAlPJWn/V6eer3kaRiMnsuSZx40OkDgI88bH4OWXwIi LOO8kzytLxNfAoL321LZQPHSXmxnp1j5YJYkuGOsdxDGpM4KDEDmPzF9v wLtGor4Mcdrg8qj5sKeLaVDE11uI+U3zogq1K7fcwOKa6a9H/IOYBXHfT a6zlHd/DRfNEgWUbbvQZJ3SNFb1CEshXSegNCOzP58rz3NSIj4L6Yist7 8r4Lo1sU89qOYbNjNCAPECEnSPn6ROxnuAfCI2eg5QpA98dgdDrGPS4VF A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836059" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836059" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639240" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639240" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:23 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 17/32] x86/fred: add a page fault entry stub for FRED Date: Thu, 23 Feb 2023 23:01:30 -0800 Message-Id: <20230224070145.3572-18-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add a page fault entry stub for FRED. On a FRED system, the faulting address (CR2) is passed on the stack, to avoid the problem of transient state. Thus we get the page fault address from the stack instead of CR2. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 2 ++ arch/x86/mm/fault.c | 20 ++++++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index f4de2cdd1c7f..de300bda60ee 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -94,6 +94,8 @@ static __always_inline unsigned long fred_event_data(stru= ct pt_regs *regs) #define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) typedef DECLARE_FRED_HANDLER((*fred_handler)); =20 +DECLARE_FRED_HANDLER(fred_exc_page_fault); + #endif /* __ASSEMBLY__ */ =20 #endif /* CONFIG_X86_FRED */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7b0d4ab894c8..f31053f32048 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -33,6 +33,7 @@ #include /* kvm_handle_async_pf */ #include /* fixup_vdso_exception() */ #include +#include /* fred_event_data() */ =20 #define CREATE_TRACE_POINTS #include @@ -1528,9 +1529,10 @@ handle_page_fault(struct pt_regs *regs, unsigned lon= g error_code, } } =20 -DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) +static __always_inline void page_fault_common(struct pt_regs *regs, + unsigned int error_code, + unsigned long address) { - unsigned long address =3D read_cr2(); irqentry_state_t state; =20 prefetchw(¤t->mm->mmap_lock); @@ -1577,3 +1579,17 @@ DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) =20 irqentry_exit(regs, state); } + +DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) +{ + page_fault_common(regs, error_code, read_cr2()); +} + +#ifdef CONFIG_X86_FRED + +DEFINE_FRED_HANDLER(fred_exc_page_fault) +{ + page_fault_common(regs, regs->orig_ax, fred_event_data(regs)); +} + +#endif /* CONFIG_X86_FRED */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA799C64ED8 for ; Fri, 24 Feb 2023 07:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230022AbjBXH2y (ORCPT ); Fri, 24 Feb 2023 02:28:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229865AbjBXH2Q (ORCPT ); Fri, 24 Feb 2023 02:28:16 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A429C3CE08; Thu, 23 Feb 2023 23:28:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223684; x=1708759684; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EaKofp4ivx0Pf/jBUb85CotBkxU7/n1s/fvnBgy99zs=; b=BcMwbxtMxM+hYb97XUyWc7PkusVVpgjwlhmFbZ1JzfmGzip92KBL/wWz t+zjYRYbZY/IV3y9Cma2QLTdqU/6bnEGIHUWZfPqCMBs7K45EBZreiiL/ yxPA92az3Ee90OB15jiTdYc7zDHwuSGRhfhkFIBVVi7f7gF54tvnqYCC/ N2+dgrLMjPD1flS49hQG7LGbCWUdzYTeQlDRQBiB2HWkQfwH9PNwFwkbV G1tgdZUNO6UMOo3gMBsxWAMchQrSxDnKxCz3BOFI1dan9cMqE/Lo9XdE8 jKpmLFvRYlLWdkH5/uTwIV4lNGdw6M4G5REvLx3X4A95lTge6kDT9e5FW w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836066" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836066" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639244" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639244" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:23 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 18/32] x86/fred: add a debug fault entry stub for FRED Date: Thu, 23 Feb 2023 23:01:31 -0800 Message-Id: <20230224070145.3572-19-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add a debug fault entry stub for FRED. On a FRED system, the debug trap status information (DR6) is passed on the stack, to avoid the problem of transient state. Furthermore, FRED transitions avoid a lot of ugly corner cases the handling of which can, and should be, skipped. The FRED debug trap status information saved on the stack differs from DR6 in both stickiness and polarity; it is exactly what debug_read_clear_dr6() returns, and exc_debug_user()/exc_debug_kernel() expect. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- Changes since v1: * call irqentry_nmi_{enter,exit}() in both IDT and FRED debug fault kernel handler (Peter Zijlstra). --- arch/x86/include/asm/fred.h | 1 + arch/x86/kernel/traps.c | 56 +++++++++++++++++++++++++++---------- 2 files changed, 42 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index de300bda60ee..def4b3455c1f 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -94,6 +94,7 @@ static __always_inline unsigned long fred_event_data(stru= ct pt_regs *regs) #define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) typedef DECLARE_FRED_HANDLER((*fred_handler)); =20 +DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); =20 #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index cebba1f49e19..4b0f63344526 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include #include @@ -1020,21 +1021,9 @@ static bool notify_debug(struct pt_regs *regs, unsig= ned long *dr6) return false; } =20 -static __always_inline void exc_debug_kernel(struct pt_regs *regs, - unsigned long dr6) +static __always_inline void debug_kernel_common(struct pt_regs *regs, + unsigned long dr6) { - /* - * Disable breakpoints during exception handling; recursive exceptions - * are exceedingly 'fun'. - * - * Since this function is NOKPROBE, and that also applies to - * HW_BREAKPOINT_X, we can't hit a breakpoint before this (XXX except a - * HW_BREAKPOINT_W on our stack) - * - * Entry text is excluded for HW_BP_X and cpu_entry_area, which - * includes the entry stack is excluded for everything. - */ - unsigned long dr7 =3D local_db_save(); irqentry_state_t irq_state =3D irqentry_nmi_enter(regs); instrumentation_begin(); =20 @@ -1062,7 +1051,8 @@ static __always_inline void exc_debug_kernel(struct p= t_regs *regs, * Catch SYSENTER with TF set and clear DR_STEP. If this hit a * watchpoint at the same time then that will still be handled. */ - if ((dr6 & DR_STEP) && is_sysenter_singlestep(regs)) + if (!cpu_feature_enabled(X86_FEATURE_FRED) && + (dr6 & DR_STEP) && is_sysenter_singlestep(regs)) dr6 &=3D ~DR_STEP; =20 /* @@ -1090,7 +1080,25 @@ static __always_inline void exc_debug_kernel(struct = pt_regs *regs, out: instrumentation_end(); irqentry_nmi_exit(regs, irq_state); +} =20 +static __always_inline void exc_debug_kernel(struct pt_regs *regs, + unsigned long dr6) +{ + /* + * Disable breakpoints during exception handling; recursive exceptions + * are exceedingly 'fun'. + * + * Since this function is NOKPROBE, and that also applies to + * HW_BREAKPOINT_X, we can't hit a breakpoint before this (XXX except a + * HW_BREAKPOINT_W on our stack) + * + * Entry text is excluded for HW_BP_X and cpu_entry_area, which + * includes the entry stack is excluded for everything. + */ + unsigned long dr7 =3D local_db_save(); + + debug_kernel_common(regs, dr6); local_db_restore(dr7); } =20 @@ -1179,6 +1187,24 @@ DEFINE_IDTENTRY_DEBUG_USER(exc_debug) { exc_debug_user(regs, debug_read_clear_dr6()); } + +# ifdef CONFIG_X86_FRED +DEFINE_FRED_HANDLER(fred_exc_debug) +{ + /* + * The FRED debug information saved onto stack differs from + * DR6 in both stickiness and polarity; it is exactly what + * debug_read_clear_dr6() returns. + */ + unsigned long dr6 =3D fred_event_data(regs); + + if (user_mode(regs)) + exc_debug_user(regs, dr6); + else + debug_kernel_common(regs, dr6); +} +# endif /* CONFIG_X86_FRED */ + #else /* 32 bit does not have separate entry points. */ DEFINE_IDTENTRY_RAW(exc_debug) --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2454C61DA3 for ; Fri, 24 Feb 2023 07:28:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230027AbjBXH25 (ORCPT ); Fri, 24 Feb 2023 02:28:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229879AbjBXH2R (ORCPT ); Fri, 24 Feb 2023 02:28:17 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0D7C410A8; Thu, 23 Feb 2023 23:28:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223685; x=1708759685; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=AmI4CVrrpson0KuyKSQFz12EZ8608BBLxIPOHAFvgP0=; b=QCQhjcTBjz5E6UsJL3EzuYgEs/2g6xWZ8LbQr3qjVvVOrji01eF9VnCq bwqvQ87BFSQsY6QFca07/031VcMyEPA+8kaMW5ly22WiE5KdTKAGt7qBb IAL6RBQfgb4pYdWCRUIFtDcv8y2UQeZSJYBIb/0LmBHKChFLEB6UDPFCg 3AblL7gS636qzLwxZZINzYzpdcYnZ9WEXhaD/Auzddg6CpQwbQZ5+xrBF DGi0hbrtB/tL6Gq8gpeA+JPaKIaN8VUOKbIS2t8DfZOf1z8olXlMDIjvX YbxjerX8+aDkX62ZhGQExD1psMgBnW9RKz4jozUFSFy1aRHNdu68yBQJe Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836077" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836077" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639248" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639248" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:23 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 19/32] x86/fred: add a NMI entry stub for FRED Date: Thu, 23 Feb 2023 23:01:32 -0800 Message-Id: <20230224070145.3572-20-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" On a FRED system, NMIs nest both with themselves and faults, transient information is saved into the stack frame, and NMI unblocking only happens when the stack frame indicates that so should happen. Thus, the NMI entry stub for FRED is really quite small... Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 1 + arch/x86/kernel/nmi.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index def4b3455c1f..753ae2adf422 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -94,6 +94,7 @@ static __always_inline unsigned long fred_event_data(stru= ct pt_regs *regs) #define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) typedef DECLARE_FRED_HANDLER((*fred_handler)); =20 +DECLARE_FRED_HANDLER(fred_exc_nmi); DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); =20 diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index cec0bfa3bc04..b8f0357e4663 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -34,6 +34,7 @@ #include #include #include +#include =20 #define CREATE_TRACE_POINTS #include @@ -537,6 +538,33 @@ DEFINE_IDTENTRY_RAW(exc_nmi_noist) EXPORT_SYMBOL_GPL(asm_exc_nmi_noist); #endif =20 +#ifdef CONFIG_X86_FRED +DEFINE_FRED_HANDLER(fred_exc_nmi) +{ + /* + * With FRED, CR2 and DR6 are pushed atomically on faults, + * so we don't have to worry about saving and restoring them. + * Breakpoint faults nest, so assume it is OK to leave DR7 + * enabled. + */ + irqentry_state_t irq_state =3D irqentry_nmi_enter(regs); + + /* + * VM exits induced by NMIs keep NMI blocked, and we do + * "int $2" to reinject the NMI w/ NMI kept being blocked. + * However "int $2" doesn't set the nmi bit in the FRED + * stack frame, so we explicitly set it to make sure a + * later ERETS will unblock NMI immediately. + */ + regs->nmi =3D 1; + + inc_irq_stat(__nmi_count); + default_do_nmi(regs); + + irqentry_nmi_exit(regs, irq_state); +} +#endif + void stop_nmi(void) { ignore_nmis++; --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EE55C677F1 for ; Fri, 24 Feb 2023 07:29:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230039AbjBXH3G (ORCPT ); Fri, 24 Feb 2023 02:29:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229653AbjBXH2W (ORCPT ); Fri, 24 Feb 2023 02:28:22 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B3B93CE03; Thu, 23 Feb 2023 23:28:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223687; x=1708759687; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EAqkkjbGdrJOIqCTsnl5LSVUAe8TJXgpl5ggPVVzxf0=; b=EfY72VDuZ+Be0HgGG2Ym+CtslreFGNRpklyX1U3NdE5em20quB6D+fr8 40+bZOJVNvsylymGnb6rAyZmgA1dDs+RuHcYPURmqrnCwhVIghAzF+mCT uhd4zGMzxxoymGVDBMTdFweTUDipU7t/8nr8hrfpd7lz6cn9H0+8/cmpl hR1CRr2ZwtyzztiYrHU1+CJ3A1SzQOjy5F7zYuZdJkDtWyNX5+ov3tZvD i2RSU31GR0qn3lOEpBzm/LBhwbiqrmWhJyZBCyA0srIgiFOKWM1fCqgAi 26o+J938TM3Kfr6wPphRsNGJbb/h5TtCDvqSgy2vbQnID21TP6Su4buwX g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836088" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836088" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639251" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639251" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:24 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 20/32] x86/fred: add a machine check entry stub for FRED Date: Thu, 23 Feb 2023 23:01:33 -0800 Message-Id: <20230224070145.3572-21-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a machine check entry stub for FRED. Unlike IDT, no need to save/restore dr7 in FRED machine check handler. Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 1 + arch/x86/kernel/cpu/mce/core.c | 11 +++++++++++ 2 files changed, 12 insertions(+) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index 753ae2adf422..3d6c5c063eef 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -97,6 +97,7 @@ typedef DECLARE_FRED_HANDLER((*fred_handler)); DECLARE_FRED_HANDLER(fred_exc_nmi); DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); +DECLARE_FRED_HANDLER(fred_exc_machine_check); =20 #endif /* __ASSEMBLY__ */ =20 diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 7832a69d170e..26fa7fa44f30 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -52,6 +52,7 @@ #include #include #include +#include =20 #include "internal.h" =20 @@ -2111,6 +2112,16 @@ DEFINE_IDTENTRY_MCE_USER(exc_machine_check) exc_machine_check_user(regs); local_db_restore(dr7); } + +#ifdef CONFIG_X86_FRED +DEFINE_FRED_HANDLER(fred_exc_machine_check) +{ + if (user_mode(regs)) + exc_machine_check_user(regs); + else + exc_machine_check_kernel(regs); +} +#endif #else /* 32bit unified entry point */ DEFINE_IDTENTRY_RAW(exc_machine_check) --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6EECC61DA3 for ; Fri, 24 Feb 2023 07:29:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230044AbjBXH3L (ORCPT ); Fri, 24 Feb 2023 02:29:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229964AbjBXH2d (ORCPT ); Fri, 24 Feb 2023 02:28:33 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6524D60D58; Thu, 23 Feb 2023 23:28:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223688; x=1708759688; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=S2Twlm4twcHRvMMSd8DU91Ix47NQlyr+yDB7wnb6UxU=; b=Z6S31isR383TJ17JrpnMKTUA8dIfHmYN8ft6GN/heFXEQ1VAieiKfPpP 59MHoHMhtUAGhc4UcDlZQ6IwrH7M/P0HKqadodsOY24DtvVIm90TGaD4U yj6/oHCUwSegiDAR/j2zWNBNR5j29XBID1qreX4+6/NE8NaKtM3tJqmwC /7qINvL7kAfblwaE6tH3bW7q6gnESnPezaWU0vOspjNgOjHWoh4T9tcFg GZ+3jM4/Nol5LKefC7RlsvS2jq4WcWgohAetXob835y80r6jKHbqky7YX /4s1J2bdeMLn3URVV2mNNGqbhky2KYKEi5DOVie6sroLZmiiR9LVzBDzl w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836098" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836098" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639255" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639255" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:24 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 21/32] x86/fred: FRED entry/exit and dispatch code Date: Thu, 23 Feb 2023 23:01:34 -0800 Message-Id: <20230224070145.3572-22-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" The code to actually handle kernel and event entry/exit using FRED. It is split up into two files thus: - entry_64_fred.S contains the actual entrypoints and exit code, and saves and restores registers. - entry_fred.c contains the two-level event dispatch code for FRED. The first-level dispatch is on the event type, and the second-level is on the event vector. Originally-by: Megha Dey Signed-off-by: H. Peter Anvin (Intel) Co-developed-by: Xin Li Signed-off-by: Xin Li --- Changes since v1: * Initialize a FRED exception handler to fred_bad_event() instead of NULL if no FRED handler defined for an exception vector (Peter Zijlstra). * Push calling irqentry_{enter,exit}() and instrumentation_{begin,end}() down into individual FRED exception handlers, instead of in the dispatch framework (Peter Zijlstra). --- arch/x86/entry/Makefile | 5 +- arch/x86/entry/entry_64_fred.S | 55 ++++++++ arch/x86/entry/entry_fred.c | 232 ++++++++++++++++++++++++++++++++ arch/x86/include/asm/idtentry.h | 8 ++ 4 files changed, 299 insertions(+), 1 deletion(-) create mode 100644 arch/x86/entry/entry_64_fred.S create mode 100644 arch/x86/entry/entry_fred.c diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile index ca2fe186994b..c93e7f5c2a06 100644 --- a/arch/x86/entry/Makefile +++ b/arch/x86/entry/Makefile @@ -18,6 +18,9 @@ obj-y +=3D vdso/ obj-y +=3D vsyscall/ =20 obj-$(CONFIG_PREEMPTION) +=3D thunk_$(BITS).o +CFLAGS_entry_fred.o +=3D -fno-stack-protector +CFLAGS_REMOVE_entry_fred.o +=3D -pg $(CC_FLAGS_FTRACE) +obj-$(CONFIG_X86_FRED) +=3D entry_64_fred.o entry_fred.o + obj-$(CONFIG_IA32_EMULATION) +=3D entry_64_compat.o syscall_32.o obj-$(CONFIG_X86_X32_ABI) +=3D syscall_x32.o - diff --git a/arch/x86/entry/entry_64_fred.S b/arch/x86/entry/entry_64_fred.S new file mode 100644 index 000000000000..1fb765fd3871 --- /dev/null +++ b/arch/x86/entry/entry_64_fred.S @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/x86/entry/entry_64_fred.S + * + * The actual FRED entry points. + */ +#include +#include +#include +#include + +#include "calling.h" + + .code64 + .section ".noinstr.text", "ax" + +.macro FRED_ENTER + UNWIND_HINT_EMPTY + PUSH_AND_CLEAR_REGS + movq %rsp, %rdi /* %rdi -> pt_regs */ +.endm + +.macro FRED_EXIT + UNWIND_HINT_REGS + POP_REGS + addq $8,%rsp /* Drop error code */ +.endm + +/* + * The new RIP value that FRED event delivery establishes is + * IA32_FRED_CONFIG & ~FFFH for events that occur in ring 3. + * Thus the FRED ring 3 entry point must be 4K page aligned. + */ + .align 4096 + +SYM_CODE_START_NOALIGN(fred_entrypoint_user) + FRED_ENTER + call fred_entry_from_user +SYM_INNER_LABEL(fred_exit_user, SYM_L_GLOBAL) + FRED_EXIT + ERETU +SYM_CODE_END(fred_entrypoint_user) + +/* + * The new RIP value that FRED event delivery establishes is + * (IA32_FRED_CONFIG & ~FFFH) + 256 for events that occur in + * ring 0, i.e., fred_entrypoint_user + 256. + */ + .org fred_entrypoint_user+256 +SYM_CODE_START_NOALIGN(fred_entrypoint_kernel) + FRED_ENTER + call fred_entry_from_kernel + FRED_EXIT + ERETS +SYM_CODE_END(fred_entrypoint_kernel) diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c new file mode 100644 index 000000000000..8d3e144670d6 --- /dev/null +++ b/arch/x86/entry/entry_fred.c @@ -0,0 +1,232 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * arch/x86/entry/entry_fred.c + * + * This contains the dispatch functions called from the entry point + * assembly. + */ + +#include +#include /* oops_begin/end, ... */ +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Badness... + */ +static DEFINE_FRED_HANDLER(fred_bad_event) +{ + irqentry_state_t irq_state =3D irqentry_nmi_enter(regs); + + instrumentation_begin(); + + /* Panic on events from a high stack level */ + if (regs->current_stack_level > 0) { + pr_emerg("PANIC: invalid or fatal FRED event; event type %u " + "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n", + regs->type, regs->vector, regs->orig_ax, + fred_event_data(regs), regs->cs, regs->ip); + die("invalid or fatal FRED event", regs, regs->orig_ax); + panic("invalid or fatal FRED event"); + } else { + unsigned long flags =3D oops_begin(); + int sig =3D SIGKILL; + + pr_alert("BUG: invalid or fatal FRED event; event type %u " + "vector %u error 0x%lx aux 0x%lx at %04x:%016lx\n", + regs->type, regs->vector, regs->orig_ax, + fred_event_data(regs), regs->cs, regs->ip); + + if (__die("Invalid or fatal FRED event", regs, regs->orig_ax)) + sig =3D 0; + + oops_end(flags, regs, sig); + } + + instrumentation_end(); + irqentry_nmi_exit(regs, irq_state); +} + +noinstr void fred_exc_double_fault(struct pt_regs *regs) +{ + exc_double_fault(regs, regs->orig_ax); +} + +/* + * Exception entry + */ +static DEFINE_FRED_HANDLER(fred_exception) +{ + /* + * Exceptions that cannot happen on FRED h/w are set to fred_bad_event(). + */ + static const fred_handler exception_handlers[NUM_EXCEPTION_VECTORS] =3D { + [X86_TRAP_DE] =3D exc_divide_error, + [X86_TRAP_DB] =3D fred_exc_debug, + [X86_TRAP_NMI] =3D fred_bad_event, /* A separate event type, not handled= here */ + [X86_TRAP_BP] =3D exc_int3, + [X86_TRAP_OF] =3D exc_overflow, + [X86_TRAP_BR] =3D exc_bounds, + [X86_TRAP_UD] =3D exc_invalid_op, + [X86_TRAP_NM] =3D exc_device_not_available, + [X86_TRAP_DF] =3D fred_exc_double_fault, + [X86_TRAP_OLD_MF] =3D fred_bad_event, /* 387 only! */ + [X86_TRAP_TS] =3D fred_exc_invalid_tss, + [X86_TRAP_NP] =3D fred_exc_segment_not_present, + [X86_TRAP_SS] =3D fred_exc_stack_segment, + [X86_TRAP_GP] =3D fred_exc_general_protection, + [X86_TRAP_PF] =3D fred_exc_page_fault, + [X86_TRAP_SPURIOUS] =3D fred_bad_event, /* Interrupts are their own even= t type */ + [X86_TRAP_MF] =3D exc_coprocessor_error, + [X86_TRAP_AC] =3D fred_exc_alignment_check, + [X86_TRAP_MC] =3D fred_exc_machine_check, + [X86_TRAP_XF] =3D exc_simd_coprocessor_error, + [X86_TRAP_VE...NUM_EXCEPTION_VECTORS-1] =3D fred_bad_event + }; + u8 vector =3D array_index_nospec((u8)regs->vector, NUM_EXCEPTION_VECTORS); + + exception_handlers[vector](regs); +} + +static __always_inline void fred_emulate_trap(struct pt_regs *regs) +{ + regs->type =3D EVENT_TYPE_SWFAULT; + regs->orig_ax =3D 0; + fred_exception(regs); +} + +static __always_inline void fred_emulate_fault(struct pt_regs *regs) +{ + regs->ip -=3D regs->instr_len; + fred_emulate_trap(regs); +} + +/* + * Emulate SYSENTER if applicable. This is not the preferred system + * call in 32-bit mode under FRED, rather int $0x80 is preferred and + * exported in the vdso. SYSCALL proper has a hard-coded early out in + * fred_entry_from_user(). + */ +static DEFINE_FRED_HANDLER(fred_syscall_slow) +{ + if (IS_ENABLED(CONFIG_IA32_EMULATION) && + likely(regs->vector =3D=3D FRED_SYSENTER)) { + /* Convert frame to a syscall frame */ + regs->orig_ax =3D regs->ax; + regs->ax =3D -ENOSYS; + do_fast_syscall_32(regs); + } else { + regs->vector =3D X86_TRAP_UD; + fred_emulate_fault(regs); + } +} + +/* + * Some software exceptions can also be triggered as int instructions, + * for historical reasons. Implement those here. The performance-critical + * int $0x80 (32-bit system call) has a hard-coded early out. + */ +static DEFINE_FRED_HANDLER(fred_sw_interrupt_user) +{ + if (IS_ENABLED(CONFIG_IA32_EMULATION) && + likely(regs->vector =3D=3D IA32_SYSCALL_VECTOR)) { + /* Convert frame to a syscall frame */ + regs->orig_ax =3D regs->ax; + regs->ax =3D -ENOSYS; + return do_int80_syscall_32(regs); + } + + switch (regs->vector) { + case X86_TRAP_BP: + case X86_TRAP_OF: + fred_emulate_trap(regs); + break; + default: + regs->vector =3D X86_TRAP_GP; + fred_emulate_fault(regs); + break; + } +} + +static DEFINE_FRED_HANDLER(fred_hw_interrupt) +{ + irqentry_state_t state =3D irqentry_enter(regs); + + instrumentation_begin(); + external_interrupt(regs, regs->vector); + instrumentation_end(); + irqentry_exit(regs, state); +} + +__visible noinstr void fred_entry_from_user(struct pt_regs *regs) +{ + static const fred_handler user_handlers[FRED_EVENT_TYPE_COUNT] =3D + { + [EVENT_TYPE_HWINT] =3D fred_hw_interrupt, + [EVENT_TYPE_RESERVED] =3D fred_bad_event, + [EVENT_TYPE_NMI] =3D fred_exc_nmi, + [EVENT_TYPE_SWINT] =3D fred_sw_interrupt_user, + [EVENT_TYPE_HWFAULT] =3D fred_exception, + [EVENT_TYPE_SWFAULT] =3D fred_exception, + [EVENT_TYPE_PRIVSW] =3D fred_exception, + [EVENT_TYPE_OTHER] =3D fred_syscall_slow + }; + + /* + * FRED employs a two-level event dispatch mechanism, with + * the first-level on the type of an event and the second-level + * on its vector. Thus a dispatch typically induces 2 calls. + * We optimize it by using early outs for the most frequent + * events, and syscalls are the first. We may also need early + * outs for page faults. + */ + if (likely(regs->type =3D=3D EVENT_TYPE_OTHER && + regs->vector =3D=3D FRED_SYSCALL)) { + /* Convert frame to a syscall frame */ + regs->orig_ax =3D regs->ax; + regs->ax =3D -ENOSYS; + do_syscall_64(regs, regs->orig_ax); + } else { + /* Not a system call */ + u8 type =3D array_index_nospec((u8)regs->type, FRED_EVENT_TYPE_COUNT); + + user_handlers[type](regs); + } +} + +static DEFINE_FRED_HANDLER(fred_sw_interrupt_kernel) +{ + switch (regs->vector) { + case X86_TRAP_NMI: + fred_exc_nmi(regs); + break; + default: + fred_bad_event(regs); + break; + } +} + +__visible noinstr void fred_entry_from_kernel(struct pt_regs *regs) +{ + static const fred_handler kernel_handlers[FRED_EVENT_TYPE_COUNT] =3D + { + [EVENT_TYPE_HWINT] =3D fred_hw_interrupt, + [EVENT_TYPE_RESERVED] =3D fred_bad_event, + [EVENT_TYPE_NMI] =3D fred_exc_nmi, + [EVENT_TYPE_SWINT] =3D fred_sw_interrupt_kernel, + [EVENT_TYPE_HWFAULT] =3D fred_exception, + [EVENT_TYPE_SWFAULT] =3D fred_exception, + [EVENT_TYPE_PRIVSW] =3D fred_exception, + [EVENT_TYPE_OTHER] =3D fred_bad_event + }; + u8 type =3D array_index_nospec((u8)regs->type, FRED_EVENT_TYPE_COUNT); + + /* The pt_regs frame on entry here is an exception frame */ + kernel_handlers[type](regs); +} diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentr= y.h index 381bc2b8c1c2..7f70ca6f0020 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -82,6 +82,7 @@ static __always_inline void __##func(struct pt_regs *regs) #define DECLARE_IDTENTRY_ERRORCODE(vector, func) \ asmlinkage void asm_##func(void); \ asmlinkage void xen_asm_##func(void); \ + __visible void fred_##func(struct pt_regs *regs); \ __visible void func(struct pt_regs *regs, unsigned long error_code) =20 /** @@ -106,6 +107,11 @@ __visible noinstr void func(struct pt_regs *regs, \ irqentry_exit(regs, state); \ } \ \ +__visible noinstr void fred_##func(struct pt_regs *regs) \ +{ \ + func (regs, regs->orig_ax); \ +} \ + \ static __always_inline void __##func(struct pt_regs *regs, \ unsigned long error_code) =20 @@ -622,6 +628,8 @@ DECLARE_IDTENTRY_RAW(X86_TRAP_MC, exc_machine_check); #ifdef CONFIG_XEN_PV DECLARE_IDTENTRY_RAW(X86_TRAP_MC, xenpv_exc_machine_check); #endif +#else +#define fred_exc_machine_check fred_bad_event #endif =20 /* NMI */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62921C61DA3 for ; Fri, 24 Feb 2023 07:29:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230073AbjBXH3U (ORCPT ); Fri, 24 Feb 2023 02:29:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230021AbjBXH2x (ORCPT ); Fri, 24 Feb 2023 02:28:53 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A8583D934; Thu, 23 Feb 2023 23:28:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223690; x=1708759690; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=28xSg02+XTlFGS4r/xeDdYsr2s7aKYpvbQExGgYKU4k=; b=Uo+wfjNwnGH7FpFQwWN8zoR7Qu/jx9BCX90DFZ6u0wWdc82aneLbam98 Y3ILAUSDKaRMCLPP6UM0Wtze9aX8ls9MsnSnJL/EjcZpxwrcyZ7NFIypr mq0SnobhzYfAW3fTAyBPCmULPp0R5AaqkJQT/Kd5Mo3X2pMSf6UejIFvE UHgOzzm7qAgMxGkIf3tLROXE5DrajnNqr17NRrS0dEtG97+qkpnNopwat 8MwPlDQ5Sb0x1pZ/25FIQTQy8hQE1LV0/GC7zgtqLnCVfxPjrfrH3oBtO 3F8quN1OEsSptHQ7iw+Tp9uj5G3uE7IWQwcnN17KMti/Qo3ieUyB6v80c A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836107" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836107" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639258" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639258" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:24 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 22/32] x86/fred: FRED initialization code Date: Thu, 23 Feb 2023 23:01:35 -0800 Message-Id: <20230224070145.3572-23-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" The code to initialize FRED when it's available and _not_ disabled. cpu_init_fred_exceptions() is the core function to initialize FRED, which 1. Sets up FRED entrypoints for events happening in ring 0 and 3. 2. Sets up a default stack for event handling. 3. Sets up dedicated event stacks for DB/NMI/MC/DF, equivalent to the IDT IST stacks. 4. Forces 32-bit system calls to use "int $0x80" only. 5. Enables FRED and invalidtes IDT. When the FRED is used, cpu_init_exception_handling() initializes FRED through calling cpu_init_fred_exceptions(), otherwise it sets up TSS IST and loads IDT. As FRED uses the ring 3 FRED entrypoint for SYSCALL and SYSENTER, it skips setting up SYSCALL/SYSENTER related MSRs, e.g., MSR_LSTAR. Signed-off-by: H. Peter Anvin (Intel) Co-developed-by: Xin Li Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 14 +++++++ arch/x86/include/asm/traps.h | 2 + arch/x86/kernel/Makefile | 1 + arch/x86/kernel/cpu/common.c | 74 +++++++++++++++++++++++------------- arch/x86/kernel/fred.c | 73 +++++++++++++++++++++++++++++++++++ arch/x86/kernel/irqinit.c | 7 +++- arch/x86/kernel/traps.c | 16 +++++++- 7 files changed, 157 insertions(+), 30 deletions(-) create mode 100644 arch/x86/kernel/fred.c diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index 3d6c5c063eef..6a417fc1e7ee 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -99,8 +99,22 @@ DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); DECLARE_FRED_HANDLER(fred_exc_machine_check); =20 +/* + * The actual assembly entry and exit points + */ +extern __visible void fred_entrypoint_user(void); + +/* + * Initialization + */ +void cpu_init_fred_exceptions(void); +void fred_setup_apic(void); + #endif /* __ASSEMBLY__ */ =20 +#else +#define cpu_init_fred_exceptions() BUG() +#define fred_setup_apic() BUG() #endif /* CONFIG_X86_FRED */ =20 #endif /* ASM_X86_FRED_H */ diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index da4c21ed68b4..69fafef1136e 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -56,6 +56,8 @@ void __noreturn handle_stack_overflow(struct pt_regs *reg= s, void f (struct pt_regs *regs) typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler)); =20 +system_interrupt_handler get_system_interrupt_handler(unsigned int i); + int external_interrupt(struct pt_regs *regs, unsigned int vector); =20 #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index dd61752f4c96..08d9c0a0bfbe 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -47,6 +47,7 @@ obj-y +=3D platform-quirks.o obj-y +=3D process_$(BITS).o signal.o signal_$(BITS).o obj-y +=3D traps.o idt.o irq.o irq_$(BITS).o dumpstack_$(BITS).o obj-y +=3D time.o ioport.o dumpstack.o nmi.o +obj-$(CONFIG_X86_FRED) +=3D fred.o obj-$(CONFIG_MODIFY_LDT_SYSCALL) +=3D ldt.o obj-y +=3D setup.o x86_init.o i8259.o irqinit.o obj-$(CONFIG_JUMP_LABEL) +=3D jump_label.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 21237cb0aa93..550da2a61ae2 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include #include @@ -2048,28 +2049,6 @@ static void wrmsrl_cstar(unsigned long val) /* May not be marked __init: used by software suspend */ void syscall_init(void) { - wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); - wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); - -#ifdef CONFIG_IA32_EMULATION - wrmsrl_cstar((unsigned long)entry_SYSCALL_compat); - /* - * This only works on Intel CPUs. - * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP. - * This does not cause SYSENTER to jump to the wrong location, because - * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit). - */ - wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, - (unsigned long)(cpu_entry_stack(smp_processor_id()) + 1)); - wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); -#else - wrmsrl_cstar((unsigned long)ignore_sysret); - wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); - wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); -#endif - /* * Flags to clear on syscall; clear as much as possible * to minimize user space-kernel interference. @@ -2080,6 +2059,41 @@ void syscall_init(void) X86_EFLAGS_IF|X86_EFLAGS_DF|X86_EFLAGS_OF| X86_EFLAGS_IOPL|X86_EFLAGS_NT|X86_EFLAGS_RF| X86_EFLAGS_AC|X86_EFLAGS_ID); + + /* + * The default user and kernel segments + */ + wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); + + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + /* Both sysexit and sysret cause #UD when FRED is enabled */ + wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); + } else { + wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); + +#ifdef CONFIG_IA32_EMULATION + wrmsrl_cstar((unsigned long)entry_SYSCALL_compat); + /* + * This only works on Intel CPUs. + * On AMD CPUs these MSRs are 32-bit, CPU truncates + * MSR_IA32_SYSENTER_EIP. + * This does not cause SYSENTER to jump to the wrong + * location, because AMD doesn't allow SYSENTER in + * long mode (either 32- or 64-bit). + */ + wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, + (unsigned long)(cpu_entry_stack(smp_processor_id()) + 1)); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); +#else + wrmsrl_cstar((unsigned long)ignore_sysret); + wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); +#endif + } } =20 #else /* CONFIG_X86_64 */ @@ -2214,18 +2228,24 @@ void cpu_init_exception_handling(void) /* paranoid_entry() gets the CPU number from the GDT */ setup_getcpu(cpu); =20 - /* IST vectors need TSS to be set up. */ - tss_setup_ist(tss); + /* Set up the TSS */ tss_setup_io_bitmap(tss); set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); - load_TR_desc(); =20 /* GHCB needs to be setup to handle #VC. */ setup_ghcb(); =20 - /* Finally load the IDT */ - load_current_idt(); + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + /* Set up FRED exception handling */ + cpu_init_fred_exceptions(); + } else { + /* IST vectors need TSS to be set up. */ + tss_setup_ist(tss); + + /* Finally load the IDT */ + load_current_idt(); + } } =20 /* diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c new file mode 100644 index 000000000000..827b58fd98d4 --- /dev/null +++ b/arch/x86/kernel/fred.c @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include +#include +#include /* For cr4_set_bits() */ +#include + +/* + * Initialize FRED on this CPU. This cannot be __init as it is called + * during CPU hotplug. + */ +void cpu_init_fred_exceptions(void) +{ + wrmsrl(MSR_IA32_FRED_CONFIG, + FRED_CONFIG_ENTRYPOINT(fred_entrypoint_user) | + FRED_CONFIG_REDZONE(8) | /* Reserve for CALL emulation */ + FRED_CONFIG_INT_STKLVL(0)); + + wrmsrl(MSR_IA32_FRED_STKLVLS, + FRED_STKLVL(X86_TRAP_DB, 1) | + FRED_STKLVL(X86_TRAP_NMI, 2) | + FRED_STKLVL(X86_TRAP_MC, 2) | + FRED_STKLVL(X86_TRAP_DF, 3)); + + /* The FRED equivalents to IST stacks... */ + wrmsrl(MSR_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB)); + wrmsrl(MSR_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI)); + wrmsrl(MSR_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF)); + + /* Not used with FRED */ + wrmsrl(MSR_LSTAR, 0ULL); + wrmsrl(MSR_CSTAR, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL); + wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL); + + /* Enable FRED */ + cr4_set_bits(X86_CR4_FRED); + idt_invalidate(); /* Any further IDT use is a bug */ + + /* Use int $0x80 for 32-bit system calls in FRED mode */ + setup_clear_cpu_cap(X86_FEATURE_SYSENTER32); + setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); +} + +/* + * Initialize system vectors from a FRED perspective, so + * lapic_assign_system_vectors() can do its job. + */ +void __init fred_setup_apic(void) +{ + int i; + + for (i =3D 0; i < FIRST_EXTERNAL_VECTOR; i++) + set_bit(i, system_vectors); + + /* + * Don't set the non assigned system vectors in the + * system_vectors bitmap. Otherwise they show up in + * /proc/interrupts. + */ +#ifdef CONFIG_SMP + set_bit(IRQ_MOVE_CLEANUP_VECTOR, system_vectors); +#endif + + for (i =3D 0; i < NR_SYSTEM_VECTORS; i++) { + if (get_system_interrupt_handler(i) !=3D NULL) { + set_bit(i + FIRST_SYSTEM_VECTOR, system_vectors); + } + } + + /* The rest are fair game... */ +} diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index c683666876f1..2a510f72dd11 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -28,6 +28,7 @@ #include #include #include +#include #include =20 /* @@ -96,7 +97,11 @@ void __init native_init_IRQ(void) /* Execute any quirks before the call gates are initialised: */ x86_init.irqs.pre_vector_init(); =20 - idt_setup_apic_and_irq_gates(); + if (cpu_feature_enabled(X86_FEATURE_FRED)) + fred_setup_apic(); + else + idt_setup_apic_and_irq_gates(); + lapic_assign_system_vectors(); =20 if (!acpi_ioapic && !of_ioapic && nr_legacy_irqs()) { diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 4b0f63344526..c7253b4901f0 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1517,12 +1517,21 @@ static system_interrupt_handler system_interrupt_ha= ndlers[NR_SYSTEM_VECTORS] =3D { =20 #undef SYSV =20 +system_interrupt_handler get_system_interrupt_handler(unsigned int i) +{ + if (i >=3D NR_SYSTEM_VECTORS) + return NULL; + + return system_interrupt_handlers[i]; +} + void __init install_system_interrupt_handler(unsigned int n, const void *a= sm_addr, const void *addr) { BUG_ON(n < FIRST_SYSTEM_VECTOR); =20 system_interrupt_handlers[n - FIRST_SYSTEM_VECTOR] =3D (system_interrupt_= handler)addr; - alloc_intr_gate(n, asm_addr); + if (!cpu_feature_enabled(X86_FEATURE_FRED)) + alloc_intr_gate(n, asm_addr); } =20 #ifndef CONFIG_X86_LOCAL_APIC @@ -1590,7 +1599,10 @@ void __init trap_init(void) =20 /* Initialize TSS before setting up traps so ISTs work */ cpu_init_exception_handling(); + /* Setup traps as cpu_init() might #GP */ - idt_setup_traps(); + if (!cpu_feature_enabled(X86_FEATURE_FRED)) + idt_setup_traps(); + cpu_init(); } --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5E5AC677F1 for ; Fri, 24 Feb 2023 07:29:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230055AbjBXH3Q (ORCPT ); Fri, 24 Feb 2023 02:29:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229806AbjBXH2m (ORCPT ); Fri, 24 Feb 2023 02:28:42 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B1F43E096; Thu, 23 Feb 2023 23:28:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223690; x=1708759690; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DXWzRKSSyqMjPoIPiIoUDCKH+1kgB2RrJrK5bG2JTVs=; b=CTVkGleiDY9r15cDXNNckV+fdWrXFU5bbmsPXx09bgjFB1XTX4UY2+xq RLEjDI2MFF8CYQyXxOOcYAL8ytwXiJm9Mkz4Lxo08X8wUq31WErUeWNCg losHk11JRrxpAcVW7MCbfk1NknJ0PLUU/ezc8pRpthkhW+OVjHMpXiFL8 H/gW5DqV64Gj7fT4PfUFpmG2S9ZYWajGf3NU7GJfnc25SHE8LjoKTzbKW Rxr18XrZ+VJ42Ul0Rf828vXe6jJCUMPwbnHqjTkmb32sGjpW+BEtIaNKI 3gz9MOSjOSIiLs9WguG+D64wMOwcrtpivZkEga6vsSvZRUq7fzm5+UanI g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836108" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836108" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639261" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639261" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:24 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 23/32] x86/fred: update MSR_IA32_FRED_RSP0 during task switch Date: Thu, 23 Feb 2023 23:01:36 -0800 Message-Id: <20230224070145.3572-24-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" MSR_IA32_FRED_RSP0 is used during ring 3 event delivery, and needs to be updated to point to the top of next task stack during task switch. Update MSR_IA32_FRED_RSP0 with WRMSR instruction for now, and will use WRMSRNS/WRMSRLIST for performance once it gets upstreamed. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/switch_to.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch= _to.h index 5c91305d09d2..00fd85abc1d2 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -68,9 +68,16 @@ static inline void update_task_stack(struct task_struct = *task) #ifdef CONFIG_X86_32 this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else - /* Xen PV enters the kernel on the thread stack. */ - if (cpu_feature_enabled(X86_FEATURE_XENPV)) + if (cpu_feature_enabled(X86_FEATURE_FRED)) { + /* + * Will use WRMSRNS/WRMSRLIST for performance once it's upstreamed. + */ + wrmsrl(MSR_IA32_FRED_RSP0, + task_top_of_stack(task) + TOP_OF_KERNEL_STACK_PADDING); + } else if (cpu_feature_enabled(X86_FEATURE_XENPV)) { + /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); + } #endif } =20 --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AF6FC61DA3 for ; Fri, 24 Feb 2023 07:29:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229717AbjBXH3X (ORCPT ); Fri, 24 Feb 2023 02:29:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230017AbjBXH2u (ORCPT ); Fri, 24 Feb 2023 02:28:50 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4AEE41B49; Thu, 23 Feb 2023 23:28:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223690; x=1708759690; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=oIslRe08H8aZv4yPi7UmQwmu1nBnCnh8gvufNu5UIkE=; b=ioL6zEeLUgNHwIbzG/7Q1cyJRmVekZaycrnjU79LMMHcMgP4UhULuTX3 bMU9K3aojGkvzWmP/AA5FUHq2o5geVs8kIDOoaYFUx8EmB9T82+Huy2nN e9yuTYp7FyTPtuURcwX7LYYEvXkheqNb84Q8So2+LFSnUO1mzkIfhaONZ h+bRlvZJ+s9EAG0zn+qryOVM+qyO4yklvq6SYb4UVhzE2k3lh1YYax5ML EUf2XdMsSullLQUKzC2UlSs7mVl90AzTBlCDHC/yGnpTtCQ8ikf8gtl9s dpOJyGIL2VYRMVSkjrwTFoZCQ1QORjpTQvtucECiQaCtJuA+j5fFCS4Hg A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836119" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836119" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639265" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639265" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:24 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 24/32] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Date: Thu, 23 Feb 2023 23:01:37 -0800 Message-Id: <20230224070145.3572-25-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Let ret_from_fork() jmp to fred_exit_user when FRED is enabled, otherwise the existing IDT code is chosen. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/entry/entry_64.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7ecd2aeeeffc..7ffd20578b8c 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -299,7 +299,12 @@ SYM_CODE_START_NOALIGN(ret_from_fork) UNWIND_HINT_REGS movq %rsp, %rdi call syscall_exit_to_user_mode /* returns with IRQs disabled */ +#ifdef CONFIG_X86_FRED + ALTERNATIVE "jmp swapgs_restore_regs_and_return_to_usermode", \ + "jmp fred_exit_user", X86_FEATURE_FRED +#else jmp swapgs_restore_regs_and_return_to_usermode +#endif =20 1: /* kernel thread */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71E29C61DA3 for ; Fri, 24 Feb 2023 07:29:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229930AbjBXH3h (ORCPT ); Fri, 24 Feb 2023 02:29:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229824AbjBXH3E (ORCPT ); Fri, 24 Feb 2023 02:29:04 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 243CA93C9; Thu, 23 Feb 2023 23:28:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223697; x=1708759697; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=IYVs/dNGzaWmYDt7WgVNUnSvBB8Ri3wL5GZJW6QmAc8=; b=dF19NyBlwnjYt1fISsvRlKjJE2K/srB3R6aGGkXaFTq0CkkQHzBimVc8 LErz/Vwsld5FxdVlm+B7negN6kvOVOqliErTqzMWa1o6ZLYtELMTdG4wy jyuy+2IGuTq9U5d1jr5SAhcKd/sUOIB99McZzJeF2DnblyVjzYHOb0k3l 6v0YzigsCBFHRhl6F1fBhT4JvdTjoCgzUjNPW0KLqePzlj6nkyfuYk1vp m5QsXHESJCN6ctfxU1o3PiCoyGtMJ5PuR+w0LBS3OteWIYTJMaeDOxJpT FiPP+DccddIFUm9YK+yf8FcMKhAIoMkuXZGPUq0dX6eHLpzNZKbZsz957 Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836126" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836126" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639268" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639268" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:25 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 25/32] x86/fred: disallow the swapgs instruction when FRED is enabled Date: Thu, 23 Feb 2023 23:01:38 -0800 Message-Id: <20230224070145.3572-26-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" The FRED architecture establishes the full supervisor/user through: 1) FRED event delivery swaps the value of the GS base address and that of the IA32_KERNEL_GS_BASE MSR. 2) ERETU swaps the value of the GS base address and that of the IA32_KERNEL_GS_BASE MSR. Thus, the swapgs instruction is disallowed when FRED is enabled, otherwise it cauess #UD. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/kernel/process_64.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 57de166dc61c..ff6594dbea4a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -165,7 +165,8 @@ static noinstr unsigned long __rdgsbase_inactive(void) =20 lockdep_assert_irqs_disabled(); =20 - if (!cpu_feature_enabled(X86_FEATURE_XENPV)) { + if (!cpu_feature_enabled(X86_FEATURE_FRED) && + !cpu_feature_enabled(X86_FEATURE_XENPV)) { native_swapgs(); gsbase =3D rdgsbase(); native_swapgs(); @@ -190,7 +191,8 @@ static noinstr void __wrgsbase_inactive(unsigned long g= sbase) { lockdep_assert_irqs_disabled(); =20 - if (!cpu_feature_enabled(X86_FEATURE_XENPV)) { + if (!cpu_feature_enabled(X86_FEATURE_FRED) && + !cpu_feature_enabled(X86_FEATURE_XENPV)) { native_swapgs(); wrgsbase(gsbase); native_swapgs(); --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C77BAC61DA3 for ; Fri, 24 Feb 2023 07:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230006AbjBXH3o (ORCPT ); Fri, 24 Feb 2023 02:29:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230048AbjBXH3N (ORCPT ); Fri, 24 Feb 2023 02:29:13 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D578363542; Thu, 23 Feb 2023 23:28:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223702; x=1708759702; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dKcGYBnXHQiTsBcKqxrhALysREBc36cYC8m/4NUk9CA=; b=Ug298TNcLjq/0dhk0ArWPlm/WgutFcIs9CJ3s0zTSKcEzYUC6tXrS6HE 9foXwpe3vCdFzKHDvsuU5qDETfe+Dsd7wmlQgu7/eSbURy7livKMGE0dr upyShuMRWSIXohF9H3LdcIVmstYTyW6D1DX5xMs2tH79Z3NE6+tLvYrHL k1RxVUB+jOAa/gGK49EEYSVE19pljvRs7bw+9tNrIPbAeXM0EQxlcam0T eLL0bvIJ9oQhLfit72ll3CtTJW+sbyIkHVVuMS9XdyXpldPB1vaWZzldg 0v6iAh+Z0y0bXqwh5EEqtjP1e0fBqt4XI4BfHUa53CXC0A0XLiEh/AIMv A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836143" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836143" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639271" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639271" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:25 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 26/32] x86/fred: no ESPFIX needed when FRED is enabled Date: Thu, 23 Feb 2023 23:01:39 -0800 Message-Id: <20230224070145.3572-27-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Because FRED always restores the full value of %rsp, ESPFIX is no longer needed when it's enabled. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/kernel/espfix_64.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c index 16f9814c9be0..48d133a54f45 100644 --- a/arch/x86/kernel/espfix_64.c +++ b/arch/x86/kernel/espfix_64.c @@ -106,6 +106,10 @@ void __init init_espfix_bsp(void) pgd_t *pgd; p4d_t *p4d; =20 + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* Install the espfix pud into the kernel page directory */ pgd =3D &init_top_pgt[pgd_index(ESPFIX_BASE_ADDR)]; p4d =3D p4d_alloc(&init_mm, pgd, ESPFIX_BASE_ADDR); @@ -129,6 +133,10 @@ void init_espfix_ap(int cpu) void *stack_page; pteval_t ptemask; =20 + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* We only have to do this once... */ if (likely(per_cpu(espfix_stack, cpu))) return; /* Already initialized */ --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 315A1C64ED8 for ; Fri, 24 Feb 2023 07:29:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230112AbjBXH3r (ORCPT ); Fri, 24 Feb 2023 02:29:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229801AbjBXH3U (ORCPT ); Fri, 24 Feb 2023 02:29:20 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D62BC63DD2; Thu, 23 Feb 2023 23:28:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223706; x=1708759706; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=eNc5nbGpboFMb1VqnWz9V+WMQa1u5sx4ZurIW4MEGgg=; b=ZPMA+RB5PiTkAWZEEM5lkeRixH5/ZcPNuQGSG12iOe9+ICygbA/0kj6v 72fKW9fCkuw4dDDr7raM0heW3Ytr/moY9PbKzGU2qs34bB13XI0+tr68+ Qxk8H5zAvgiCWg16+n8movixqvLEP2a+a1R6Aj/YMRU1/15OvOSVi6yE7 2z/XY65XB8ZZhqTxF9LWy/RWZca1T8SSYjRsk4mQJCjA6kxKK/0uSaLFF b3FLIgc/2v0FOLlBmpDnbTBqrFooH/pccc1dhX/b3jcxP2msaP9XQTjUf NcYyDOokrRF5hYlxw4xCMLzQbK25kGsA2DYPEjNQOAiJJzwdEbQaTGA7M w==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836150" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836150" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639274" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639274" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:25 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 27/32] x86/fred: allow single-step trap and NMI when starting a new thread Date: Thu, 23 Feb 2023 23:01:40 -0800 Message-Id: <20230224070145.3572-28-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Allow single-step trap and NMI when starting a new thread, thus once the new thread returns to ring3, single-step trap and NMI are both enabled immediately. High-order 48 bits above the lowest 16 bit CS are discarded by the legacy IRET instruction, thus can be set unconditionally, even when FRED is not enabled. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 11 +++++++++++ arch/x86/kernel/process_64.c | 13 +++++++------ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index 6a417fc1e7ee..958751f16c94 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -52,6 +52,14 @@ #define FRED_CSL_ALLOW_SINGLE_STEP _BITUL(25) #define FRED_CSL_INTERRUPT_SHADOW _BITUL(24) =20 +/* + * High-order 48 bits above the lowest 16 bit CS are discarded by the + * legacy IRET instruction, thus can be set unconditionally, even when + * FRED is not enabled. + */ +#define CSL_PROCESS_START \ + (FRED_CSL_ENABLE_NMI | FRED_CSL_ALLOW_SINGLE_STEP) + #ifndef __ASSEMBLY__ =20 #include @@ -115,6 +123,9 @@ void fred_setup_apic(void); #else #define cpu_init_fred_exceptions() BUG() #define fred_setup_apic() BUG() + +#define CSL_PROCESS_START 0 + #endif /* CONFIG_X86_FRED */ =20 #endif /* ASM_X86_FRED_H */ diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index ff6594dbea4a..ac3895f4a360 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -55,6 +55,7 @@ #include #include #include +#include #ifdef CONFIG_IA32_EMULATION /* Not included via unistd.h */ #include @@ -506,7 +507,7 @@ void x86_gsbase_write_task(struct task_struct *task, un= signed long gsbase) static void start_thread_common(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp, - unsigned int _cs, unsigned int _ss, unsigned int _ds) + u16 _cs, u16 _ss, u16 _ds) { WARN_ON_ONCE(regs !=3D current_pt_regs()); =20 @@ -521,11 +522,11 @@ start_thread_common(struct pt_regs *regs, unsigned lo= ng new_ip, loadsegment(ds, _ds); load_gs_index(0); =20 - regs->ip =3D new_ip; - regs->sp =3D new_sp; - regs->cs =3D _cs; - regs->ss =3D _ss; - regs->flags =3D X86_EFLAGS_IF; + regs->ip =3D new_ip; + regs->sp =3D new_sp; + regs->csl =3D _cs | CSL_PROCESS_START; + regs->ssl =3D _ss; + regs->flags =3D X86_EFLAGS_IF | X86_EFLAGS_FIXED; } =20 void --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27C46C61DA3 for ; Fri, 24 Feb 2023 07:30:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229912AbjBXH37 (ORCPT ); Fri, 24 Feb 2023 02:29:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229893AbjBXH3b (ORCPT ); Fri, 24 Feb 2023 02:29:31 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E35FC63DE2; Thu, 23 Feb 2023 23:28:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223710; x=1708759710; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JFgGgK1UiImaF1he4az5OO5OcUrrSSoji4V3Q7e0Ou0=; b=HENWigI6OocZmtzS48CF///m0o6droz+Zur3LZ1GnFIpBQmUmD63KKcx YX+vr7wNMNxQSzUYXvpVgMVlJNXuP4tXWuIz4YvcLU1xCQ2Vkw5SJGu1+ +ZCXElpgrqeveq8GtN7/Jhlodn6Vrj1Sk4xfDr+GX0AcjJpXeiVHLZbUK aB7K6bqOQBY9HJNIprWJtCP/bxLl/NIrY/11uw4Oa+uznz48mJc58P1j4 7qHAM2YHcVW8ryKICk5ng84PjS5ivIxbv8yyDytMrhT077ZJDPTudbpxQ gj5S3pbbj2ggAfbvxq0VOe1fe97bqJTVWpKeU7KjeP7m88jSjtKRHuVqw g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836160" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836160" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639278" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639278" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:25 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 28/32] x86/fred: fixup fault on ERETU by jumping to fred_entrypoint_user Date: Thu, 23 Feb 2023 23:01:41 -0800 Message-Id: <20230224070145.3572-29-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If the stack frame contains an invalid user context (e.g. due to invalid SS, a non-canonical RIP, etc.) the ERETU instruction will trap (#SS or #GP). From a Linux point of view, this really should be considered a user space failure, so use the standard fault fixup mechanism to intercept the fault, fix up the exception frame, and redirect execution to fred_entrypoint_user. The end result is that it appears just as if the hardware had taken the exception immediately after completing the transition to user space. Suggested-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/entry/entry_64_fred.S | 8 +++++-- arch/x86/include/asm/extable_fixup_types.h | 4 +++- arch/x86/mm/extable.c | 28 ++++++++++++++++++++++ 3 files changed, 37 insertions(+), 3 deletions(-) diff --git a/arch/x86/entry/entry_64_fred.S b/arch/x86/entry/entry_64_fred.S index 1fb765fd3871..027ef8f1e600 100644 --- a/arch/x86/entry/entry_64_fred.S +++ b/arch/x86/entry/entry_64_fred.S @@ -5,8 +5,10 @@ * The actual FRED entry points. */ #include -#include +#include #include +#include +#include #include =20 #include "calling.h" @@ -38,7 +40,9 @@ SYM_CODE_START_NOALIGN(fred_entrypoint_user) call fred_entry_from_user SYM_INNER_LABEL(fred_exit_user, SYM_L_GLOBAL) FRED_EXIT - ERETU +1: ERETU + + _ASM_EXTABLE_TYPE(1b, fred_entrypoint_user, EX_TYPE_ERETU) SYM_CODE_END(fred_entrypoint_user) =20 /* diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/= asm/extable_fixup_types.h index 991e31cfde94..1585c798a02f 100644 --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -64,6 +64,8 @@ #define EX_TYPE_UCOPY_LEN4 (EX_TYPE_UCOPY_LEN | EX_DATA_IMM(4)) #define EX_TYPE_UCOPY_LEN8 (EX_TYPE_UCOPY_LEN | EX_DATA_IMM(8)) =20 -#define EX_TYPE_ZEROPAD 20 /* longword load with zeropad on fault */ +#define EX_TYPE_ZEROPAD 20 /* longword load with zeropad on fault */ + +#define EX_TYPE_ERETU 21 =20 #endif diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 60814e110a54..31542a2507ae 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -6,6 +6,7 @@ #include =20 #include +#include #include #include #include @@ -195,6 +196,29 @@ static bool ex_handler_ucopy_len(const struct exceptio= n_table_entry *fixup, return ex_handler_uaccess(fixup, regs, trapnr); } =20 +#ifdef CONFIG_X86_FRED +static bool ex_handler_eretu(const struct exception_table_entry *fixup, + struct pt_regs *regs, unsigned long error_code) +{ + struct pt_regs *uregs =3D (struct pt_regs *)(regs->sp - offsetof(struct p= t_regs, ip)); + unsigned short ss =3D uregs->ss; + unsigned short cs =3D uregs->cs; + + fred_info(uregs)->edata =3D fred_event_data(regs); + uregs->ssl =3D regs->ssl; + uregs->ss =3D ss; + uregs->csl =3D regs->csl; + uregs->current_stack_level =3D 0; + uregs->cs =3D cs; + + /* Copy error code to uregs and adjust stack pointer accordingly */ + uregs->orig_ax =3D error_code; + regs->sp -=3D 8; + + return ex_handler_default(fixup, regs); +} +#endif + int ex_get_fixup_type(unsigned long ip) { const struct exception_table_entry *e =3D search_exception_tables(ip); @@ -272,6 +296,10 @@ int fixup_exception(struct pt_regs *regs, int trapnr, = unsigned long error_code, return ex_handler_ucopy_len(e, regs, trapnr, reg, imm); case EX_TYPE_ZEROPAD: return ex_handler_zeropad(e, regs, fault_addr); +#ifdef CONFIG_X86_FRED + case EX_TYPE_ERETU: + return ex_handler_eretu(e, regs, error_code); +#endif } BUG(); } --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CAD1C61DA3 for ; Fri, 24 Feb 2023 07:29:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229909AbjBXH3z (ORCPT ); Fri, 24 Feb 2023 02:29:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229901AbjBXH3c (ORCPT ); Fri, 24 Feb 2023 02:29:32 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E39B663DE3; Thu, 23 Feb 2023 23:28:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223710; x=1708759710; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Nh0EZ36XDc6eXxI1es5e8QKbI0iZ09qaD62YA+DOlsU=; b=fIIhs/sJTGOm3IydHWcV+Q2yljXToDPegOamvuue7xCo98EU3zbZalrd GhLE7fKEF2IWU9hiuC0IdQVzQRkXkE4eakZwm9YGXPeVnMC7o6MXi8LqA L0MkKSQESa3PJ3Gq4SSE5qbTE1tX6faEJHJINyR3xUK0Zvl7OtIZJ+wHZ QZDSITtplqpErifp1kqcxg60WYTiMS6ZwQk95T5iDFNTkYXmHklzJrCh1 8v8iQ7SH89sFAxdzYWsCVXfNiqY9j3dZWBMl25CWujDwcLEDiCUA64oXx DnrZQ4Mb66aWk0SUcVxca9qixj4HitW5UnDTH8ly5TY1CzbR9Ae8pCSny A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836169" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836169" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639281" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639281" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:26 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 29/32] x86/ia32: do not modify the DPL bits for a null selector Date: Thu, 23 Feb 2023 23:01:42 -0800 Message-Id: <20230224070145.3572-30-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When a null selector is to be loaded into a segment register, reload_segments() sets its DPL bits to 3. Later when the IRET instruction loads it, it zeros the segment register. The two operations offset each other to actually effect a nop. Unlike IRET, ERETU does not make any of DS, ES, FS, or GS null if it is found to have DPL < 3. It is expected that a FRED-enabled operating system will return to ring 3 (in compatibility mode) only when those segments all have DPL =3D 3. Thus when FRED is enabled, we end up with having 3 in a segment register even when it is initially set to 0. Fix it by not modifying the DPL bits for a null selector. Signed-off-by: Xin Li --- arch/x86/kernel/signal_32.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c index 9027fc088f97..7796cf84fca2 100644 --- a/arch/x86/kernel/signal_32.c +++ b/arch/x86/kernel/signal_32.c @@ -36,22 +36,27 @@ #ifdef CONFIG_IA32_EMULATION #include =20 +static inline u16 usrseg(u16 sel) +{ + return sel <=3D 3 ? sel : sel | 3; +} + static inline void reload_segments(struct sigcontext_32 *sc) { unsigned int cur; =20 savesegment(gs, cur); - if ((sc->gs | 0x03) !=3D cur) - load_gs_index(sc->gs | 0x03); + if (usrseg(sc->gs) !=3D cur) + load_gs_index(usrseg(sc->gs)); savesegment(fs, cur); - if ((sc->fs | 0x03) !=3D cur) - loadsegment(fs, sc->fs | 0x03); + if (usrseg(sc->fs) !=3D cur) + loadsegment(fs, usrseg(sc->fs)); savesegment(ds, cur); - if ((sc->ds | 0x03) !=3D cur) - loadsegment(ds, sc->ds | 0x03); + if (usrseg(sc->ds) !=3D cur) + loadsegment(ds, usrseg(sc->ds)); savesegment(es, cur); - if ((sc->es | 0x03) !=3D cur) - loadsegment(es, sc->es | 0x03); + if (usrseg(sc->es) !=3D cur) + loadsegment(es, usrseg(sc->es)); } =20 #define sigset32_t compat_sigset_t --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69E3BC64ED8 for ; Fri, 24 Feb 2023 07:30:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230144AbjBXHaH (ORCPT ); Fri, 24 Feb 2023 02:30:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230037AbjBXH3g (ORCPT ); Fri, 24 Feb 2023 02:29:36 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 912263CE3F; Thu, 23 Feb 2023 23:28:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223715; x=1708759715; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=vOCTlznkoD0xViNzFeXZJiO0RcJUwUxfB9Rg+mZ2/DA=; b=L0uzyDIf7INkAII59lFLHsCGOtxV53+Kw8LONDS6JR3gWL5MH83A0h47 q8uagWnSFZfdYryw3rTSfECQwq38tvfDNJ+5AWh/PKQRElDG5GO94QD2P ArGXNgwXP2UkWkLggiB3HDv73733hnuipmBnW99Zx0+Gnz3Io8/w1YK0Q RXNuwIT1b20UOUq4FDLLAhSZEhnqiqA8E/MKIYp2fbeUy/oq4bwtk2mIp gudiAfpqtRjjDl/AxyYrMDZPtEl8YJNTCuWV3mUrehqx9PbjMn8lxil/z Vee1h4lF2EG8Lk5SBxLyIzIXFouv5nVA3DoeqbIt3kjo8pNDufyHgIXHz Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836174" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836174" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639284" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639284" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:26 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 30/32] x86/fred: allow FRED systems to use interrupt vectors 0x10-0x1f Date: Thu, 23 Feb 2023 23:01:43 -0800 Message-Id: <20230224070145.3572-31-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" FRED inherits the Intel VT-x enhancement of classified events with a two-level event dispatch logic. The first-level dispatch is on the event type, and the second-level is on the event vector. This also means that vectors in different event types are orthogonal, thus, vectors 0x10-0x1f become available as hardware interrupts. Enable interrupt vectors 0x10-0x1f on FRED systems (interrupt 0x80 is already enabled.) Most of these changes are about removing the assumption that the lowest-priority vector is hard-wired to 0x20. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/idtentry.h | 4 ++-- arch/x86/include/asm/irq.h | 5 +++++ arch/x86/include/asm/irq_vectors.h | 15 +++++++++++---- arch/x86/kernel/apic/apic.c | 11 ++++++++--- arch/x86/kernel/apic/vector.c | 8 +++++++- arch/x86/kernel/fred.c | 4 ++-- arch/x86/kernel/idt.c | 6 +++--- arch/x86/kernel/irq.c | 2 +- arch/x86/kernel/traps.c | 2 ++ 9 files changed, 41 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentr= y.h index 7f70ca6f0020..bdfd15ac1311 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -546,8 +546,8 @@ __visible noinstr void func(struct pt_regs *regs, \ */ .align IDT_ALIGN SYM_CODE_START(irq_entries_start) - vector=3DFIRST_EXTERNAL_VECTOR - .rept NR_EXTERNAL_VECTORS + vector=3DFIRST_EXTERNAL_VECTOR_IDT + .rept FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR_IDT UNWIND_HINT_IRET_REGS 0 : ENDBR diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h index 768aa234cbb4..e4be6f8409ad 100644 --- a/arch/x86/include/asm/irq.h +++ b/arch/x86/include/asm/irq.h @@ -11,6 +11,11 @@ #include #include =20 +/* + * The first available IRQ vector + */ +extern unsigned int __ro_after_init first_external_vector; + /* * The irq entry code is in the noinstr section and the start/end of * __irqentry_text is emitted via labels. Make the build fail if diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_= vectors.h index 43dcb9284208..cb3670a7c18f 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -31,15 +31,23 @@ =20 /* * IDT vectors usable for external interrupt sources start at 0x20. - * (0x80 is the syscall vector, 0x30-0x3f are for ISA) + * (0x80 is the syscall vector, 0x30-0x3f are for ISA). + * + * With FRED we can also use 0x10-0x1f even though those overlap + * exception vectors as FRED distinguishes exceptions and interrupts. + * Therefore, FIRST_EXTERNAL_VECTOR is no longer a constant. */ -#define FIRST_EXTERNAL_VECTOR 0x20 +#define FIRST_EXTERNAL_VECTOR_IDT 0x20 +#define FIRST_EXTERNAL_VECTOR_FRED 0x10 +#define FIRST_EXTERNAL_VECTOR first_external_vector =20 /* * Reserve the lowest usable vector (and hence lowest priority) 0x20 for * triggering cleanup after irq migration. 0x21-0x2f will still be used * for device interrupts. */ +#define IRQ_MOVE_CLEANUP_VECTOR_IDT FIRST_EXTERNAL_VECTOR_IDT +#define IRQ_MOVE_CLEANUP_VECTOR_FRED FIRST_EXTERNAL_VECTOR_FRED #define IRQ_MOVE_CLEANUP_VECTOR FIRST_EXTERNAL_VECTOR =20 #define IA32_SYSCALL_VECTOR 0x80 @@ -48,7 +56,7 @@ * Vectors 0x30-0x3f are used for ISA interrupts. * round up to the next 16-vector boundary */ -#define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR + 16) & ~15) + irq) +#define ISA_IRQ_VECTOR(irq) (((FIRST_EXTERNAL_VECTOR_IDT + 16) & ~15) + i= rq) =20 /* * Special IRQ vectors used by the SMP architecture, 0xf0-0xff @@ -114,7 +122,6 @@ #define FIRST_SYSTEM_VECTOR NR_VECTORS #endif =20 -#define NR_EXTERNAL_VECTORS (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR) #define NR_SYSTEM_VECTORS (NR_VECTORS - FIRST_SYSTEM_VECTOR) =20 /* diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 20d9a604da7c..eef67f64aa81 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1621,12 +1621,17 @@ static void setup_local_APIC(void) /* * Set Task Priority to 'accept all except vectors 0-31'. An APIC * vector in the 16-31 range could be delivered if TPR =3D=3D 0, but we - * would think it's an exception and terrible things will happen. We - * never change this later on. + * would think it's an exception and terrible things will happen, + * unless we are using FRED in which case interrupts and + * exceptions are distinguished by type code. + * + * We never change this later on. */ + BUG_ON(!first_external_vector); + value =3D apic_read(APIC_TASKPRI); value &=3D ~APIC_TPRI_MASK; - value |=3D 0x10; + value |=3D (first_external_vector - 0x10) & APIC_TPRI_MASK; apic_write(APIC_TASKPRI, value); =20 /* Clear eventually stale ISR/IRR bits */ diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index c1efebd27e6c..f4325445fd78 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -46,6 +46,7 @@ static struct irq_matrix *vector_matrix; #ifdef CONFIG_SMP static DEFINE_PER_CPU(struct hlist_head, cleanup_list); #endif +unsigned int first_external_vector =3D FIRST_EXTERNAL_VECTOR_IDT; =20 void lock_vector_lock(void) { @@ -796,7 +797,12 @@ int __init arch_early_irq_init(void) * Allocate the vector matrix allocator data structure and limit the * search area. */ - vector_matrix =3D irq_alloc_matrix(NR_VECTORS, FIRST_EXTERNAL_VECTOR, + if (cpu_feature_enabled(X86_FEATURE_FRED)) + first_external_vector =3D FIRST_EXTERNAL_VECTOR_FRED; + else + first_external_vector =3D FIRST_EXTERNAL_VECTOR_IDT; + + vector_matrix =3D irq_alloc_matrix(NR_VECTORS, first_external_vector, FIRST_SYSTEM_VECTOR); BUG_ON(!vector_matrix); =20 diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c index 827b58fd98d4..04f057219c6e 100644 --- a/arch/x86/kernel/fred.c +++ b/arch/x86/kernel/fred.c @@ -51,7 +51,7 @@ void __init fred_setup_apic(void) { int i; =20 - for (i =3D 0; i < FIRST_EXTERNAL_VECTOR; i++) + for (i =3D 0; i < FIRST_EXTERNAL_VECTOR_FRED; i++) set_bit(i, system_vectors); =20 /* @@ -60,7 +60,7 @@ void __init fred_setup_apic(void) * /proc/interrupts. */ #ifdef CONFIG_SMP - set_bit(IRQ_MOVE_CLEANUP_VECTOR, system_vectors); + set_bit(IRQ_MOVE_CLEANUP_VECTOR_FRED, system_vectors); #endif =20 for (i =3D 0; i < NR_SYSTEM_VECTORS; i++) { diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index a58c6bc1cd68..d3fd86f85de9 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -131,7 +131,7 @@ static const __initconst struct idt_data apic_idts[] = =3D { INTG(RESCHEDULE_VECTOR, asm_sysvec_reschedule_ipi), INTG(CALL_FUNCTION_VECTOR, asm_sysvec_call_function), INTG(CALL_FUNCTION_SINGLE_VECTOR, asm_sysvec_call_function_single), - INTG(IRQ_MOVE_CLEANUP_VECTOR, asm_sysvec_irq_move_cleanup), + INTG(IRQ_MOVE_CLEANUP_VECTOR_IDT, asm_sysvec_irq_move_cleanup), INTG(REBOOT_VECTOR, asm_sysvec_reboot), #endif =20 @@ -274,13 +274,13 @@ static void __init idt_map_in_cea(void) */ void __init idt_setup_apic_and_irq_gates(void) { - int i =3D FIRST_EXTERNAL_VECTOR; + int i =3D FIRST_EXTERNAL_VECTOR_IDT; void *entry; =20 idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true); =20 for_each_clear_bit_from(i, system_vectors, FIRST_SYSTEM_VECTOR) { - entry =3D irq_entries_start + IDT_ALIGN * (i - FIRST_EXTERNAL_VECTOR); + entry =3D irq_entries_start + IDT_ALIGN * (i - FIRST_EXTERNAL_VECTOR_IDT= ); set_intr_gate(i, entry); } =20 diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 7e125fff45ab..b7511e02959c 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -359,7 +359,7 @@ void fixup_irqs(void) * vector_lock because the cpu is already marked !online, so * nothing else will touch it. */ - for (vector =3D FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { + for (vector =3D first_external_vector; vector < NR_VECTORS; vector++) { if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector]))) continue; =20 diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index c7253b4901f0..c46eba091728 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1544,6 +1544,8 @@ DEFINE_IDTENTRY_IRQ(spurious_interrupt) pr_info("Spurious interrupt (vector 0x%x) on CPU#%d, should never happen.= \n", vector, smp_processor_id()); } + +unsigned int first_external_vector =3D FIRST_EXTERNAL_VECTOR_IDT; #endif =20 /* --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95F88C677F1 for ; Fri, 24 Feb 2023 07:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229815AbjBXHaJ (ORCPT ); Fri, 24 Feb 2023 02:30:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbjBXH3i (ORCPT ); Fri, 24 Feb 2023 02:29:38 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F00D83B640; Thu, 23 Feb 2023 23:28:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; 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([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:26 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 31/32] x86/fred: allow dynamic stack frame size Date: Thu, 23 Feb 2023 23:01:44 -0800 Message-Id: <20230224070145.3572-32-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" A FRED stack frame could contain different amount of information for different event types, or perhaps even for different instances of the same event type. Thus we need to eliminate the need of any advance information of the stack frame size to allow dynamic stack frame size. Implement it through: 1) add a new field user_pt_regs to thread_info, and initialize it with a pointer to a virtual pt_regs structure at the top of a thread stack. 2) save a pointer to the user-space pt_regs structure created by fred_entrypoint_user() to user_pt_regs in fred_entry_from_user(). 3) initialize the init_thread_info's user_pt_regs with a pointer to a virtual pt_regs structure at the top of init stack. This approach also works for IDT, thus we unify the code. Suggested-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/entry/entry_32.S | 2 +- arch/x86/entry/entry_fred.c | 2 ++ arch/x86/include/asm/entry-common.h | 3 +++ arch/x86/include/asm/processor.h | 12 +++------ arch/x86/include/asm/switch_to.h | 3 +-- arch/x86/include/asm/thread_info.h | 41 ++++------------------------- arch/x86/kernel/head_32.S | 3 +-- arch/x86/kernel/process.c | 5 ++++ kernel/fork.c | 6 +++++ 9 files changed, 27 insertions(+), 50 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 91397f58ac30..5adc4cf33d92 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1244,7 +1244,7 @@ SYM_CODE_START(rewind_stack_and_make_dead) xorl %ebp, %ebp =20 movl PER_CPU_VAR(pcpu_hot + X86_top_of_stack), %esi - leal -TOP_OF_KERNEL_STACK_PADDING-PTREGS_SIZE(%esi), %esp + leal -PTREGS_SIZE(%esi), %esp =20 call make_task_dead 1: jmp 1b diff --git a/arch/x86/entry/entry_fred.c b/arch/x86/entry/entry_fred.c index 8d3e144670d6..a72167c83923 100644 --- a/arch/x86/entry/entry_fred.c +++ b/arch/x86/entry/entry_fred.c @@ -178,6 +178,8 @@ __visible noinstr void fred_entry_from_user(struct pt_r= egs *regs) [EVENT_TYPE_OTHER] =3D fred_syscall_slow }; =20 + current->thread_info.user_pt_regs =3D regs; + /* * FRED employs a two-level event dispatch mechanism, with * the first-level on the type of an event and the second-level diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/ent= ry-common.h index 117903881fe4..5b7d0f47f188 100644 --- a/arch/x86/include/asm/entry-common.h +++ b/arch/x86/include/asm/entry-common.h @@ -12,6 +12,9 @@ /* Check that the stack and regs on entry from user mode are sane. */ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) { + if (!cpu_feature_enabled(X86_FEATURE_FRED)) + current->thread_info.user_pt_regs =3D regs; + if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) { /* * Make sure that the entry code gave us a sensible EFLAGS diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/proces= sor.h index 8d73004e4cac..4a50d2a2c14b 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -626,17 +626,11 @@ static inline void spin_lock_prefetch(const void *x) prefetchw(x); } =20 -#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack)= - \ - TOP_OF_KERNEL_STACK_PADDING) +#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack)) =20 -#define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1)) +#define task_top_of_stack(task) ((unsigned long)task_stack_page(task) + TH= READ_SIZE) =20 -#define task_pt_regs(task) \ -({ \ - unsigned long __ptr =3D (unsigned long)task_stack_page(task); \ - __ptr +=3D THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \ - ((struct pt_regs *)__ptr) - 1; \ -}) +#define task_pt_regs(task) ((task)->thread_info.user_pt_regs) =20 #ifdef CONFIG_X86_32 #define INIT_THREAD { \ diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch= _to.h index 00fd85abc1d2..0a31da150808 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -72,8 +72,7 @@ static inline void update_task_stack(struct task_struct *= task) /* * Will use WRMSRNS/WRMSRLIST for performance once it's upstreamed. */ - wrmsrl(MSR_IA32_FRED_RSP0, - task_top_of_stack(task) + TOP_OF_KERNEL_STACK_PADDING); + wrmsrl(MSR_IA32_FRED_RSP0, task_top_of_stack(task)); } else if (cpu_feature_enabled(X86_FEATURE_XENPV)) { /* Xen PV enters the kernel on the thread stack. */ load_sp0(task_top_of_stack(task)); diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thre= ad_info.h index 998483078d5f..ced0a01e0a3e 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -13,42 +13,6 @@ #include #include =20 -/* - * TOP_OF_KERNEL_STACK_PADDING is a number of unused bytes that we - * reserve at the top of the kernel stack. We do it because of a nasty - * 32-bit corner case. On x86_32, the hardware stack frame is - * variable-length. Except for vm86 mode, struct pt_regs assumes a - * maximum-length frame. If we enter from CPL 0, the top 8 bytes of - * pt_regs don't actually exist. Ordinarily this doesn't matter, but it - * does in at least one case: - * - * If we take an NMI early enough in SYSENTER, then we can end up with - * pt_regs that extends above sp0. On the way out, in the espfix code, - * we can read the saved SS value, but that value will be above sp0. - * Without this offset, that can result in a page fault. (We are - * careful that, in this case, the value we read doesn't matter.) - * - * In vm86 mode, the hardware frame is much longer still, so add 16 - * bytes to make room for the real-mode segments. - * - * x86-64 has a fixed-length stack frame, but it depends on whether - * or not FRED is enabled. Future versions of FRED might make this - * dynamic, but for now it is always 2 words longer. - */ -#ifdef CONFIG_X86_32 -# ifdef CONFIG_VM86 -# define TOP_OF_KERNEL_STACK_PADDING 16 -# else -# define TOP_OF_KERNEL_STACK_PADDING 8 -# endif -#else /* x86-64 */ -# ifdef CONFIG_X86_FRED -# define TOP_OF_KERNEL_STACK_PADDING (2*8) -# else -# define TOP_OF_KERNEL_STACK_PADDING 0 -# endif -#endif - /* * low level task data that entry.S needs immediate access to * - this struct should fit entirely inside of one cache line @@ -56,6 +20,7 @@ */ #ifndef __ASSEMBLY__ struct task_struct; +struct pt_regs; #include #include =20 @@ -66,11 +31,14 @@ struct thread_info { #ifdef CONFIG_SMP u32 cpu; /* current CPU */ #endif + struct pt_regs *user_pt_regs; }; =20 +#define INIT_TASK_PT_REGS ((struct pt_regs *)TOP_OF_INIT_STACK - 1) #define INIT_THREAD_INFO(tsk) \ { \ .flags =3D 0, \ + .user_pt_regs =3D INIT_TASK_PT_REGS, \ } =20 #else /* !__ASSEMBLY__ */ @@ -240,6 +208,7 @@ static inline int arch_within_stack_frames(const void *= const stack, =20 extern void arch_task_cache_init(void); extern int arch_dup_task_struct(struct task_struct *dst, struct task_struc= t *src); +extern void arch_init_user_pt_regs(struct task_struct *tsk); extern void arch_release_task_struct(struct task_struct *tsk); extern void arch_setup_new_exec(void); #define arch_setup_new_exec arch_setup_new_exec diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 67c8ed99144b..0201ddcd7576 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -517,8 +517,7 @@ SYM_DATA_END(initial_page_table) * reliably detect the end of the stack. */ SYM_DATA(initial_stack, - .long init_thread_union + THREAD_SIZE - - SIZEOF_PTREGS - TOP_OF_KERNEL_STACK_PADDING) + .long init_thread_union + THREAD_SIZE - SIZEOF_PTREGS) =20 __INITRODATA int_msg: diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index e57cd31bfec4..e176a376bde6 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -98,6 +98,11 @@ int arch_dup_task_struct(struct task_struct *dst, struct= task_struct *src) return 0; } =20 +void arch_init_user_pt_regs(struct task_struct *tsk) +{ + tsk->thread_info.user_pt_regs =3D (struct pt_regs *)task_top_of_stack(tsk= )- 1; +} + #ifdef CONFIG_X86_64 void arch_release_task_struct(struct task_struct *tsk) { diff --git a/kernel/fork.c b/kernel/fork.c index 82b2b5846aae..90d5dbd6b522 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -961,6 +961,10 @@ int __weak arch_dup_task_struct(struct task_struct *ds= t, return 0; } =20 +void __weak arch_init_user_pt_regs(struct task_struct *tsk) +{ +} + void set_task_stack_end_magic(struct task_struct *tsk) { unsigned long *stackend; @@ -988,6 +992,8 @@ static struct task_struct *dup_task_struct(struct task_= struct *orig, int node) if (err) goto free_tsk; =20 + arch_init_user_pt_regs(tsk); + #ifdef CONFIG_THREAD_INFO_IN_TASK refcount_set(&tsk->stack_refcount, 1); #endif --=20 2.34.1 From nobody Wed Sep 10 06:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8A0DC61DA3 for ; Fri, 24 Feb 2023 07:30:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230151AbjBXHaU (ORCPT ); Fri, 24 Feb 2023 02:30:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230094AbjBXH3m (ORCPT ); Fri, 24 Feb 2023 02:29:42 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 878F563DF2; Thu, 23 Feb 2023 23:28:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223725; x=1708759725; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Ya0P11FPkFOyO+yBLyGUvt4s2z0lBoRy6ViZph9dwjI=; b=dkuMacOhSDqoB2MVaomQ49B+vZfYOseK/jkjtYO8tLlxPEdmO4bO8bts Gi17ZhRTI5XJD4kzlY5HgR21eBYtNZZZfqkkNsAQDvSsYUy07y6B5SQAu ndGH7lWB7zd6oJyPT+d3AkBrqe2CZBATzDrFNO+japzsjRFusUo8YA8E/ Swoh221gFUHT33hEQWPI9ygczR7uOmeowBfBxu1+ulyh58FSBz2AAwavr 1y19ujS0GC9694K9l267J1KqBSf1Xsicl8DHOtc7Ftm182l7HPDaFZG4M xCQ4pzGl/in6VCkFWuGRpoO8YLxce7eLHowPOFVzvJSunupbYoY+HYlgI g==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836193" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836193" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639290" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639290" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:26 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v3 32/32] x86/fred: disable FRED by default in its early stage Date: Thu, 23 Feb 2023 23:01:45 -0800 Message-Id: <20230224070145.3572-33-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Disable FRED by default in its early stage. To enable FRED, a new kernel command line option "fred" needs to be added. Signed-off-by: Xin Li --- Documentation/admin-guide/kernel-parameters.txt | 4 ++++ arch/x86/kernel/cpu/common.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 1d2f92edb5a1..7d0a0c303e06 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1519,6 +1519,10 @@ Warning: use of this parameter will taint the kernel and may cause unknown problems. =20 + fred + Forcefully enable flexible return and event delivery, + which is otherwise disabled by default. + ftrace=3D[tracer] [FTRACE] will set and start the specified tracer as early as possible in order to facilitate early diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 550da2a61ae2..8f1a6cdb0108 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1461,6 +1461,9 @@ static void __init cpu_parse_early_param(void) char *argptr =3D arg, *opt; int arglen, taint =3D 0; =20 + if (!cmdline_find_option_bool(boot_command_line, "fred")) + setup_clear_cpu_cap(X86_FEATURE_FRED); + #ifdef CONFIG_X86_32 if (cmdline_find_option_bool(boot_command_line, "no387")) #ifdef CONFIG_MATH_EMULATION --=20 2.34.1