From nobody Fri Dec 19 14:15:38 2025 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B42B313BAE5 for ; Wed, 3 Jul 2024 08:55:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719996913; cv=none; b=oloiH601OMeHhKo+udV2fq2oWWe3PEdUiPxC0XJinXg/E878aLxh7plWU8sNkTD89LaHPRs5iShxsKxh4xY+m8LoCHLuVXhxsc0DmvKbs7coll8YZaseJBCtjwhLheeJ1V6kQLMHDdTIh0NgJXKYC4rlQdDWN2iG6THmlhbImps= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719996913; c=relaxed/simple; bh=qWdd/U5P843zZgQZi8pLesLG9Ojih5CBGvIIxi8Vhjs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=da5m4VVhS5xMVw2gdwZOQKlG3NNRakknEh81C5xhVcVKWvnBqQZtTVXl6clm14shXKbo5jH5CuhmhxnobMktv2tETOZx3YGN0mQxqC2Dk521NbjZrvsDT0dM+a0jqqhfvT8nLE1UJ4lC7LgQuoOqVVXFLlMg/5eGBj/C7kJX+bg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=fjru07oX; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="fjru07oX" Received: from terminus.zytor.com (terminus.zytor.com [IPv6:2607:7c80:54:3:0:0:0:136]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 4638sQ19274819 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 3 Jul 2024 01:54:33 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 4638sQ19274819 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1719996874; bh=ioOo8doTD6S3vVDLWeOjIsJkTYwDmB9mJWFS1Qkccb8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fjru07oXkjTbBgMZ/4zzzBEtGbyCK7dRi9pKBpayaskwjRWeSJK6ujK9hPPq414E5 UzeUmE3DT2YRX1fUDHpSAfqOY7cfRKFlM8k4+iLvF2Vdta627cg9n8Ikz2ZNvG6SpV V3PLlya2xZknZ0W2wkxwiosQ38XiakKvv/Sroct48UvkaEb5nsEEpP4cCgJXmDxJuF FxMTXf1WXPUnKlS+uSvdaa2ZYV2Xn8HYHm1IwYQudMVTsFGcV520eAHv5bypcD0et2 E/pw2UrCx6wGS5LDf87KAXrhv0p89lrffJBadZG9AyO/j7nBWvxM82ebS5FirAhNQ/ Ap+KPueGqXL+A== From: "Xin Li (Intel)" To: linux-kernel@vger.kernel.org Cc: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, peterz@infradead.org, andrew.cooper3@citrix.com, nik.borisov@suse.com, houwenlong.hwl@antgroup.com Subject: [PATCH v1 3/4] x86/fred: Split FRED RSP initialization into a separate function Date: Wed, 3 Jul 2024 01:54:25 -0700 Message-ID: <20240703085426.274801-4-xin@zytor.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703085426.274801-1-xin@zytor.com> References: <20240703085426.274801-1-xin@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" To enable FRED earlier, split FRED RSP initialization into a separate function, as they are initialized with memory from CPU entry areas, thus their initialization has to be kept after setup_cpu_entry_areas(). No functional change intended. Signed-off-by: Xin Li (Intel) --- arch/x86/include/asm/fred.h | 2 ++ arch/x86/kernel/cpu/common.c | 6 ++++-- arch/x86/kernel/fred.c | 28 +++++++++++++++++++--------- 3 files changed, 25 insertions(+), 11 deletions(-) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index e86c7ba32435..66d7dbe2d314 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -84,11 +84,13 @@ static __always_inline void fred_entry_from_kvm(unsigne= d int type, unsigned int } =20 void cpu_init_fred_exceptions(void); +void cpu_init_fred_rsps(void); void fred_complete_exception_setup(void); =20 #else /* CONFIG_X86_FRED */ static __always_inline unsigned long fred_event_data(struct pt_regs *regs)= { return 0; } static inline void cpu_init_fred_exceptions(void) { } +static inline void cpu_init_fred_rsps(void) { } static inline void fred_complete_exception_setup(void) { } static __always_inline void fred_entry_from_kvm(unsigned int type, unsigne= d int vector) { } #endif /* CONFIG_X86_FRED */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9a904fe7c829..022ae4ba7997 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2195,10 +2195,12 @@ void cpu_init_exception_handling(void) /* GHCB needs to be setup to handle #VC. */ setup_ghcb(); =20 - if (cpu_feature_enabled(X86_FEATURE_FRED)) + if (cpu_feature_enabled(X86_FEATURE_FRED)) { cpu_init_fred_exceptions(); - else + cpu_init_fred_rsps(); + } else { load_current_idt(); + } } =20 /* diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c index b202685b8e77..1788f28754f3 100644 --- a/arch/x86/kernel/fred.c +++ b/arch/x86/kernel/fred.c @@ -32,6 +32,25 @@ void cpu_init_fred_exceptions(void) FRED_CONFIG_INT_STKLVL(0) | FRED_CONFIG_ENTRYPOINT(asm_fred_entrypoint_user)); =20 + wrmsrns(MSR_IA32_FRED_STKLVLS, 0); + wrmsrns(MSR_IA32_FRED_RSP0, 0); + wrmsrns(MSR_IA32_FRED_RSP1, 0); + wrmsrns(MSR_IA32_FRED_RSP2, 0); + wrmsrns(MSR_IA32_FRED_RSP3, 0); + + /* Enable FRED */ + cr4_set_bits(X86_CR4_FRED); + /* Any further IDT use is a bug */ + idt_invalidate(); + + /* 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); +} + +/* Must be called after setup_cpu_entry_areas() */ +void cpu_init_fred_rsps(void) +{ /* * The purpose of separate stacks for NMI, #DB and #MC *in the kernel* * (remember that user space faults are always taken on stack level 0) @@ -47,13 +66,4 @@ void cpu_init_fred_exceptions(void) wrmsrns(MSR_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB)); wrmsrns(MSR_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI)); wrmsrns(MSR_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF)); - - /* Enable FRED */ - cr4_set_bits(X86_CR4_FRED); - /* Any further IDT use is a bug */ - idt_invalidate(); - - /* 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); } --=20 2.45.2