From nobody Thu Sep 18 23:17:10 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 5E6AAC43217 for ; Thu, 1 Dec 2022 11:05:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231273AbiLALFa (ORCPT ); Thu, 1 Dec 2022 06:05:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231194AbiLALEZ (ORCPT ); Thu, 1 Dec 2022 06:04:25 -0500 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A2811167EB; Thu, 1 Dec 2022 03:04:13 -0800 (PST) Received: from jinankjain-dranzer.zrrkmle5drku1h0apvxbr2u2ee.ix.internal.cloudapp.net (unknown [20.188.121.5]) by linux.microsoft.com (Postfix) with ESMTPSA id 840BE20B83E5; Thu, 1 Dec 2022 03:04:08 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 840BE20B83E5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1669892653; bh=Qb+/xMIUURF2qw1ybF3Cm9sldgz9mUzBUTrN37WRKvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tOHjliGqx/XyZF7N/1VP5/oZmWVnyvR2npDlg71bDbFug1cemQlbrwI5gIjiisVse 3I6uXrF7USDHpl/7sWBjcYUmBUhXTp6f1sUoF08g5NA6XabsuDItuRksi/uRVLFGgX aiFjkuNSAfB7PaSrg2P3/t5Sb95qxfZ3wTqQhKnc= From: Jinank Jain To: jinankjain@microsoft.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, arnd@arndb.de, peterz@infradead.org, jpoimboe@kernel.org, jinankjain@linux.microsoft.com, seanjc@google.com, kirill.shutemov@linux.intel.com, ak@linux.intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, anrayabh@linux.microsoft.com, mikelley@microsoft.com Subject: [PATCH v7 5/5] x86/hyperv: Change interrupt vector for nested root partition Date: Thu, 1 Dec 2022 11:03:39 +0000 Message-Id: <4a36d47f50aca7a7de8e89dbfb0cd407de549bed.1669788587.git.jinankjain@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: 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" Traditionally we have been using the HYPERVISOR_CALLBACK_VECTOR to relay the VMBus interrupt. But this does not work in case of nested hypervisor. Microsoft Hypervisor reserves 0x31 to 0x34 as the interrupt vector range for VMBus and thus we have to use one of the vectors from that range and setup the IDT accordingly. Signed-off-by: Jinank Jain --- arch/x86/include/asm/idtentry.h | 2 ++ arch/x86/include/asm/irq_vectors.h | 6 ++++++ arch/x86/kernel/cpu/mshyperv.c | 15 +++++++++++++++ arch/x86/kernel/idt.c | 9 +++++++++ drivers/hv/vmbus_drv.c | 3 ++- 5 files changed, 34 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentr= y.h index 72184b0b2219..c0648e3e4d4a 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -686,6 +686,8 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR, sysv= ec_kvm_posted_intr_nested DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR, sysvec_hyperv_callback= ); DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR, sysvec_hyperv_reenl= ightenment); DECLARE_IDTENTRY_SYSVEC(HYPERV_STIMER0_VECTOR, sysvec_hyperv_stimer0); +DECLARE_IDTENTRY_SYSVEC(HYPERV_INTR_NESTED_VMBUS_VECTOR, + sysvec_hyperv_nested_vmbus_intr); #endif =20 #if IS_ENABLED(CONFIG_ACRN_GUEST) diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_= vectors.h index 43dcb9284208..729d19eab7f5 100644 --- a/arch/x86/include/asm/irq_vectors.h +++ b/arch/x86/include/asm/irq_vectors.h @@ -102,6 +102,12 @@ #if IS_ENABLED(CONFIG_HYPERV) #define HYPERV_REENLIGHTENMENT_VECTOR 0xee #define HYPERV_STIMER0_VECTOR 0xed +/* + * FIXME: Change this, once Microsoft Hypervisor changes its assumption + * around VMBus interrupt vector allocation for nested root partition. + * Or provides a better interface to detect this instead of hardcoding. + */ +#define HYPERV_INTR_NESTED_VMBUS_VECTOR 0x31 #endif =20 #define LOCAL_TIMER_VECTOR 0xec diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index f2f6e10301a8..9f31c7704715 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -130,6 +130,21 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback) set_irq_regs(old_regs); } =20 +DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_nested_vmbus_intr) +{ + struct pt_regs *old_regs =3D set_irq_regs(regs); + + inc_irq_stat(irq_hv_callback_count); + + if (vmbus_handler) + vmbus_handler(); + + if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED) + ack_APIC_irq(); + + set_irq_regs(old_regs); +} + void hv_setup_vmbus_handler(void (*handler)(void)) { vmbus_handler =3D handler; diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index a58c6bc1cd68..ace648856a0b 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -160,6 +160,15 @@ static const __initconst struct idt_data apic_idts[] = =3D { # endif INTG(SPURIOUS_APIC_VECTOR, asm_sysvec_spurious_apic_interrupt), INTG(ERROR_APIC_VECTOR, asm_sysvec_error_interrupt), +#ifdef CONFIG_HYPERV + /* + * This is a hack because we cannot install this interrupt handler via al= loc_intr_gate + * as it does not allow interrupt vector less than FIRST_SYSTEM_VECTORS. = And hyperv + * does not want anything other than 0x31-0x34 as the interrupt vector fo= r vmbus + * interrupt in case of nested setup. + */ + INTG(HYPERV_INTR_NESTED_VMBUS_VECTOR, asm_sysvec_hyperv_nested_vmbus_intr= ), +#endif #endif }; =20 diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 6324e01d5eec..740878367426 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -2768,7 +2768,8 @@ static int __init hv_acpi_init(void) * normal Linux IRQ mechanism is not used in this case. */ #ifdef HYPERVISOR_CALLBACK_VECTOR - vmbus_interrupt =3D HYPERVISOR_CALLBACK_VECTOR; + vmbus_interrupt =3D hv_nested ? HYPERV_INTR_NESTED_VMBUS_VECTOR : + HYPERVISOR_CALLBACK_VECTOR; vmbus_irq =3D -1; #endif =20 --=20 2.25.1