From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756872AbZFDLMc (ORCPT ); Thu, 4 Jun 2009 07:12:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754585AbZFDLMJ (ORCPT ); Thu, 4 Jun 2009 07:12:09 -0400 Received: from one.firstfloor.org ([213.235.205.2]:55287 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751169AbZFDLMG (ORCPT ); Thu, 4 Jun 2009 07:12:06 -0400 From: Andi Kleen References: <20090604112.650907584@firstfloor.org> In-Reply-To: <20090604112.650907584@firstfloor.org> To: ying.huang@intel.com, avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] [2/2] KVM: Add VT-x machine check support Message-Id: <20090604111205.C47C31D0282@basil.firstfloor.org> Date: Thu, 4 Jun 2009 13:12:05 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Avi could you please still consider this patch for your 2.6.31 patchqueue? It's fairly simple, but important to handle memory errors in guests] VT-x needs an explicit MC vector intercept to handle machine checks in the hyper visor. It also has a special option to catch machine checks that happen during VT entry. Do these interceptions and forward them to the Linux machine check handler. Make it always look like user space is interrupted because the machine check handler treats kernel/user space differently. Thanks to Huang Ying and Jiang Yunhong for help and testing. Cc: ying.huang@intel.com Signed-off-by: Andi Kleen --- arch/x86/include/asm/vmx.h | 1 + arch/x86/kvm/vmx.c | 26 ++++++++++++++++++++++++-- 2 files changed, 25 insertions(+), 2 deletions(-) Index: linux/arch/x86/include/asm/vmx.h =================================================================== --- linux.orig/arch/x86/include/asm/vmx.h 2009-05-28 10:47:53.000000000 +0200 +++ linux/arch/x86/include/asm/vmx.h 2009-06-04 11:58:49.000000000 +0200 @@ -247,6 +247,7 @@ #define EXIT_REASON_MSR_READ 31 #define EXIT_REASON_MSR_WRITE 32 #define EXIT_REASON_MWAIT_INSTRUCTION 36 +#define EXIT_REASON_MACHINE_CHECK 41 #define EXIT_REASON_TPR_BELOW_THRESHOLD 43 #define EXIT_REASON_APIC_ACCESS 44 #define EXIT_REASON_EPT_VIOLATION 48 Index: linux/arch/x86/kvm/vmx.c =================================================================== --- linux.orig/arch/x86/kvm/vmx.c 2009-05-28 10:47:53.000000000 +0200 +++ linux/arch/x86/kvm/vmx.c 2009-06-04 12:05:44.000000000 +0200 @@ -32,6 +32,7 @@ #include #include #include +#include #define __ex(x) __kvm_handle_fault_on_reboot(x) @@ -478,7 +479,7 @@ { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR); + eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR); if (!vcpu->fpu_active) eb |= 1u << NM_VECTOR; if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) { @@ -2585,6 +2586,23 @@ return 0; } +/* + * Trigger machine check on the host. We assume all the MSRs are already set up + * by the CPU and that we still run on the same CPU as the MCE occurred on. + * We pass a fake environment to the machine check handler because we want + * the guest to be always treated like user space, no matter what context + * it used internally. + */ +static int handle_machine_check(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) +{ + struct pt_regs regs = { + .cs = 3, /* Fake ring 3 no matter what the guest ran on */ + .flags = X86_EFLAGS_IF, + }; + do_machine_check(®s, 0); + return 1; +} + static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -2596,6 +2614,10 @@ vect_info = vmx->idt_vectoring_info; intr_info = vmcs_read32(VM_EXIT_INTR_INFO); + ex_no = intr_info & INTR_INFO_VECTOR_MASK; + if (ex_no == MCE_VECTOR) + return handle_machine_check(vcpu, kvm_run); + if ((vect_info & VECTORING_INFO_VALID_MASK) && !is_page_fault(intr_info)) printk(KERN_ERR "%s: unexpected, vectoring info 0x%x " @@ -2648,7 +2670,6 @@ return 1; } - ex_no = intr_info & INTR_INFO_VECTOR_MASK; switch (ex_no) { case DB_VECTOR: dr6 = vmcs_readl(EXIT_QUALIFICATION); @@ -3150,6 +3171,7 @@ [EXIT_REASON_WBINVD] = handle_wbinvd, [EXIT_REASON_TASK_SWITCH] = handle_task_switch, [EXIT_REASON_EPT_VIOLATION] = handle_ept_violation, + [EXIT_REASON_MACHINE_CHECK] = handle_machine_check, }; static const int kvm_vmx_max_exit_handlers =