From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
vkuznets@redhat.com, Jim Mattson <jmattson@google.com>,
stable@vger.kernel.org
Subject: [PATCH 01/43] KVM: VMX: Fix handling of #MC that occurs during VM-Entry
Date: Thu, 13 Jun 2019 19:02:47 +0200 [thread overview]
Message-ID: <1560445409-17363-2-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1560445409-17363-1-git-send-email-pbonzini@redhat.com>
From: Sean Christopherson <sean.j.christopherson@intel.com>
A previous fix to prevent KVM from consuming stale VMCS state after a
failed VM-Entry inadvertantly blocked KVM's handling of machine checks
that occur during VM-Entry.
Per Intel's SDM, a #MC during VM-Entry is handled in one of three ways,
depending on when the #MC is recognoized. As it pertains to this bug
fix, the third case explicitly states EXIT_REASON_MCE_DURING_VMENTRY
is handled like any other VM-Exit during VM-Entry, i.e. sets bit 31 to
indicate the VM-Entry failed.
If a machine-check event occurs during a VM entry, one of the following occurs:
- The machine-check event is handled as if it occurred before the VM entry:
...
- The machine-check event is handled after VM entry completes:
...
- A VM-entry failure occurs as described in Section 26.7. The basic
exit reason is 41, for "VM-entry failure due to machine-check event".
Explicitly handle EXIT_REASON_MCE_DURING_VMENTRY as a one-off case in
vmx_vcpu_run() instead of binning it into vmx_complete_atomic_exit().
Doing so allows vmx_vcpu_run() to handle VMX_EXIT_REASONS_FAILED_VMENTRY
in a sane fashion and also simplifies vmx_complete_atomic_exit() since
VMCS.VM_EXIT_INTR_INFO is guaranteed to be fresh.
Fixes: b060ca3b2e9e7 ("kvm: vmx: Handle VMLAUNCH/VMRESUME failure properly")
Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/vmx/vmx.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5d903f8909d1..1b3ca0582a0c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6107,28 +6107,21 @@ static void vmx_apicv_post_state_restore(struct kvm_vcpu *vcpu)
static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
{
- u32 exit_intr_info = 0;
- u16 basic_exit_reason = (u16)vmx->exit_reason;
-
- if (!(basic_exit_reason == EXIT_REASON_MCE_DURING_VMENTRY
- || basic_exit_reason == EXIT_REASON_EXCEPTION_NMI))
+ if (vmx->exit_reason != EXIT_REASON_EXCEPTION_NMI)
return;
- if (!(vmx->exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
- exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
- vmx->exit_intr_info = exit_intr_info;
+ vmx->exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
/* if exit due to PF check for async PF */
- if (is_page_fault(exit_intr_info))
+ if (is_page_fault(vmx->exit_intr_info))
vmx->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason();
/* Handle machine checks before interrupts are enabled */
- if (basic_exit_reason == EXIT_REASON_MCE_DURING_VMENTRY ||
- is_machine_check(exit_intr_info))
+ if (is_machine_check(vmx->exit_intr_info))
kvm_machine_check();
/* We need to handle NMIs before interrupts are enabled */
- if (is_nmi(exit_intr_info)) {
+ if (is_nmi(vmx->exit_intr_info)) {
kvm_before_interrupt(&vmx->vcpu);
asm("int $2");
kvm_after_interrupt(&vmx->vcpu);
@@ -6535,6 +6528,9 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->idt_vectoring_info = 0;
vmx->exit_reason = vmx->fail ? 0xdead : vmcs_read32(VM_EXIT_REASON);
+ if ((u16)vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY)
+ kvm_machine_check();
+
if (vmx->fail || (vmx->exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
return;
--
1.8.3.1
next prev parent reply other threads:[~2019-06-13 17:03 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 17:02 [PATCH 00/43] VMX optimizations Paolo Bonzini
2019-06-13 17:02 ` Paolo Bonzini [this message]
2019-06-13 17:24 ` [PATCH 01/43] KVM: VMX: Fix handling of #MC that occurs during VM-Entry Jim Mattson
2019-06-13 17:02 ` [PATCH 02/43] kvm: nVMX: small cleanup in handle_exception Paolo Bonzini
2019-06-13 17:02 ` [PATCH 03/43] KVM: VMX: Read cached VM-Exit reason to detect external interrupt Paolo Bonzini
2019-06-13 17:02 ` [PATCH 04/43] KVM: VMX: Store the host kernel's IDT base in a global variable Paolo Bonzini
2019-06-13 17:02 ` [PATCH 05/43] KVM: x86: Move kvm_{before,after}_interrupt() calls to vendor code Paolo Bonzini
2019-06-13 17:02 ` [PATCH 06/43] KVM: VMX: Handle NMIs, #MCs and async #PFs in common irqs-disabled fn Paolo Bonzini
2019-06-13 17:02 ` [PATCH 07/43] KVM: nVMX: Intercept VMWRITEs to read-only shadow VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 08/43] KVM: nVMX: Intercept VMWRITEs to GUEST_{CS,SS}_AR_BYTES Paolo Bonzini
2019-06-13 17:02 ` [PATCH 09/43] KVM: nVMX: Track vmcs12 offsets for shadowed VMCS fields Paolo Bonzini
2019-06-13 17:02 ` [PATCH 10/43] KVM: nVMX: Lift sync_vmcs12() out of prepare_vmcs12() Paolo Bonzini
2019-06-13 17:02 ` [PATCH 11/43] KVM: nVMX: Use descriptive names for VMCS sync functions and flags Paolo Bonzini
2019-06-13 17:02 ` [PATCH 12/43] KVM: nVMX: Add helpers to identify shadowed VMCS fields Paolo Bonzini
2019-06-14 16:10 ` Sean Christopherson
2019-06-13 17:02 ` [PATCH 13/43] KVM: nVMX: Sync rarely accessed guest fields only when needed Paolo Bonzini
2019-06-13 17:03 ` [PATCH 14/43] KVM: nVMX: Rename prepare_vmcs02_*_full to prepare_vmcs02_*_rare Paolo Bonzini
2019-06-13 17:03 ` [PATCH 15/43] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value Paolo Bonzini
2019-06-13 17:03 ` [PATCH 16/43] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01 Paolo Bonzini
[not found] ` <20190615221602.93C5721851@mail.kernel.org>
2019-06-15 22:40 ` Liran Alon
2019-06-13 17:03 ` [PATCH 17/43] KVM: nVMX: Write ENCLS-exiting bitmap once per vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 18/43] KVM: nVMX: Don't rewrite GUEST_PML_INDEX during nested VM-Entry Paolo Bonzini
2019-06-13 17:03 ` [PATCH 19/43] KVM: VMX: simplify vmx_prepare_switch_to_{guest,host} Paolo Bonzini
2019-06-13 17:03 ` [PATCH 20/43] KVM: nVMX: Don't "put" vCPU or host state when switching VMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 21/43] KVM: nVMX: Don't reread VMCS-agnostic " Paolo Bonzini
2019-06-14 16:25 ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 22/43] KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped Paolo Bonzini
2019-06-17 19:17 ` Radim Krčmář
2019-06-17 20:07 ` Sean Christopherson
2019-06-18 9:43 ` Paolo Bonzini
2019-06-13 17:03 ` [PATCH 23/43] KVM: nVMX: Don't speculatively write virtual-APIC page address Paolo Bonzini
2019-06-13 17:03 ` [PATCH 24/43] KVM: nVMX: Don't speculatively write APIC-access " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 25/43] KVM: nVMX: Update vmcs12 for MSR_IA32_CR_PAT when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 26/43] KVM: nVMX: Update vmcs12 for SYSENTER MSRs when they're written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 27/43] KVM: nVMX: Update vmcs12 for MSR_IA32_DEBUGCTLMSR when it's written Paolo Bonzini
2019-06-13 17:03 ` [PATCH 28/43] KVM: nVMX: Don't update GUEST_BNDCFGS if it's clean in HV eVMCS Paolo Bonzini
2019-06-13 17:03 ` [PATCH 29/43] KVM: x86: introduce is_pae_paging Paolo Bonzini
2019-06-13 17:03 ` [PATCH 30/43] KVM: nVMX: Copy PDPTRs to/from vmcs12 only when necessary Paolo Bonzini
2019-06-13 17:03 ` [PATCH 31/43] KVM: nVMX: Use adjusted pin controls for vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 32/43] KVM: VMX: Add builder macros for shadowing controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 33/43] KVM: VMX: Shadow VMCS pin controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 34/43] KVM: VMX: Shadow VMCS primary execution controls Paolo Bonzini
2019-06-13 17:03 ` [PATCH 35/43] KVM: VMX: Shadow VMCS secondary " Paolo Bonzini
2019-06-13 17:03 ` [PATCH 36/43] KVM: nVMX: Shadow VMCS controls on a per-VMCS basis Paolo Bonzini
2019-06-13 17:03 ` [PATCH 37/43] KVM: nVMX: Don't reset VMCS controls shadow on VMCS switch Paolo Bonzini
2019-06-13 17:03 ` [PATCH 38/43] KVM: VMX: Explicitly initialize controls shadow at VMCS allocation Paolo Bonzini
2019-06-13 17:03 ` [PATCH 39/43] KVM: nVMX: Preserve last USE_MSR_BITMAPS when preparing vmcs02 Paolo Bonzini
2019-06-13 17:03 ` [PATCH 40/43] KVM: nVMX: Preset *DT exiting in vmcs02 when emulating UMIP Paolo Bonzini
2019-06-13 17:03 ` [PATCH 41/43] KVM: VMX: Drop hv_timer_armed from 'struct loaded_vmcs' Paolo Bonzini
2019-06-13 17:03 ` [PATCH 42/43] KVM: VMX: Leave preemption timer running when it's disabled Paolo Bonzini
2019-06-14 16:34 ` Sean Christopherson
2019-06-13 17:03 ` [PATCH 43/43] KVM: nVMX: shadow pin based execution controls Paolo Bonzini
2019-06-14 16:34 ` Sean Christopherson
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