Messages in this thread Patch in this message |  | | From | Melody Wang <> | | Subject | [PATCH v4 5/7] KVM: SVM: Inject MCEs when Restricted Injection is active | | Date | Fri, 24 Apr 2026 17:42:09 +0000 |
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When Restricted Injection is active, only #HV exceptions can be injected into the SEV-SNP guest.
Detect that, and then follow the #HV doorbell communication from the GHCB specification to inject the MCEs.
Co-developed-by: Thomas Lendacky <thomas.lendacky@amd.com> Signed-off-by: Thomas Lendacky <thomas.lendacky@amd.com> Signed-off-by: Melody Wang <huibo.wang@amd.com> --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/sev.c | 16 ++++++++++++++-- arch/x86/kvm/svm/svm.c | 17 +++++++++++++++++ arch/x86/kvm/svm/svm.h | 2 ++ arch/x86/kvm/vmx/main.c | 10 ++++++++++ arch/x86/kvm/vmx/vmx.c | 5 +++++ arch/x86/kvm/vmx/x86_ops.h | 1 + arch/x86/kvm/x86.c | 7 +++++++ 9 files changed, 58 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 3776cf5382a2..c8bff1e9325e 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -79,6 +79,7 @@ KVM_X86_OP(inject_exception) KVM_X86_OP(cancel_injection) KVM_X86_OP(interrupt_allowed) KVM_X86_OP(nmi_allowed) +KVM_X86_OP_OPTIONAL(mce_allowed) KVM_X86_OP(get_nmi_mask) KVM_X86_OP(set_nmi_mask) KVM_X86_OP(enable_nmi_window) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c470e40a00aa..2e445fbc6796 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1860,6 +1860,7 @@ struct kvm_x86_ops { void (*cancel_injection)(struct kvm_vcpu *vcpu); int (*interrupt_allowed)(struct kvm_vcpu *vcpu, bool for_injection); int (*nmi_allowed)(struct kvm_vcpu *vcpu, bool for_injection); + int (*mce_allowed)(struct kvm_vcpu *vcpu); bool (*get_nmi_mask)(struct kvm_vcpu *vcpu); void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked); /* Whether or not a virtual NMI is pending in hardware. */ diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 61e1e54deb07..2483357bdd97 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -5371,6 +5371,8 @@ static void __sev_snp_inject(enum inject_type type, struct kvm_vcpu *vcpu) if (type == INJECT_NMI) hvdb->events.nmi = 1; + else if (type == INJECT_MCE) + hvdb->events.mce = 1; else hvdb->events.vector = vcpu->arch.interrupt.nr; @@ -5386,6 +5388,11 @@ bool sev_snp_queue_exception(struct kvm_vcpu *vcpu) if (!sev_snp_is_rinj_active(vcpu)) return false; + if (vcpu->arch.exception.vector == MC_VECTOR) { + __sev_snp_inject(INJECT_MCE, vcpu); + return true; + } + /* * Restricted Injection is enabled, only #HV is supported. * If the vector is not HV_VECTOR, do not inject the exception, @@ -5454,7 +5461,7 @@ void sev_snp_cancel_injection(struct kvm_vcpu *vcpu) /* * KVM only injects a single event each time (prepare_hv_injection), - * so when events.nmi is true, the vector will be zero + * so when events.nmi is true, the MCE and vector will be zero. */ if (hvdb->events.vector) svm->vmcb->control.event_inj |= hvdb->events.vector | @@ -5463,6 +5470,9 @@ void sev_snp_cancel_injection(struct kvm_vcpu *vcpu) if (hvdb->events.nmi) svm->vmcb->control.event_inj |= SVM_EVTINJ_TYPE_NMI; + if (hvdb->events.mce) + svm->vmcb->control.event_inj |= MC_VECTOR | SVM_EVTINJ_TYPE_EXEPT; + hvdb->events.pending_events = 0; out: @@ -5488,9 +5498,11 @@ bool sev_snp_blocked(enum inject_type type, struct kvm_vcpu *vcpu) if (!hvdb) return true; - /* Indicate NMIs and interrupts blocked based on guest acknowledgment */ + /* Indicate NMIs, MCEs and interrupts blocked based on guest acknowledgment */ if (type == INJECT_NMI) blocked = hvdb->events.nmi; + else if (type == INJECT_MCE) + blocked = hvdb->events.mce; else blocked = !!hvdb->events.vector; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 925e284374b6..68bf30ab3a12 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4038,6 +4038,22 @@ static int svm_interrupt_allowed(struct kvm_vcpu *vcpu, bool for_injection) return 1; } +bool svm_mce_blocked(struct kvm_vcpu *vcpu) +{ + if (sev_snp_is_rinj_active(vcpu)) + return sev_snp_blocked(INJECT_MCE, vcpu); + + return false; +} + +static int svm_mce_allowed(struct kvm_vcpu *vcpu) +{ + if (svm_mce_blocked(vcpu)) + return 0; + + return 1; +} + static void svm_enable_irq_window(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -5351,6 +5367,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = { .cancel_injection = svm_cancel_injection, .interrupt_allowed = svm_interrupt_allowed, .nmi_allowed = svm_nmi_allowed, + .mce_allowed = svm_mce_allowed, .get_nmi_mask = svm_get_nmi_mask, .set_nmi_mask = svm_set_nmi_mask, .enable_nmi_window = svm_enable_nmi_window, diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 16cb76b9fdd5..9254a463041a 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -58,6 +58,7 @@ extern struct kvm_x86_ops svm_x86_ops __initdata; enum inject_type { INJECT_IRQ, INJECT_NMI, + INJECT_MCE, }; /* @@ -798,6 +799,7 @@ void svm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4); void disable_nmi_singlestep(struct vcpu_svm *svm); bool svm_smi_blocked(struct kvm_vcpu *vcpu); bool svm_nmi_blocked(struct kvm_vcpu *vcpu); +bool svm_mce_blocked(struct kvm_vcpu *vcpu); bool svm_interrupt_blocked(struct kvm_vcpu *vcpu); void svm_set_gif(struct vcpu_svm *svm, bool value); int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code); diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index dbebddf648be..f9c4703dda54 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -812,6 +812,15 @@ static void vt_cancel_hv_timer(struct kvm_vcpu *vcpu) } #endif +static int vt_mce_allowed(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) + return 0; + + return vmx_mce_allowed(vcpu); +} + + static void vt_setup_mce(struct kvm_vcpu *vcpu) { if (is_td_vcpu(vcpu)) @@ -945,6 +954,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .cancel_injection = vt_op(cancel_injection), .interrupt_allowed = vt_op(interrupt_allowed), .nmi_allowed = vt_op(nmi_allowed), + .mce_allowed = vt_op(mce_allowed), .get_nmi_mask = vt_op(get_nmi_mask), .set_nmi_mask = vt_op(set_nmi_mask), .enable_nmi_window = vt_op(enable_nmi_window), diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index a29896a9ef14..7aa728c1e946 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -5210,6 +5210,11 @@ int vmx_interrupt_allowed(struct kvm_vcpu *vcpu, bool for_injection) return !vmx_interrupt_blocked(vcpu); } +int vmx_mce_allowed(struct kvm_vcpu *vcpu) +{ + return 1; +} + int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr) { void __user *ret; diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index d09abeac2b56..b75dfe7f039d 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -92,6 +92,7 @@ void vmx_inject_exception(struct kvm_vcpu *vcpu); void vmx_cancel_injection(struct kvm_vcpu *vcpu); int vmx_interrupt_allowed(struct kvm_vcpu *vcpu, bool for_injection); int vmx_nmi_allowed(struct kvm_vcpu *vcpu, bool for_injection); +int vmx_mce_allowed(struct kvm_vcpu *vcpu); bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu); void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked); void vmx_enable_nmi_window(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0a1b63c63d1a..420f1ec0dcfb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10789,6 +10789,12 @@ static int kvm_check_and_inject_events(struct kvm_vcpu *vcpu, kvm_update_dr7(vcpu); } + if (vcpu->arch.exception.vector == MC_VECTOR) { + r = static_call(kvm_x86_mce_allowed)(vcpu); + if (!r) + goto out_except; + } + kvm_inject_exception(vcpu); vcpu->arch.exception.pending = false; @@ -10796,6 +10802,7 @@ static int kvm_check_and_inject_events(struct kvm_vcpu *vcpu, can_inject = false; } +out_except: /* Don't inject interrupts if the user asked to avoid doing so */ if (vcpu->guest_debug & KVM_GUESTDBG_BLOCKIRQ) -- 2.43.0
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