>diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
>index b9b82aaea9a3..3830084b569b 100644
>--- a/arch/x86/include/asm/kvm_host.h
>+++ b/arch/x86/include/asm/kvm_host.h
>@@ -736,6 +736,7 @@ struct kvm_queued_exception {
> u32 error_code;
> unsigned long payload;
> bool has_payload;
>+ bool nested;
> u64 event_data;
how "nested" is migrated in live migration?
> };
[..]
>
>diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>index d81144bd648f..03f42b218554 100644
>--- a/arch/x86/kvm/vmx/vmx.c
>+++ b/arch/x86/kvm/vmx/vmx.c
>@@ -1910,8 +1910,11 @@ void vmx_inject_exception(struct kvm_vcpu *vcpu)
> vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
> vmx->vcpu.arch.event_exit_inst_len);
> intr_info |= INTR_TYPE_SOFT_EXCEPTION;
>- } else
>+ } else {
> intr_info |= INTR_TYPE_HARD_EXCEPTION;
>+ if (ex->nested)
>+ intr_info |= INTR_INFO_NESTED_EXCEPTION_MASK;
how about moving the is_fred_enable() check from kvm_multiple_exception() to here? i.e.,
if (ex->nested && is_fred_enabled(vcpu))
intr_info |= INTR_INFO_NESTED_EXCEPTION_MASK;
It is slightly clearer because FRED details don't bleed into kvm_multiple_exception().
>+ }
>
> vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info);
>
>@@ -7290,6 +7293,7 @@ static void __vmx_complete_interrupts(struct kvm_vcpu *vcpu,
> kvm_requeue_exception(vcpu, vector,
> idt_vectoring_info & VECTORING_INFO_DELIVER_CODE_MASK,
> error_code,
>+ idt_vectoring_info & VECTORING_INFO_NESTED_EXCEPTION_MASK,
> event_data);
> break;
> }
>diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>index 7a55c1eb5297..8546629166e9 100644
>--- a/arch/x86/kvm/x86.c
>+++ b/arch/x86/kvm/x86.c
>@@ -874,6 +874,11 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu, unsigned int nr,
> vcpu->arch.exception.pending = true;
> vcpu->arch.exception.injected = false;
>
>+ vcpu->arch.exception.nested = vcpu->arch.exception.nested ||
>+ (is_fred_enabled(vcpu) &&
>+ (vcpu->arch.nmi_injected ||
>+ vcpu->arch.interrupt.injected));
>+
> vcpu->arch.exception.has_error_code = has_error;
> vcpu->arch.exception.vector = nr;
> vcpu->arch.exception.error_code = error_code;
>@@ -903,8 +908,13 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu, unsigned int nr,
> vcpu->arch.exception.injected = false;
> vcpu->arch.exception.pending = false;
>
>+ /* #DF is NOT a nested event, per its definition. */
>+ vcpu->arch.exception.nested = false;
>+
> kvm_queue_exception_e(vcpu, DF_VECTOR, 0);
> } else {
>+ vcpu->arch.exception.nested = is_fred_enabled(vcpu);
>+
> /* replace previous exception with a new one in a hope
> that instruction re-execution will regenerate lost
> exception */
