On 6/7/2022 6:37 PM, Maxim Levitsky wrote:
> On Thu, 2022-06-02 at 19:56 +0530, Santosh Shukla wrote:
>> VMCB intr_ctrl bit12 (V_NMI_MASK) is set by the processor when handling
>> NMI in guest and is cleared after the NMI is handled. Treat V_NMI_MASK as
>> read-only in the hypervisor and do not populate set accessors.
>>
>> Signed-off-by: Santosh Shukla <santosh.shukla@xxxxxxx>
>> ---
>> arch/x86/kvm/svm/svm.c | 20 +++++++++++++++++++-
>> 1 file changed, 19 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
>> index 860f28c668bd..d67a54517d95 100644
>> --- a/arch/x86/kvm/svm/svm.c
>> +++ b/arch/x86/kvm/svm/svm.c
>> @@ -323,6 +323,16 @@ static int is_external_interrupt(u32 info)
>> return info == (SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR);
>> }
>>
>> +static bool is_vnmi_enabled(struct vmcb *vmcb)
>> +{
>> + return vnmi && (vmcb->control.int_ctl & V_NMI_ENABLE);
>> +}
>
> Following Paolo's suggestion I recently removed vgif_enabled(),
> based on the logic that vgif_enabled == vgif, because
> we always enable vGIF for L1 as long as 'vgif' module param is set,
> which is set unless either hardware or user cleared it.
>
Yes. In v2, Thanks!.
> Note that here vmcb is the current vmcb, which can be vmcb02,
> and it might be wrong
>
>> +
>> +static bool is_vnmi_mask_set(struct vmcb *vmcb)
>> +{
>> + return !!(vmcb->control.int_ctl & V_NMI_MASK);
>> +}
>> +
>> static u32 svm_get_interrupt_shadow(struct kvm_vcpu *vcpu)
>> {
>> struct vcpu_svm *svm = to_svm(vcpu);
>> @@ -3502,13 +3512,21 @@ static int svm_nmi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
>>
>> static bool svm_get_nmi_mask(struct kvm_vcpu *vcpu)
>> {
>> - return !!(vcpu->arch.hflags & HF_NMI_MASK);
>> + struct vcpu_svm *svm = to_svm(vcpu);
>> +
>> + if (is_vnmi_enabled(svm->vmcb))
>> + return is_vnmi_mask_set(svm->vmcb);
>> + else
>> + return !!(vcpu->arch.hflags & HF_NMI_MASK);
>> }
>>
>> static void svm_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
>> {
>> struct vcpu_svm *svm = to_svm(vcpu);
>>
>> + if (is_vnmi_enabled(svm->vmcb))
>> + return;
>
> What if the KVM wants to mask NMI, shoudn't we update the
> V_NMI_MASK value in int_ctl instead of doing nothing?
>
> Best regards,
> Maxim Levitsky
>
>
>> +
>> if (masked) {
>> vcpu->arch.hflags |= HF_NMI_MASK;
>> if (!sev_es_guest(vcpu->kvm))
>
>
