From: Sean Christopherson <seanjc@google.com>
To: Santosh Shukla <santosh.shukla@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Maxim Levitsky <mlevitsk@redhat.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv2 5/7] KVM: SVM: Add VNMI support in inject_nmi
Date: Wed, 20 Jul 2022 21:41:14 +0000 [thread overview]
Message-ID: <Yth2eik6usFvC4vW@google.com> (raw)
In-Reply-To: <20220709134230.2397-6-santosh.shukla@amd.com>
On Sat, Jul 09, 2022, Santosh Shukla wrote:
> Inject the NMI by setting V_NMI in the VMCB interrupt control. processor
> will clear V_NMI to acknowledge processing has started and will keep the
> V_NMI_MASK set until the processor is done with processing the NMI event.
>
> Signed-off-by: Santosh Shukla <santosh.shukla@amd.com>
> ---
> v2:
> - Added WARN_ON check for vnmi pending.
> - use `get_vnmi_vmcb` to get correct vmcb so to inject vnmi.
>
> arch/x86/kvm/svm/svm.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 44c1f2317b45..c73a1809a7c7 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3375,12 +3375,20 @@ static void pre_svm_run(struct kvm_vcpu *vcpu)
> static void svm_inject_nmi(struct kvm_vcpu *vcpu)
> {
> struct vcpu_svm *svm = to_svm(vcpu);
> + struct vmcb *vmcb = NULL;
> +
> + ++vcpu->stat.nmi_injections;
> + if (is_vnmi_enabled(svm)) {
> + vmcb = get_vnmi_vmcb(svm);
> + WARN_ON(vmcb->control.int_ctl & V_NMI_PENDING);
Haven't read the spec, but based on the changelog I assume the flag doesn't get
cleared until the NMI is fully delivered. That means this WARN will fire if a
VM-Exit occurs during delivery as KVM will re-inject the event, e.g. if KVM is
using shadow paging and a #PF handle by KVM occurs during delivery.
> + vmcb->control.int_ctl |= V_NMI_PENDING;
> + return;
> + }
>
> svm->vmcb->control.event_inj = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;
> vcpu->arch.hflags |= HF_NMI_MASK;
> if (!sev_es_guest(vcpu->kvm))
> svm_set_intercept(svm, INTERCEPT_IRET);
> - ++vcpu->stat.nmi_injections;
> }
>
> static void svm_inject_irq(struct kvm_vcpu *vcpu)
> --
> 2.25.1
>
next prev parent reply other threads:[~2022-07-20 21:41 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-09 13:42 [PATCHv2 0/7] Virtual NMI feature Santosh Shukla
2022-07-09 13:42 ` [PATCHv2 1/7] x86/cpu: Add CPUID feature bit for VNMI Santosh Shukla
2022-07-09 13:42 ` [PATCHv2 2/7] KVM: SVM: Add VNMI bit definition Santosh Shukla
2022-07-09 13:42 ` [PATCHv2 3/7] KVM: SVM: Add VNMI support in get/set_nmi_mask Santosh Shukla
2022-07-10 16:15 ` Maxim Levitsky
2022-07-21 9:34 ` Shukla, Santosh
2022-07-21 12:01 ` Maxim Levitsky
2022-07-21 13:12 ` Shukla, Santosh
2022-07-21 15:48 ` Maxim Levitsky
2022-07-09 13:42 ` [PATCHv2 4/7] KVM: SVM: Report NMI not allowed when Guest busy handling VNMI Santosh Shukla
2022-07-20 21:54 ` Sean Christopherson
2022-07-21 12:05 ` Maxim Levitsky
2022-07-21 14:59 ` Sean Christopherson
2022-07-21 15:31 ` Maxim Levitsky
2022-07-21 16:08 ` Sean Christopherson
2022-07-21 16:17 ` Maxim Levitsky
2022-07-21 16:25 ` Sean Christopherson
2022-07-29 5:51 ` Shukla, Santosh
2022-07-29 14:41 ` Sean Christopherson
2022-08-04 9:51 ` Shukla, Santosh
2022-07-09 13:42 ` [PATCHv2 5/7] KVM: SVM: Add VNMI support in inject_nmi Santosh Shukla
2022-07-20 21:41 ` Sean Christopherson [this message]
2022-07-20 22:46 ` Jim Mattson
2022-07-20 23:04 ` Sean Christopherson
2022-07-29 6:06 ` Shukla, Santosh
2022-07-29 13:53 ` Sean Christopherson
2022-07-29 13:55 ` Shukla, Santosh
2022-07-09 13:42 ` [PATCHv2 6/7] KVM: nSVM: implement nested VNMI Santosh Shukla
2022-07-09 13:42 ` [PATCHv2 7/7] KVM: SVM: Enable VNMI feature Santosh Shukla
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