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From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 19 Apr 2024 13:58:07 +0200
Message-ID: <CABgObfbNd2Z85o3Wb-yr5qYSWYTadxZGuh6PP=r-5dNpa06ErA@mail.gmail.com>
Subject: Re: [PATCH v13 08/26] KVM: SEV: Add initial SEV-SNP support
To: Michael Roth <michael.roth@amd.com>
Cc: kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, 
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	Brijesh Singh <brijesh.singh@amd.com>
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On Thu, Apr 18, 2024 at 9:51=E2=80=AFPM Michael Roth <michael.roth@amd.com>=
 wrote:
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 535018f152a3..d31404953bf1 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -4899,7 +4899,8 @@ static int svm_vm_init(struct kvm *kvm)
>
>         if (type !=3D KVM_X86_DEFAULT_VM &&
>             type !=3D KVM_X86_SW_PROTECTED_VM) {
> -               kvm->arch.has_protected_state =3D (type =3D=3D KVM_X86_SE=
V_ES_VM);
> +               kvm->arch.has_protected_state =3D
> +                       (type =3D=3D KVM_X86_SEV_ES_VM || type =3D=3D KVM=
_X86_SNP_VM);

I'd rather set has_private_mem here too, rather than in x86.c

Also this patch is the place to have

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d31404953bf1..6209f70ab11a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2056,6 +2056,9 @@ static int npf_interception(struct kvm_vcpu *vcpu)
     if (WARN_ON_ONCE(error_code & PFERR_SYNTHETIC_MASK))
         error_code &=3D ~PFERR_SYNTHETIC_MASK;

+    if (sev_snp_guest(vcpu) && (error_code & PFERR_GUEST_ENC_MASK))
+        error_code |=3D PFERR_PRIVATE_ACCESS;
+
     trace_kvm_page_fault(vcpu, fault_address, error_code);
     return kvm_mmu_page_fault(vcpu, fault_address, error_code,
             static_cpu_has(X86_FEATURE_DECODEASSISTS) ?


for the final shape of the MMU changes.

Paolo

> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 83b8260443a3..9923921904a2 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -12598,7 +12598,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned lo=
ng type)
>
>         kvm->arch.vm_type =3D type;
>         kvm->arch.has_private_mem =3D
> -               (type =3D=3D KVM_X86_SW_PROTECTED_VM);
> +               (type =3D=3D KVM_X86_SW_PROTECTED_VM || type =3D=3D KVM_X=
86_SNP_VM);
>
>         ret =3D kvm_page_track_init(kvm);
>         if (ret)
> --
> 2.25.1
>