On 8/20/2025 5:18 AM, Sean Christopherson wrote:
> Set the RESET value for the GHCB "MSR" during sev_es_init_vmcb() instead
> of sev_es_vcpu_reset() to allow for dropping sev_es_vcpu_reset() entirely.
>
> Note, the call to sev_init_vmcb() from sev_migrate_from() also kinda sorta
> emulates a RESET, but sev_migrate_from() immediate overwrites ghcb_gpa
s/immediate/immediately/
> with the source's current value, so whether or not stuffing the GHCB
> version is correct/desirable is moot.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Nikunj A Dadhania <nikunj@xxxxxxx>
> ---
> arch/x86/kvm/svm/sev.c | 24 +++++++++++-------------
> 1 file changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index c5726b091680..ee7a05843548 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -4480,7 +4480,7 @@ void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm)
> vcpu->arch.reserved_gpa_bits &= ~(1UL << (best->ebx & 0x3f));
> }
>
> -static void sev_es_init_vmcb(struct vcpu_svm *svm)
> +static void sev_es_init_vmcb(struct vcpu_svm *svm, bool init_event)
> {
> struct kvm_sev_info *sev = to_kvm_sev_info(svm->vcpu.kvm);
> struct vmcb *vmcb = svm->vmcb01.ptr;
> @@ -4541,6 +4541,15 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm)
>
> /* Can't intercept XSETBV, HV can't modify XCR0 directly */
> svm_clr_intercept(svm, INTERCEPT_XSETBV);
> +
> + /*
> + * Set the GHCB MSR value as per the GHCB specification when emulating
> + * vCPU RESET for an SEV-ES guest.
> + */
> + if (!init_event)
> + set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
> + GHCB_VERSION_MIN,
> + sev_enc_bit));
> }
>
> void sev_init_vmcb(struct vcpu_svm *svm, bool init_event)
> @@ -4560,7 +4569,7 @@ void sev_init_vmcb(struct vcpu_svm *svm, bool init_event)
> sev_snp_init_protected_guest_state(vcpu);
>
> if (sev_es_guest(vcpu->kvm))
> - sev_es_init_vmcb(svm);
> + sev_es_init_vmcb(svm, init_event);
> }
>
> int sev_vcpu_create(struct kvm_vcpu *vcpu)
> @@ -4585,17 +4594,6 @@ int sev_vcpu_create(struct kvm_vcpu *vcpu)
>
> void sev_es_vcpu_reset(struct vcpu_svm *svm)
> {
> - struct kvm_vcpu *vcpu = &svm->vcpu;
> - struct kvm_sev_info *sev = to_kvm_sev_info(vcpu->kvm);
> -
> - /*
> - * Set the GHCB MSR value as per the GHCB specification when emulating
> - * vCPU RESET for an SEV-ES guest.
> - */
> - set_ghcb_msr(svm, GHCB_MSR_SEV_INFO((__u64)sev->ghcb_version,
> - GHCB_VERSION_MIN,
> - sev_enc_bit));
> -
> mutex_init(&svm->sev_es.snp_vmsa_mutex);
> }
>
