Re: [PATCH v3 2/2] KVM: SEV: Restrict userspace return codes for KVM_HC_MAP_GPA_RANGE

[Michael Roth <michael.roth@amd.com>]

On Fri, Feb 06, 2026 at 10:28:29PM +0000, Sagi Shahar wrote:
> To align with the updated TDX api that allows userspace to request
> that guests retry MAP_GPA operations, make sure that userspace is only
> returning EINVAL or EAGAIN as possible error codes.
> 
> Signed-off-by: Sagi Shahar <sagis@google.com>

Reviewed-by: Michael Roth <michael.roth@amd.com>

> ---
>  arch/x86/kvm/svm/sev.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index f59c65abe3cf..5f78e4c3eb5d 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -3722,9 +3722,13 @@ static int snp_rmptable_psmash(kvm_pfn_t pfn)
>  
>  static int snp_complete_psc_msr(struct kvm_vcpu *vcpu)
>  {
> +	u64 hypercall_ret = READ_ONCE(vcpu->run->hypercall.ret);
>  	struct vcpu_svm *svm = to_svm(vcpu);
>  
> -	if (vcpu->run->hypercall.ret)
> +	if (!kvm_is_valid_map_gpa_range_ret(hypercall_ret))
> +		return -EINVAL;
> +
> +	if (hypercall_ret)
>  		set_ghcb_msr(svm, GHCB_MSR_PSC_RESP_ERROR);
>  	else
>  		set_ghcb_msr(svm, GHCB_MSR_PSC_RESP);
> @@ -3815,10 +3819,14 @@ static void __snp_complete_one_psc(struct vcpu_svm *svm)
>  
>  static int snp_complete_one_psc(struct kvm_vcpu *vcpu)
>  {
> +	u64 hypercall_ret = READ_ONCE(vcpu->run->hypercall.ret);
>  	struct vcpu_svm *svm = to_svm(vcpu);
>  	struct psc_buffer *psc = svm->sev_es.ghcb_sa;
>  
> -	if (vcpu->run->hypercall.ret) {
> +	if (!kvm_is_valid_map_gpa_range_ret(hypercall_ret))
> +		return -EINVAL;
> +
> +	if (hypercall_ret) {
>  		snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC);
>  		return 1; /* resume guest */
>  	}
> -- 
> 2.53.0.rc2.204.g2597b5adb4-goog
>