Re: [PATCH Part2 RFC v4 23/40] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_START command
From: Peter Gonda
Date: Mon Jul 12 2021 - 14:46:15 EST
>
> +static int snp_decommission_context(struct kvm *kvm)
> +{
> + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> + struct sev_data_snp_decommission data = {};
> + int ret;
> +
> + /* If context is not created then do nothing */
> + if (!sev->snp_context)
> + return 0;
> +
> + data.gctx_paddr = __sme_pa(sev->snp_context);
> + ret = snp_guest_decommission(&data, NULL);
> + if (ret)
> + return ret;
Should we WARN or pr_err here? I see in the case of
snp_launch_start's e_free_context we do not warn the user they have
leaked a firmware page.
>
> +
> + /* free the context page now */
> + snp_free_firmware_page(sev->snp_context);
> + sev->snp_context = NULL;
> +
> + return 0;
> +}
> +
> void sev_vm_destroy(struct kvm *kvm)
> {
> struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> @@ -1847,7 +1969,15 @@ void sev_vm_destroy(struct kvm *kvm)
>
> mutex_unlock(&kvm->lock);
>
> - sev_unbind_asid(kvm, sev->handle);
> + if (sev_snp_guest(kvm)) {
> + if (snp_decommission_context(kvm)) {
> + pr_err("Failed to free SNP guest context, leaking asid!\n");
Should these errors be a WARN since we are leaking some state?
> + return;
> + }
> + } else {
> + sev_unbind_asid(kvm, sev->handle);
> + }
> +
> sev_asid_free(sev);
> }
>