Re: [PATCH v12 03/13] KVM: SVM: Add KVM_SEV_SEND_FINISH command

[Steve Rutherford <srutherford@google.com>]

On Mon, Apr 12, 2021 at 12:44 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote:
>
> From: Brijesh Singh <brijesh.singh@amd.com>
>
> The command is used to finailize the encryption context created with
> KVM_SEV_SEND_START command.
>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: x86@kernel.org
> Cc: kvm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> ---
>  .../virt/kvm/amd-memory-encryption.rst        |  8 +++++++
>  arch/x86/kvm/svm/sev.c                        | 23 +++++++++++++++++++
>  2 files changed, 31 insertions(+)
>
> diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst
> index 3c5456e0268a..26c4e6c83f62 100644
> --- a/Documentation/virt/kvm/amd-memory-encryption.rst
> +++ b/Documentation/virt/kvm/amd-memory-encryption.rst
> @@ -335,6 +335,14 @@ Returns: 0 on success, -negative on error
>                  __u32 trans_len;
>          };
>
> +12. KVM_SEV_SEND_FINISH
> +------------------------
> +
> +After completion of the migration flow, the KVM_SEV_SEND_FINISH command can be
> +issued by the hypervisor to delete the encryption context.
> +
> +Returns: 0 on success, -negative on error
> +
>  References
>  ==========
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 30527285a39a..92325d9527ce 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -1350,6 +1350,26 @@ static int sev_send_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
>         return ret;
>  }
>
> +static int sev_send_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
> +{
> +       struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> +       struct sev_data_send_finish *data;
> +       int ret;
> +
> +       if (!sev_guest(kvm))
> +               return -ENOTTY;
> +
> +       data = kzalloc(sizeof(*data), GFP_KERNEL);
> +       if (!data)
> +               return -ENOMEM;
> +
> +       data->handle = sev->handle;
> +       ret = sev_issue_cmd(kvm, SEV_CMD_SEND_FINISH, data, &argp->error);
> +
> +       kfree(data);
> +       return ret;
> +}
> +
>  int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
>  {
>         struct kvm_sev_cmd sev_cmd;
> @@ -1409,6 +1429,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
>         case KVM_SEV_SEND_UPDATE_DATA:
>                 r = sev_send_update_data(kvm, &sev_cmd);
>                 break;
> +       case KVM_SEV_SEND_FINISH:
> +               r = sev_send_finish(kvm, &sev_cmd);
> +               break;
>         default:
>                 r = -EINVAL;
>                 goto out;
> --
> 2.17.1
>
Reviewed-by: Steve Rutherford <srutherford@google.com>