Re: [PATCH 03/12] KVM: SVM: Add KVM_SEV_SEND_FINISH command

From: Steve Rutherford <srutherford@google.com>
To: Ashish Kalra <Ashish.Kalra@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@suse.de>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	David Rientjes <rientjes@google.com>, X86 ML <x86@kernel.org>,
	KVM list <kvm@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 03/12] KVM: SVM: Add KVM_SEV_SEND_FINISH command
Date: Mon, 9 Mar 2020 18:09:06 -0700	[thread overview]
Message-ID: <CABayD+dB-CQ7HwhDvkgxXne9fhy6Wbh8iQLVhEkegWhYMoLGGw@mail.gmail.com> (raw)
In-Reply-To: <d6f21be0c775fd51a63565c8944b03b3bf099e0f.1581555616.git.ashish.kalra@amd.com>

On Wed, Feb 12, 2020 at 5:16 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: "Radim Krčmář" <rkrcmar@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.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 0f1c3860360f..f22f09ad72bd 100644
> --- a/Documentation/virt/kvm/amd-memory-encryption.rst
> +++ b/Documentation/virt/kvm/amd-memory-encryption.rst
> @@ -289,6 +289,14 @@ 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.c b/arch/x86/kvm/svm.c
> index ae97f774e979..c55c1865f9e0 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -7387,6 +7387,26 @@ 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;
> +}
> +
>  static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
>  {
>         struct kvm_sev_cmd sev_cmd;
> @@ -7434,6 +7454,9 @@ static 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>