Re: [PATCH v7 03/18] KVM: SVM: Add KVM_SEV_SEND_FINISH command

[Venu Busireddy <venu.busireddy@oracle.com>]

On 2020-04-30 08:41:08 +0000, Ashish Kalra 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
> Reviewed-by: Steve Rutherford <srutherford@google.com>
> 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 f46817ef7019..a45dcb5f8687 100644
> --- a/Documentation/virt/kvm/amd-memory-encryption.rst
> +++ b/Documentation/virt/kvm/amd-memory-encryption.rst
> @@ -314,6 +314,14 @@ Returns: 0 on success, -negative on error

As I commented in the v6 patches
(see https://lore.kernel.org/kvm/20200402181710.GA655710@vbusired-dt/),
there are multiple occurrences of the word "-negative" in
amd-memory-encryption.rst. Can these be changed to either "negative" or
"less than 0"?


>                  __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 0c92c16505ab..81d661706d31 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -1153,6 +1153,26 @@ 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;
> @@ -1203,6 +1223,9 @@ 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
>