Re: [PATCH v6 03/14] KVM: SVM: Add KVM_SEV_SEND_FINISH command

[Venu Busireddy]

On 2020-03-30 06:20:49 +0000, Ashish Kalra wrote:
> From: Brijesh Singh <Brijesh.Singh@xxxxxxx>
> 
> The command is used to finailize the encryption context created with
> KVM_SEV_SEND_START command.
> 
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: "Radim KrÄmÃÅ" <rkrcmar@xxxxxxxxxx>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: kvm@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Reviewed-by: Steve Rutherford <srutherford@xxxxxxxxxx>
> Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> ---
>  .../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 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
>                  __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

Didn't notice this earlier. I would suggest changing all occurrences of
"-negative" to either "negative" or "less than 0" in this file.

> +
>  References
>  ==========
>  
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 8561c47cc4f9..71a4cb3b817d 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -7399,6 +7399,26 @@ 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;
> @@ -7449,6 +7469,9 @@ 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
>