Re: [PATCH v6 06/14] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command

[Steve Rutherford]

On Thu, Apr 2, 2020 at 3:27 PM Krish Sadhukhan
<krish.sadhukhan@xxxxxxxxxx> wrote:
>
>
> On 3/29/20 11:21 PM, Ashish Kalra wrote:
> > From: Brijesh Singh <Brijesh.Singh@xxxxxxx>
> >
> > The command finalize the guest receiving process and make the SEV guest
> > ready for the execution.
> >
> > 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
> > 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 554aa33a99cc..93cd95d9a6c0 100644
> > --- a/Documentation/virt/kvm/amd-memory-encryption.rst
> > +++ b/Documentation/virt/kvm/amd-memory-encryption.rst
> > @@ -375,6 +375,14 @@ Returns: 0 on success, -negative on error
> >                   __u32 trans_len;
> >           };
> >
> > +15. KVM_SEV_RECEIVE_FINISH
> > +------------------------
> > +
> > +After completion of the migration flow, the KVM_SEV_RECEIVE_FINISH command can be
> > +issued by the hypervisor to make the guest ready for execution.
> > +
> > +Returns: 0 on success, -negative on error
> > +
> >   References
> >   ==========
> >
> > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> > index 5fc5355536d7..7c2721e18b06 100644
> > --- a/arch/x86/kvm/svm.c
> > +++ b/arch/x86/kvm/svm.c
> > @@ -7573,6 +7573,26 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
> >       return ret;
> >   }
> >
> > +static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
> > +{
> > +     struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
> > +     struct sev_data_receive_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_RECEIVE_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;
> > @@ -7632,6 +7652,9 @@ static int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
> >       case KVM_SEV_RECEIVE_UPDATE_DATA:
> >               r = sev_receive_update_data(kvm, &sev_cmd);
> >               break;
> > +     case KVM_SEV_RECEIVE_FINISH:
> > +             r = sev_receive_finish(kvm, &sev_cmd);
> > +             break;
> >       default:
> >               r = -EINVAL;
> >               goto out;
> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>

As to ENOTTY, man page for ioctl translates it as "The specified
request does not apply to the kind of object that the file descriptor
fd references", which seems appropriate here.
Reviewed-by: Steve Rutherford <srutherford@xxxxxxxxxx>