Re: [PATCH 02/12] KVM: SVM: Add KVM_SEND_UPDATE_DATA command

[Ashish Kalra]

On Mon, Mar 09, 2020 at 06:04:56PM -0700, Steve Rutherford wrote:
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index 17bef4c245e1..d9dc81bb9c55 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -1570,6 +1570,15 @@ struct kvm_sev_send_start {
> >         __u32 session_len;
> >  };
> >
> > +struct kvm_sev_send_update_data {
> > +       __u64 hdr_uaddr;
> > +       __u32 hdr_len;
> > +       __u64 guest_uaddr;
> > +       __u32 guest_len;
> > +       __u64 trans_uaddr;
> > +       __u32 trans_len;
> > +};
> Input from others is welcome here, but I'd put the padding in
> intentionally (explicitly fill in the reserved u8s between *_len and
> *_uaddr). I had to double check that this pattern was intentional and
> matched the SEV spec.

struct kvm_sev_send_update_data{} is used to get/send the information 
from/to userspace, while struct sev_data_send_update_data{} has the
paddings and is packed as required by the SEV spec.

Thanks,
Ashish