Re: [PATCH 2/3 V2] KVM, SEV: Add support for SEV intra host migration

[Brijesh Singh]

On 7/14/21 11:01 AM, Peter Gonda wrote:
> For SEV to work with intra host migration, contents of the SEV info struct
> such as the ASID (used to index the encryption key in the AMD SP) and
> the list of memory regions need to be transferred to the target VM.
> This change adds commands for sending and receiving the sev info.
>
> To avoid exposing this internal state to userspace and prevent other
> processes from importing state they shouldn't have access to, the send
> returns a token to userspace that is handed off to the target VM. The
> target passes in this token to receive the sent state. The token is only
> valid for one-time use. Functionality on the source becomes limited
> after send has been performed. If the source is destroyed before the
> target has received, the token becomes invalid.
>
> The target is expected to be initialized (sev_guest_init), but not
> launched state (sev_launch_start) when performing receive. Once the
> target has received, it will be in a launched state and will not
> need to perform the typical SEV launch commands.
>
> Co-developed-by: Lars Bull <larsbull@xxxxxxxxxx>
> Signed-off-by: Lars Bull <larsbull@xxxxxxxxxx>
> Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: Dr. David Alan Gilbert <dgilbert@xxxxxxxxxx>
> Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> Cc: Jim Mattson <jmattson@xxxxxxxxxx>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: kvm@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx

Reviewed-by: Brijesh Singh <brijesh.singh@xxxxxxx>

thanks