Re: [PATCH v9 05/22] KVM: s390: vsie: simulate VCPU SIE entry/exit

Cornelia Huck
2018-08-14T08:50:03Z

On Mon, 13 Aug 2018 17:48:02 -0400
Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:

> From: David Hildenbrand <david@redhat.com>
>
> VCPU requests and VCPU blocking right now don't take care of the vSIE
> (as it was not necessary until now). But we want to have VCPU requests
> that will also be handled before running the vSIE again.
>
> So let's simulate a SIE entry when entering the vSIE loop and check
> for PROG_ flags. The existing infrastructure (e.g. exit_sie()) will then
> detect that the SIE (in form of the vSIE execution loop) is running and
> properly kick the vSIE CPU, resulting in it leaving the vSIE loop and
> therefore the vSIE interception handler, allowing it to handle VCPU
> requests.
>
> E.g. if we want to modify the crycb of the VCPU and make sure that any
> masks also get applied to the VSIE crycb shadow (which uses masks from the
> VCPU crycb), we will need a way to hinder the vSIE from running and make
> sure to process the updated crycb before reentering the vSIE again.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> arch/s390/kvm/kvm-s390.c | 9 ++++++++-
> arch/s390/kvm/kvm-s390.h | 1 +
> arch/s390/kvm/vsie.c | 20 ++++++++++++++++++--
> 3 files changed, 27 insertions(+), 3 deletions(-)

I think that is the RFC version of David's patch, not the v1? Again,
not really relevant for reviewing, but I hope that you test the final
version.