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

Tony Krowiak
2018-08-14T12:46:40Z

On 08/14/2018 04:50 AM, Cornelia Huck wrote:
> 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.

Will do.

>