From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 8 Aug 2018 14:44:14 +0200 From: Cornelia Huck Subject: Re: [PATCH RFC 1/2] KVM: s390: vsie: simulate VCPU SIE entry/exit Message-ID: <20180808144414.75369a40.cohuck@redhat.com> In-Reply-To: <20180807125131.3606-2-david@redhat.com> References: <20180807125131.3606-1-david@redhat.com> <20180807125131.3606-2-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Janosch Frank , Christian Borntraeger , Pierre Morel List-ID: On Tue, 7 Aug 2018 14:51:30 +0200 David Hildenbrand wrote: > 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 > --- > 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(-) Reviewed-by: Cornelia Huck