From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH RFC 0/2] KVM: s390: vsie: support VCPU requests References: <20180807125131.3606-1-david@redhat.com> From: Pierre Morel Date: Tue, 7 Aug 2018 19:15:02 +0200 MIME-Version: 1.0 In-Reply-To: <20180807125131.3606-1-david@redhat.com> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Content-Language: en-US Message-Id: <65aefa0e-275f-1a30-2237-904aa4c6d63b@linux.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: David Hildenbrand , linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Cornelia Huck , Janosch Frank , Christian Borntraeger List-ID: On 07/08/2018 14:51, David Hildenbrand wrote: > While discussing AP changes, we discovered that we will have to force > a CPU using the vSIE to regenerate/reload shadow data structures. For now, > we have no mechanism for that. > > E.g. when clearing AP masks later, we could still have a vSIE CPU making > use of AP adapters as the masks might not be considered yet in the vSIE > data structures. We need a way to block entering the vSIE and regenerate > all shadow data structures once done. > > Looks like we can achieve that by simply simulating an ordinary SIE > entry/exit in the VCPU sie control block (while entering the vSIE loop). > > This way, we can support blocking and also synchronous CPU requests. > > Only compile tested. > > David Hildenbrand (2): > KVM: s390: vsie: simulate VCPU SIE entry/exit > KVM: s390: introduce and use KVM_REQ_VSIE_RESTART > > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/kvm-s390.c | 16 ++++++++++++++-- > arch/s390/kvm/kvm-s390.h | 1 + > arch/s390/kvm/vsie.c | 20 ++++++++++++++++++-- > 4 files changed, 34 insertions(+), 4 deletions(-) > Thanks David for your patches. Following my tests, they work fine for our AP use case. Best regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany