From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v2 2/5] KVM: s390: vsie: Only accept FORMAT1 CRYCB for guest2 Date: Thu, 23 Aug 2018 09:42:19 +0200 Message-ID: References: <1534956717-14087-1-git-send-email-pmorel@linux.ibm.com> <1534956717-14087-3-git-send-email-pmorel@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, borntraeger@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com List-ID: On 22/08/2018 18:55, David Hildenbrand wrote: > On 22.08.2018 18:51, Pierre Morel wrote: >> As the comment above the function suggested the shadowing >> of the guest2 CRYCB can only accept a format 1 since >> AP instructions are not supported in the guest. >> >> Let's modify the check which allowed to accept a format 2 too. > > As the bit is ignored without AP/APXA, it is perfectly valid to accept a > format 2, we just have to interpret it as format 1 (which is what we do) > > What am I missing? > Nothing. I was still having AP interpretation in mind. >> >> Signed-off-by: Pierre Morel >> --- >> arch/s390/kvm/vsie.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >> index 12b9707..56a9d47 100644 >> --- a/arch/s390/kvm/vsie.c >> +++ b/arch/s390/kvm/vsie.c >> @@ -156,7 +156,9 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >> u8 ecb3_flags; >> >> scb_s->crycbd = 0; >> - if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1)) >> + if (!(crycbd_o == CRYCB_FORMAT1)) >> + return 0; > > huh, this looks very broken. The address is still in there. completely broken you are right anyway this broken useless patch disappear. Thanks, regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany