From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH v2 5/5] KVM: s390: vsie: Do the CRYCB validation first Date: Wed, 22 Aug 2018 19:15:49 +0200 Message-ID: References: <1534956717-14087-1-git-send-email-pmorel@linux.ibm.com> <1534956717-14087-6-git-send-email-pmorel@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1534956717-14087-6-git-send-email-pmorel@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Pierre Morel 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 18:51, Pierre Morel wrote: > When entering the SIE the CRYCB validation better > be done independently of the instruction's > availability. > > Signed-off-by: Pierre Morel > --- > arch/s390/kvm/vsie.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c > index 7ee4329..fca25aa 100644 > --- a/arch/s390/kvm/vsie.c > +++ b/arch/s390/kvm/vsie.c > @@ -164,17 +164,18 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) > /* format-1 is supported with message-security-assist extension 3 */ > if (!test_kvm_facility(vcpu->kvm, 76)) > return 0; > - /* we may only allow it if enabled for guest 2 */ > - ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & > - (ECB3_AES | ECB3_DEA); > - if (!ecb3_flags) > - return 0; > > if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK)) > return set_validity_icpt(scb_s, 0x003CU); > if (!crycb_addr) > return set_validity_icpt(scb_s, 0x0039U); > > + /* we may only allow it if enabled for guest 2 */ > + ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & > + (ECB3_AES | ECB3_DEA); > + if (!ecb3_flags) > + return 0; > + > /* copy only the wrapping keys */ > if (read_guest_real(vcpu, crycb_addr + 72, > vsie_page->crycb.dea_wrapping_key_mask, 56)) > That makes sense, especially if ECB3_AES is used but effectively turned off by us. What is the expected behavior if ECB3_AES | ECB3_DEA are not set by g2 for g3? -- Thanks, David / dhildenb