From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v2 5/5] KVM: s390: vsie: Do the CRYCB validation first Date: Thu, 23 Aug 2018 09:17:38 +0200 Message-ID: <01047750-cdc6-b462-1e4f-c79c1036ab94@linux.ibm.com> References: <1534956717-14087-1-git-send-email-pmorel@linux.ibm.com> <1534956717-14087-6-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 19:15, David Hildenbrand wrote: > 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? > The use of functions PCKMO-Encrypt-DEA/AES induce a specification error. However other MSA3 function will continue to be usable. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany