From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v3 3/3] KVM: s390: vsie: Make use of CRYCB FORMAT2 clear Date: Thu, 23 Aug 2018 13:40:34 +0200 Message-ID: <3d50d093-f92f-660e-cf7c-9b2cf0fddd83@linux.ibm.com> References: <1535019956-23539-1-git-send-email-pmorel@linux.ibm.com> <1535019956-23539-4-git-send-email-pmorel@linux.ibm.com> <912d013c-c925-fb3e-ed1d-2d778a60c189@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 , Janosch Frank Cc: linux-kernel@vger.kernel.org, cohuck@redhat.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, akrowiak@linux.ibm.com, borntraeger@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com List-ID: On 23/08/2018 13:21, David Hildenbrand wrote: > On 23.08.2018 13:05, Janosch Frank wrote: >> On 8/23/18 12:25 PM, Pierre Morel wrote: >>> The comment preceding the shadow_crycb function is >>> misleading, we effectively accept FORMAT2 CRYCB in the >>> guest. >> >> I beg to differ: >> >> if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1)) >> return 0; > > FORMAT2 includes bit FORMAT1 (backwards compatible) > >> >>> >>> When using FORMAT2 in the host we do not need to or with >>> FORMAT1. >>> >>> Signed-off-by: Pierre Morel >>> --- >>> arch/s390/kvm/vsie.c | 6 +++--- >>> 1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c >>> index 38ea5da..e0e6fbf 100644 >>> --- a/arch/s390/kvm/vsie.c >>> +++ b/arch/s390/kvm/vsie.c >>> @@ -140,7 +140,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>> * Create a shadow copy of the crycb block and setup key wrapping, if >>> * requested for guest 3 and enabled for guest 2. >>> * >>> - * We only accept format-1 (no AP in g2), but convert it into format-2 >>> + * We accept format-1 or format-2, but we treat it as a format-1 (no AP in g2), >>> + * and we convert it into format-2 in the shadow CRYCB. >>> * There is nothing to do for format-0. >>> * >>> * Returns: - 0 if shadowed or nothing to do >>> @@ -179,8 +180,7 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) >>> return set_validity_icpt(scb_s, 0x0035U); >>> >>> scb_s->ecb3 |= ecb3_flags; >>> - scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 | >>> - CRYCB_FORMAT2; >>> + scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; >> >> That's purely cosmetic but valid. >> >>> >>> /* xor both blocks in one run */ >>> b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; > > Reviewed-by: David Hildenbrand > Thanks, regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany