Messages in this thread | | | Subject | Re: [PATCH v2 5/5] KVM: s390: vsie: Do the CRYCB validation first | From | Pierre Morel <> | Date | Thu, 23 Aug 2018 09:17:38 +0200 |
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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 <pmorel@linux.ibm.com> >> --- >> 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
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