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 <pmorel@xxxxxxxxxxxxx> >> --- >> 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 <david@xxxxxxxxxx> -- Thanks, David / dhildenb
