Re: [PATCH v2 2/5] KVM: s390: vsie: Only accept FORMAT1 CRYCB for guest2

[Pierre Morel]

On 22/08/2018 18:55, David Hildenbrand wrote:
> On 22.08.2018 18:51, Pierre Morel wrote:
> > As the comment above the function suggested the shadowing
> > of the guest2 CRYCB can only accept a format 1 since
> > AP instructions are not supported in the guest.
> >
> > Let's modify the check which allowed to accept a format 2 too.
>
> As the bit is ignored without AP/APXA, it is perfectly valid to accept a
> format 2, we just have to interpret it as format 1 (which is what we do)
>
> What am I missing?

Nothing.
I was still having AP interpretation in mind.


> > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
> > ---
> >   arch/s390/kvm/vsie.c | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
> > index 12b9707..56a9d47 100644
> > --- a/arch/s390/kvm/vsie.c
> > +++ b/arch/s390/kvm/vsie.c
> > @@ -156,7 +156,9 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
> >   	u8 ecb3_flags;
> >   
> >   	scb_s->crycbd = 0;
> > -	if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
> > +	if (!(crycbd_o == CRYCB_FORMAT1))
> > +		return 0;
>
> huh, this looks very broken. The address is still in there.
completely broken you are right

anyway this broken useless patch disappear.

Thanks,

regards,
Pierre


--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany