Re: [PATCH v2 2/2] s390/kvm: VSIE: fix MVPG handling for prefixing and MSO

[Christian Borntraeger]

On 23.03.21 16:21, Claudio Imbrenda wrote:
> On Tue, 23 Mar 2021 16:16:18 +0100
> Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
>
> > On 23.03.21 16:11, David Hildenbrand wrote:
> > > On 23.03.21 16:07, Christian Borntraeger wrote:
> > > > On 22.03.21 15:05, Claudio Imbrenda wrote:
> > > > > Prefixing needs to be applied to the guest real address to
> > > > > translate it into a guest absolute address.
> > > > >
> > > > > The value of MSO needs to be added to a guest-absolute address in
> > > > > order to obtain the host-virtual.
> > > > >
> > > > > Fixes: 223ea46de9e79 ("s390/kvm: VSIE: correctly handle MVPG when
> > > > > in VSIE") Cc: stable@xxxxxxxxxxxxxxx
> > > > > Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> > > > > Reported-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> > > > > ---
> > > > >     arch/s390/kvm/vsie.c | 6 +++++-
> > > > >     1 file changed, 5 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
> > > > > index 48aab6290a77..ac86f11e46dc 100644
> > > > > --- a/arch/s390/kvm/vsie.c
> > > > > +++ b/arch/s390/kvm/vsie.c
> > > > > @@ -1002,7 +1002,7 @@ static u64 vsie_get_register(struct
> > > > > kvm_vcpu *vcpu, struct vsie_page *vsie_page, static int
> > > > > vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page
> > > > > *vsie_page) { struct kvm_s390_sie_block *scb_s =
> > > > > &vsie_page->scb_s;
> > > > > -    unsigned long pei_dest, pei_src, src, dest, mask;
> > > > > +    unsigned long pei_dest, pei_src, dest, src, mask, mso,
> > > > > prefix; u64 *pei_block = &vsie_page->scb_o->mcic;
> > > > >         int edat, rc_dest, rc_src;
> > > > >         union ctlreg0 cr0;
> > > > > @@ -1010,9 +1010,13 @@ static int vsie_handle_mvpg(struct
> > > > > kvm_vcpu *vcpu, struct vsie_page *vsie_page) cr0.val =
> > > > > vcpu->arch.sie_block->gcr[0]; edat = cr0.edat &&
> > > > > test_kvm_facility(vcpu->kvm, 8); mask =
> > > > > _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK);
> > > > > +    mso = scb_s->mso & ~(1UL << 20);
> > > >              shouldnt that be ~((1UL << 20 ) -1)
>
> oops
>
> > > Looking at shadow_scb(), we can simply take scb_s->mso unmodified.
> >
> > Right, I think I can fix this up (and get rid of the local mso
>
> I think that's easier/simpler
>
> > variable) when queueing. Or shall Claudio send a new version of the
> > patch?

queued (with fixup). Please note: can you use "KVM: s390:" instead of "s390/kvm" for the future patches.