[PATCH 5.11 093/601] KVM: s390: VSIE: fix MVPG handling for prefixing and MSO

Greg Kroah-Hartman
2021-05-12T17:02:12Z

From: Claudio Imbrenda <imbrenda@linux.ibm.com>

commit c3171e94cc1cdcc3229565244112e869f052b8d9 upstream.

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: bdf7509bbefa ("s390/kvm: VSIE: correctly handle MVPG when in VSIE")
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210322140559.500716-3-imbrenda@linux.ibm.com
[borntraeger@de.ibm.com simplify mso]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/s390/kvm/vsie.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -1001,7 +1001,7 @@ static u64 vsie_get_register(struct kvm_
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, src, dest, mask, prefix;
u64 *pei_block = &vsie_page->scb_o->mcic;
int edat, rc_dest, rc_src;
union ctlreg0 cr0;
@@ -1009,9 +1009,12 @@ static int vsie_handle_mvpg(struct kvm_v
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);
+ prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;

dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
+ dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso;
src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
+ src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso;

rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest);
rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src);