[PATCH 5.10 2/3] KVM: s390: Return error on SIDA memop on normal guest

From: Greg Kroah-Hartman
Date: Wed Feb 09 2022 - 14:18:03 EST


From: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx>

commit 2c212e1baedcd782b2535a3f86bc491977677c0e upstream.

Refuse SIDA memops on guests which are not protected.
For normal guests, the secure instruction data address designation,
which determines the location we access, is not under control of KVM.

Fixes: 19e122776886 (KVM: S390: protvirt: Introduce instruction data area bounce buffer)
Signed-off-by: Janis Schoetterl-Glausch <scgl@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4654,6 +4654,8 @@ static long kvm_s390_guest_sida_op(struc
return -EINVAL;
if (mop->size + mop->sida_offset > sida_size(vcpu->arch.sie_block))
return -E2BIG;
+ if (!kvm_s390_pv_cpu_is_protected(vcpu))
+ return -EINVAL;

switch (mop->op) {
case KVM_S390_MEMOP_SIDA_READ: