github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 10:09:10 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

KVM: s390: Fix S390_USER_OPEREXEC enablement without STFLE 74

Browse Source 
The KVM_CAP_S390_USER_OPEREXEC capability allows operation exceptions
to be forwarded to userspace. But the actual enablement at the hardware
level occurs in kvm_arch_vcpu_postcreate(), and only if STFLE.74 or
user_instr0 are enabled. The latter is associated with a separate
capability (KVM_CAP_S390_USER_INSTR0), so the only way this happens
for the USER_OPEREXEC capability is if STFLE.74 is enabled. KVM
unconditionally enables this bit in kvm_arch_init_vm(), but the guest
could disable it from the CPU model and thus ignore this capability.

Add USER_OPEREXEC to the check in kvm_arch_vcpu_postcreate(), such that
either capability would enable this type of exception.

Fixes: 8e8678e740 ("KVM: s390: Add capability that forwards operation exceptions")
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
[Fixed patch title, as recommended by frankja@linux.ibm.com]
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260507200836.3500368-2-farman@linux.ibm.com>
This commit is contained in:
Eric Farman 2026-05-07 22:08:34 +02:00 committed by Claudio Imbrenda
parent 8cd9520d35
commit 02d61d3370
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/s390/kvm/kvm-s390.c
View File

@ -3542,7 +3542,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
vcpu->arch.gmap = vcpu->kvm->arch.gmap;
sca_add_vcpu(vcpu);
}
if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0)
if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0 ||
vcpu->kvm->arch.user_operexec)
vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
}