[PATCH 4.14 027/183] KVM: s390: use created_vcpus in more places

From: Greg Kroah-Hartman
Date: Wed Apr 25 2018 - 06:38:37 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Christian Borntraeger <borntraeger@xxxxxxxxxx>


[ Upstream commit 241e3ec0faf5ab1a0d9b1f6c43eefa919fb9c112 ]

commit a03825bbd0c3 ("KVM: s390: use kvm->created_vcpus") introduced
kvm->created_vcpus to avoid races with the existing kvm->online_vcpus
scheme. One place was "forgotten" and one new place was "added".
Let's fix those.

Reported-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Fixes: 4e0b1ab72b8a ("KVM: s390: gs support for kvm guests")
Fixes: a03825bbd0c3 ("KVM: s390: use kvm->created_vcpus")
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -601,7 +601,7 @@ static int kvm_vm_ioctl_enable_cap(struc
case KVM_CAP_S390_GS:
r = -EINVAL;
mutex_lock(&kvm->lock);
- if (atomic_read(&kvm->online_vcpus)) {
+ if (kvm->created_vcpus) {
r = -EBUSY;
} else if (test_facility(133)) {
set_kvm_facility(kvm->arch.model.fac_mask, 133);
@@ -1121,7 +1121,7 @@ static int kvm_s390_set_processor_feat(s
return -EINVAL;

mutex_lock(&kvm->lock);
- if (!atomic_read(&kvm->online_vcpus)) {
+ if (!kvm->created_vcpus) {
bitmap_copy(kvm->arch.cpu_feat, (unsigned long *) data.feat,
KVM_S390_VM_CPU_FEAT_NR_BITS);
ret = 0;