diff options
| author | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2026-08-03 14:40:39 +0200 |
|---|---|---|
| committer | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2026-08-03 16:51:34 +0200 |
| commit | 9187a9186d0ac7b260b07917aabc672a80d37c3c (patch) | |
| tree | f28ea6d65db454f2244e3faa7f97f0b54d556a24 | |
| parent | 216c5289dd66d9cde6b42cbe68ee8dec5669678a (diff) | |
KVM: s390: Fix ordering when adding to SCA
When adding a new vCPU to the SCA area, the validity bit in the MCN was
set before the pointer to the state description, potentially allowing
for a race.
Fix by setting the pointer before setting the bit.
Fixes: 14542a0a54c5 ("KVM: S390: Remove sca_lock")
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260803124040.126471-13-imbrenda@linux.ibm.com>
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 9b8a35e7dc82..518a69c55e85 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3485,8 +3485,8 @@ static void sca_add_vcpu(struct kvm_vcpu *vcpu) if (!kvm_s390_use_sca_entries()) return; + WRITE_ONCE(sca->cpu[vcpu->vcpu_id].sda, virt_to_phys(vcpu->arch.sie_block)); set_bit_inv(vcpu->vcpu_id, (unsigned long *)sca->mcn); - sca->cpu[vcpu->vcpu_id].sda = virt_to_phys(vcpu->arch.sie_block); } static int sca_can_add_vcpu(struct kvm *kvm, unsigned int id) |