From: Halil Pasic pasic@linux.ibm.com
[ Upstream commit 0e9ff65f455dfd0a8aea5e7843678ab6fe097e21 ]
Changing the deliverable mask in __airqs_kick_single_vcpu() is a bug. If one idle vcpu can't take the interrupts we want to deliver, we should look for another vcpu that can, instead of saying that we don't want to deliver these interrupts by clearing the bits from the deliverable_mask.
Fixes: 9f30f6216378 ("KVM: s390: add gib_alert_irq_handler()") Signed-off-by: Halil Pasic pasic@linux.ibm.com Reviewed-by: Christian Borntraeger borntraeger@de.ibm.com Reviewed-by: Michael Mueller mimu@linux.ibm.com Reviewed-by: Claudio Imbrenda imbrenda@linux.ibm.com Link: https://lore.kernel.org/r/20211019175401.3757927-3-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/kvm/interrupt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 16256e17a544..ee9d052476b5 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -3053,13 +3053,14 @@ static void __airqs_kick_single_vcpu(struct kvm *kvm, u8 deliverable_mask) int vcpu_idx, online_vcpus = atomic_read(&kvm->online_vcpus); struct kvm_s390_gisa_interrupt *gi = &kvm->arch.gisa_int; struct kvm_vcpu *vcpu; + u8 vcpu_isc_mask;
for_each_set_bit(vcpu_idx, kvm->arch.idle_mask, online_vcpus) { vcpu = kvm_get_vcpu(kvm, vcpu_idx); if (psw_ioint_disabled(vcpu)) continue; - deliverable_mask &= (u8)(vcpu->arch.sie_block->gcr[6] >> 24); - if (deliverable_mask) { + vcpu_isc_mask = (u8)(vcpu->arch.sie_block->gcr[6] >> 24); + if (deliverable_mask & vcpu_isc_mask) { /* lately kicked but not yet running */ if (test_and_set_bit(vcpu_idx, gi->kicked_mask)) return;