Commit 0e9ff65f authored Oct 19, 2021 by Halil Pasic Committed by Christian Borntraeger Oct 20, 2021

KVM: s390: preserve deliverable_mask in __airqs_kick_single_vcpu



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: 9f30f621 ("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>

parent 9b57e9d5

arch/s390/kvm/interrupt.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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;