Commit 0624fca9 authored Oct 01, 2018 by Paolo Bonzini

kvm/x86: return meaningful value from KVM_SIGNAL_MSI



If kvm_apic_map_get_dest_lapic() finds a disabled LAPIC,
it will return with bitmap==0 and (*r == -1) will be returned to
userspace.

QEMU may then record "KVM: injection failed, MSI lost
(Operation not permitted)" in its log, which is quite puzzling.

Reported-by: Peng Hao <penghao122@sina.com.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 4fef0f49

arch/x86/kvm/lapic.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -960,14 +960,14 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm kvm, struct kvm_lapic src,
		map = rcu_dereference(kvm->arch.apic_map);

		ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dst, &bitmap);
		if (ret)
		if (ret) {
		*r = 0;
		for_each_set_bit(i, &bitmap, 16) {
		if (!dst[i])
		continue;
		if (*r < 0)
		*r = 0;
		*r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);
		}
		}

		rcu_read_unlock();
		return ret;