From 0624fca9512d08cbd9b5d098d904c840d3432404 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 1 Oct 2018 16:07:18 +0200 Subject: [PATCH] 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 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 91ffb63397f5..452eed992aea 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -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; -- 2.30.2