KVM: i8259: initialize isr_ack

isr_ack is never initialized.  So, until the first PIC reset, interrupts
may fail to be injected.  This can cause Windows XP to fail to boot, as
reported in the fallout from the fix to
https://bugzilla.kernel.org/show_bug.cgi?id=21962.

Reported-and-tested-by: Nicolas Prochazka <prochazka.nicolas@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index f628234fbeca06683876543f07476f10111812b7..3cece05e4ac4622853c8eeb20e3bd04a02f851c7 100644 (file)
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -575,6 +575,8 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
        s->pics[1].elcr_mask = 0xde;
        s->pics[0].pics_state = s;
        s->pics[1].pics_state = s;
+       s->pics[0].isr_ack = 0xff;
+       s->pics[1].isr_ack = 0xff;
 
        /*
         * Initialize PIO device