From: Avi Kivity <avi@redhat.com>
Date: Fri, 14 Jan 2011 12:10:17 +0000 (-0200)
Subject: KVM: i8259: initialize isr_ack
X-Git-Tag: v2.6.36.4~32
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=295c639bff96e344913cd99118eecadf211e2e68;p=thirdparty%2Fkernel%2Fstable.git

KVM: i8259: initialize isr_ack

commit a0272630bb594b4eac03a79e77957df7dad8eade upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 4b7b73ce20989..9f163e61283c7 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -570,6 +570,8 @@ 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