From 25de4443cdeba63d8d717069776ea1b526bf3da5 Mon Sep 17 00:00:00 2001
From: Eduardo Habkost <ehabkost@redhat.com>
Date: Thu, 3 Sep 2009 13:44:03 -0300
Subject: [PATCH 2/3] kvm: fix ack not being delivered when msi present

Message-id: <20090804175713.GC3751@redhat.com>
RH-Author: Michael S. Tsirkin <mst@redhat.com>
Patchwork-id: 3157
O-Subject: [PATCH 2/3] kvm: fix ack not being delivered when msi present
Bugzilla: 515549
CVE:
RH-Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Don Dutile <ddutile@redhat.com>
RH-Acked-by: Zachary Amsden <zamsden@redhat.com>
RH-Acked-by: Gleb Natapov <gleb@redhat.com>

Backport fix for upstream bug:

kvm_notify_acked_irq does not check irq type, so that it sometimes
interprets msi vector as irq.  As a result, ack notifiers are not
called, which typially hangs the guest.  The fix is to track and
check irq type.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/linux/kvm_host.h |    1 +
 virt/kvm/irq_comm.c      |    4 +++-
 2 files changed, 4 insertions(+), 1 deletions(-)

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 include/linux/kvm_host.h |    1 +
 virt/kvm/irq_comm.c      |    4 +++-
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 84c08e8..02974e0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -109,6 +109,7 @@ struct kvm_memory_slot {
 
 struct kvm_kernel_irq_routing_entry {
 	u32 gsi;
+	u32 type;
 	int (*set)(struct kvm_kernel_irq_routing_entry *e,
 		    struct kvm *kvm, int level);
 	union {
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 5f50def..f45c30d 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -203,7 +203,8 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 	unsigned gsi = pin;
 
 	list_for_each_entry(e, &kvm->irq_routing, link)
-		if (e->irqchip.irqchip == irqchip &&
+		if (e->type == KVM_IRQ_ROUTING_IRQCHIP &&
+		    e->irqchip.irqchip == irqchip &&
 		    e->irqchip.pin == pin) {
 			gsi = e->gsi;
 			break;
@@ -302,6 +303,7 @@ int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 	int delta;
 
 	e->gsi = ue->gsi;
+	e->type = ue->type;
 	switch (ue->type) {
 	case KVM_IRQ_ROUTING_IRQCHIP:
 		delta = 0;
-- 
1.6.3.rc4.29.g8146