[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH v2][resend] apic: fixup fallthrough to PIC

From: Mark Asselstine
Subject: [Qemu-devel] [PATCH v2][resend] apic: fixup fallthrough to PIC
Date: Thu, 4 Apr 2013 11:43:05 -0400

Commit 0e21e12bb311c4c1095d0269dc2ef81196ccb60a [Don't route PIC
interrupts through the local APIC if the local APIC config says so.]
missed a check to ensure the local APIC is enabled. Since if the local
APIC is disabled it doesn't matter what the local APIC config says.

If this check isn't done and the guest has disabled the local APIC the
guest will receive a general protection fault, similar to what is seen


The GPF is caused by an attempt to service interrupt 0xffffffff. This
comes about since cpu_get_pic_interrupt() calls apic_accept_pic_intr()
(with the local APIC disabled apic_get_interrupt() returns -1).
apic_accept_pic_intr() returns 0 and thus the interrupt number which
is returned from cpu_get_pic_interrupt(), and which is attempted to be
serviced, is -1.

Signed-off-by: Mark Asselstine <address@hidden>

*v2*  moved the checks to a single line

Resending since I would like to get this into the tree.

 hw/apic.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/apic.c b/hw/apic.c
index d2395f0..e5e3435 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -590,7 +590,7 @@ int apic_accept_pic_intr(DeviceState *d)
     APICCommonState *s = DO_UPCAST(APICCommonState, busdev.qdev, d);
     uint32_t lvt0;
-    if (!s)
+    if (!s || !(s->spurious_vec & APIC_SV_ENABLE))
         return -1;
     lvt0 = s->lvt[APIC_LVT_LINT0];

reply via email to

[Prev in Thread] Current Thread [Next in Thread]