1From dc2a8ccd440ee3741b61606eafed3f7e092f4312 Mon Sep 17 00:00:00 2001 2From: Mark Asselstine <mark.asselstine@windriver.com> 3Date: Tue, 26 Feb 2013 11:43:28 -0500 4Subject: [PATCH 03/12] apic: fixup fallthrough to PIC 5 6Commit 0e21e12bb311c4c1095d0269dc2ef81196ccb60a [Don't route PIC 7interrupts through the local APIC if the local APIC config says so.] 8missed a check to ensure the local APIC is enabled. Since if the local 9APIC is disabled it doesn't matter what the local APIC config says. 10 11If this check isn't done and the guest has disabled the local APIC the 12guest will receive a general protection fault, similar to what is seen 13here: 14 15https://lists.gnu.org/archive/html/qemu-devel/2012-12/msg02304.html 16 17The GPF is caused by an attempt to service interrupt 0xffffffff. This 18comes about since cpu_get_pic_interrupt() calls apic_accept_pic_intr() 19(with the local APIC disabled apic_get_interrupt() returns -1). 20apic_accept_pic_intr() returns 0 and thus the interrupt number which 21is returned from cpu_get_pic_interrupt(), and which is attempted to be 22serviced, is -1. 23 24Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com> 25Upstream-Status: Submitted [https://lists.gnu.org/archive/html/qemu-devel/2013-04/msg00878.html] 26Signed-off-by: He Zhe <zhe.he@windriver.com> 27 28--- 29 hw/intc/apic.c | 2 +- 30 1 file changed, 1 insertion(+), 1 deletion(-) 31 32Index: qemu-8.0.0/hw/intc/apic.c 33=================================================================== 34--- qemu-8.0.0.orig/hw/intc/apic.c 35+++ qemu-8.0.0/hw/intc/apic.c 36@@ -607,7 +607,7 @@ int apic_accept_pic_intr(DeviceState *de 37 APICCommonState *s = APIC(dev); 38 uint32_t lvt0; 39 40- if (!s) 41+ if (!s || !(s->spurious_vec & APIC_SV_ENABLE)) 42 return -1; 43 44 lvt0 = s->lvt[APIC_LVT_LINT0]; 45