From: Avi Kivity <avi@redhat.com>
Date: Wed, 4 Jan 2012 14:28:42 +0000 (+0200)
Subject: pci: fix corrupted pci conf index register by unaligned write
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cdde6ffc27517bdf069734fbc5693ce2b14edc75;p=qemu.git

pci: fix corrupted pci conf index register by unaligned write

Commit d0ed8076cbdc261 converted the PCI config access to the memory
API, but also inadvertantly changed it to accept unaligned writes,
and corrupt the index register in the process.  This causes a regression
booting NetBSD.

Fix by ignoring unaligned or non-dword writes.

https://bugs.launchpad.net/qemu/+bug/897771

Reported-by: Andreas Gustafsson <gson@gson.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/hw/pci_host.c b/hw/pci_host.c
index 44c6c207a9..804177891a 100644
--- a/hw/pci_host.c
+++ b/hw/pci_host.c
@@ -101,6 +101,9 @@ static void pci_host_config_write(void *opaque, target_phys_addr_t addr,
 
     PCI_DPRINTF("%s addr " TARGET_FMT_plx " len %d val %"PRIx64"\n",
                 __func__, addr, len, val);
+    if (addr != 0 || len != 4) {
+        return;
+    }
     s->config_reg = val;
 }