[Xen-changelog] [xen-unstable] [QEMU] Simpler workaround for guest writes to PCI config

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID f66f7c3a82a7420d80714b0d349ee9a24b50ec28
# Parent  ccc419cbe0bada0ae901e0d426dabce70a429876
[QEMU] Simpler workaround for guest writes to PCI config
space that extend past byte 0xff.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
 tools/ioemu/hw/pci.c |   24 ++++++++----------------
 tools/ioemu/vl.h     |    7 +++++--
 2 files changed, 13 insertions(+), 18 deletions(-)

diff -r ccc419cbe0ba -r f66f7c3a82a7 tools/ioemu/hw/pci.c
--- a/tools/ioemu/hw/pci.c      Thu Nov 30 17:27:00 2006 +0000
+++ b/tools/ioemu/hw/pci.c      Thu Nov 30 17:32:16 2006 +0000
@@ -221,23 +221,16 @@ uint32_t pci_default_read_config(PCIDevi
                                  uint32_t address, int len)
 {
     uint32_t val;
-
     switch(len) {
+    case 1:
+        val = d->config[address];
+        break;
+    case 2:
+        val = le16_to_cpu(*(uint16_t *)(d->config + address));
+        break;
     default:
     case 4:
-       if (address <= 0xfc) {
-           val = le32_to_cpu(*(uint32_t *)(d->config + address));
-           break;
-       }
-       /* fall through */
-    case 2:
-        if (address <= 0xfe) {
-           val = le16_to_cpu(*(uint16_t *)(d->config + address));
-           break;
-       }
-       /* fall through */
-    case 1:
-        val = d->config[address];
+        val = le32_to_cpu(*(uint32_t *)(d->config + address));
         break;
     }
     return val;
@@ -340,8 +333,7 @@ void pci_default_write_config(PCIDevice 
 
             d->config[addr] = val;
         }
-        if (++addr > 0xff)
-               break;
+        addr++;
         val >>= 8;
     }
 
diff -r ccc419cbe0ba -r f66f7c3a82a7 tools/ioemu/vl.h
--- a/tools/ioemu/vl.h  Thu Nov 30 17:27:00 2006 +0000
+++ b/tools/ioemu/vl.h  Thu Nov 30 17:32:16 2006 +0000
@@ -650,8 +650,11 @@ typedef struct PCIIORegion {
 #define PCI_MAX_LAT            0x3f    /* 8 bits */
 
 struct PCIDevice {
-    /* PCI config space */
-    uint8_t config[256];
+    /*
+     * PCI config space. The 4 extra bytes are a safety buffer for guest
+     * word/dword writes that can extend past byte 0xff.
+     */
+    uint8_t config[256+4];
 
     /* the following fields are read only */
     PCIBus *bus;

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