[Xen-devel] [PATCH] ioemu: pass-through: pt_bar_mapping fix

[NISHIGUCHI Naoki <nisiguti@xxxxxxxxxxxxxx>]

Hi,

In pt_bar_mapping function, r->addr should not be changed by invalid
value(-1).
This value(-1) causes failure of mapping BAR when I/O Space or Memory
Space enable bit is updated repeatedly by native windows driver.

This situation occurs in Windows Vista guest.

Attached patch fixes this problem.


Signed-off-by: Naoki Nishiguchi <nisiguti@xxxxxxxxxxxxxx>

Regards,
Naoki Nishiguchi

diff -r bd97e45e073a tools/ioemu/hw/pass-through.c
--- a/tools/ioemu/hw/pass-through.c     Tue Jul 08 09:28:50 2008 +0100
+++ b/tools/ioemu/hw/pass-through.c     Wed Jul 09 15:36:14 2008 +0900
@@ -1519,7 +1519,7 @@ static void pt_bar_mapping(struct pt_dev
     PCIDevice *dev = (PCIDevice *)&ptdev->dev;
     PCIIORegion *r;
     struct pt_region *base = NULL;
-    uint32_t r_size = 0;
+    uint32_t r_size = 0, r_addr = -1;
     int ret = 0;
     int i;
 
@@ -1537,30 +1537,33 @@ static void pt_bar_mapping(struct pt_dev
            (base->bar_flag == PT_BAR_FLAG_UPPER))
                continue;
 
+        /* copy region address to temporary */
+        r_addr = r->addr;
+
         /* clear region address in case I/O Space or Memory Space disable */
         if (((base->bar_flag == PT_BAR_FLAG_IO) && !io_enable ) ||
             ((base->bar_flag == PT_BAR_FLAG_MEM) && !mem_enable ))
-            r->addr = -1;
+            r_addr = -1;
 
         /* prevent guest software mapping memory resource to 00000000h */
-        if ((base->bar_flag == PT_BAR_FLAG_MEM) && (r->addr == 0))
-            r->addr = -1;
+        if ((base->bar_flag == PT_BAR_FLAG_MEM) && (r_addr == 0))
+            r_addr = -1;
 
         /* align resource size (memory type only) */
         r_size = r->size;
         PT_GET_EMUL_SIZE(base->bar_flag, r_size);
 
         /* check overlapped address */
-        ret = pt_chk_bar_overlap(dev->bus, dev->devfn, r->addr, r_size);
+        ret = pt_chk_bar_overlap(dev->bus, dev->devfn, r_addr, r_size);
         if (ret > 0)
             PT_LOG("Base Address[%d] is overlapped. "
-                "[Address:%08xh][Size:%04xh]\n", i, r->addr, r_size);
+                "[Address:%08xh][Size:%04xh]\n", i, r_addr, r_size);
 
         /* check whether we need to update the mapping or not */
-        if (r->addr != ptdev->bases[i].e_physbase)
+        if (r_addr != ptdev->bases[i].e_physbase)
         {
             /* mapping BAR */
-            r->map_func((PCIDevice *)ptdev, i, r->addr, 
+            r->map_func((PCIDevice *)ptdev, i, r_addr, 
                          r_size, r->type);
         }
     }

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