[Qemu-devel] [PATCH] pci: allow 0 address for PCI IO/MEM regions

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Some kernels program a 0 address for io regions. PCI 3.0 spec
section 6.2.5.1 doesn't seem to disallow this.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 hw/pci/pci.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 371699c..8dda27d 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1034,7 +1034,7 @@ static pcibus_t pci_bar_address(PCIDevice *d,
         /* Check if 32 bit BAR wraps around explicitly.
          * TODO: make priorities correct and remove this work around.
          */
-        if (last_addr <= new_addr || new_addr == 0 || last_addr >= UINT32_MAX) {
+        if (last_addr <= new_addr || last_addr >= UINT32_MAX) {
             return PCI_BAR_UNMAPPED;
         }
         return new_addr;
@@ -1058,8 +1058,7 @@ static pcibus_t pci_bar_address(PCIDevice *d,
     /* XXX: as we cannot support really dynamic
        mappings, we handle specific values as invalid
        mappings. */
-    if (last_addr <= new_addr || new_addr == 0 ||
-        last_addr == PCI_BAR_UNMAPPED) {
+    if (last_addr <= new_addr || last_addr == PCI_BAR_UNMAPPED) {
         return PCI_BAR_UNMAPPED;
     }
 
-- 
1.9.1