[Qemu-devel] [PATCH] pci: do not pci_update_mappings when guest gets bar size

[arei.gonglei]

From: ChenLiang <address@hidden>

Power-up software can determine how much address space the device
requires by writing a value of all 1's to the register and then
reading the value back(PCI specification). Qemu should not do
pci_update_mappings. Qemu may exit, because the wrong address of
this bar is overlap with other memslots.

Signed-off-by: ChenLiang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
 hw/pci/pci.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 6ce75aa..4d44b44 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1158,12 +1158,12 @@ void pci_default_write_config(PCIDevice *d, uint32_t 
addr, uint32_t val_in, int
         d->config[addr + i] = (d->config[addr + i] & ~wmask) | (val & wmask);
         d->config[addr + i] &= ~(val & w1cmask); /* W1C: Write 1 to Clear */
     }
-    if (ranges_overlap(addr, l, PCI_BASE_ADDRESS_0, 24) ||
+    if (((ranges_overlap(addr, l, PCI_BASE_ADDRESS_0, 24) ||
         ranges_overlap(addr, l, PCI_ROM_ADDRESS, 4) ||
-        ranges_overlap(addr, l, PCI_ROM_ADDRESS1, 4) ||
-        range_covers_byte(addr, l, PCI_COMMAND))
+        ranges_overlap(addr, l, PCI_ROM_ADDRESS1, 4)) &&
+        val_in != 0xffffffff) || range_covers_byte(addr, l, PCI_COMMAND)) {
         pci_update_mappings(d);
-
+    }
     if (range_covers_byte(addr, l, PCI_COMMAND)) {
         pci_update_irq_disabled(d, was_irq_disabled);
         memory_region_set_enabled(&d->bus_master_enable_region,
-- 
1.7.12.4