qemu/pci: clarify pci config load routine

PCI load routine has to be called with size equal to 256 (otherwise it
will crash in weird ways).  So assert this, making code clearer.
Also avoid dynamically sized array on stack - good for portability.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/hw/pci.c b/hw/pci.c
index bd65db223926c80dac19790e4e04f86ee61e2209..d63285a96ac50fc108c08e5eb7114c858bdbbe7e 100644 (file)
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -193,14 +193,15 @@ int pci_bus_num(PCIBus *s)
 static int get_pci_config_device(QEMUFile *f, void *pv, size_t size)
 {
     PCIDevice *s = container_of(pv, PCIDevice, config);
-    uint8_t config[size];
+    uint8_t config[PCI_CONFIG_SPACE_SIZE];
     int i;
 
-    qemu_get_buffer(f, config, size);
-    for (i = 0; i < size; ++i)
+    assert(size == sizeof config);
+    qemu_get_buffer(f, config, sizeof config);
+    for (i = 0; i < sizeof config; ++i)
         if ((config[i] ^ s->config[i]) & s->cmask[i] & ~s->wmask[i])
             return -EINVAL;
-    memcpy(s->config, config, size);
+    memcpy(s->config, config, sizeof config);
 
     pci_update_mappings(s);