[Qemu-devel] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus

[Alexey Kardashevskiy <aik@ozlabs.ru>]

Currently sPAPR always creates a primary PCI host bridge for emulated PCI
devices.  However, because the platform supports native virtual IO, and
can also support multiple independent PCI host bridges, it's quite often
useful to disable the primary bridge for debugging purposes.

This patch, therefore, makes the code cope more gracefully with a missing
primary host bridge.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/ppc/spapr.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index c96ac81..d07c74a 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -732,7 +732,7 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
     const char *boot_device = args->boot_device;
     PowerPCCPU *cpu;
     CPUPPCState *env;
-    PCIHostState *phb;
+    PCIHostState *phb = NULL;
     int i;
     MemoryRegion *sysmem = get_system_memory();
     MemoryRegion *ram = g_new(MemoryRegion, 1);
@@ -898,11 +898,11 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
     }
 
     /* Graphics */
-    if (spapr_vga_init(phb->bus)) {
+    if (phb && spapr_vga_init(phb->bus)) {
         spapr->has_graphics = true;
     }
 
-    if (usb_enabled(spapr->has_graphics)) {
+    if (phb && usb_enabled(spapr->has_graphics)) {
         pci_create_simple(phb->bus, -1, "pci-ohci");
         if (spapr->has_graphics) {
             usbdevice_create("keyboard");
-- 
1.7.10.4