Re: [Qemu-devel] [PATCH] pci: fix bridge IO/BASE

[Blue Swirl]

On Sun, Mar 4, 2012 at 13:22, Michael S. Tsirkin <address@hidden> wrote:
> On Sun, Mar 04, 2012 at 02:41:33PM +0200, Avi Kivity wrote:
>> On 03/04/2012 02:38 PM, Blue Swirl wrote:
>> > >>
>> > >> This unassigned memory exception is triggered because CMD646 IDE I/O
>> > >> registers are not accessible:
>> > >>
>> > >> (qemu) info pci
>> > >>   Bus  0, device   5, function 0:
>> > >>     IDE controller: PCI device 1095:0646
>> > >>       IRQ 1.
>> > >>       BAR0: I/O at 0xffffffffffffffff [0x0006].
>> > >>       BAR1: I/O at 0xffffffffffffffff [0x0002].
>> > >>       BAR2: I/O at 0xffffffffffffffff [0x0006].
>> > >>       BAR3: I/O at 0xffffffffffffffff [0x0002].
>> > >>       BAR4: I/O at 0xffffffffffffffff [0x000e].
>> > >>       id ""
>> > >
>> > > The BARs are not initialized, so they aren't accessible.
>> > >
>> > > But perhaps the dump was not taken at the point of failure, can you
>> > > provide a relevant dump if so?
>> >
>> > No, this is after failure.
>>
>> I don't see why the guest expects the BARs to work then.
>
> I don't belive it does - it probably got hang before
> initializing BARs.

This is later, the crash happens when IDE driver is accessing CMD646
registers after the PCI device is configured.

I changed OpenBIOS to disable any bridges with no devices, but that
didn't help. It looks like this is not related to bridges, I disabled
the secondary bridges with this patch and still there is the crash.

diff --git a/hw/apb_pci.c b/hw/apb_pci.c
index 1d25da8..ed9dc68 100644
--- a/hw/apb_pci.c
+++ b/hw/apb_pci.c
@@ -256,11 +256,13 @@ static const MemoryRegionOps pci_ioport_ops = {
     .endianness = DEVICE_NATIVE_ENDIAN,
 };

+#if 0
 /* The APB host has an IRQ line for each IRQ line of each slot.  */
 static int pci_apb_map_irq(PCIDevice *pci_dev, int irq_num)
 {
     return ((pci_dev->devfn & 0x18) >> 1) + irq_num;
 }
+#endif

 static int pci_pbm_map_irq(PCIDevice *pci_dev, int irq_num)
 {
@@ -322,8 +324,10 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
     SysBusDevice *s;
     APBState *d;
     unsigned int i;
+#if 0
     PCIDevice *pci_dev;
     PCIBridge *br;
+#endif

     /* Ultrasparc PBM main bus */
     dev = qdev_create(NULL, "pbm");
@@ -352,6 +356,7 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,

     pci_create_simple(d->bus, 0, "pbm-pci");

+#if 0
     /* APB secondary busses */
     pci_dev = pci_create_multifunction(d->bus, PCI_DEVFN(1, 0), true,
                                    "pbm-bridge");
@@ -368,7 +373,7 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
                        pci_apb_map_irq);
     qdev_init_nofail(&pci_dev->qdev);
     *bus3 = pci_bridge_get_sec_bus(br);
-
+#endif
     return d->bus;
 }

>
>> --
>> error compiling committee.c: too many arguments to function