[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of
From: |
Alexander Graf |
Subject: |
Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus |
Date: |
Tue, 30 Apr 2013 13:56:06 +0200 |
Am 30.04.2013 um 13:52 schrieb Alexey Kardashevskiy <address@hidden>:
> On 04/30/2013 09:30 PM, Alexander Graf wrote:
>>
>>
>> Am 30.04.2013 um 13:15 schrieb Alexey Kardashevskiy <address@hidden>:
>>
>>> On 04/30/2013 07:45 PM, Alexander Graf wrote:
>>>>
>>>> On 30.04.2013, at 06:33, Alexey Kardashevskiy wrote:
>>>>
>>>>> 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.
>>>>
>>>> Does this handle the -net case too? What about disks?
>>>>
>>>> If those use a different mechanism to find their bus, maybe it'd be better
>>>> to instead do
>>>>
>>>> if (phb) {
>>>> pcibus = phb->bus;
>>>> } else {
>>>> pcibus = find_pci_bus();
>>>> }
>>>>
>>>> In fact, maybe the code already deals with bus==NULL?
>>>
>>>
>>> I needed it to deal with phb==NULL.
>>>
>>> The story behind this patch is that while doing VFIO stuff, I have to deal
>>> with multiple PHBs. And sometime I want to be 100% sure that it is just
>>> VFIO PHB and no emulated PCI stuff (especially when I debug USB PCI card in
>>> VFIO) so I simply commented out the call which creates default emulated PHB
>>> and that would be it if the existing code did not try to use phb->bus.
>>
>> Then this code does nor belong in upstream. If you want to have full control
>> over instantiated devices, implement -nodefaults.
>
>
> -nodefaults means no default devices but it is still expected to create PCI
> bus and libvirt heavily uses this feature.
Your patch only addresses default device creation.
Alex
>
>
>
>>
>>
>> Alex
>>
>>>
>>>
>>>
>>>
>>>>
>>>>
>>>> Alex
>>>>
>>>>>
>>>>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>>>>> Signed-off-by: David Gibson <address@hidden>
>>>>> ---
>>>>> 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
>>>
>>>
>>> --
>>> Alexey
>
>
> --
> Alexey
- [Qemu-ppc] [0/4] General updates for pseries, Alexey Kardashevskiy, 2013/04/30
- [Qemu-ppc] [PATCH 1/4] pseries: Factor out check for out-of-bounds LIOBN, Alexey Kardashevskiy, 2013/04/30
- [Qemu-ppc] [PATCH 2/4] pseries: Fix debug message for out-of-bounds address in H_PUT_TCE, Alexey Kardashevskiy, 2013/04/30
- [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexey Kardashevskiy, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexander Graf, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexey Kardashevskiy, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexander Graf, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexey Kardashevskiy, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus,
Alexander Graf <=
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexey Kardashevskiy, 2013/04/30
- Re: [Qemu-ppc] [PATCH 3/4] spapr: Code more defensively against lack of primary PCI bus, Alexander Graf, 2013/04/30
[Qemu-ppc] [PATCH 4/4] pseries: Update SLOF firmware image, Alexey Kardashevskiy, 2013/04/30
Re: [Qemu-ppc] [0/4] General updates for pseries, Alexander Graf, 2013/04/30