Re: [Qemu-devel] [PATCH] hw/arm/virt: Add linux, pci-domain property

[Jan Kiszka]

On 2018-04-23 15:11, Peter Maydell wrote:
> On 23 April 2018 at 06:18, Jan Kiszka <address@hidden> wrote:
>> From: Jan Kiszka <address@hidden>
>>
>> This allows to pin the host controller in the Linux PCI domain space.
>> Linux requires that property to be available consistently or not at all,
>> in which case the domain number becomes unstable on additions/removals.
>> Adding it here won't make a difference in practice for most setups as we
>> only expose one controller.
>>
>> However, enabling Jailhouse on top may introduce another controller, and
>> that one would like to have stable address as well. So the property is
>> needed for the first controller as well.
> 
> Am I right in thinking that for ACPI the PCI domain number is
> communicated via the _SEG method? If so, looks like we already
> set that, and we set it to 0, which matches what we're doing here
> in the DT, so that's good.

Looking at the related arm64 kernel code (not the spec), it seems __SEG
is involved, yet.

Jan

> 
>> Signed-off-by: Jan Kiszka <address@hidden>
>> ---
>>  hw/arm/virt.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 94dcb125d3..943371b75e 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -1023,6 +1023,7 @@ static void create_pcie(const VirtMachineState *vms, 
>> qemu_irq *pic)
>>      qemu_fdt_setprop_string(vms->fdt, nodename, "device_type", "pci");
>>      qemu_fdt_setprop_cell(vms->fdt, nodename, "#address-cells", 3);
>>      qemu_fdt_setprop_cell(vms->fdt, nodename, "#size-cells", 2);
>> +    qemu_fdt_setprop_cell(vms->fdt, nodename, "linux,pci-domain", 0);
>>      qemu_fdt_setprop_cells(vms->fdt, nodename, "bus-range", 0,
>>                             nr_pcie_buses - 1);
>>      qemu_fdt_setprop(vms->fdt, nodename, "dma-coherent", NULL, 0);
>> --
> 
> Drew -- is minor changes to the DTC something we can do without
> having to condition it on machine version? I forget...
> 
> thanks
> -- PMM
>

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