Re: [Qemu-arm] [Qemu-devel] [RFC v2 3/7] hw/intc/arm_gicv3: Introduce redist-region-count array property

[Auger Eric <eric.auger@redhat.com>]

Hi Peter,

On 05/29/2018 11:13 AM, Peter Maydell wrote:
> On 29 May 2018 at 10:08, Auger Eric <eric.auger@redhat.com> wrote:
>> Hi Peter,
>> On 05/22/2018 02:27 PM, Peter Maydell wrote:
>>> On 13 May 2018 at 15:35, Eric Auger <eric.auger@redhat.com> wrote:
>>>> To prepare for multiple redistributor regions, we introduce
>>>> an array of uint32_t properties that stores the redistributor
>>>> count of each redistributor region.
>>>>
>>>> Non accelerated VGICv3 only supports a single redistributor region.
>>>> The capacity of all redist regions is checked against the number of
>>>> vcpus.
>>>>
>>>> Machvirt is updated to set the count to 123 vcpus for the unique
>>>> redistributor region we currently have.
> 
>>>> +
>>>> +    if (type == 3) {
>>>> +        qdev_prop_set_uint32(gicdev, "len-redist-region-count", 1);
>>>> +        qdev_prop_set_uint32(gicdev , "redist-region-count[0]",
>>>> +                             vms->memmap[VIRT_GIC_REDIST].size / 0x20000);
>>>
>>> We used to create a region which had num_cpu redistributors in it;
>>> won't this cause us to create one which has as many redistributors
>>> as will fit in the space ?
>> Is that an issue? From a machine perspective the whole region is
>> reserved for rdist. dt and ACPI will expose this whole region and the
>> device will use a subset of it? I agree I need to document this change
>> in the commit message though.
> 
> It's a difference, and a guest-visible difference too. This
> patchset is supposed to be introducing split-redistributor-regions,
> not changing the behaviour of other configs. Also, I don't think
> it makes sense to model a GIC with more redistributors than CPUs:
> real hardware doesn't look like that AFAIK.

OK I updated the series accordingly.

Thanks

Eric
> 
> thanks
> -- PMM
>