> On 4. Aug 2025, at 21:50, Pierrick Bouvier <pierrick.bouv...@linaro.org>
> wrote:
>
> On 8/4/25 7:23 AM, Mohamed Mediouni wrote:
>> Windows Hypervisor Platform's vGIC doesn't support ITS.
>> Deal with this by reporting to the user and not creating the ITS device.
>> Signed-off-by: Mohamed Mediouni <moha...@unpredictable.fr>
>> ---
>> hw/arm/virt.c | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 98a1c74c42..0039f6a12b 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -741,6 +741,16 @@ static void create_its(VirtMachineState *vms)
>> return;
>> }
>> + if (whpx_enabled() && vms->tcg_its) {
>> + /*
>> + * Signal to the user when ITS is neither supported by the host
>> + * nor emulated by the machine.
>> + */
>> + info_report("ITS not supported on WHPX.");
>> + info_report("To support MSIs, use its=off to enable GICv3 +
>> GICv2m.");
>> + return;
>> + }
>> +
>> dev = qdev_new(its_class_name());
>> object_property_set_link(OBJECT(dev), "parent-gicv3",
>> OBJECT(vms->gic),
>
> Is it equivalent to simply using its=off, or is there a difference?
> The info_report seems to imply it's not the same.
Not equivalent.
Regular system: GICv3 + ITS
This configuration (for the newest machine version): GICv3 with no MSIs
And its=off explicitly: GICv3 + GICv2m
It became not equivalent since the intro of GICv3 + GICv2m in patch 2 of this
series.
Thank you,
