On Mon, Jul 14, 2025 at 04:59:33PM +0100, Shameer Kolothum wrote:
> For accelerated SMMUv3, we need nested parent domain creation. Add the
> callback support so that VFIO can create a nested parent.
>
> Since 'accel=on' for SMMUv3 requires the guest SMMUv3 to be configured
> in Stage 1 mode, ensure that the 'stage' property is explicitly set to
> Stage 1.
>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com>
Reviewed-by: Nicolin Chen <nicol...@nvidia.com>
> @@ -81,8 +82,22 @@ static AddressSpace *smmuv3_accel_find_add_as(PCIBus *bus,
> void *opaque,
> }
> }
>
> +static uint64_t smmuv3_accel_get_viommu_cap(void *opaque)
> +{
> + /*
> + * Accelerated smmuv3 support only allowes Guest S1
s/allowes/allows
> + * configuration. Hence report VIOMMU_CAP_STAGE1
> + * so that VFIO can create nested parent domain.
Aligning with the kernel uAPI docs:
s/nested/a nesting
> + * The real nested support should be reported from host
"The real HW nested stage-1 translation must be supported by the .."
> + * SMMUv3 and if it doesn't, the nested parent allocation
s/nested/nesting
> + * will fail anyway.
> + */
And I think the lines are wrapped a bit too early. Should QEMU allow
up-to-80 characters?
Thanks
Nicolin
