Re: [RFC PATCH v2 04/20] hw/arm/virt: Add support for smmuv3-accel

[Nicolin Chen <nicolinc@nvidia.com>]

On Tue, Mar 11, 2025 at 02:10:29PM +0000, Shameer Kolothum wrote:
> Allow cold-plug smmuv3-accel to virt If the machine wide smmuv3
> is not specified.
> 
> No FDT support is added for now.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  hw/arm/virt.c         | 12 ++++++++++++
>  hw/core/sysbus-fdt.c  |  1 +
>  include/hw/arm/virt.h |  1 +
>  3 files changed, 14 insertions(+)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 4a5a9666e9..84a323da55 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -73,6 +73,7 @@
>  #include "qobject/qlist.h"
>  #include "standard-headers/linux/input.h"
>  #include "hw/arm/smmuv3.h"
> +#include "hw/arm/smmuv3-accel.h"

smmuv3-accel.h included smmuv3.h in the patch prior.

> @@ -2911,6 +2912,16 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>              platform_bus_link_device(PLATFORM_BUS_DEVICE(vms->platform_bus_dev),
>                                       SYS_BUS_DEVICE(dev));
>          }
> +        if (object_dynamic_cast(OBJECT(dev), TYPE_ARM_SMMUV3_ACCEL)) {
> +            if (vms->iommu == VIRT_IOMMU_SMMUV3) {
> +                error_setg(errp,
> +                           "iommu=smmuv3 is already specified. can't create smmuv3-accel dev");
> +                return;
> +            }
> +            if (vms->iommu != VIRT_IOMMU_SMMUV3_ACCEL) {
> +                vms->iommu = VIRT_IOMMU_SMMUV3_ACCEL;
> +            }

Looks like it is to support TYPE_VIRTIO_IOMMU_PCI?

Just asking: should SMMUV3_ACCEL work with that?

Nicolin