Hi, Shameer
On Fri, 31 Oct 2025 at 18:54, Shameer Kolothum <[email protected]> wrote:
>
> Just before the device gets attached to the SMMUv3, make sure QEMU SMMUv3
> features are compatible with the host SMMUv3.
>
> Not all fields in the host SMMUv3 IDR registers are meaningful for userspace.
> Only the following fields can be used:
>
> - IDR0: ST_LEVEL, TERM_MODEL, STALL_MODEL, TTENDIAN, CD2L, ASID16, TTF
> - IDR1: SIDSIZE, SSIDSIZE
> - IDR3: BBML, RIL
> - IDR5: VAX, GRAN64K, GRAN16K, GRAN4K
>
> For now, the check is to make sure the features are in sync to enable
> basic accelerated SMMUv3 support.
>
> Signed-off-by: Shameer Kolothum <[email protected]>
> ---
> hw/arm/smmuv3-accel.c | 100 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 100 insertions(+)
>
> diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
> index a2deda3c32..8b9f88dd8e 100644
> --- a/hw/arm/smmuv3-accel.c
> +++ b/hw/arm/smmuv3-accel.c
> @@ -28,6 +28,98 @@ MemoryRegion root;
> MemoryRegion sysmem;
> static AddressSpace *shared_as_sysmem;
>
> +static bool
> +smmuv3_accel_check_hw_compatible(SMMUv3State *s,
> + struct iommu_hw_info_arm_smmuv3 *info,
> + Error **errp)
> +{
> + /* QEMU SMMUv3 supports architecture version 3.1 */
> + if (info->aidr < s->aidr) {
> + error_setg(errp, "Host SMMUv3 architecture version not compatible");
> + return false;
> + }
Why has this requirement?
We have SMMUv3 version 3.0 and info->aidr = 0.
and qemu fails to boot here.
Thanks
