On Thu, 20 Nov 2025 at 21:25, Shameer Kolothum <[email protected]> wrote:
>
> QEMU SMMUv3 does not enable ATS (Address Translation Services) by default.
> When accelerated mode is enabled and the host SMMUv3 supports ATS, it can
> be useful to report ATS capability to the guest so it can take advantage
> of it if the device also supports ATS.
>
> Note: ATS support cannot be reliably detected from the host SMMUv3 IDR
> registers alone, as firmware ACPI IORT tables may override them. The
> user must therefore ensure the support before enabling it.
>
> The ATS support enabled here is only relevant for vfio-pci endpoints,
> as SMMUv3 accelerated mode does not support emulated endpoint devices.
> QEMU’s SMMUv3 implementation still lacks support for handling ATS
> translation requests, which would be required for emulated endpoints.
>
> Reviewed-by: Jonathan Cameron <[email protected]>
> Tested-by: Zhangfei Gao <[email protected]>
> Signed-off-by: Shameer Kolothum <[email protected]>
> ---
> hw/arm/smmuv3-accel.c | 3 +++
> hw/arm/smmuv3.c | 21 ++++++++++++++++++++-
> hw/arm/virt-acpi-build.c | 10 ++++++++--
> include/hw/arm/smmuv3.h | 1 +
> 4 files changed, 32 insertions(+), 3 deletions(-)
>
> diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
> index b6429c8b42..73c7ce586a 100644
> --- a/hw/arm/smmuv3-accel.c
> +++ b/hw/arm/smmuv3-accel.c
> @@ -647,6 +647,9 @@ void smmuv3_accel_idr_override(SMMUv3State *s)
>
> /* By default QEMU SMMUv3 has RIL. Update IDR3 if user has disabled it */
> s->idr[3] = FIELD_DP32(s->idr[3], IDR3, RIL, s->ril);
> +
> + /* QEMU SMMUv3 has no ATS. Advertise ATS if opt-on by property */
> + s->idr[0] = FIELD_DP32(s->idr[0], IDR0, ATS, s->ats);
> }
>
> /* Based on SMUUv3 GPBA.ABORT configuration, attach a corresponding HWPT */
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index 296afbe503..ad476146f6 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -1498,13 +1498,24 @@ static int smmuv3_cmdq_consume(SMMUv3State *s, Error
> **errp)
> */
> smmuv3_range_inval(bs, &cmd, SMMU_STAGE_2);
> break;
> + case SMMU_CMD_ATC_INV:
> + SMMUDevice *sdev = smmu_find_sdev(bs, CMD_SID(&cmd));
> +
> + if (!sdev) {
> + break;
> + }
> +
> + if (!smmuv3_accel_issue_inv_cmd(s, &cmd, sdev, errp)) {
> + cmd_error = SMMU_CERROR_ILL;
> + break;
> + }
> + break;
got build error here, need { }
../hw/arm/smmuv3.c: In function ‘smmuv3_cmdq_consume’:
../hw/arm/smmuv3.c:1505:13: error: a label can only be part of a
statement and a declaration is not a statement
1505 | SMMUDevice *sdev = smmu_find_sdev(bs, CMD_SID(&cmd));
| ^~~~~~~~~~
Thanks
