On 2/26/26 11:50 AM, Shameer Kolothum wrote:
> Use IOMMU_GET_HW_INFO to check whether the host supports Tegra241 CMDQV.
>
> Validate the returned data type, version, number of vCMDQs and SIDs per
> VM. Fail the probe if the host does not meet the expected requirements.
Can you explain why it is important to check
number of vCMDQs and SIDs per VM?
>
> Signed-off-by: Shameer Kolothum <[email protected]>
> ---
> hw/arm/tegra241-cmdqv.h | 5 +++++
> hw/arm/tegra241-cmdqv.c | 32 ++++++++++++++++++++++++++++++--
> 2 files changed, 35 insertions(+), 2 deletions(-)
>
> diff --git a/hw/arm/tegra241-cmdqv.h b/hw/arm/tegra241-cmdqv.h
> index 07e10e86ee..312064a081 100644
> --- a/hw/arm/tegra241-cmdqv.h
> +++ b/hw/arm/tegra241-cmdqv.h
> @@ -10,6 +10,11 @@
> #ifndef HW_ARM_TEGRA241_CMDQV_H
> #define HW_ARM_TEGRA241_CMDQV_H
>
> +#define TEGRA241_CMDQV_VERSION 1
> +#define TEGRA241_CMDQV_NUM_CMDQ_LOG2 1
> +#define TEGRA241_CMDQV_MAX_CMDQ (1U <<
> TEGRA241_CMDQV_NUM_CMDQ_LOG2)
> +#define TEGRA241_CMDQV_NUM_SID_PER_VM_LOG2 4
> +
> const SMMUv3AccelCmdqvOps *tegra241_cmdqv_get_ops(void);
>
> #endif /* HW_ARM_TEGRA241_CMDQV_H */
> diff --git a/hw/arm/tegra241-cmdqv.c b/hw/arm/tegra241-cmdqv.c
> index ad5a0d4611..a270fa7ce4 100644
> --- a/hw/arm/tegra241-cmdqv.c
> +++ b/hw/arm/tegra241-cmdqv.c
> @@ -38,8 +38,36 @@ static bool tegra241_cmdqv_init(SMMUv3State *s, Error
> **errp)
> static bool tegra241_cmdqv_probe(SMMUv3State *s, HostIOMMUDeviceIOMMUFD
> *idev,
> Error **errp)
> {
> - error_setg(errp, "NVIDIA Tegra241 CMDQV is unsupported");
> - return false;
> + uint32_t data_type = IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV;
> + struct iommu_hw_info_tegra241_cmdqv cmdqv_info;
> + uint64_t caps;
> +
> + if (!iommufd_backend_get_device_info(idev->iommufd, idev->devid,
> &data_type,
> + &cmdqv_info, sizeof(cmdqv_info),
> &caps,
> + NULL, errp)) {
> + return false;
> + }
> + if (data_type != IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV) {
> + error_setg(errp, "Host CMDQV: unexpected data type %u (expected %u)",
> + data_type, IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV);
> + return false;
> + }
> + if (cmdqv_info.version != TEGRA241_CMDQV_VERSION) {
> + error_setg(errp, "Host CMDQV: unsupported version %u (expected %u)",
> + cmdqv_info.version, TEGRA241_CMDQV_VERSION);
> + return false;
> + }
> + if (cmdqv_info.log2vcmdqs < TEGRA241_CMDQV_NUM_CMDQ_LOG2) {
> + error_setg(errp, "Host CMDQV: insufficient vCMDQs log2=%u (need >=
> %u)",
> + cmdqv_info.log2vcmdqs, TEGRA241_CMDQV_NUM_CMDQ_LOG2);
> + return false;
> + }
> + if (cmdqv_info.log2vsids < TEGRA241_CMDQV_NUM_SID_PER_VM_LOG2) {
> + error_setg(errp, "Host CMDQV: insufficient SIDs log2=%u (need >=
> %u)",
> + cmdqv_info.log2vsids, TEGRA241_CMDQV_NUM_SID_PER_VM_LOG2);
> + return false;
> + }
> + return true;
> }
>
> static const SMMUv3AccelCmdqvOps tegra241_cmdqv_ops = {
Besides
Reviewed-by: Eric Auger <[email protected]>
Eric
