On 3/9/23 4:09 PM, Yi Liu wrote:
This provides a way for userspace to probe the supported hwpt data types by kernel. Currently, kernel only supports IOMMU_HWPT_TYPE_DEFAULT, new types would be added per vendor drivers' extension.
Userspace that wants to allocate hw_pagetable with user data should check this. While for the allocation without user data, no need for it. It is supported by default.
Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com
drivers/iommu/iommufd/device.c | 1 + drivers/iommu/iommufd/hw_pagetable.c | 18 +++++++++++++++--- drivers/iommu/iommufd/iommufd_private.h | 2 ++ drivers/iommu/iommufd/main.c | 2 +- include/uapi/linux/iommufd.h | 8 ++++++++ 5 files changed, 27 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 19cd6df46c6a..0328071dcac1 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -322,6 +322,7 @@ int iommufd_device_get_hw_info(struct iommufd_ucmd *ucmd) cmd->out_data_type = ops->driver_type; cmd->data_len = length;
- cmd->out_hwpt_type_bitmap = iommufd_hwpt_type_bitmaps[ops->driver_type];
rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 67facca98de1..160712256c64 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -173,6 +173,14 @@ static const size_t iommufd_hwpt_alloc_data_size[] = { [IOMMU_HWPT_TYPE_DEFAULT] = 0, }; +/*
- bitmaps of supported hwpt types of by underlying iommu, indexed
- by ops->driver_type which is one of enum iommu_hw_info_type.
- */
+const u64 iommufd_hwpt_type_bitmaps[] = {
- [IOMMU_HW_INFO_TYPE_DEFAULT] = BIT_ULL(IOMMU_HWPT_TYPE_DEFAULT),
+};
I am a bit confused here. Why do you need this array? What I read is that you want to convert ops->driver_type to a bit position in cmd->out_hwpt_type_bitmap.
Am I getting it right?
If so, why not just cmd->out_hwpt_type_bitmap = BIT_ULL(ops->driver_type);
?
Best regards, baolu