On Fri, Mar 10, 2023 at 11:30:04AM +0800, Baolu Lu wrote:
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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);
?
A driver_type would be IOMMUFD_HW_INFO_TYPExx. What's inside the BIT_ULL is IOMMUFD_HWPT_TYPE_*. It seems to get a bit confusing after several rounds of renaming though. And they do seem to be a bit of duplications at the actual values, at least for now.
I recall that we only had one enum for the types, yet later did a separation into driver_types and hwpt_types after a discussion regarding future PASID support?
Thanks Nic