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@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
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
