From: Baolu Lu baolu.lu@linux.intel.com Sent: Friday, March 10, 2023 11:16 AM
On 3/9/23 4:09 PM, Yi Liu wrote:
In nested translation, the stage-1 page table is user-managed and used by IOMMU hardware, so destroying mappings in the stage-1 page table
should
be followed with an IOTLB invalidation.
s/destroying mappings/update of any present page table entry/
Right. Not only destroying.
This adds IOMMU_HWPT_INVALIDATE for IOTLB invalidation.
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/hw_pagetable.c | 56
+++++++++++++++++++++++++
drivers/iommu/iommufd/iommufd_private.h | 9 ++++ drivers/iommu/iommufd/main.c | 3 ++ include/uapi/linux/iommufd.h | 27 ++++++++++++ 4 files changed, 95 insertions(+)
diff --git a/drivers/iommu/iommufd/hw_pagetable.c
b/drivers/iommu/iommufd/hw_pagetable.c
index 64e7cf7142e1..67facca98de1 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -284,3 +284,59 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd
*ucmd)
iommufd_put_object(&idev->obj); return rc; }
+/*
- size of page table type specific invalidate_info, indexed by
- enum iommu_hwpt_type.
- */
+static const size_t iommufd_hwpt_invalidate_info_size[] = {};
+int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd) +{
- struct iommu_hwpt_invalidate *cmd = ucmd->cmd;
- struct iommufd_hw_pagetable *hwpt;
- u64 user_ptr;
- u32 user_data_len, klen;
- int rc = 0;
- /*
* For a user-managed HWPT, type should not beIOMMU_HWPT_TYPE_DEFAULT.
* data_len should not exceed the size ofiommufd_invalidate_buffer.
*/- if (cmd->data_type == IOMMU_HWPT_TYPE_DEFAULT || !cmd-
data_len ||
cmd->data_type >=ARRAY_SIZE(iommufd_hwpt_invalidate_info_size))
"data_len should not exceed the size of iommufd_invalidate_buffer."
How is this checked?
Hmmm, this is a stale comment I suppose.
return -EOPNOTSUPP;- hwpt = iommufd_get_hwpt(ucmd, cmd->hwpt_id);
- if (IS_ERR(hwpt))
return PTR_ERR(hwpt);- /* Do not allow any kernel-managed hw_pagetable */
- if (!hwpt->parent) {
rc = -EINVAL;goto out_put_hwpt;- }
- klen = iommufd_hwpt_invalidate_info_size[cmd->data_type];
- if (!klen) {
rc = -EINVAL;goto out_put_hwpt;- }
- /*
* Copy the needed fields before reusing the ucmd buffer, this* avoids memory allocation in this path.*/- user_ptr = cmd->data_uptr;
- user_data_len = cmd->data_len;
Is it a valid case if "user_data_len < klen"?
Yes. e.g. an old qemu running on a new kernel which has new field added in the end of the data structure.
Regards, Yi Liu