Re: [PATCH v7 2/9] iommufd: Add IOMMU_HWPT_INVALIDATE
From: Yi Liu
Date: Mon Dec 25 2023 - 22:58:31 EST
On 2023/12/22 11:19, Tian, Kevin wrote:
From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
Sent: Thursday, December 21, 2023 11:40 PM
+
+int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd)
+{
+ struct iommu_hwpt_invalidate *cmd = ucmd->cmd;
+ struct iommu_user_data_array data_array = {
+ .type = cmd->req_type,
+ .uptr = u64_to_user_ptr(cmd->reqs_uptr),
+ .entry_len = cmd->req_len,
+ .entry_num = cmd->req_num,
+ };
+ struct iommufd_hw_pagetable *hwpt;
+ u32 done_num = 0;
+ int rc;
+
+ if (cmd->req_num && (!cmd->reqs_uptr || !cmd->req_len)) {
+ rc = -EINVAL;
+ goto out;
+ }
miss a check on the __reserved field.
done.
@@ -323,6 +323,7 @@ union ucmd_buffer {
struct iommu_hwpt_alloc hwpt;
struct iommu_hwpt_get_dirty_bitmap get_dirty_bitmap;
struct iommu_hwpt_set_dirty_tracking set_dirty_tracking;
+ struct iommu_hwpt_invalidate cache;
this should be in alphabetic order. I gave this comment in v6 too:
https://lore.kernel.org/linux-iommu/BN9PR11MB5276D8406BF08B853329288C8CB4A@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
oops, I did miss it. sigh, I paid too much attention to the error code
discussion in the end. :( I've revisited the comments and should have
done now.
+/**
+ * enum iommu_hwpt_invalidate_data_type - IOMMU HWPT Cache
Invalidation
+ * Data Type
+ * @IOMMU_HWPT_INVALIDATE_DATA_VTD_S1: Invalidation data for
VTD_S1
+ */
+enum iommu_hwpt_invalidate_data_type {
+ IOMMU_HWPT_INVALIDATE_DATA_VTD_S1,
+};
Defining DATA_VTD_S1 at this point is fine, if there is no usage on
DATA_NONE. But following vtd specific definitions should be moved
to the later vtd specific patches. they are not used by the common
code anyway.
sure.
+
+/**
+ * enum iommu_hwpt_vtd_s1_invalidate_flags - Flags for Intel VT-d
+ * stage-1 cache invalidation
+ * @IOMMU_VTD_INV_FLAGS_LEAF: The LEAF flag indicates whether only
the
+ * leaf PTE caching needs to be invalidated
+ * and other paging structure caches can be
+ * preserved.
"indicates whether the invalidation applies to all-levels page structure
cache or just the leaf PTE cache"
done.
+ */
+enum iommu_hwpt_vtd_s1_invalidate_flags {
+ IOMMU_VTD_INV_FLAGS_LEAF = 1 << 0,
+};
+
+/**
+ * enum iommu_hwpt_vtd_s1_invalidate_error - Result of invalidation
"hardware error of invalidation"
done.
+ * @IOMMU_HWPT_INVALIDATE_VTD_S1_ICE: Invalidation Completion
Error, details
+ * refer to 11.4.7.1 Fault Status Register
+ * of VT-d specification.
+ * @IOMMU_HWPT_INVALIDATE_VTD_S1_ITE: Invalidation Time-out Error,
details
+ * refer to 11.4.7.1 Fault Status Register
+ * of VT-d specification.
+ */
+enum iommu_hwpt_vtd_s1_invalidate_error {
+ IOMMU_HWPT_INVALIDATE_VTD_S1_ICE = 1 << 0,
+ IOMMU_HWPT_INVALIDATE_VTD_S1_ITE = 1 << 1,
+};
+
+/**
+ * struct iommu_hwpt_vtd_s1_invalidate - Intel VT-d cache invalidation
+ * (IOMMU_HWPT_INVALIDATE_DATA_VTD_S1)
+ * @addr: The start address of the addresses to be invalidated. It needs
+ * to be 4KB aligned.
'of the range'
done.
+ * @npages: Number of contiguous 4K pages to be invalidated.
+ * @flags: Combination of enum iommu_hwpt_vtd_s1_invalidate_flags
+ * @inv_error: One of enum iommu_hwpt_vtd_s1_invalidate_error
'@hw_error'
done.
+ *
+ * The Intel VT-d specific invalidation data for user-managed stage-1 cache
+ * invalidation in nested translation. Userspace uses this structure to
+ * tell the impacted cache scope after modifying the stage-1 page table.
+ *
+ * Invalidating all the caches related to the page table by setting @addr
+ * to be 0 and @npages to be U64_MAX.
here should clarify that the invalidation applies to device TLB automatically
for VT-d.
done.
+ *
+ * @inv_error is meaningful only if the request is handled by kernel. This
+ * can be known by checking struct iommu_hwpt_invalidate::req_num
output.
+ * @inv_error only covers the errors detected by hardware after submitting
the
+ * invalidation. The software detected errors would go through the normal
+ * ioctl errno.
+ */
+struct iommu_hwpt_vtd_s1_invalidate {
+ __aligned_u64 addr;
+ __aligned_u64 npages;
+ __u32 flags;
+ __u32 inv_error;
+};
+
+/**
+ * struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE)
+ * @size: sizeof(struct iommu_hwpt_invalidate)
+ * @hwpt_id: HWPT ID of a nested HWPT for cache invalidation
+ * @reqs_uptr: User pointer to an array having @req_num of cache
invalidation
+ * requests. The request entries in the array are of fixed width
+ * @req_len, and contain a user data structure for invalidation
+ * request specific to the given hardware page table.
Just:
'User pointer to an array of driver-specific cache invalidation requests'
done.
+ * @req_type: One of enum iommu_hwpt_invalidate_data_type, defining
the data
+ * type of all the entries in the invalidation request array. It
+ * should be a type supported by the hwpt pointed by @hwpt_id.
+ * @req_len: Length (in bytes) of a request entry in the request array
+ * @req_num: Input the number of cache invalidation requests in the array.
s/req_len/entry_len, s/req_num/entry_num per the comments in last version.
+ * Output the number of requests successfully handled by kernel.
+ * @__reserved: Must be 0.
+ *
+ * Invalidate the iommu cache for user-managed page table. Modifications
on a
+ * user-managed page table should be followed by this operation to sync
cache.
+ * Each ioctl can support one or more cache invalidation requests in the
array
+ * that has a total size of @req_len * @req_num.
+ *
+ * An empty invalidation request array by setting @req_num==0 is allowed,
and
+ * @req_len and @reqs_uptr would be ignored in this case. This can be
used to
+ * check if the given @req_type is supported or not by kernel.
+ */
+struct iommu_hwpt_invalidate {
+ __u32 size;
+ __u32 hwpt_id;
+ __aligned_u64 reqs_uptr;
+ __u32 req_type;
+ __u32 req_len;
+ __u32 req_num;
+ __u32 __reserved;
+};
+#define IOMMU_HWPT_INVALIDATE _IO(IOMMUFD_TYPE,
IOMMUFD_CMD_HWPT_INVALIDATE)
#endif
--
2.34.1
--
Regards,
Yi Liu