On Mon, Jan 22, 2024 at 03:38:58PM +0800, Lu Baolu wrote:
+/**
+ * enum iommu_hwpt_pgfault_flags - flags for struct iommu_hwpt_pgfault
+ * @IOMMU_PGFAULT_FLAGS_PASID_VALID: The pasid field of the fault data is
+ * valid.
+ * @IOMMU_PGFAULT_FLAGS_LAST_PAGE: It's the last fault of a fault group.
+ */
+enum iommu_hwpt_pgfault_flags {
+ IOMMU_PGFAULT_FLAGS_PASID_VALID = (1 << 0),
+ IOMMU_PGFAULT_FLAGS_LAST_PAGE = (1 << 1),
+};
+
+/**
+ * enum iommu_hwpt_pgfault_perm - perm bits for struct iommu_hwpt_pgfault
+ * @IOMMU_PGFAULT_PERM_READ: request for read permission
+ * @IOMMU_PGFAULT_PERM_WRITE: request for write permission
+ * @IOMMU_PGFAULT_PERM_EXEC: request for execute permission
+ * @IOMMU_PGFAULT_PERM_PRIV: request for privileged permission
You are going to have to elaborate what PRIV is for.. We don't have
any concept of this in the UAPI for iommufd so what is a userspace
supposed to do if it hits this? EXEC is similar, we can't actually
enable exec permissions from userspace IIRC..
+enum iommu_hwpt_pgfault_perm {
+ IOMMU_PGFAULT_PERM_READ = (1 << 0),
+ IOMMU_PGFAULT_PERM_WRITE = (1 << 1),
+ IOMMU_PGFAULT_PERM_EXEC = (1 << 2),
+ IOMMU_PGFAULT_PERM_PRIV = (1 << 3),
+};
+
+/**
+ * struct iommu_hwpt_pgfault - iommu page fault data
+ * @size: sizeof(struct iommu_hwpt_pgfault)
+ * @flags: Combination of enum iommu_hwpt_pgfault_flags
+ * @dev_id: id of the originated device
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @perm: Combination of enum iommu_hwpt_pgfault_perm
+ * @addr: page address
+ */
+struct iommu_hwpt_pgfault {
+ __u32 size;
+ __u32 flags;
+ __u32 dev_id;
+ __u32 pasid;
+ __u32 grpid;
+ __u32 perm;
+ __u64 addr;
+};
Do we need an addr + size here? I've seen a few things where I wonder
if that might become an enhancment someday.
+/**
+ * struct iommu_hwpt_page_response - IOMMU page fault response
+ * @size: sizeof(struct iommu_hwpt_page_response)
+ * @flags: Must be set to 0
+ * @dev_id: device ID of target device for the response
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @code: response code. The supported codes include:
+ * 0: Successful; 1: Response Failure; 2: Invalid Request.
This should be an enum
+ * @addr: The fault address. Must match the addr field of the
+ * last iommu_hwpt_pgfault of a reported iopf group.
+ */
+struct iommu_hwpt_page_response {
+ __u32 size;
+ __u32 flags;
+ __u32 dev_id;
+ __u32 pasid;
+ __u32 grpid;
+ __u32 code;
+ __u64 addr;
+};
Do we want some kind of opaque ID value from the kernel here to match
request with response exactly? Or is the plan to search on the addr?