[PATCH v3 3/8] iommufd: Add fault and response message definitions

[Lu Baolu]

iommu_hwpt_pgfaults represent fault messages that the userspace can
retrieve. Multiple iommu_hwpt_pgfaults might be put in an iopf group,
with the IOMMU_PGFAULT_FLAGS_LAST_PAGE flag set only for the last
iommu_hwpt_pgfault.

An iommu_hwpt_page_response is a response message that the userspace
should send to the kernel after finishing handling a group of fault
messages. The @dev_id, @pasid, and @grpid fields in the message
identify an outstanding iopf group for a device. The @addr field,
which matches the fault address of the last fault in the group, will
be used by the kernel for a sanity check.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 include/uapi/linux/iommufd.h | 67 ++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 1dfeaa2e649e..d59e839ae49e 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -692,4 +692,71 @@ struct iommu_hwpt_invalidate {
 	__u32 __reserved;
 };
 #define IOMMU_HWPT_INVALIDATE _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_INVALIDATE)
+
+/**
+ * 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
+ */
+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;
+};
+
+/**
+ * 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.
+ * @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;
+};
 #endif
-- 
2.34.1