Commit c714f158 authored by Lu Baolu's avatar Lu Baolu Committed by Jason Gunthorpe
Browse files

iommufd: Add fault and response message definitions 

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 @cookie field,
which matches the cookie field of the last fault in the group, will
be used by the kernel to look up the pending message.

Link: https://lore.kernel.org/r/20240702063444.105814-6-baolu.lu@linux.intel.com


Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 8519e689

include/uapi/linux/iommufd.h

+83 −0
Original line number Diff line number Diff line
@@ -692,4 +692,87 @@ 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: (PCIE 10.4.1) request with a PASID that has the

 *                           Execute Requested bit set in PASID TLP Prefix.

 * @IOMMU_PGFAULT_PERM_PRIV: (PCIE 10.4.1) request with a PASID that has the

 *                           Privileged Mode Requested bit set in PASID TLP

 *                           Prefix.

 */

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

 * @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: Fault address

 * @length: a hint of how much data the requestor is expecting to fetch. For

 *          example, if the PRI initiator knows it is going to do a 10MB

 *          transfer, it could fill in 10MB and the OS could pre-fault in

 *          10MB of IOVA. It's default to 0 if there's no such hint.

 * @cookie: kernel-managed cookie identifying a group of fault messages. The

 *          cookie number encoded in the last page fault of the group should

 *          be echoed back in the response message.

 */

struct iommu_hwpt_pgfault {

	__u32 flags;

	__u32 dev_id;

	__u32 pasid;

	__u32 grpid;

	__u32 perm;

	__u64 addr;

	__u32 length;

	__u32 cookie;

};



/**

 * enum iommufd_page_response_code - Return status of fault handlers

 * @IOMMUFD_PAGE_RESP_SUCCESS: Fault has been handled and the page tables

 *                             populated, retry the access. This is the

 *                             "Success" defined in PCI 10.4.2.1.

 * @IOMMUFD_PAGE_RESP_INVALID: Could not handle this fault, don't retry the

 *                             access. This is the "Invalid Request" in PCI

 *                             10.4.2.1.

 * @IOMMUFD_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from

 *                             this device if possible. This is the "Response

 *                             Failure" in PCI 10.4.2.1.

 */

enum iommufd_page_response_code {

	IOMMUFD_PAGE_RESP_SUCCESS = 0,

	IOMMUFD_PAGE_RESP_INVALID,

	IOMMUFD_PAGE_RESP_FAILURE,

};



/**

 * struct iommu_hwpt_page_response - IOMMU page fault response

 * @cookie: The kernel-managed cookie reported in the fault message.

 * @code: One of response code in enum iommufd_page_response_code.

 */

struct iommu_hwpt_page_response {

	__u32 cookie;

	__u32 code;

};

#endif