Commit 861f96a7 authored by Lu Baolu's avatar Lu Baolu Committed by Jason Gunthorpe
Browse files

iommufd: Remove IOMMUFD_PAGE_RESP_FAILURE 

The response code of IOMMUFD_PAGE_RESP_FAILURE was defined to be
equivalent to the "Response Failure" in PCI spec, section 10.4.2.1.
This response code indicates that one or more pages within the
associated request group have encountered or caused an unrecoverable
error. Therefore, this response disables the PRI at the function.

Modern I/O virtualization technologies, like SR-IOV, share PRI among
the assignable device units. Therefore, a response failure on one unit
might cause I/O failure on other units.

Remove this response code so that user space can only respond with
SUCCESS or INVALID. The VMM is recommended to emulate a failure response
as a PRI reset, or PRI disable and changing to a non-PRI domain.

Fixes: c714f158 ("iommufd: Add fault and response message definitions")
Link: https://lore.kernel.org/r/20240710083341.44617-2-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 a11dda72

include/uapi/linux/iommufd.h

+0 −4
Original line number Diff line number Diff line
@@ -765,14 +765,10 @@ struct iommu_hwpt_pgfault { 
 * @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,

};



/**