From bf3255b3cfe2d06280340dbac3f44b65d3ee6da3 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Mon, 3 Jun 2019 15:57:49 +0100 Subject: iommu: Add recoverable fault reporting Some IOMMU hardware features, for example PCI PRI and Arm SMMU Stall, enable recoverable I/O page faults. Allow IOMMU drivers to report PRI Page Requests and Stall events through the new fault reporting API. The consumer of the fault can be either an I/O page fault handler in the host, or a guest OS. Once handled, the fault must be completed by sending a page response back to the IOMMU. Add an iommu_page_response() function to complete a page fault. There are two ways to extend the userspace API: * Add a field to iommu_page_response and a flag to iommu_page_response::flags describing the validity of this field. * Introduce a new iommu_page_response_X structure with a different version number. The kernel must then support both versions. Signed-off-by: Jacob Pan Signed-off-by: Jean-Philippe Brucker Signed-off-by: Joerg Roedel --- include/uapi/linux/iommu.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h index 796402174d6c..f45d8e9e59c3 100644 --- a/include/uapi/linux/iommu.h +++ b/include/uapi/linux/iommu.h @@ -115,4 +115,39 @@ struct iommu_fault { struct iommu_fault_page_request prm; }; }; + +/** + * enum iommu_page_response_code - Return status of fault handlers + * @IOMMU_PAGE_RESP_SUCCESS: Fault has been handled and the page tables + * populated, retry the access. This is "Success" in PCI PRI. + * @IOMMU_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from + * this device if possible. This is "Response Failure" in PCI PRI. + * @IOMMU_PAGE_RESP_INVALID: Could not handle this fault, don't retry the + * access. This is "Invalid Request" in PCI PRI. + */ +enum iommu_page_response_code { + IOMMU_PAGE_RESP_SUCCESS = 0, + IOMMU_PAGE_RESP_INVALID, + IOMMU_PAGE_RESP_FAILURE, +}; + +/** + * struct iommu_page_response - Generic page response information + * @version: API version of this structure + * @flags: encodes whether the corresponding fields are valid + * (IOMMU_FAULT_PAGE_RESPONSE_* values) + * @pasid: Process Address Space ID + * @grpid: Page Request Group Index + * @code: response code from &enum iommu_page_response_code + */ +struct iommu_page_response { +#define IOMMU_PAGE_RESP_VERSION_1 1 + __u32 version; +#define IOMMU_PAGE_RESP_PASID_VALID (1 << 0) + __u32 flags; + __u32 pasid; + __u32 grpid; + __u32 code; +}; + #endif /* _UAPI_IOMMU_H */ -- cgit