From 4e32348ba5269aac1165f496b78189201568dd8c Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Mon, 3 Jun 2019 15:57:47 +0100 Subject: iommu: Introduce device fault data Device faults detected by IOMMU can be reported outside the IOMMU subsystem for further processing. This patch introduces a generic device fault data structure. The fault can be either an unrecoverable fault or a page request, also referred to as a recoverable fault. We only care about non internal faults that are likely to be reported to an external subsystem. Signed-off-by: Jacob Pan Signed-off-by: Jean-Philippe Brucker Signed-off-by: Liu, Yi L Signed-off-by: Ashok Raj Signed-off-by: Eric Auger Signed-off-by: Joerg Roedel --- include/uapi/linux/iommu.h | 118 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 include/uapi/linux/iommu.h (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h new file mode 100644 index 000000000000..796402174d6c --- /dev/null +++ b/include/uapi/linux/iommu.h @@ -0,0 +1,118 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * IOMMU user API definitions + */ + +#ifndef _UAPI_IOMMU_H +#define _UAPI_IOMMU_H + +#include + +#define IOMMU_FAULT_PERM_READ (1 << 0) /* read */ +#define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */ +#define IOMMU_FAULT_PERM_EXEC (1 << 2) /* exec */ +#define IOMMU_FAULT_PERM_PRIV (1 << 3) /* privileged */ + +/* Generic fault types, can be expanded IRQ remapping fault */ +enum iommu_fault_type { + IOMMU_FAULT_DMA_UNRECOV = 1, /* unrecoverable fault */ + IOMMU_FAULT_PAGE_REQ, /* page request fault */ +}; + +enum iommu_fault_reason { + IOMMU_FAULT_REASON_UNKNOWN = 0, + + /* Could not access the PASID table (fetch caused external abort) */ + IOMMU_FAULT_REASON_PASID_FETCH, + + /* PASID entry is invalid or has configuration errors */ + IOMMU_FAULT_REASON_BAD_PASID_ENTRY, + + /* + * PASID is out of range (e.g. exceeds the maximum PASID + * supported by the IOMMU) or disabled. + */ + IOMMU_FAULT_REASON_PASID_INVALID, + + /* + * An external abort occurred fetching (or updating) a translation + * table descriptor + */ + IOMMU_FAULT_REASON_WALK_EABT, + + /* + * Could not access the page table entry (Bad address), + * actual translation fault + */ + IOMMU_FAULT_REASON_PTE_FETCH, + + /* Protection flag check failed */ + IOMMU_FAULT_REASON_PERMISSION, + + /* access flag check failed */ + IOMMU_FAULT_REASON_ACCESS, + + /* Output address of a translation stage caused Address Size fault */ + IOMMU_FAULT_REASON_OOR_ADDRESS, +}; + +/** + * struct iommu_fault_unrecoverable - Unrecoverable fault data + * @reason: reason of the fault, from &enum iommu_fault_reason + * @flags: parameters of this fault (IOMMU_FAULT_UNRECOV_* values) + * @pasid: Process Address Space ID + * @perm: requested permission access using by the incoming transaction + * (IOMMU_FAULT_PERM_* values) + * @addr: offending page address + * @fetch_addr: address that caused a fetch abort, if any + */ +struct iommu_fault_unrecoverable { + __u32 reason; +#define IOMMU_FAULT_UNRECOV_PASID_VALID (1 << 0) +#define IOMMU_FAULT_UNRECOV_ADDR_VALID (1 << 1) +#define IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID (1 << 2) + __u32 flags; + __u32 pasid; + __u32 perm; + __u64 addr; + __u64 fetch_addr; +}; + +/** + * struct iommu_fault_page_request - Page Request data + * @flags: encodes whether the corresponding fields are valid and whether this + * is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values) + * @pasid: Process Address Space ID + * @grpid: Page Request Group Index + * @perm: requested page permissions (IOMMU_FAULT_PERM_* values) + * @addr: page address + * @private_data: device-specific private information + */ +struct iommu_fault_page_request { +#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID (1 << 0) +#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE (1 << 1) +#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA (1 << 2) + __u32 flags; + __u32 pasid; + __u32 grpid; + __u32 perm; + __u64 addr; + __u64 private_data[2]; +}; + +/** + * struct iommu_fault - Generic fault data + * @type: fault type from &enum iommu_fault_type + * @padding: reserved for future use (should be zero) + * @event: fault event, when @type is %IOMMU_FAULT_DMA_UNRECOV + * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ + */ +struct iommu_fault { + __u32 type; + __u32 padding; + union { + struct iommu_fault_unrecoverable event; + struct iommu_fault_page_request prm; + }; +}; +#endif /* _UAPI_IOMMU_H */ -- cgit v1.2.3 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 v1.2.3 From 58b55c859ac00c6845b6aed8852c541bc204c935 Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Wed, 12 Jun 2019 18:59:38 +0100 Subject: iommu: Add padding to struct iommu_fault Ease future extensions of struct iommu_fault_page_request and struct iommu_fault_unrecoverable by adding a few bytes of padding. That way, a new field can be added to either of these structures by simply introducing a new flag. To extend it after the size limit is reached, a new fault reporting structure will have to be negotiated with userspace. With 56 bytes of padding, the total size of iommu_fault is 64 bytes and fits in a cache line on a lot of contemporary machines, while providing 16 and 24 bytes of extension to structures iommu_fault_page_request and iommu_fault_unrecoverable respectively. Signed-off-by: Jean-Philippe Brucker Acked-by: Jacob Pan Reviewed-by: Eric Auger Signed-off-by: Joerg Roedel --- include/uapi/linux/iommu.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h index f45d8e9e59c3..fc00c5d4741b 100644 --- a/include/uapi/linux/iommu.h +++ b/include/uapi/linux/iommu.h @@ -106,6 +106,7 @@ struct iommu_fault_page_request { * @padding: reserved for future use (should be zero) * @event: fault event, when @type is %IOMMU_FAULT_DMA_UNRECOV * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ + * @padding2: sets the fault size to allow for future extensions */ struct iommu_fault { __u32 type; @@ -113,6 +114,7 @@ struct iommu_fault { union { struct iommu_fault_unrecoverable event; struct iommu_fault_page_request prm; + __u8 padding2[56]; }; }; -- cgit v1.2.3