[PATCH v3 00/11] iommu: Prepare to deliver page faults to user space

[PATCH v3 00/11] iommu: Prepare to deliver page faults to user space

[Lu Baolu]

When a user-managed page table is attached to an IOMMU, it is necessary
to deliver IO page faults to user space so that they can be handled
appropriately. One use case for this is nested translation, which is
currently being discussed in the mailing list.

I have posted a RFC series [1] that describes the implementation of
delivering page faults to user space through IOMMUFD. This series has
received several comments on the IOMMU refactoring, which I am trying to
address in this series.

The major refactoring includes:

- [PATCH 01 ~ 04] Move include/uapi/linux/iommu.h to
  include/linux/iommu.h. Remove the unrecoverable fault data definition.
- [PATCH 05 ~ 06] Remove iommu_[un]register_device_fault_handler().
- [PATCH 07 ~ 11] Separate SVA and IOPF. Make IOPF a generic page fault
  handling framework. 

This is also available at github [2]. I would appreciate your feedback
on this series.

[1] https://lore.kernel.org/linux-iommu/20230530053724.232765-1-baolu.lu@linux.intel.com/
[2] https://github.com/LuBaolu/intel-iommu/commits/preparatory-io-pgfault-delivery-v3

Change log:
v3:
 - Convert the fault data structures from uAPI to kAPI.
 - Merge iopf_device_param into iommu_fault_param.
 - Add debugging on domain lifetime for iopf.
 - Remove patch "iommu: Change the return value of dev_iommu_get()".
 - Remove patch "iommu: Add helper to set iopf handler for domain".
 - Misc code refactoring and refining.

v2: https://lore.kernel.org/linux-iommu/20230727054837.147050-1-baolu.lu@linux.intel.com/
 - Remove unrecoverable fault data definition as suggested by Kevin.
 - Drop the per-device fault cookie code considering that doesn't make
   much sense for SVA.
 - Make the IOMMU page fault handling framework generic. So that it can
   avaible for use cases other than SVA.

v1: https://lore.kernel.org/linux-iommu/20230711010642.19707-1-baolu.lu@linux.intel.com/

Lu Baolu (11):
  iommu: Move iommu fault data to linux/iommu.h
  iommu/arm-smmu-v3: Remove unrecoverable faults reporting
  iommu: Remove unrecoverable fault data
  iommu: Cleanup iopf data structure definitions
  iommu: Merge iopf_device_param into iommu_fault_param
  iommu: Remove iommu_[un]register_device_fault_handler()
  iommu: Prepare for separating SVA and IOPF
  iommu: Move iopf_handler() to iommu-sva.c
  iommu: Make iommu_queue_iopf() more generic
  iommu: Add debugging on domain lifetime for iopf
  iommu: Separate SVA and IOPF in Makefile and Kconfig

 include/linux/iommu.h                         | 202 ++++++++++++++---
 drivers/iommu/iommu-sva.h                     |  71 ------
 include/uapi/linux/iommu.h                    | 161 --------------
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  14 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  47 ++--
 drivers/iommu/intel/iommu.c                   |  25 +--
 drivers/iommu/intel/svm.c                     |   1 -
 drivers/iommu/io-pgfault.c                    | 208 ++++++++----------
 drivers/iommu/iommu-sva.c                     |  49 ++++-
 drivers/iommu/iommu.c                         | 132 +++--------
 MAINTAINERS                                   |   1 -
 drivers/iommu/Kconfig                         |   4 +
 drivers/iommu/Makefile                        |   3 +-
 drivers/iommu/intel/Kconfig                   |   1 +
 14 files changed, 362 insertions(+), 557 deletions(-)
 delete mode 100644 drivers/iommu/iommu-sva.h
 delete mode 100644 include/uapi/linux/iommu.h

-- 
2.34.1

[PATCH v3 01/11] iommu: Move iommu fault data to linux/iommu.h

[Lu Baolu]

The iommu fault data is currently defined in uapi/linux/iommu.h, but is
only used inside the iommu subsystem. Move it to linux/iommu.h, where it
will be more accessible to kernel drivers.

With this done, uapi/linux/iommu.h becomes empty and can be removed from
the tree.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 include/linux/iommu.h      | 152 +++++++++++++++++++++++++++++++++-
 include/uapi/linux/iommu.h | 161 -------------------------------------
 MAINTAINERS                |   1 -
 3 files changed, 151 insertions(+), 163 deletions(-)
 delete mode 100644 include/uapi/linux/iommu.h

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 411ce9b998dc..10f17e1b6c91 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -13,7 +13,6 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <uapi/linux/iommu.h>
 
 #define IOMMU_READ	(1 << 0)
 #define IOMMU_WRITE	(1 << 1)
@@ -42,6 +41,157 @@ struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
 
+#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).
+ *         When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
+ *         must have the same PASID value as the page request. When it is clear,
+ *         the page response should not have a PASID.
+ * @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)
+#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID	(1 << 3)
+	__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
+ * @padding2: sets the fault size to allow for future extensions
+ */
+struct iommu_fault {
+	__u32	type;
+	__u32	padding;
+	union {
+		struct iommu_fault_unrecoverable event;
+		struct iommu_fault_page_request prm;
+		__u8 padding2[56];
+	};
+};
+
+/**
+ * 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
+ * @argsz: User filled size of this data
+ * @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 {
+	__u32	argsz;
+#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;
+};
+
+
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
 #define IOMMU_FAULT_WRITE	0x1
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
deleted file mode 100644
index 65d8b0234f69..000000000000
--- a/include/uapi/linux/iommu.h
+++ /dev/null
@@ -1,161 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * IOMMU user API definitions
- */
-
-#ifndef _UAPI_IOMMU_H
-#define _UAPI_IOMMU_H
-
-#include <linux/types.h>
-
-#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).
- *         When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
- *         must have the same PASID value as the page request. When it is clear,
- *         the page response should not have a PASID.
- * @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)
-#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID	(1 << 3)
-	__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
- * @padding2: sets the fault size to allow for future extensions
- */
-struct iommu_fault {
-	__u32	type;
-	__u32	padding;
-	union {
-		struct iommu_fault_unrecoverable event;
-		struct iommu_fault_page_request prm;
-		__u8 padding2[56];
-	};
-};
-
-/**
- * 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
- * @argsz: User filled size of this data
- * @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 {
-	__u32	argsz;
-#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 */
diff --git a/MAINTAINERS b/MAINTAINERS
index 660f4e9d2ac3..ae34a8e69a38 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10889,7 +10889,6 @@ F:	drivers/iommu/
 F:	include/linux/iommu.h
 F:	include/linux/iova.h
 F:	include/linux/of_iommu.h
-F:	include/uapi/linux/iommu.h
 
 IOMMUFD
 M:	Jason Gunthorpe <jgg@nvidia.com>
-- 
2.34.1

[PATCH v3 02/11] iommu/arm-smmu-v3: Remove unrecoverable faults reporting

[Lu Baolu]

No device driver registers fault handler to handle the reported
unrecoveraable faults. Remove it to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 46 ++++++---------------
 1 file changed, 13 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index ee70687f060b..e08d2e27a9e5 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1469,7 +1469,6 @@ arm_smmu_find_master(struct arm_smmu_device *smmu, u32 sid)
 static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
 {
 	int ret;
-	u32 reason;
 	u32 perm = 0;
 	struct arm_smmu_master *master;
 	bool ssid_valid = evt[0] & EVTQ_0_SSV;
@@ -1479,16 +1478,9 @@ static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
 
 	switch (FIELD_GET(EVTQ_0_ID, evt[0])) {
 	case EVT_ID_TRANSLATION_FAULT:
-		reason = IOMMU_FAULT_REASON_PTE_FETCH;
-		break;
 	case EVT_ID_ADDR_SIZE_FAULT:
-		reason = IOMMU_FAULT_REASON_OOR_ADDRESS;
-		break;
 	case EVT_ID_ACCESS_FAULT:
-		reason = IOMMU_FAULT_REASON_ACCESS;
-		break;
 	case EVT_ID_PERMISSION_FAULT:
-		reason = IOMMU_FAULT_REASON_PERMISSION;
 		break;
 	default:
 		return -EOPNOTSUPP;
@@ -1498,6 +1490,9 @@ static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
 	if (evt[1] & EVTQ_1_S2)
 		return -EFAULT;
 
+	if (!(evt[1] & EVTQ_1_STALL))
+		return -EOPNOTSUPP;
+
 	if (evt[1] & EVTQ_1_RnW)
 		perm |= IOMMU_FAULT_PERM_READ;
 	else
@@ -1509,32 +1504,17 @@ static int arm_smmu_handle_evt(struct arm_smmu_device *smmu, u64 *evt)
 	if (evt[1] & EVTQ_1_PnU)
 		perm |= IOMMU_FAULT_PERM_PRIV;
 
-	if (evt[1] & EVTQ_1_STALL) {
-		flt->type = IOMMU_FAULT_PAGE_REQ;
-		flt->prm = (struct iommu_fault_page_request) {
-			.flags = IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE,
-			.grpid = FIELD_GET(EVTQ_1_STAG, evt[1]),
-			.perm = perm,
-			.addr = FIELD_GET(EVTQ_2_ADDR, evt[2]),
-		};
+	flt->type = IOMMU_FAULT_PAGE_REQ;
+	flt->prm = (struct iommu_fault_page_request) {
+		.flags = IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE,
+		.grpid = FIELD_GET(EVTQ_1_STAG, evt[1]),
+		.perm = perm,
+		.addr = FIELD_GET(EVTQ_2_ADDR, evt[2]),
+	};
 
-		if (ssid_valid) {
-			flt->prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
-			flt->prm.pasid = FIELD_GET(EVTQ_0_SSID, evt[0]);
-		}
-	} else {
-		flt->type = IOMMU_FAULT_DMA_UNRECOV;
-		flt->event = (struct iommu_fault_unrecoverable) {
-			.reason = reason,
-			.flags = IOMMU_FAULT_UNRECOV_ADDR_VALID,
-			.perm = perm,
-			.addr = FIELD_GET(EVTQ_2_ADDR, evt[2]),
-		};
-
-		if (ssid_valid) {
-			flt->event.flags |= IOMMU_FAULT_UNRECOV_PASID_VALID;
-			flt->event.pasid = FIELD_GET(EVTQ_0_SSID, evt[0]);
-		}
+	if (ssid_valid) {
+		flt->prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
+		flt->prm.pasid = FIELD_GET(EVTQ_0_SSID, evt[0]);
 	}
 
 	mutex_lock(&smmu->streams_mutex);
-- 
2.34.1

[PATCH v3 03/11] iommu: Remove unrecoverable fault data

[Lu Baolu]

The unrecoverable fault data is not used anywhere. Remove it to avoid
dead code.

Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 include/linux/iommu.h | 70 +------------------------------------------
 1 file changed, 1 insertion(+), 69 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 10f17e1b6c91..e65ba78f3d38 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -48,69 +48,9 @@ struct iommu_dma_cookie;
 
 /* 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
@@ -140,19 +80,11 @@ struct iommu_fault_page_request {
 /**
  * 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
- * @padding2: sets the fault size to allow for future extensions
  */
 struct iommu_fault {
 	__u32	type;
-	__u32	padding;
-	union {
-		struct iommu_fault_unrecoverable event;
-		struct iommu_fault_page_request prm;
-		__u8 padding2[56];
-	};
+	struct iommu_fault_page_request prm;
 };
 
 /**
-- 
2.34.1

[PATCH v3 04/11] iommu: Cleanup iopf data structure definitions

[Lu Baolu]

struct iommu_fault_page_request and struct iommu_page_response are not
part of uAPI anymore. Convert them to data structures for kAPI.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h      | 27 +++++++++++----------------
 drivers/iommu/io-pgfault.c |  1 -
 drivers/iommu/iommu.c      |  4 ----
 3 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e65ba78f3d38..fd11bfa278f1 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -69,12 +69,12 @@ struct iommu_fault_page_request {
 #define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE	(1 << 1)
 #define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA	(1 << 2)
 #define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID	(1 << 3)
-	__u32	flags;
-	__u32	pasid;
-	__u32	grpid;
-	__u32	perm;
-	__u64	addr;
-	__u64	private_data[2];
+	u32	flags;
+	u32	pasid;
+	u32	grpid;
+	u32	perm;
+	u64	addr;
+	u64	private_data[2];
 };
 
 /**
@@ -83,7 +83,7 @@ struct iommu_fault_page_request {
  * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ
  */
 struct iommu_fault {
-	__u32	type;
+	u32 type;
 	struct iommu_fault_page_request prm;
 };
 
@@ -104,8 +104,6 @@ enum iommu_page_response_code {
 
 /**
  * struct iommu_page_response - Generic page response information
- * @argsz: User filled size of this data
- * @version: API version of this structure
  * @flags: encodes whether the corresponding fields are valid
  *         (IOMMU_FAULT_PAGE_RESPONSE_* values)
  * @pasid: Process Address Space ID
@@ -113,14 +111,11 @@ enum iommu_page_response_code {
  * @code: response code from &enum iommu_page_response_code
  */
 struct iommu_page_response {
-	__u32	argsz;
-#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;
+	u32	flags;
+	u32	pasid;
+	u32	grpid;
+	u32	code;
 };
 
 
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index e5b8b9110c13..24b5545352ae 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -56,7 +56,6 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 			       enum iommu_page_response_code status)
 {
 	struct iommu_page_response resp = {
-		.version		= IOMMU_PAGE_RESP_VERSION_1,
 		.pasid			= iopf->fault.prm.pasid,
 		.grpid			= iopf->fault.prm.grpid,
 		.code			= status,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 71b9c41f2a9e..1aae0264bbb8 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1455,10 +1455,6 @@ int iommu_page_response(struct device *dev,
 	if (!param || !param->fault_param)
 		return -EINVAL;
 
-	if (msg->version != IOMMU_PAGE_RESP_VERSION_1 ||
-	    msg->flags & ~IOMMU_PAGE_RESP_PASID_VALID)
-		return -EINVAL;
-
 	/* Only send response if there is a fault report pending */
 	mutex_lock(&param->fault_param->lock);
 	if (list_empty(&param->fault_param->faults)) {
-- 
2.34.1

[PATCH v3 05/11] iommu: Merge iopf_device_param into iommu_fault_param

[Lu Baolu]

The struct dev_iommu contains two pointers, fault_param and iopf_param.
The fault_param pointer points to a data structure that is used to store
pending faults that are awaiting responses. The iopf_param pointer points
to a data structure that is used to store partial faults that are part of
a Page Request Group.

The fault_param and iopf_param pointers are essentially duplicate. This
causes memory waste. Merge the iopf_device_param pointer into the
iommu_fault_param pointer to consolidate the code and save memory. The
consolidated pointer would be allocated on demand when the device driver
enables the iopf on device, and would be freed after iopf is disabled.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h      |  20 +++++--
 drivers/iommu/io-pgfault.c | 113 ++++++++++++++++++-------------------
 drivers/iommu/iommu.c      |  34 ++---------
 3 files changed, 76 insertions(+), 91 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fd11bfa278f1..78e14a7440f5 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -40,6 +40,7 @@ struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
+struct iopf_queue;
 
 #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
 #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
@@ -472,21 +473,31 @@ struct iommu_fault_event {
  * struct iommu_fault_param - per-device IOMMU fault data
  * @handler: Callback function to handle IOMMU faults at device level
  * @data: handler private data
- * @faults: holds the pending faults which needs response
  * @lock: protect pending faults list
+ * @dev: the device that owns this param
+ * @queue: IOPF queue
+ * @queue_list: index into queue->devices
+ * @partial: faults that are part of a Page Request Group for which the last
+ *           request hasn't been submitted yet.
+ * @faults: holds the pending faults which needs response
  */
 struct iommu_fault_param {
 	iommu_dev_fault_handler_t handler;
 	void *data;
-	struct list_head faults;
-	struct mutex lock;
+	struct mutex			lock;
+
+	struct device			*dev;
+	struct iopf_queue		*queue;
+	struct list_head		queue_list;
+
+	struct list_head		partial;
+	struct list_head		faults;
 };
 
 /**
  * struct dev_iommu - Collection of per-device IOMMU data
  *
  * @fault_param: IOMMU detected device fault reporting data
- * @iopf_param:	 I/O Page Fault queue and data
  * @fwspec:	 IOMMU fwspec data
  * @iommu_dev:	 IOMMU device this device is linked to
  * @priv:	 IOMMU Driver private data
@@ -501,7 +512,6 @@ struct iommu_fault_param {
 struct dev_iommu {
 	struct mutex lock;
 	struct iommu_fault_param	*fault_param;
-	struct iopf_device_param	*iopf_param;
 	struct iommu_fwspec		*fwspec;
 	struct iommu_device		*iommu_dev;
 	void				*priv;
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 24b5545352ae..b1cf28055525 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -25,21 +25,6 @@ struct iopf_queue {
 	struct mutex			lock;
 };
 
-/**
- * struct iopf_device_param - IO Page Fault data attached to a device
- * @dev: the device that owns this param
- * @queue: IOPF queue
- * @queue_list: index into queue->devices
- * @partial: faults that are part of a Page Request Group for which the last
- *           request hasn't been submitted yet.
- */
-struct iopf_device_param {
-	struct device			*dev;
-	struct iopf_queue		*queue;
-	struct list_head		queue_list;
-	struct list_head		partial;
-};
-
 struct iopf_fault {
 	struct iommu_fault		fault;
 	struct list_head		list;
@@ -144,7 +129,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
 	int ret;
 	struct iopf_group *group;
 	struct iopf_fault *iopf, *next;
-	struct iopf_device_param *iopf_param;
+	struct iommu_fault_param *iopf_param;
 
 	struct device *dev = cookie;
 	struct dev_iommu *param = dev->iommu;
@@ -159,7 +144,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
 	 * As long as we're holding param->lock, the queue can't be unlinked
 	 * from the device and therefore cannot disappear.
 	 */
-	iopf_param = param->iopf_param;
+	iopf_param = param->fault_param;
 	if (!iopf_param)
 		return -ENODEV;
 
@@ -229,14 +214,14 @@ EXPORT_SYMBOL_GPL(iommu_queue_iopf);
 int iopf_queue_flush_dev(struct device *dev)
 {
 	int ret = 0;
-	struct iopf_device_param *iopf_param;
+	struct iommu_fault_param *iopf_param;
 	struct dev_iommu *param = dev->iommu;
 
 	if (!param)
 		return -ENODEV;
 
 	mutex_lock(&param->lock);
-	iopf_param = param->iopf_param;
+	iopf_param = param->fault_param;
 	if (iopf_param)
 		flush_workqueue(iopf_param->queue->wq);
 	else
@@ -260,7 +245,7 @@ EXPORT_SYMBOL_GPL(iopf_queue_flush_dev);
 int iopf_queue_discard_partial(struct iopf_queue *queue)
 {
 	struct iopf_fault *iopf, *next;
-	struct iopf_device_param *iopf_param;
+	struct iommu_fault_param *iopf_param;
 
 	if (!queue)
 		return -EINVAL;
@@ -287,34 +272,38 @@ EXPORT_SYMBOL_GPL(iopf_queue_discard_partial);
  */
 int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev)
 {
-	int ret = -EBUSY;
-	struct iopf_device_param *iopf_param;
+	int ret = 0;
 	struct dev_iommu *param = dev->iommu;
-
-	if (!param)
-		return -ENODEV;
-
-	iopf_param = kzalloc(sizeof(*iopf_param), GFP_KERNEL);
-	if (!iopf_param)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&iopf_param->partial);
-	iopf_param->queue = queue;
-	iopf_param->dev = dev;
+	struct iommu_fault_param *fault_param;
 
 	mutex_lock(&queue->lock);
 	mutex_lock(&param->lock);
-	if (!param->iopf_param) {
-		list_add(&iopf_param->queue_list, &queue->devices);
-		param->iopf_param = iopf_param;
-		ret = 0;
+	if (param->fault_param) {
+		ret = -EBUSY;
+		goto done_unlock;
 	}
+
+	get_device(dev);
+	fault_param = kzalloc(sizeof(*fault_param), GFP_KERNEL);
+	if (!fault_param) {
+		put_device(dev);
+		ret = -ENOMEM;
+		goto done_unlock;
+	}
+
+	mutex_init(&fault_param->lock);
+	INIT_LIST_HEAD(&fault_param->faults);
+	INIT_LIST_HEAD(&fault_param->partial);
+	fault_param->dev = dev;
+	list_add(&fault_param->queue_list, &queue->devices);
+	fault_param->queue = queue;
+
+	param->fault_param = fault_param;
+
+done_unlock:
 	mutex_unlock(&param->lock);
 	mutex_unlock(&queue->lock);
 
-	if (ret)
-		kfree(iopf_param);
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(iopf_queue_add_device);
@@ -330,34 +319,42 @@ EXPORT_SYMBOL_GPL(iopf_queue_add_device);
  */
 int iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev)
 {
-	int ret = -EINVAL;
+	int ret = 0;
 	struct iopf_fault *iopf, *next;
-	struct iopf_device_param *iopf_param;
 	struct dev_iommu *param = dev->iommu;
-
-	if (!param || !queue)
-		return -EINVAL;
+	struct iommu_fault_param *fault_param = param->fault_param;
 
 	mutex_lock(&queue->lock);
 	mutex_lock(&param->lock);
-	iopf_param = param->iopf_param;
-	if (iopf_param && iopf_param->queue == queue) {
-		list_del(&iopf_param->queue_list);
-		param->iopf_param = NULL;
-		ret = 0;
+	if (!fault_param) {
+		ret = -ENODEV;
+		goto unlock;
 	}
-	mutex_unlock(&param->lock);
-	mutex_unlock(&queue->lock);
-	if (ret)
-		return ret;
+
+	if (fault_param->queue != queue) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	if (!list_empty(&fault_param->faults)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	list_del(&fault_param->queue_list);
 
 	/* Just in case some faults are still stuck */
-	list_for_each_entry_safe(iopf, next, &iopf_param->partial, list)
+	list_for_each_entry_safe(iopf, next, &fault_param->partial, list)
 		kfree(iopf);
 
-	kfree(iopf_param);
+	param->fault_param = NULL;
+	kfree(fault_param);
+	put_device(dev);
+unlock:
+	mutex_unlock(&param->lock);
+	mutex_unlock(&queue->lock);
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(iopf_queue_remove_device);
 
@@ -403,7 +400,7 @@ EXPORT_SYMBOL_GPL(iopf_queue_alloc);
  */
 void iopf_queue_free(struct iopf_queue *queue)
 {
-	struct iopf_device_param *iopf_param, *next;
+	struct iommu_fault_param *iopf_param, *next;
 
 	if (!queue)
 		return;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 1aae0264bbb8..89e101baa08b 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1316,27 +1316,18 @@ int iommu_register_device_fault_handler(struct device *dev,
 	struct dev_iommu *param = dev->iommu;
 	int ret = 0;
 
-	if (!param)
+	if (!param || !param->fault_param)
 		return -EINVAL;
 
 	mutex_lock(&param->lock);
 	/* Only allow one fault handler registered for each device */
-	if (param->fault_param) {
+	if (param->fault_param->handler) {
 		ret = -EBUSY;
 		goto done_unlock;
 	}
 
-	get_device(dev);
-	param->fault_param = kzalloc(sizeof(*param->fault_param), GFP_KERNEL);
-	if (!param->fault_param) {
-		put_device(dev);
-		ret = -ENOMEM;
-		goto done_unlock;
-	}
 	param->fault_param->handler = handler;
 	param->fault_param->data = data;
-	mutex_init(&param->fault_param->lock);
-	INIT_LIST_HEAD(&param->fault_param->faults);
 
 done_unlock:
 	mutex_unlock(&param->lock);
@@ -1357,29 +1348,16 @@ EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler);
 int iommu_unregister_device_fault_handler(struct device *dev)
 {
 	struct dev_iommu *param = dev->iommu;
-	int ret = 0;
 
-	if (!param)
+	if (!param || !param->fault_param)
 		return -EINVAL;
 
 	mutex_lock(&param->lock);
-
-	if (!param->fault_param)
-		goto unlock;
-
-	/* we cannot unregister handler if there are pending faults */
-	if (!list_empty(&param->fault_param->faults)) {
-		ret = -EBUSY;
-		goto unlock;
-	}
-
-	kfree(param->fault_param);
-	param->fault_param = NULL;
-	put_device(dev);
-unlock:
+	param->fault_param->handler = NULL;
+	param->fault_param->data = NULL;
 	mutex_unlock(&param->lock);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler);
 
-- 
2.34.1

[PATCH v3 06/11] iommu: Remove iommu_[un]register_device_fault_handler()

[Lu Baolu]

The individual iommu driver reports the iommu page faults by calling
iommu_report_device_fault(), where a pre-registered device fault handler
is called to route the fault to another fault handler installed on the
corresponding iommu domain.

The pre-registered device fault handler is static and won't be dynamic
as the fault handler is eventually per iommu domain. Replace calling
device fault handler with iommu_queue_iopf().

After this replacement, the registering and unregistering fault handler
interfaces are not needed anywhere. Remove the interfaces and the related
data structures to avoid dead code.

Convert cookie parameter of iommu_queue_iopf() into a device pointer that
is really passed.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 include/linux/iommu.h                         | 23 ------
 drivers/iommu/iommu-sva.h                     |  4 +-
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 13 +---
 drivers/iommu/intel/iommu.c                   | 24 ++----
 drivers/iommu/io-pgfault.c                    |  6 +-
 drivers/iommu/iommu.c                         | 76 +------------------
 6 files changed, 13 insertions(+), 133 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 78e14a7440f5..8243d72098ea 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -126,7 +126,6 @@ struct iommu_page_response {
 
 typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
 			struct device *, unsigned long, int, void *);
-typedef int (*iommu_dev_fault_handler_t)(struct iommu_fault *, void *);
 
 struct iommu_domain_geometry {
 	dma_addr_t aperture_start; /* First address that can be mapped    */
@@ -471,8 +470,6 @@ struct iommu_fault_event {
 
 /**
  * struct iommu_fault_param - per-device IOMMU fault data
- * @handler: Callback function to handle IOMMU faults at device level
- * @data: handler private data
  * @lock: protect pending faults list
  * @dev: the device that owns this param
  * @queue: IOPF queue
@@ -482,8 +479,6 @@ struct iommu_fault_event {
  * @faults: holds the pending faults which needs response
  */
 struct iommu_fault_param {
-	iommu_dev_fault_handler_t handler;
-	void *data;
 	struct mutex			lock;
 
 	struct device			*dev;
@@ -616,11 +611,6 @@ extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
 extern struct iommu_group *iommu_group_get(struct device *dev);
 extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group);
 extern void iommu_group_put(struct iommu_group *group);
-extern int iommu_register_device_fault_handler(struct device *dev,
-					iommu_dev_fault_handler_t handler,
-					void *data);
-
-extern int iommu_unregister_device_fault_handler(struct device *dev);
 
 extern int iommu_report_device_fault(struct device *dev,
 				     struct iommu_fault_event *evt);
@@ -1006,19 +996,6 @@ static inline void iommu_group_put(struct iommu_group *group)
 {
 }
 
-static inline
-int iommu_register_device_fault_handler(struct device *dev,
-					iommu_dev_fault_handler_t handler,
-					void *data)
-{
-	return -ENODEV;
-}
-
-static inline int iommu_unregister_device_fault_handler(struct device *dev)
-{
-	return 0;
-}
-
 static inline
 int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt)
 {
diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
index 54946b5a7caf..de7819c796ce 100644
--- a/drivers/iommu/iommu-sva.h
+++ b/drivers/iommu/iommu-sva.h
@@ -13,7 +13,7 @@ struct iommu_fault;
 struct iopf_queue;
 
 #ifdef CONFIG_IOMMU_SVA
-int iommu_queue_iopf(struct iommu_fault *fault, void *cookie);
+int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev);
 
 int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev);
 int iopf_queue_remove_device(struct iopf_queue *queue,
@@ -26,7 +26,7 @@ enum iommu_page_response_code
 iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
 
 #else /* CONFIG_IOMMU_SVA */
-static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
+static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 {
 	return -ENODEV;
 }
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 5e6b39881c04..7748ee30f8c0 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -437,7 +437,6 @@ bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master)
 
 static int arm_smmu_master_sva_enable_iopf(struct arm_smmu_master *master)
 {
-	int ret;
 	struct device *dev = master->dev;
 
 	/*
@@ -450,16 +449,7 @@ static int arm_smmu_master_sva_enable_iopf(struct arm_smmu_master *master)
 	if (!master->iopf_enabled)
 		return -EINVAL;
 
-	ret = iopf_queue_add_device(master->smmu->evtq.iopf, dev);
-	if (ret)
-		return ret;
-
-	ret = iommu_register_device_fault_handler(dev, iommu_queue_iopf, dev);
-	if (ret) {
-		iopf_queue_remove_device(master->smmu->evtq.iopf, dev);
-		return ret;
-	}
-	return 0;
+	return iopf_queue_add_device(master->smmu->evtq.iopf, dev);
 }
 
 static void arm_smmu_master_sva_disable_iopf(struct arm_smmu_master *master)
@@ -469,7 +459,6 @@ static void arm_smmu_master_sva_disable_iopf(struct arm_smmu_master *master)
 	if (!master->iopf_enabled)
 		return;
 
-	iommu_unregister_device_fault_handler(dev);
 	iopf_queue_remove_device(master->smmu->evtq.iopf, dev);
 }
 
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index dd8ff358867d..35839ef69089 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4574,23 +4574,15 @@ static int intel_iommu_enable_iopf(struct device *dev)
 	if (ret)
 		return ret;
 
-	ret = iommu_register_device_fault_handler(dev, iommu_queue_iopf, dev);
-	if (ret)
-		goto iopf_remove_device;
-
 	ret = pci_enable_pri(pdev, PRQ_DEPTH);
-	if (ret)
-		goto iopf_unregister_handler;
+	if (ret) {
+		iopf_queue_remove_device(iommu->iopf_queue, dev);
+		return ret;
+	}
+
 	info->pri_enabled = 1;
 
 	return 0;
-
-iopf_unregister_handler:
-	iommu_unregister_device_fault_handler(dev);
-iopf_remove_device:
-	iopf_queue_remove_device(iommu->iopf_queue, dev);
-
-	return ret;
 }
 
 static int intel_iommu_disable_iopf(struct device *dev)
@@ -4613,11 +4605,9 @@ static int intel_iommu_disable_iopf(struct device *dev)
 	info->pri_enabled = 0;
 
 	/*
-	 * With PRI disabled and outstanding PRQs drained, unregistering
-	 * fault handler and removing device from iopf queue should never
-	 * fail.
+	 * With PRI disabled and outstanding PRQs drained, removing device
+	 * from iopf queue should never fail.
 	 */
-	WARN_ON(iommu_unregister_device_fault_handler(dev));
 	WARN_ON(iopf_queue_remove_device(iommu->iopf_queue, dev));
 
 	return 0;
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index b1cf28055525..31832aeacdba 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -87,7 +87,7 @@ static void iopf_handler(struct work_struct *work)
 /**
  * iommu_queue_iopf - IO Page Fault handler
  * @fault: fault event
- * @cookie: struct device, passed to iommu_register_device_fault_handler.
+ * @dev: struct device.
  *
  * Add a fault to the device workqueue, to be handled by mm.
  *
@@ -124,14 +124,12 @@ static void iopf_handler(struct work_struct *work)
  *
  * Return: 0 on success and <0 on error.
  */
-int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
+int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 {
 	int ret;
 	struct iopf_group *group;
 	struct iopf_fault *iopf, *next;
 	struct iommu_fault_param *iopf_param;
-
-	struct device *dev = cookie;
 	struct dev_iommu *param = dev->iommu;
 
 	lockdep_assert_held(&param->lock);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 89e101baa08b..b280b9f4d8b4 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1291,76 +1291,6 @@ void iommu_group_put(struct iommu_group *group)
 }
 EXPORT_SYMBOL_GPL(iommu_group_put);
 
-/**
- * iommu_register_device_fault_handler() - Register a device fault handler
- * @dev: the device
- * @handler: the fault handler
- * @data: private data passed as argument to the handler
- *
- * When an IOMMU fault event is received, this handler gets called with the
- * fault event and data as argument. The handler should return 0 on success. If
- * the fault is recoverable (IOMMU_FAULT_PAGE_REQ), the consumer should also
- * complete the fault by calling iommu_page_response() with one of the following
- * response code:
- * - IOMMU_PAGE_RESP_SUCCESS: retry the translation
- * - IOMMU_PAGE_RESP_INVALID: terminate the fault
- * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop reporting
- *   page faults if possible.
- *
- * Return 0 if the fault handler was installed successfully, or an error.
- */
-int iommu_register_device_fault_handler(struct device *dev,
-					iommu_dev_fault_handler_t handler,
-					void *data)
-{
-	struct dev_iommu *param = dev->iommu;
-	int ret = 0;
-
-	if (!param || !param->fault_param)
-		return -EINVAL;
-
-	mutex_lock(&param->lock);
-	/* Only allow one fault handler registered for each device */
-	if (param->fault_param->handler) {
-		ret = -EBUSY;
-		goto done_unlock;
-	}
-
-	param->fault_param->handler = handler;
-	param->fault_param->data = data;
-
-done_unlock:
-	mutex_unlock(&param->lock);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler);
-
-/**
- * iommu_unregister_device_fault_handler() - Unregister the device fault handler
- * @dev: the device
- *
- * Remove the device fault handler installed with
- * iommu_register_device_fault_handler().
- *
- * Return 0 on success, or an error.
- */
-int iommu_unregister_device_fault_handler(struct device *dev)
-{
-	struct dev_iommu *param = dev->iommu;
-
-	if (!param || !param->fault_param)
-		return -EINVAL;
-
-	mutex_lock(&param->lock);
-	param->fault_param->handler = NULL;
-	param->fault_param->data = NULL;
-	mutex_unlock(&param->lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler);
-
 /**
  * iommu_report_device_fault() - Report fault event to device driver
  * @dev: the device
@@ -1385,10 +1315,6 @@ int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt)
 	/* we only report device fault if there is a handler registered */
 	mutex_lock(&param->lock);
 	fparam = param->fault_param;
-	if (!fparam || !fparam->handler) {
-		ret = -EINVAL;
-		goto done_unlock;
-	}
 
 	if (evt->fault.type == IOMMU_FAULT_PAGE_REQ &&
 	    (evt->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE)) {
@@ -1403,7 +1329,7 @@ int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt)
 		mutex_unlock(&fparam->lock);
 	}
 
-	ret = fparam->handler(&evt->fault, fparam->data);
+	ret = iommu_queue_iopf(&evt->fault, dev);
 	if (ret && evt_pending) {
 		mutex_lock(&fparam->lock);
 		list_del(&evt_pending->list);
-- 
2.34.1

[PATCH v3 07/11] iommu: Prepare for separating SVA and IOPF

[Lu Baolu]

Move iopf_group data structure to iommu.h. This is being done to make it
a minimal set of faults that a domain's page fault handler should handle.

Add two new helpers for the domain's page fault handler:
- iopf_free_group: free a fault group after all faults in the group are
  handled.
- iopf_queue_work: queue a given work item for a fault group.

This will simplify the sequential patches.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h      | 12 ++++++++++
 drivers/iommu/io-pgfault.c | 49 ++++++++++++++++++++++----------------
 2 files changed, 41 insertions(+), 20 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8243d72098ea..ff292eea9d31 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -516,6 +516,18 @@ struct dev_iommu {
 	u32				require_direct:1;
 };
 
+struct iopf_fault {
+	struct iommu_fault		fault;
+	struct list_head		list;
+};
+
+struct iopf_group {
+	struct iopf_fault		last_fault;
+	struct list_head		faults;
+	struct work_struct		work;
+	struct device			*dev;
+};
+
 int iommu_device_register(struct iommu_device *iommu,
 			  const struct iommu_ops *ops,
 			  struct device *hwdev);
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 31832aeacdba..d07586cd37fd 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -25,17 +25,17 @@ struct iopf_queue {
 	struct mutex			lock;
 };
 
-struct iopf_fault {
-	struct iommu_fault		fault;
-	struct list_head		list;
-};
+static void iopf_free_group(struct iopf_group *group)
+{
+	struct iopf_fault *iopf, *next;
 
-struct iopf_group {
-	struct iopf_fault		last_fault;
-	struct list_head		faults;
-	struct work_struct		work;
-	struct device			*dev;
-};
+	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+		if (!(iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
+			kfree(iopf);
+	}
+
+	kfree(group);
+}
 
 static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 			       enum iommu_page_response_code status)
@@ -55,9 +55,9 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 
 static void iopf_handler(struct work_struct *work)
 {
+	struct iopf_fault *iopf;
 	struct iopf_group *group;
 	struct iommu_domain *domain;
-	struct iopf_fault *iopf, *next;
 	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
 
 	group = container_of(work, struct iopf_group, work);
@@ -66,7 +66,7 @@ static void iopf_handler(struct work_struct *work)
 	if (!domain || !domain->iopf_handler)
 		status = IOMMU_PAGE_RESP_INVALID;
 
-	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+	list_for_each_entry(iopf, &group->faults, list) {
 		/*
 		 * For the moment, errors are sticky: don't handle subsequent
 		 * faults in the group if there is an error.
@@ -74,14 +74,21 @@ static void iopf_handler(struct work_struct *work)
 		if (status == IOMMU_PAGE_RESP_SUCCESS)
 			status = domain->iopf_handler(&iopf->fault,
 						      domain->fault_data);
-
-		if (!(iopf->fault.prm.flags &
-		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
-			kfree(iopf);
 	}
 
 	iopf_complete_group(group->dev, &group->last_fault, status);
-	kfree(group);
+	iopf_free_group(group);
+}
+
+static int iopf_queue_work(struct iopf_group *group, work_func_t func)
+{
+	struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
+
+	INIT_WORK(&group->work, func);
+	if (!queue_work(fault_param->queue->wq, &group->work))
+		return -EBUSY;
+
+	return 0;
 }
 
 /**
@@ -174,7 +181,6 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 	group->last_fault.fault = *fault;
 	INIT_LIST_HEAD(&group->faults);
 	list_add(&group->last_fault.list, &group->faults);
-	INIT_WORK(&group->work, iopf_handler);
 
 	/* See if we have partial faults for this group */
 	list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
@@ -183,8 +189,11 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 			list_move(&iopf->list, &group->faults);
 	}
 
-	queue_work(iopf_param->queue->wq, &group->work);
-	return 0;
+	ret = iopf_queue_work(group, iopf_handler);
+	if (ret)
+		iopf_free_group(group);
+
+	return ret;
 
 cleanup_partial:
 	list_for_each_entry_safe(iopf, next, &iopf_param->partial, list) {
-- 
2.34.1

[PATCH v3 08/11] iommu: Move iopf_handler() to iommu-sva.c

[Lu Baolu]

The iopf_handler() function handles a fault_group for a SVA domain. Move
it to the right place.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/iommu-sva.h  | 17 +++++++++++++
 drivers/iommu/io-pgfault.c | 50 +++-----------------------------------
 drivers/iommu/iommu-sva.c  | 48 ++++++++++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+), 46 deletions(-)

diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
index de7819c796ce..510a7df23fba 100644
--- a/drivers/iommu/iommu-sva.h
+++ b/drivers/iommu/iommu-sva.h
@@ -24,6 +24,9 @@ void iopf_queue_free(struct iopf_queue *queue);
 int iopf_queue_discard_partial(struct iopf_queue *queue);
 enum iommu_page_response_code
 iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
+void iopf_free_group(struct iopf_group *group);
+int iopf_queue_work(struct iopf_group *group, work_func_t func);
+int iommu_sva_handle_iopf_group(struct iopf_group *group);
 
 #else /* CONFIG_IOMMU_SVA */
 static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
@@ -67,5 +70,19 @@ iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
 {
 	return IOMMU_PAGE_RESP_INVALID;
 }
+
+static inline void iopf_free_group(struct iopf_group *group)
+{
+}
+
+static inline int iopf_queue_work(struct iopf_group *group, work_func_t func)
+{
+	return -ENODEV;
+}
+
+static inline int iommu_sva_handle_iopf_group(struct iopf_group *group)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_IOMMU_SVA */
 #endif /* _IOMMU_SVA_H */
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index d07586cd37fd..00c2e447b740 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -25,7 +25,8 @@ struct iopf_queue {
 	struct mutex			lock;
 };
 
-static void iopf_free_group(struct iopf_group *group)
+/* Called by the iopf handler to free the iopf group. */
+void iopf_free_group(struct iopf_group *group)
 {
 	struct iopf_fault *iopf, *next;
 
@@ -37,50 +38,7 @@ static void iopf_free_group(struct iopf_group *group)
 	kfree(group);
 }
 
-static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
-			       enum iommu_page_response_code status)
-{
-	struct iommu_page_response resp = {
-		.pasid			= iopf->fault.prm.pasid,
-		.grpid			= iopf->fault.prm.grpid,
-		.code			= status,
-	};
-
-	if ((iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) &&
-	    (iopf->fault.prm.flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID))
-		resp.flags = IOMMU_PAGE_RESP_PASID_VALID;
-
-	return iommu_page_response(dev, &resp);
-}
-
-static void iopf_handler(struct work_struct *work)
-{
-	struct iopf_fault *iopf;
-	struct iopf_group *group;
-	struct iommu_domain *domain;
-	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
-
-	group = container_of(work, struct iopf_group, work);
-	domain = iommu_get_domain_for_dev_pasid(group->dev,
-				group->last_fault.fault.prm.pasid, 0);
-	if (!domain || !domain->iopf_handler)
-		status = IOMMU_PAGE_RESP_INVALID;
-
-	list_for_each_entry(iopf, &group->faults, list) {
-		/*
-		 * For the moment, errors are sticky: don't handle subsequent
-		 * faults in the group if there is an error.
-		 */
-		if (status == IOMMU_PAGE_RESP_SUCCESS)
-			status = domain->iopf_handler(&iopf->fault,
-						      domain->fault_data);
-	}
-
-	iopf_complete_group(group->dev, &group->last_fault, status);
-	iopf_free_group(group);
-}
-
-static int iopf_queue_work(struct iopf_group *group, work_func_t func)
+int iopf_queue_work(struct iopf_group *group, work_func_t func)
 {
 	struct iommu_fault_param *fault_param = group->dev->iommu->fault_param;
 
@@ -189,7 +147,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 			list_move(&iopf->list, &group->faults);
 	}
 
-	ret = iopf_queue_work(group, iopf_handler);
+	ret = iommu_sva_handle_iopf_group(group);
 	if (ret)
 		iopf_free_group(group);
 
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index b78671a8a914..df8734b6ec00 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -210,3 +210,51 @@ void mm_pasid_drop(struct mm_struct *mm)
 
 	iommu_free_global_pasid(mm->pasid);
 }
+
+static int iommu_sva_complete_iopf(struct device *dev, struct iopf_fault *iopf,
+				   enum iommu_page_response_code status)
+{
+	struct iommu_page_response resp = {
+		.pasid			= iopf->fault.prm.pasid,
+		.grpid			= iopf->fault.prm.grpid,
+		.code			= status,
+	};
+
+	if ((iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID) &&
+	    (iopf->fault.prm.flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID))
+		resp.flags = IOMMU_PAGE_RESP_PASID_VALID;
+
+	return iommu_page_response(dev, &resp);
+}
+
+static void iommu_sva_iopf_handler(struct work_struct *work)
+{
+	struct iopf_fault *iopf;
+	struct iopf_group *group;
+	struct iommu_domain *domain;
+	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
+
+	group = container_of(work, struct iopf_group, work);
+	domain = iommu_get_domain_for_dev_pasid(group->dev,
+				group->last_fault.fault.prm.pasid, 0);
+	if (!domain || !domain->iopf_handler)
+		status = IOMMU_PAGE_RESP_INVALID;
+
+	list_for_each_entry(iopf, &group->faults, list) {
+		/*
+		 * For the moment, errors are sticky: don't handle subsequent
+		 * faults in the group if there is an error.
+		 */
+		if (status == IOMMU_PAGE_RESP_SUCCESS)
+			status = domain->iopf_handler(&iopf->fault,
+						      domain->fault_data);
+	}
+
+	iommu_sva_complete_iopf(group->dev, &group->last_fault, status);
+	iopf_free_group(group);
+}
+
+int iommu_sva_handle_iopf_group(struct iopf_group *group)
+{
+	return iopf_queue_work(group, iommu_sva_iopf_handler);
+}
-- 
2.34.1

[PATCH v3 09/11] iommu: Make iommu_queue_iopf() more generic

[Lu Baolu]

This completely separates the IO page fault handling framework from the
SVA implementation. Previously, the SVA implementation was tightly coupled
with the IO page fault handling framework. This makes SVA a "customer" of
the IO page fault handling framework by converting domain's page fault
handler to handle a group of faults and calling it directly from
iommu_queue_iopf().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h      |  5 +++--
 drivers/iommu/iommu-sva.h  |  8 --------
 drivers/iommu/io-pgfault.c | 16 +++++++++++++---
 drivers/iommu/iommu-sva.c  | 14 ++++----------
 drivers/iommu/iommu.c      |  4 ++--
 5 files changed, 22 insertions(+), 25 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ff292eea9d31..cf1cb0bb46af 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -41,6 +41,7 @@ struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
 struct iopf_queue;
+struct iopf_group;
 
 #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
 #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
@@ -175,8 +176,7 @@ struct iommu_domain {
 	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
-	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
-						      void *data);
+	int (*iopf_handler)(struct iopf_group *group);
 	void *fault_data;
 	union {
 		struct {
@@ -526,6 +526,7 @@ struct iopf_group {
 	struct list_head		faults;
 	struct work_struct		work;
 	struct device			*dev;
+	void				*data;
 };
 
 int iommu_device_register(struct iommu_device *iommu,
diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
index 510a7df23fba..cf41e88fac17 100644
--- a/drivers/iommu/iommu-sva.h
+++ b/drivers/iommu/iommu-sva.h
@@ -22,8 +22,6 @@ int iopf_queue_flush_dev(struct device *dev);
 struct iopf_queue *iopf_queue_alloc(const char *name);
 void iopf_queue_free(struct iopf_queue *queue);
 int iopf_queue_discard_partial(struct iopf_queue *queue);
-enum iommu_page_response_code
-iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
 void iopf_free_group(struct iopf_group *group);
 int iopf_queue_work(struct iopf_group *group, work_func_t func);
 int iommu_sva_handle_iopf_group(struct iopf_group *group);
@@ -65,12 +63,6 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
 	return -ENODEV;
 }
 
-static inline enum iommu_page_response_code
-iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
-{
-	return IOMMU_PAGE_RESP_INVALID;
-}
-
 static inline void iopf_free_group(struct iopf_group *group)
 {
 }
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 00c2e447b740..a61c2aabd1b8 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -11,8 +11,6 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
-#include "iommu-sva.h"
-
 /**
  * struct iopf_queue - IO Page Fault queue
  * @wq: the fault workqueue
@@ -93,6 +91,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 {
 	int ret;
 	struct iopf_group *group;
+	struct iommu_domain *domain;
 	struct iopf_fault *iopf, *next;
 	struct iommu_fault_param *iopf_param;
 	struct dev_iommu *param = dev->iommu;
@@ -124,6 +123,16 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 		return 0;
 	}
 
+	if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)
+		domain = iommu_get_domain_for_dev_pasid(dev, fault->prm.pasid, 0);
+	else
+		domain = iommu_get_domain_for_dev(dev);
+
+	if (!domain || !domain->iopf_handler) {
+		ret = -ENODEV;
+		goto cleanup_partial;
+	}
+
 	group = kzalloc(sizeof(*group), GFP_KERNEL);
 	if (!group) {
 		/*
@@ -137,6 +146,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 
 	group->dev = dev;
 	group->last_fault.fault = *fault;
+	group->data = domain->fault_data;
 	INIT_LIST_HEAD(&group->faults);
 	list_add(&group->last_fault.list, &group->faults);
 
@@ -147,7 +157,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 			list_move(&iopf->list, &group->faults);
 	}
 
-	ret = iommu_sva_handle_iopf_group(group);
+	ret = domain->iopf_handler(group);
 	if (ret)
 		iopf_free_group(group);
 
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index df8734b6ec00..2811f34947ab 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -148,13 +148,14 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
 /*
  * I/O page fault handler for SVA
  */
-enum iommu_page_response_code
+static enum iommu_page_response_code
 iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
 {
 	vm_fault_t ret;
 	struct vm_area_struct *vma;
-	struct mm_struct *mm = data;
 	unsigned int access_flags = 0;
+	struct iommu_domain *domain = data;
+	struct mm_struct *mm = domain->mm;
 	unsigned int fault_flags = FAULT_FLAG_REMOTE;
 	struct iommu_fault_page_request *prm = &fault->prm;
 	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
@@ -231,23 +232,16 @@ static void iommu_sva_iopf_handler(struct work_struct *work)
 {
 	struct iopf_fault *iopf;
 	struct iopf_group *group;
-	struct iommu_domain *domain;
 	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
 
 	group = container_of(work, struct iopf_group, work);
-	domain = iommu_get_domain_for_dev_pasid(group->dev,
-				group->last_fault.fault.prm.pasid, 0);
-	if (!domain || !domain->iopf_handler)
-		status = IOMMU_PAGE_RESP_INVALID;
-
 	list_for_each_entry(iopf, &group->faults, list) {
 		/*
 		 * For the moment, errors are sticky: don't handle subsequent
 		 * faults in the group if there is an error.
 		 */
 		if (status == IOMMU_PAGE_RESP_SUCCESS)
-			status = domain->iopf_handler(&iopf->fault,
-						      domain->fault_data);
+			status = iommu_sva_handle_iopf(&iopf->fault, group->data);
 	}
 
 	iommu_sva_complete_iopf(group->dev, &group->last_fault, status);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index b280b9f4d8b4..9b622088c741 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3395,8 +3395,8 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
 	domain->type = IOMMU_DOMAIN_SVA;
 	mmgrab(mm);
 	domain->mm = mm;
-	domain->iopf_handler = iommu_sva_handle_iopf;
-	domain->fault_data = mm;
+	domain->iopf_handler = iommu_sva_handle_iopf_group;
+	domain->fault_data = domain;
 
 	return domain;
 }
-- 
2.34.1

[PATCH v3 10/11] iommu: Add debugging on domain lifetime for iopf

[Lu Baolu]

The iopf handling framework in the core requires the domain's lifetime
should cover all possible iopfs. This has been documented in the comments
for iommu_queue_iopf() which is the entry of the framework.

Add some debugging to enforce this.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/io-pgfault.c |  3 +++
 drivers/iommu/iommu.c      | 24 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index a61c2aabd1b8..bf667ed39b01 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -129,6 +129,9 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
 		domain = iommu_get_domain_for_dev(dev);
 
 	if (!domain || !domain->iopf_handler) {
+		dev_warn_ratelimited(dev,
+			"iopf from pasid %d received without handler installed\n",
+			 fault->prm.pasid);
 		ret = -ENODEV;
 		goto cleanup_partial;
 	}
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9b622088c741..c170bcd3f05e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2032,6 +2032,28 @@ int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain)
 	return 0;
 }
 
+static void assert_no_pending_iopf(struct device *dev, ioasid_t pasid)
+{
+	struct iommu_fault_param *iopf_param = dev->iommu->fault_param;
+	struct iommu_fault_event *evt;
+	struct iopf_fault *iopf;
+
+	if (!iopf_param)
+		return;
+
+	mutex_lock(&iopf_param->lock);
+	list_for_each_entry(iopf, &iopf_param->partial, list) {
+		if (WARN_ON(iopf->fault.prm.pasid == pasid))
+			break;
+	}
+
+	list_for_each_entry(evt, &iopf_param->faults, list) {
+		if (WARN_ON(evt->fault.prm.pasid == pasid))
+			break;
+	}
+	mutex_unlock(&iopf_param->lock);
+}
+
 void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 {
 	/* Caller must be a probed driver on dev */
@@ -2040,6 +2062,7 @@ void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
 	if (!group)
 		return;
 
+	assert_no_pending_iopf(dev, IOMMU_NO_PASID);
 	mutex_lock(&group->mutex);
 	if (WARN_ON(domain != group->domain) ||
 	    WARN_ON(list_count_nodes(&group->devices) != 1))
@@ -3340,6 +3363,7 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
 	/* Caller must be a probed driver on dev */
 	struct iommu_group *group = dev->iommu_group;
 
+	assert_no_pending_iopf(dev, pasid);
 	mutex_lock(&group->mutex);
 	__iommu_remove_group_pasid(group, pasid);
 	WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);
-- 
2.34.1

[PATCH v3 11/11] iommu: Separate SVA and IOPF in Makefile and Kconfig

[Lu Baolu]

Add CONFIG_IOMMU_IOPF for page fault handling framework and select it
from its real consumer. Move iopf function declaration from iommu-sva.h
to iommu.h and remove iommu-sva.h as it's empty now.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 include/linux/iommu.h                         | 63 +++++++++++++++
 drivers/iommu/iommu-sva.h                     | 80 -------------------
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  1 -
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  1 -
 drivers/iommu/intel/iommu.c                   |  1 -
 drivers/iommu/intel/svm.c                     |  1 -
 drivers/iommu/iommu-sva.c                     |  3 +-
 drivers/iommu/iommu.c                         |  2 -
 drivers/iommu/Kconfig                         |  4 +
 drivers/iommu/Makefile                        |  3 +-
 drivers/iommu/intel/Kconfig                   |  1 +
 11 files changed, 71 insertions(+), 89 deletions(-)
 delete mode 100644 drivers/iommu/iommu-sva.h

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index cf1cb0bb46af..5349e1a9fc12 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,7 @@ struct iommu_fault_event;
 struct iommu_dma_cookie;
 struct iopf_queue;
 struct iopf_group;
+struct iopf_queue;
 
 #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
 #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
@@ -1284,6 +1285,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm);
 void iommu_sva_unbind_device(struct iommu_sva *handle);
 u32 iommu_sva_get_pasid(struct iommu_sva *handle);
+int iommu_sva_handle_iopf_group(struct iopf_group *group);
 #else
 static inline struct iommu_sva *
 iommu_sva_bind_device(struct device *dev, struct mm_struct *mm)
@@ -1302,6 +1304,67 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 static inline void mm_pasid_init(struct mm_struct *mm) {}
 static inline bool mm_valid_pasid(struct mm_struct *mm) { return false; }
 static inline void mm_pasid_drop(struct mm_struct *mm) {}
+static inline int iommu_sva_handle_iopf_group(struct iopf_group *group)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_IOMMU_SVA */
 
+#ifdef CONFIG_IOMMU_IOPF
+int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev);
+int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev);
+int iopf_queue_remove_device(struct iopf_queue *queue,
+			     struct device *dev);
+int iopf_queue_flush_dev(struct device *dev);
+struct iopf_queue *iopf_queue_alloc(const char *name);
+void iopf_queue_free(struct iopf_queue *queue);
+int iopf_queue_discard_partial(struct iopf_queue *queue);
+void iopf_free_group(struct iopf_group *group);
+int iopf_queue_work(struct iopf_group *group, work_func_t func);
+#else /* CONFIG_IOMMU_IOPF */
+static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline int iopf_queue_add_device(struct iopf_queue *queue,
+					struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline int iopf_queue_remove_device(struct iopf_queue *queue,
+					   struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline int iopf_queue_flush_dev(struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline struct iopf_queue *iopf_queue_alloc(const char *name)
+{
+	return NULL;
+}
+
+static inline void iopf_queue_free(struct iopf_queue *queue)
+{
+}
+
+static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
+{
+	return -ENODEV;
+}
+
+static inline void iopf_free_group(struct iopf_group *group)
+{
+}
+
+static inline int iopf_queue_work(struct iopf_group *group, work_func_t func)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_IOMMU_IOPF */
 #endif /* __LINUX_IOMMU_H */
diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
deleted file mode 100644
index cf41e88fac17..000000000000
--- a/drivers/iommu/iommu-sva.h
+++ /dev/null
@@ -1,80 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * SVA library for IOMMU drivers
- */
-#ifndef _IOMMU_SVA_H
-#define _IOMMU_SVA_H
-
-#include <linux/mm_types.h>
-
-/* I/O Page fault */
-struct device;
-struct iommu_fault;
-struct iopf_queue;
-
-#ifdef CONFIG_IOMMU_SVA
-int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev);
-
-int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev);
-int iopf_queue_remove_device(struct iopf_queue *queue,
-			     struct device *dev);
-int iopf_queue_flush_dev(struct device *dev);
-struct iopf_queue *iopf_queue_alloc(const char *name);
-void iopf_queue_free(struct iopf_queue *queue);
-int iopf_queue_discard_partial(struct iopf_queue *queue);
-void iopf_free_group(struct iopf_group *group);
-int iopf_queue_work(struct iopf_group *group, work_func_t func);
-int iommu_sva_handle_iopf_group(struct iopf_group *group);
-
-#else /* CONFIG_IOMMU_SVA */
-static inline int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline int iopf_queue_add_device(struct iopf_queue *queue,
-					struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline int iopf_queue_remove_device(struct iopf_queue *queue,
-					   struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline int iopf_queue_flush_dev(struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline struct iopf_queue *iopf_queue_alloc(const char *name)
-{
-	return NULL;
-}
-
-static inline void iopf_queue_free(struct iopf_queue *queue)
-{
-}
-
-static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
-{
-	return -ENODEV;
-}
-
-static inline void iopf_free_group(struct iopf_group *group)
-{
-}
-
-static inline int iopf_queue_work(struct iopf_group *group, work_func_t func)
-{
-	return -ENODEV;
-}
-
-static inline int iommu_sva_handle_iopf_group(struct iopf_group *group)
-{
-	return -ENODEV;
-}
-#endif /* CONFIG_IOMMU_SVA */
-#endif /* _IOMMU_SVA_H */
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index 7748ee30f8c0..fad7de25d28a 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -10,7 +10,6 @@
 #include <linux/slab.h>
 
 #include "arm-smmu-v3.h"
-#include "../../iommu-sva.h"
 #include "../../io-pgtable-arm.h"
 
 struct arm_smmu_mmu_notifier {
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index e08d2e27a9e5..b78738fc3f0e 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -29,7 +29,6 @@
 
 #include "arm-smmu-v3.h"
 #include "../../dma-iommu.h"
-#include "../../iommu-sva.h"
 
 static bool disable_bypass = true;
 module_param(disable_bypass, bool, 0444);
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 35839ef69089..bddc060aa615 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -26,7 +26,6 @@
 #include "iommu.h"
 #include "../dma-iommu.h"
 #include "../irq_remapping.h"
-#include "../iommu-sva.h"
 #include "pasid.h"
 #include "cap_audit.h"
 #include "perfmon.h"
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 9fbae9af6615..99b74033fd15 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -22,7 +22,6 @@
 #include "iommu.h"
 #include "pasid.h"
 #include "perf.h"
-#include "../iommu-sva.h"
 #include "trace.h"
 
 static irqreturn_t prq_event_thread(int irq, void *d);
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 2811f34947ab..4cd376227678 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -6,8 +6,7 @@
 #include <linux/mutex.h>
 #include <linux/sched/mm.h>
 #include <linux/iommu.h>
-
-#include "iommu-sva.h"
+#include <linux/mm_types.h>
 
 static DEFINE_MUTEX(iommu_sva_lock);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c170bcd3f05e..80fef24cf215 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -35,8 +35,6 @@
 
 #include "dma-iommu.h"
 
-#include "iommu-sva.h"
-
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
 static DEFINE_IDA(iommu_global_pasid_ida);
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 2b12b583ef4b..e7b87ec525a7 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -158,6 +158,9 @@ config IOMMU_DMA
 config IOMMU_SVA
 	bool
 
+config IOMMU_IOPF
+	bool
+
 config FSL_PAMU
 	bool "Freescale IOMMU support"
 	depends on PCI
@@ -404,6 +407,7 @@ config ARM_SMMU_V3_SVA
 	bool "Shared Virtual Addressing support for the ARM SMMUv3"
 	depends on ARM_SMMU_V3
 	select IOMMU_SVA
+	select IOMMU_IOPF
 	select MMU_NOTIFIER
 	help
 	  Support for sharing process address spaces with devices using the
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 769e43d780ce..6d114fe7ae89 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
 obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
 obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
 obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
-obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o io-pgfault.o
+obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o
+obj-$(CONFIG_IOMMU_IOPF) += io-pgfault.o
 obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
 obj-$(CONFIG_APPLE_DART) += apple-dart.o
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 2e56bd79f589..613f149510a7 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -50,6 +50,7 @@ config INTEL_IOMMU_SVM
 	depends on X86_64
 	select MMU_NOTIFIER
 	select IOMMU_SVA
+	select IOMMU_IOPF
 	help
 	  Shared Virtual Memory (SVM) provides a facility for devices
 	  to access DMA resources through process address space by
-- 
2.34.1

Re: [PATCH v3 04/11] iommu: Cleanup iopf data structure definitions

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 07:40:40AM +0800, Lu Baolu wrote:
> struct iommu_fault_page_request and struct iommu_page_response are not
> part of uAPI anymore. Convert them to data structures for kAPI.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  include/linux/iommu.h      | 27 +++++++++++----------------
>  drivers/iommu/io-pgfault.c |  1 -
>  drivers/iommu/iommu.c      |  4 ----
>  3 files changed, 11 insertions(+), 21 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

Re: [PATCH v3 05/11] iommu: Merge iopf_device_param into iommu_fault_param

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 07:40:41AM +0800, Lu Baolu wrote:
> @@ -472,21 +473,31 @@ struct iommu_fault_event {
>   * struct iommu_fault_param - per-device IOMMU fault data
>   * @handler: Callback function to handle IOMMU faults at device level
>   * @data: handler private data
> - * @faults: holds the pending faults which needs response
>   * @lock: protect pending faults list
> + * @dev: the device that owns this param
> + * @queue: IOPF queue
> + * @queue_list: index into queue->devices
> + * @partial: faults that are part of a Page Request Group for which the last
> + *           request hasn't been submitted yet.
> + * @faults: holds the pending faults which needs response
>   */
>  struct iommu_fault_param {
>  	iommu_dev_fault_handler_t handler;
>  	void *data;
> -	struct list_head faults;
> -	struct mutex lock;
> +	struct mutex			lock;
> +
> +	struct device			*dev;
> +	struct iopf_queue		*queue;
> +	struct list_head		queue_list;
> +
> +	struct list_head		partial;
> +	struct list_head		faults;
>  };

Don't add the horizontal spaces

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason
-

Re: [PATCH v3 07/11] iommu: Prepare for separating SVA and IOPF

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 07:40:43AM +0800, Lu Baolu wrote:
> Move iopf_group data structure to iommu.h. This is being done to make it
> a minimal set of faults that a domain's page fault handler should handle.
> 
> Add two new helpers for the domain's page fault handler:
> - iopf_free_group: free a fault group after all faults in the group are
>   handled.
> - iopf_queue_work: queue a given work item for a fault group.
> 
> This will simplify the sequential patches.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  include/linux/iommu.h      | 12 ++++++++++
>  drivers/iommu/io-pgfault.c | 49 ++++++++++++++++++++++----------------
>  2 files changed, 41 insertions(+), 20 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

Re: [PATCH v3 09/11] iommu: Make iommu_queue_iopf() more generic

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 07:40:45AM +0800, Lu Baolu wrote:
> This completely separates the IO page fault handling framework from the
> SVA implementation. Previously, the SVA implementation was tightly coupled
> with the IO page fault handling framework. This makes SVA a "customer" of
> the IO page fault handling framework by converting domain's page fault
> handler to handle a group of faults and calling it directly from
> iommu_queue_iopf().
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  include/linux/iommu.h      |  5 +++--
>  drivers/iommu/iommu-sva.h  |  8 --------
>  drivers/iommu/io-pgfault.c | 16 +++++++++++++---
>  drivers/iommu/iommu-sva.c  | 14 ++++----------
>  drivers/iommu/iommu.c      |  4 ++--
>  5 files changed, 22 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index ff292eea9d31..cf1cb0bb46af 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -41,6 +41,7 @@ struct iommu_sva;
>  struct iommu_fault_event;
>  struct iommu_dma_cookie;
>  struct iopf_queue;
> +struct iopf_group;
>  
>  #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
>  #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
> @@ -175,8 +176,7 @@ struct iommu_domain {
>  	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
>  	struct iommu_domain_geometry geometry;
>  	struct iommu_dma_cookie *iova_cookie;
> -	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
> -						      void *data);
> +	int (*iopf_handler)(struct iopf_group *group);
>  	void *fault_data;
>  	union {
>  		struct {
> @@ -526,6 +526,7 @@ struct iopf_group {
>  	struct list_head		faults;
>  	struct work_struct		work;
>  	struct device			*dev;
> +	void				*data;
>  };
>  
>  int iommu_device_register(struct iommu_device *iommu,
> diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
> index 510a7df23fba..cf41e88fac17 100644
> --- a/drivers/iommu/iommu-sva.h
> +++ b/drivers/iommu/iommu-sva.h
> @@ -22,8 +22,6 @@ int iopf_queue_flush_dev(struct device *dev);
>  struct iopf_queue *iopf_queue_alloc(const char *name);
>  void iopf_queue_free(struct iopf_queue *queue);
>  int iopf_queue_discard_partial(struct iopf_queue *queue);
> -enum iommu_page_response_code
> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
>  void iopf_free_group(struct iopf_group *group);
>  int iopf_queue_work(struct iopf_group *group, work_func_t func);
>  int iommu_sva_handle_iopf_group(struct iopf_group *group);
> @@ -65,12 +63,6 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
>  	return -ENODEV;
>  }
>  
> -static inline enum iommu_page_response_code
> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> -{
> -	return IOMMU_PAGE_RESP_INVALID;
> -}
> -
>  static inline void iopf_free_group(struct iopf_group *group)
>  {
>  }
> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
> index 00c2e447b740..a61c2aabd1b8 100644
> --- a/drivers/iommu/io-pgfault.c
> +++ b/drivers/iommu/io-pgfault.c
> @@ -11,8 +11,6 @@
>  #include <linux/slab.h>
>  #include <linux/workqueue.h>
>  
> -#include "iommu-sva.h"
> -
>  /**
>   * struct iopf_queue - IO Page Fault queue
>   * @wq: the fault workqueue
> @@ -93,6 +91,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>  {
>  	int ret;
>  	struct iopf_group *group;
> +	struct iommu_domain *domain;
>  	struct iopf_fault *iopf, *next;
>  	struct iommu_fault_param *iopf_param;
>  	struct dev_iommu *param = dev->iommu;
> @@ -124,6 +123,16 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>  		return 0;
>  	}
>  
> +	if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)
> +		domain = iommu_get_domain_for_dev_pasid(dev, fault->prm.pasid, 0);
> +	else
> +		domain = iommu_get_domain_for_dev(dev);
> +
> +	if (!domain || !domain->iopf_handler) {
> +		ret = -ENODEV;
> +		goto cleanup_partial;
> +	}
> +
>  	group = kzalloc(sizeof(*group), GFP_KERNEL);
>  	if (!group) {
>  		/*
> @@ -137,6 +146,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>  
>  	group->dev = dev;
>  	group->last_fault.fault = *fault;
> +	group->data = domain->fault_data;
>  	INIT_LIST_HEAD(&group->faults);
>  	list_add(&group->last_fault.list, &group->faults);
>  
> @@ -147,7 +157,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>  			list_move(&iopf->list, &group->faults);
>  	}
>  
> -	ret = iommu_sva_handle_iopf_group(group);
> +	ret = domain->iopf_handler(group);
>  	if (ret)
>  		iopf_free_group(group);
>  
> diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
> index df8734b6ec00..2811f34947ab 100644
> --- a/drivers/iommu/iommu-sva.c
> +++ b/drivers/iommu/iommu-sva.c
> @@ -148,13 +148,14 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
>  /*
>   * I/O page fault handler for SVA
>   */
> -enum iommu_page_response_code
> +static enum iommu_page_response_code
>  iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
>  {
>  	vm_fault_t ret;
>  	struct vm_area_struct *vma;
> -	struct mm_struct *mm = data;
>  	unsigned int access_flags = 0;
> +	struct iommu_domain *domain = data;
> +	struct mm_struct *mm = domain->mm;
>  	unsigned int fault_flags = FAULT_FLAG_REMOTE;
>  	struct iommu_fault_page_request *prm = &fault->prm;
>  	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
> @@ -231,23 +232,16 @@ static void iommu_sva_iopf_handler(struct work_struct *work)
>  {
>  	struct iopf_fault *iopf;
>  	struct iopf_group *group;
> -	struct iommu_domain *domain;
>  	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
>  
>  	group = container_of(work, struct iopf_group, work);
> -	domain = iommu_get_domain_for_dev_pasid(group->dev,
> -				group->last_fault.fault.prm.pasid, 0);
> -	if (!domain || !domain->iopf_handler)
> -		status = IOMMU_PAGE_RESP_INVALID;
> -
>  	list_for_each_entry(iopf, &group->faults, list) {
>  		/*
>  		 * For the moment, errors are sticky: don't handle subsequent
>  		 * faults in the group if there is an error.
>  		 */
>  		if (status == IOMMU_PAGE_RESP_SUCCESS)
> -			status = domain->iopf_handler(&iopf->fault,
> -						      domain->fault_data);
> +			status = iommu_sva_handle_iopf(&iopf->fault, group->data);
>  	}
>  
>  	iommu_sva_complete_iopf(group->dev, &group->last_fault, status);
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index b280b9f4d8b4..9b622088c741 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -3395,8 +3395,8 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
>  	domain->type = IOMMU_DOMAIN_SVA;
>  	mmgrab(mm);
>  	domain->mm = mm;
> -	domain->iopf_handler = iommu_sva_handle_iopf;
> -	domain->fault_data = mm;
> +	domain->iopf_handler = iommu_sva_handle_iopf_group;
> +	domain->fault_data = domain;

Why fault_data? The domain handling the fault should be passed
through naturally without relying on fault_data.

eg make 

  iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)

into
  iommu_sva_handle_iopf(struct iommu_fault *fault, struct iommu_domain *domain)

And delete domain->fault_data until we have some use for it.

The core code should be keeping track of the iommu_domain lifetime.

Jason

Re: [PATCH v3 00/11] iommu: Prepare to deliver page faults to user space

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 07:40:36AM +0800, Lu Baolu wrote:
> When a user-managed page table is attached to an IOMMU, it is necessary
> to deliver IO page faults to user space so that they can be handled
> appropriately. One use case for this is nested translation, which is
> currently being discussed in the mailing list.
> 
> I have posted a RFC series [1] that describes the implementation of
> delivering page faults to user space through IOMMUFD. This series has
> received several comments on the IOMMU refactoring, which I am trying to
> address in this series.

Looking at this after all the patches are applied..

iommu_report_device_fault() and iommu_queue_iopf() should be put in
the same file.

iommu_queue_iopf() seems misnamed since it isn't queuing anything. It
is delivering the fault to the domain.

It is weird that iommu_sva_domain_alloc is not in the sva file

iopf_queue_work() wrappers a work queue, but it should trampoline
through another function before invoking the driver's callback and not
invoke it with a weird work_struct - decode the group and get back the
domain. Every single handler will require the group and domain.

Same for domain->iopf_handler, the domain should be an argument if we
are invoking the function on a domain.

Perhaps group->domain is a simple answer.

Jason

Re: [PATCH v3 05/11] iommu: Merge iopf_device_param into iommu_fault_param

[Baolu Lu]

On 2023/8/22 1:04, Jason Gunthorpe wrote:
> On Fri, Aug 18, 2023 at 07:40:41AM +0800, Lu Baolu wrote:
>> @@ -472,21 +473,31 @@ struct iommu_fault_event {
>>    * struct iommu_fault_param - per-device IOMMU fault data
>>    * @handler: Callback function to handle IOMMU faults at device level
>>    * @data: handler private data
>> - * @faults: holds the pending faults which needs response
>>    * @lock: protect pending faults list
>> + * @dev: the device that owns this param
>> + * @queue: IOPF queue
>> + * @queue_list: index into queue->devices
>> + * @partial: faults that are part of a Page Request Group for which the last
>> + *           request hasn't been submitted yet.
>> + * @faults: holds the pending faults which needs response
>>    */
>>   struct iommu_fault_param {
>>   	iommu_dev_fault_handler_t handler;
>>   	void *data;
>> -	struct list_head faults;
>> -	struct mutex lock;
>> +	struct mutex			lock;
>> +
>> +	struct device			*dev;
>> +	struct iopf_queue		*queue;
>> +	struct list_head		queue_list;
>> +
>> +	struct list_head		partial;
>> +	struct list_head		faults;
>>   };
> Don't add the horizontal spaces

Fixed. Thanks!

Best regards,
baolu

Re: [PATCH v3 09/11] iommu: Make iommu_queue_iopf() more generic

[Baolu Lu]

On 2023/8/22 1:11, Jason Gunthorpe wrote:
> On Fri, Aug 18, 2023 at 07:40:45AM +0800, Lu Baolu wrote:
>> This completely separates the IO page fault handling framework from the
>> SVA implementation. Previously, the SVA implementation was tightly coupled
>> with the IO page fault handling framework. This makes SVA a "customer" of
>> the IO page fault handling framework by converting domain's page fault
>> handler to handle a group of faults and calling it directly from
>> iommu_queue_iopf().
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>>   include/linux/iommu.h      |  5 +++--
>>   drivers/iommu/iommu-sva.h  |  8 --------
>>   drivers/iommu/io-pgfault.c | 16 +++++++++++++---
>>   drivers/iommu/iommu-sva.c  | 14 ++++----------
>>   drivers/iommu/iommu.c      |  4 ++--
>>   5 files changed, 22 insertions(+), 25 deletions(-)
>>
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index ff292eea9d31..cf1cb0bb46af 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -41,6 +41,7 @@ struct iommu_sva;
>>   struct iommu_fault_event;
>>   struct iommu_dma_cookie;
>>   struct iopf_queue;
>> +struct iopf_group;
>>   
>>   #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
>>   #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
>> @@ -175,8 +176,7 @@ struct iommu_domain {
>>   	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
>>   	struct iommu_domain_geometry geometry;
>>   	struct iommu_dma_cookie *iova_cookie;
>> -	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
>> -						      void *data);
>> +	int (*iopf_handler)(struct iopf_group *group);
>>   	void *fault_data;
>>   	union {
>>   		struct {
>> @@ -526,6 +526,7 @@ struct iopf_group {
>>   	struct list_head		faults;
>>   	struct work_struct		work;
>>   	struct device			*dev;
>> +	void				*data;
>>   };
>>   
>>   int iommu_device_register(struct iommu_device *iommu,
>> diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h
>> index 510a7df23fba..cf41e88fac17 100644
>> --- a/drivers/iommu/iommu-sva.h
>> +++ b/drivers/iommu/iommu-sva.h
>> @@ -22,8 +22,6 @@ int iopf_queue_flush_dev(struct device *dev);
>>   struct iopf_queue *iopf_queue_alloc(const char *name);
>>   void iopf_queue_free(struct iopf_queue *queue);
>>   int iopf_queue_discard_partial(struct iopf_queue *queue);
>> -enum iommu_page_response_code
>> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data);
>>   void iopf_free_group(struct iopf_group *group);
>>   int iopf_queue_work(struct iopf_group *group, work_func_t func);
>>   int iommu_sva_handle_iopf_group(struct iopf_group *group);
>> @@ -65,12 +63,6 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
>>   	return -ENODEV;
>>   }
>>   
>> -static inline enum iommu_page_response_code
>> -iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
>> -{
>> -	return IOMMU_PAGE_RESP_INVALID;
>> -}
>> -
>>   static inline void iopf_free_group(struct iopf_group *group)
>>   {
>>   }
>> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
>> index 00c2e447b740..a61c2aabd1b8 100644
>> --- a/drivers/iommu/io-pgfault.c
>> +++ b/drivers/iommu/io-pgfault.c
>> @@ -11,8 +11,6 @@
>>   #include <linux/slab.h>
>>   #include <linux/workqueue.h>
>>   
>> -#include "iommu-sva.h"
>> -
>>   /**
>>    * struct iopf_queue - IO Page Fault queue
>>    * @wq: the fault workqueue
>> @@ -93,6 +91,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>>   {
>>   	int ret;
>>   	struct iopf_group *group;
>> +	struct iommu_domain *domain;
>>   	struct iopf_fault *iopf, *next;
>>   	struct iommu_fault_param *iopf_param;
>>   	struct dev_iommu *param = dev->iommu;
>> @@ -124,6 +123,16 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>>   		return 0;
>>   	}
>>   
>> +	if (fault->prm.flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)
>> +		domain = iommu_get_domain_for_dev_pasid(dev, fault->prm.pasid, 0);
>> +	else
>> +		domain = iommu_get_domain_for_dev(dev);
>> +
>> +	if (!domain || !domain->iopf_handler) {
>> +		ret = -ENODEV;
>> +		goto cleanup_partial;
>> +	}
>> +
>>   	group = kzalloc(sizeof(*group), GFP_KERNEL);
>>   	if (!group) {
>>   		/*
>> @@ -137,6 +146,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>>   
>>   	group->dev = dev;
>>   	group->last_fault.fault = *fault;
>> +	group->data = domain->fault_data;
>>   	INIT_LIST_HEAD(&group->faults);
>>   	list_add(&group->last_fault.list, &group->faults);
>>   
>> @@ -147,7 +157,7 @@ int iommu_queue_iopf(struct iommu_fault *fault, struct device *dev)
>>   			list_move(&iopf->list, &group->faults);
>>   	}
>>   
>> -	ret = iommu_sva_handle_iopf_group(group);
>> +	ret = domain->iopf_handler(group);
>>   	if (ret)
>>   		iopf_free_group(group);
>>   
>> diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
>> index df8734b6ec00..2811f34947ab 100644
>> --- a/drivers/iommu/iommu-sva.c
>> +++ b/drivers/iommu/iommu-sva.c
>> @@ -148,13 +148,14 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
>>   /*
>>    * I/O page fault handler for SVA
>>    */
>> -enum iommu_page_response_code
>> +static enum iommu_page_response_code
>>   iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
>>   {
>>   	vm_fault_t ret;
>>   	struct vm_area_struct *vma;
>> -	struct mm_struct *mm = data;
>>   	unsigned int access_flags = 0;
>> +	struct iommu_domain *domain = data;
>> +	struct mm_struct *mm = domain->mm;
>>   	unsigned int fault_flags = FAULT_FLAG_REMOTE;
>>   	struct iommu_fault_page_request *prm = &fault->prm;
>>   	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
>> @@ -231,23 +232,16 @@ static void iommu_sva_iopf_handler(struct work_struct *work)
>>   {
>>   	struct iopf_fault *iopf;
>>   	struct iopf_group *group;
>> -	struct iommu_domain *domain;
>>   	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
>>   
>>   	group = container_of(work, struct iopf_group, work);
>> -	domain = iommu_get_domain_for_dev_pasid(group->dev,
>> -				group->last_fault.fault.prm.pasid, 0);
>> -	if (!domain || !domain->iopf_handler)
>> -		status = IOMMU_PAGE_RESP_INVALID;
>> -
>>   	list_for_each_entry(iopf, &group->faults, list) {
>>   		/*
>>   		 * For the moment, errors are sticky: don't handle subsequent
>>   		 * faults in the group if there is an error.
>>   		 */
>>   		if (status == IOMMU_PAGE_RESP_SUCCESS)
>> -			status = domain->iopf_handler(&iopf->fault,
>> -						      domain->fault_data);
>> +			status = iommu_sva_handle_iopf(&iopf->fault, group->data);
>>   	}
>>   
>>   	iommu_sva_complete_iopf(group->dev, &group->last_fault, status);
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index b280b9f4d8b4..9b622088c741 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -3395,8 +3395,8 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev,
>>   	domain->type = IOMMU_DOMAIN_SVA;
>>   	mmgrab(mm);
>>   	domain->mm = mm;
>> -	domain->iopf_handler = iommu_sva_handle_iopf;
>> -	domain->fault_data = mm;
>> +	domain->iopf_handler = iommu_sva_handle_iopf_group;
>> +	domain->fault_data = domain;
> 
> Why fault_data? The domain handling the fault should be passed
> through naturally without relying on fault_data.
> 
> eg make
> 
>    iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
> 
> into
>    iommu_sva_handle_iopf(struct iommu_fault *fault, struct iommu_domain *domain)

See your point now. I will remove "void *data" and move "domain" to
"group->domain".

> 
> And delete domain->fault_data until we have some use for it.

Perhaps we will soon have a use for it.

In the iommufd case, the iommufd iopf handler has a need to retrieve the
hwpt pointer from a domain pointer, right? With the domain->fault_data
pointing to the hwpt, the iopf handler has no need to lookup it in the
critical path.

> 
> The core code should be keeping track of the iommu_domain lifetime.

I added the debugging code in the next patch as you suggested.

Best regards,
baolu

Re: [PATCH v3 00/11] iommu: Prepare to deliver page faults to user space

[Baolu Lu]

On 2023/8/22 2:31, Jason Gunthorpe wrote:
> On Fri, Aug 18, 2023 at 07:40:36AM +0800, Lu Baolu wrote:
>> When a user-managed page table is attached to an IOMMU, it is necessary
>> to deliver IO page faults to user space so that they can be handled
>> appropriately. One use case for this is nested translation, which is
>> currently being discussed in the mailing list.
>>
>> I have posted a RFC series [1] that describes the implementation of
>> delivering page faults to user space through IOMMUFD. This series has
>> received several comments on the IOMMU refactoring, which I am trying to
>> address in this series.
> 
> Looking at this after all the patches are applied..

Thank you very much for reviewing my patches.

> 
> iommu_report_device_fault() and iommu_queue_iopf() should be put in
> the same file.

Yes. I will move both into io-pgfault.c. After that, iommu_queue_iopf()
becomes static.

> 
> iommu_queue_iopf() seems misnamed since it isn't queuing anything. It
> is delivering the fault to the domain.

Yeah, perhaps we can rename it to iommu_handle_iopf().

/**
  * iommu_handle_iopf - IO Page Fault handler
  * @fault: fault event
  * @dev: struct device.

> 
> It is weird that iommu_sva_domain_alloc is not in the sva file

Agreed. I will move it to iommu-sva.c.

> iopf_queue_work() wrappers a work queue, but it should trampoline
> through another function before invoking the driver's callback and not
> invoke it with a weird work_struct - decode the group and get back the
> domain. Every single handler will require the group and domain.

The work queue wrapper is duplicate. I will remove it and let the driver
to call queue_work() directly.

> 
> Same for domain->iopf_handler, the domain should be an argument if we
> are invoking the function on a domain.
> 
> Perhaps group->domain is a simple answer.

Yes. I will add domain in fault group and make it part of the parameters
of the callback.

Best regards,
baolu