[PATCH v4 00/12] iommu: SVA and IOPF refactoring

[PATCH v4 00/12] iommu: SVA and IOPF refactoring

[Lu Baolu]

Hi folks,

The former part of this series refactors the IOMMU SVA code by assigning
an SVA type of iommu_domain to a shared virtual address and replacing
sva_bind/unbind iommu ops with attach/detach_dev_pasid domain ops.

The latter part changes the existing I/O page fault handling framework
from only serving SVA to a generic one. Any driver or component could
handle the I/O page faults for its domain in its own way by installing
an I/O page fault handler.

This series has been functionally tested on an x86 machine and compile
tested for other architectures. 

This series is also available on github:
[2] https://github.com/LuBaolu/intel-iommu/commits/iommu-sva-refactoring-v4

Please review and suggest.

Best regards,
baolu

Change log:
v4:
 - Solve the overlap with another series and make this series
   self-contained.
 - No objection to the abstraction of data structure during v3 review.
   Hence remove the RFC subject prefix.
 - Refine the immutable singleton group code according to Kevin's
   comments.

v3:
 - https://lore.kernel.org/linux-iommu/20220410102443.294128-1-baolu.lu@linux.intel.com/
 - Rework iommu_group_singleton_lockdown() by adding a flag to the group
   that positively indicates the group can never have more than one
   member, even after hot plug.
 - Abstract the data structs used for iommu sva in a separated patches to
   make it easier for review.
 - I still keep the RFC prefix in this series as above two significant
   changes need at least another round review to be finalized.
 - Several misc refinements.

v2:
 - https://lore.kernel.org/linux-iommu/20220329053800.3049561-1-baolu.lu@linux.intel.com/
 - Add sva domain life cycle management to avoid race between unbind and
   page fault handling.
 - Use a single domain for each mm.
 - Return a single sva handler for the same binding.
 - Add a new helper to meet singleton group requirement.
 - Rework the SVA domain allocation for arm smmu v3 driver and move the
   pasid_bit initialization to device probe.
 - Drop the patch "iommu: Handle IO page faults directly".
 - Add mmget_not_zero(mm) in SVA page fault handler.

v1:
 - https://lore.kernel.org/linux-iommu/20220320064030.2936936-1-baolu.lu@linux.intel.com/
 - Initial post.

Dave Jiang (1):
  dmaengine: idxd: Separate user and kernel pasid enabling

Lu Baolu (11):
  iommu: Add pasid_bits field in struct dev_iommu
  iommu: Add attach/detach_dev_pasid domain ops
  iommu/sva: Basic data structures for SVA
  iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support
  iommu/vt-d: Add SVA domain support
  arm-smmu-v3/sva: Add SVA domain support
  iommu/sva: Use attach/detach_pasid_dev in SVA interfaces
  iommu: Remove SVA related callbacks from iommu ops
  iommu: Prepare IOMMU domain for IOPF
  iommu: Per-domain I/O page fault handling
  iommu: Rename iommu-sva-lib.{c,h}

 include/linux/intel-iommu.h                   |   5 +-
 include/linux/iommu.h                         | 106 ++++--
 drivers/dma/idxd/idxd.h                       |   6 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  25 +-
 .../iommu/{iommu-sva-lib.h => iommu-sva.h}    |   8 +-
 drivers/dma/idxd/cdev.c                       |   4 +-
 drivers/dma/idxd/init.c                       |  30 +-
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  85 ++---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  28 +-
 drivers/iommu/intel/iommu.c                   |  20 +-
 drivers/iommu/intel/svm.c                     | 135 +++----
 drivers/iommu/io-pgfault.c                    |  71 +---
 drivers/iommu/iommu-sva-lib.c                 |  71 ----
 drivers/iommu/iommu-sva.c                     | 331 ++++++++++++++++++
 drivers/iommu/iommu.c                         | 219 +++++++-----
 drivers/iommu/Makefile                        |   2 +-
 16 files changed, 721 insertions(+), 425 deletions(-)
 rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (88%)
 delete mode 100644 drivers/iommu/iommu-sva-lib.c
 create mode 100644 drivers/iommu/iommu-sva.c

-- 
2.25.1

[PATCH v4 00/12] iommu: SVA and IOPF refactoring

[Lu Baolu]

Hi folks,

The former part of this series refactors the IOMMU SVA code by assigning
an SVA type of iommu_domain to a shared virtual address and replacing
sva_bind/unbind iommu ops with attach/detach_dev_pasid domain ops.

The latter part changes the existing I/O page fault handling framework
from only serving SVA to a generic one. Any driver or component could
handle the I/O page faults for its domain in its own way by installing
an I/O page fault handler.

This series has been functionally tested on an x86 machine and compile
tested for other architectures. 

This series is also available on github:
[2] https://github.com/LuBaolu/intel-iommu/commits/iommu-sva-refactoring-v4

Please review and suggest.

Best regards,
baolu

Change log:
v4:
 - Solve the overlap with another series and make this series
   self-contained.
 - No objection to the abstraction of data structure during v3 review.
   Hence remove the RFC subject prefix.
 - Refine the immutable singleton group code according to Kevin's
   comments.

v3:
 - https://lore.kernel.org/linux-iommu/20220410102443.294128-1-baolu.lu@linux.intel.com/
 - Rework iommu_group_singleton_lockdown() by adding a flag to the group
   that positively indicates the group can never have more than one
   member, even after hot plug.
 - Abstract the data structs used for iommu sva in a separated patches to
   make it easier for review.
 - I still keep the RFC prefix in this series as above two significant
   changes need at least another round review to be finalized.
 - Several misc refinements.

v2:
 - https://lore.kernel.org/linux-iommu/20220329053800.3049561-1-baolu.lu@linux.intel.com/
 - Add sva domain life cycle management to avoid race between unbind and
   page fault handling.
 - Use a single domain for each mm.
 - Return a single sva handler for the same binding.
 - Add a new helper to meet singleton group requirement.
 - Rework the SVA domain allocation for arm smmu v3 driver and move the
   pasid_bit initialization to device probe.
 - Drop the patch "iommu: Handle IO page faults directly".
 - Add mmget_not_zero(mm) in SVA page fault handler.

v1:
 - https://lore.kernel.org/linux-iommu/20220320064030.2936936-1-baolu.lu@linux.intel.com/
 - Initial post.

Dave Jiang (1):
  dmaengine: idxd: Separate user and kernel pasid enabling

Lu Baolu (11):
  iommu: Add pasid_bits field in struct dev_iommu
  iommu: Add attach/detach_dev_pasid domain ops
  iommu/sva: Basic data structures for SVA
  iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support
  iommu/vt-d: Add SVA domain support
  arm-smmu-v3/sva: Add SVA domain support
  iommu/sva: Use attach/detach_pasid_dev in SVA interfaces
  iommu: Remove SVA related callbacks from iommu ops
  iommu: Prepare IOMMU domain for IOPF
  iommu: Per-domain I/O page fault handling
  iommu: Rename iommu-sva-lib.{c,h}

 include/linux/intel-iommu.h                   |   5 +-
 include/linux/iommu.h                         | 106 ++++--
 drivers/dma/idxd/idxd.h                       |   6 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  25 +-
 .../iommu/{iommu-sva-lib.h => iommu-sva.h}    |   8 +-
 drivers/dma/idxd/cdev.c                       |   4 +-
 drivers/dma/idxd/init.c                       |  30 +-
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   |  85 ++---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  28 +-
 drivers/iommu/intel/iommu.c                   |  20 +-
 drivers/iommu/intel/svm.c                     | 135 +++----
 drivers/iommu/io-pgfault.c                    |  71 +---
 drivers/iommu/iommu-sva-lib.c                 |  71 ----
 drivers/iommu/iommu-sva.c                     | 331 ++++++++++++++++++
 drivers/iommu/iommu.c                         | 219 +++++++-----
 drivers/iommu/Makefile                        |   2 +-
 16 files changed, 721 insertions(+), 425 deletions(-)
 rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (88%)
 delete mode 100644 drivers/iommu/iommu-sva-lib.c
 create mode 100644 drivers/iommu/iommu-sva.c

-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 01/12] dmaengine: idxd: Separate user and kernel pasid enabling

[Lu Baolu]

From: Dave Jiang <dave.jiang@intel.com>

The idxd driver always gated the pasid enabling under a single knob and
this assumption is incorrect. The pasid used for kernel operation can be
independently toggled and has no dependency on the user pasid (and vice
versa). Split the two so they are independent "enabled" flags.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/linux-iommu/20220315050713.2000518-10-jacob.jun.pan@linux.intel.com/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/dma/idxd/idxd.h |  6 ++++++
 drivers/dma/idxd/cdev.c |  4 ++--
 drivers/dma/idxd/init.c | 30 ++++++++++++++++++------------
 3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index da72eb15f610..ccbefd0be617 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -239,6 +239,7 @@ enum idxd_device_flag {
 	IDXD_FLAG_CONFIGURABLE = 0,
 	IDXD_FLAG_CMD_RUNNING,
 	IDXD_FLAG_PASID_ENABLED,
+	IDXD_FLAG_USER_PASID_ENABLED,
 };
 
 struct idxd_dma_dev {
@@ -469,6 +470,11 @@ static inline bool device_pasid_enabled(struct idxd_device *idxd)
 	return test_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 }
 
+static inline bool device_user_pasid_enabled(struct idxd_device *idxd)
+{
+	return test_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
+}
+
 static inline bool device_swq_supported(struct idxd_device *idxd)
 {
 	return (support_enqcmd && device_pasid_enabled(idxd));
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index b9b2b4a4124e..7df996deffbe 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -99,7 +99,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 	ctx->wq = wq;
 	filp->private_data = ctx;
 
-	if (device_pasid_enabled(idxd)) {
+	if (device_user_pasid_enabled(idxd)) {
 		sva = iommu_sva_bind_device(dev, current->mm, NULL);
 		if (IS_ERR(sva)) {
 			rc = PTR_ERR(sva);
@@ -152,7 +152,7 @@ static int idxd_cdev_release(struct inode *node, struct file *filep)
 	if (wq_shared(wq)) {
 		idxd_device_drain_pasid(idxd, ctx->pasid);
 	} else {
-		if (device_pasid_enabled(idxd)) {
+		if (device_user_pasid_enabled(idxd)) {
 			/* The wq disable in the disable pasid function will drain the wq */
 			rc = idxd_wq_disable_pasid(wq);
 			if (rc < 0)
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 993a5dcca24f..e1b5d1e4a949 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -513,16 +513,19 @@ static int idxd_probe(struct idxd_device *idxd)
 
 	if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
 		rc = iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA);
-		if (rc == 0) {
-			rc = idxd_enable_system_pasid(idxd);
-			if (rc < 0) {
-				iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
-				dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
-			} else {
-				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
-			}
-		} else {
+		if (rc) {
+			/*
+			 * Do not bail here since legacy DMA is still
+			 * supported, both user and in-kernel DMA with
+			 * PASID rely on SVA feature.
+			 */
 			dev_warn(dev, "Unable to turn on SVA feature.\n");
+		} else {
+			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
+			if (idxd_enable_system_pasid(idxd))
+				dev_warn(dev, "No in-kernel DMA with PASID.\n");
+			else
+				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 		}
 	} else if (!sva) {
 		dev_warn(dev, "User forced SVA off via module param.\n");
@@ -561,7 +564,8 @@ static int idxd_probe(struct idxd_device *idxd)
  err:
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
 	return rc;
 }
 
@@ -574,7 +578,8 @@ static void idxd_cleanup(struct idxd_device *idxd)
 	idxd_cleanup_internals(idxd);
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
 }
 
 static int idxd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -691,7 +696,8 @@ static void idxd_remove(struct pci_dev *pdev)
 	free_irq(irq_entry->vector, irq_entry);
 	pci_free_irq_vectors(pdev);
 	pci_iounmap(pdev, idxd->reg_base);
-	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
 	pci_disable_device(pdev);
 	destroy_workqueue(idxd->wq);
 	perfmon_pmu_remove(idxd);
-- 
2.25.1

[PATCH v4 01/12] dmaengine: idxd: Separate user and kernel pasid enabling

[Lu Baolu]

From: Dave Jiang <dave.jiang@intel.com>

The idxd driver always gated the pasid enabling under a single knob and
this assumption is incorrect. The pasid used for kernel operation can be
independently toggled and has no dependency on the user pasid (and vice
versa). Split the two so they are independent "enabled" flags.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/linux-iommu/20220315050713.2000518-10-jacob.jun.pan@linux.intel.com/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/dma/idxd/idxd.h |  6 ++++++
 drivers/dma/idxd/cdev.c |  4 ++--
 drivers/dma/idxd/init.c | 30 ++++++++++++++++++------------
 3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index da72eb15f610..ccbefd0be617 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -239,6 +239,7 @@ enum idxd_device_flag {
 	IDXD_FLAG_CONFIGURABLE = 0,
 	IDXD_FLAG_CMD_RUNNING,
 	IDXD_FLAG_PASID_ENABLED,
+	IDXD_FLAG_USER_PASID_ENABLED,
 };
 
 struct idxd_dma_dev {
@@ -469,6 +470,11 @@ static inline bool device_pasid_enabled(struct idxd_device *idxd)
 	return test_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 }
 
+static inline bool device_user_pasid_enabled(struct idxd_device *idxd)
+{
+	return test_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
+}
+
 static inline bool device_swq_supported(struct idxd_device *idxd)
 {
 	return (support_enqcmd && device_pasid_enabled(idxd));
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index b9b2b4a4124e..7df996deffbe 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -99,7 +99,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 	ctx->wq = wq;
 	filp->private_data = ctx;
 
-	if (device_pasid_enabled(idxd)) {
+	if (device_user_pasid_enabled(idxd)) {
 		sva = iommu_sva_bind_device(dev, current->mm, NULL);
 		if (IS_ERR(sva)) {
 			rc = PTR_ERR(sva);
@@ -152,7 +152,7 @@ static int idxd_cdev_release(struct inode *node, struct file *filep)
 	if (wq_shared(wq)) {
 		idxd_device_drain_pasid(idxd, ctx->pasid);
 	} else {
-		if (device_pasid_enabled(idxd)) {
+		if (device_user_pasid_enabled(idxd)) {
 			/* The wq disable in the disable pasid function will drain the wq */
 			rc = idxd_wq_disable_pasid(wq);
 			if (rc < 0)
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 993a5dcca24f..e1b5d1e4a949 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -513,16 +513,19 @@ static int idxd_probe(struct idxd_device *idxd)
 
 	if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
 		rc = iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA);
-		if (rc == 0) {
-			rc = idxd_enable_system_pasid(idxd);
-			if (rc < 0) {
-				iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
-				dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
-			} else {
-				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
-			}
-		} else {
+		if (rc) {
+			/*
+			 * Do not bail here since legacy DMA is still
+			 * supported, both user and in-kernel DMA with
+			 * PASID rely on SVA feature.
+			 */
 			dev_warn(dev, "Unable to turn on SVA feature.\n");
+		} else {
+			set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);
+			if (idxd_enable_system_pasid(idxd))
+				dev_warn(dev, "No in-kernel DMA with PASID.\n");
+			else
+				set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
 		}
 	} else if (!sva) {
 		dev_warn(dev, "User forced SVA off via module param.\n");
@@ -561,7 +564,8 @@ static int idxd_probe(struct idxd_device *idxd)
  err:
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
 	return rc;
 }
 
@@ -574,7 +578,8 @@ static void idxd_cleanup(struct idxd_device *idxd)
 	idxd_cleanup_internals(idxd);
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
-	iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
 }
 
 static int idxd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
@@ -691,7 +696,8 @@ static void idxd_remove(struct pci_dev *pdev)
 	free_irq(irq_entry->vector, irq_entry);
 	pci_free_irq_vectors(pdev);
 	pci_iounmap(pdev, idxd->reg_base);
-	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	if (device_user_pasid_enabled(idxd) || device_pasid_enabled(idxd))
+		iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
 	pci_disable_device(pdev);
 	destroy_workqueue(idxd->wq);
 	perfmon_pmu_remove(idxd);
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 02/12] iommu: Add pasid_bits field in struct dev_iommu

[Lu Baolu]

Use this field to save the pasid/ssid bits that a device is able to
support with its IOMMU hardware. It is a generic attribute of a device
and lifting it into the per-device dev_iommu struct makes it possible
to allocate a PASID for device without calls into the IOMMU drivers.
Any iommu driver which suports PASID related features should set this
field before features are enabled on the devices.

For initialization of this field in the VT-d driver, the
info->pasid_supported is only set for PCI devices. So the status is
that non-PCI SVA hasn't been supported yet. Setting this field only for
PCI devices has no functional change.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h                       | 1 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 ++
 drivers/iommu/intel/iommu.c                 | 5 ++++-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6ef2df258673..36f43af0af53 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -368,6 +368,7 @@ struct dev_iommu {
 	struct iommu_fwspec		*fwspec;
 	struct iommu_device		*iommu_dev;
 	void				*priv;
+	unsigned int			pasid_bits;
 };
 
 int iommu_device_register(struct iommu_device *iommu,
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 627a3ed5ee8f..afc63fce6107 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2681,6 +2681,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 	    smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
 		master->stall_enabled = true;
 
+	dev->iommu->pasid_bits = master->ssid_bits;
+
 	return &smmu->iommu;
 
 err_free_master:
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index df5c62ecf942..ffad7f8f2d73 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4593,8 +4593,11 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
 			if (pasid_supported(iommu)) {
 				int features = pci_pasid_features(pdev);
 
-				if (features >= 0)
+				if (features >= 0) {
 					info->pasid_supported = features | 1;
+					dev->iommu->pasid_bits =
+						fls(pci_max_pasids(pdev)) - 1;
+				}
 			}
 
 			if (info->ats_supported && ecap_prs(iommu->ecap) &&
-- 
2.25.1

[PATCH v4 02/12] iommu: Add pasid_bits field in struct dev_iommu

[Lu Baolu]

Use this field to save the pasid/ssid bits that a device is able to
support with its IOMMU hardware. It is a generic attribute of a device
and lifting it into the per-device dev_iommu struct makes it possible
to allocate a PASID for device without calls into the IOMMU drivers.
Any iommu driver which suports PASID related features should set this
field before features are enabled on the devices.

For initialization of this field in the VT-d driver, the
info->pasid_supported is only set for PCI devices. So the status is
that non-PCI SVA hasn't been supported yet. Setting this field only for
PCI devices has no functional change.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h                       | 1 +
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 ++
 drivers/iommu/intel/iommu.c                 | 5 ++++-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6ef2df258673..36f43af0af53 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -368,6 +368,7 @@ struct dev_iommu {
 	struct iommu_fwspec		*fwspec;
 	struct iommu_device		*iommu_dev;
 	void				*priv;
+	unsigned int			pasid_bits;
 };
 
 int iommu_device_register(struct iommu_device *iommu,
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 627a3ed5ee8f..afc63fce6107 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2681,6 +2681,8 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 	    smmu->features & ARM_SMMU_FEAT_STALL_FORCE)
 		master->stall_enabled = true;
 
+	dev->iommu->pasid_bits = master->ssid_bits;
+
 	return &smmu->iommu;
 
 err_free_master:
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index df5c62ecf942..ffad7f8f2d73 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4593,8 +4593,11 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
 			if (pasid_supported(iommu)) {
 				int features = pci_pasid_features(pdev);
 
-				if (features >= 0)
+				if (features >= 0) {
 					info->pasid_supported = features | 1;
+					dev->iommu->pasid_bits =
+						fls(pci_max_pasids(pdev)) - 1;
+				}
 			}
 
 			if (info->ats_supported && ecap_prs(iommu->ecap) &&
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Lu Baolu]

Attaching an IOMMU domain to a PASID of a device is a generic operation
for modern IOMMU drivers which support PASID-granular DMA address
translation. Currently visible usage scenarios include (but not limited):

 - SVA (Shared Virtual Address)
 - kernel DMA with PASID
 - hardware-assist mediated device

This adds a pair of common domain ops for this purpose and adds helpers
to attach/detach a domain to/from a {device, PASID}. Some buses, like
PCI, route packets without considering the PASID value. Thus a DMA target
address with PASID might be treated as P2P if the address falls into the
MMIO BAR of other devices in the group. To make things simple, these
interfaces only apply to devices belonging to the singleton groups, and
the singleton is immutable in fabric i.e. not affected by hotplug.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h | 21 ++++++++++
 drivers/iommu/iommu.c | 95 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 36f43af0af53..fe7d9ee2bc2b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -262,6 +262,8 @@ struct iommu_ops {
  * struct iommu_domain_ops - domain specific operations
  * @attach_dev: attach an iommu domain to a device
  * @detach_dev: detach an iommu domain from a device
+ * @attach_dev_pasid: attach an iommu domain to a pasid of device
+ * @detach_dev_pasid: detach an iommu domain from a pasid of device
  * @map: map a physically contiguous memory region to an iommu domain
  * @map_pages: map a physically contiguous set of pages of the same size to
  *             an iommu domain.
@@ -279,6 +281,10 @@ struct iommu_ops {
 struct iommu_domain_ops {
 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
 	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
+	int (*attach_dev_pasid)(struct iommu_domain *domain,
+				struct device *dev, ioasid_t pasid);
+	void (*detach_dev_pasid)(struct iommu_domain *domain,
+				 struct device *dev, ioasid_t pasid);
 
 	int (*map)(struct iommu_domain *domain, unsigned long iova,
 		   phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
@@ -672,6 +678,10 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner);
 void iommu_group_release_dma_owner(struct iommu_group *group);
 bool iommu_group_dma_owner_claimed(struct iommu_group *group);
 
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+			      struct device *dev, ioasid_t pasid);
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+			       struct device *dev, ioasid_t pasid);
 #else /* CONFIG_IOMMU_API */
 
 struct iommu_ops {};
@@ -1040,6 +1050,17 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 {
 	return false;
 }
+
+static inline int iommu_attach_device_pasid(struct iommu_domain *domain,
+					    struct device *dev, ioasid_t pasid)
+{
+	return -ENODEV;
+}
+
+static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
+					     struct device *dev, ioasid_t pasid)
+{
+}
 #endif /* CONFIG_IOMMU_API */
 
 /**
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0c42ece25854..c6fdc0067d76 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -38,6 +38,7 @@ struct iommu_group {
 	struct kobject kobj;
 	struct kobject *devices_kobj;
 	struct list_head devices;
+	struct xarray pasid_array;
 	struct mutex mutex;
 	void *iommu_data;
 	void (*iommu_data_release)(void *iommu_data);
@@ -630,6 +631,7 @@ struct iommu_group *iommu_group_alloc(void)
 	mutex_init(&group->mutex);
 	INIT_LIST_HEAD(&group->devices);
 	INIT_LIST_HEAD(&group->entry);
+	xa_init(&group->pasid_array);
 
 	ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
 	if (ret < 0) {
@@ -3167,3 +3169,96 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 	return user;
 }
 EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+static int has_pci_alias(struct pci_dev *pdev, u16 alias, void *opaque)
+{
+	return (pdev != opaque) ? -EEXIST : 0;
+}
+
+/*
+ * Use standard PCI bus topology, isolation features, and DMA
+ * alias quirks to check the immutable singleton attribute. If
+ * the device came from DT, assume it is static and then
+ * singleton can know from the device count in the group.
+ */
+static bool device_group_immutable_singleton(struct device *dev)
+{
+	struct iommu_group *group = iommu_group_get(dev);
+	int count;
+
+	if (!group)
+		return false;
+
+	mutex_lock(&group->mutex);
+	count = iommu_group_device_count(group);
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	if (count != 1)
+		return false;
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		/*
+		 * The device could be considered to be fully isolated if
+		 * all devices on the path from the device to the host-PCI
+		 * bridge are protected from peer-to-peer DMA by ACS.
+		 */
+		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
+			return false;
+
+		/* Filter out devices which has any alias device. */
+		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
+			return false;
+
+		return true;
+	}
+
+	/*
+	 * If the device came from DT, assume it is static and then
+	 * singleton can know from the device count in the group.
+	 */
+	return is_of_node(dev_fwnode(dev));
+}
+
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+			      struct device *dev, ioasid_t pasid)
+{
+	struct iommu_group *group;
+	int ret = -EINVAL;
+	void *curr;
+
+	if (!domain->ops->attach_dev_pasid)
+		return -EINVAL;
+
+	if (!device_group_immutable_singleton(dev))
+		return -EINVAL;
+
+	group = iommu_group_get(dev);
+	mutex_lock(&group->mutex);
+	curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
+	if (curr)
+		goto out_unlock;
+	ret = domain->ops->attach_dev_pasid(domain, dev, pasid);
+	if (ret)
+		xa_erase(&group->pasid_array, pasid);
+out_unlock:
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	return ret;
+}
+
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+			       struct device *dev, ioasid_t pasid)
+{
+	struct iommu_group *group = iommu_group_get(dev);
+
+	mutex_lock(&group->mutex);
+	domain->ops->detach_dev_pasid(domain, dev, pasid);
+	xa_erase(&group->pasid_array, pasid);
+	mutex_unlock(&group->mutex);
+
+	iommu_group_put(group);
+}
-- 
2.25.1

[PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Lu Baolu]

Attaching an IOMMU domain to a PASID of a device is a generic operation
for modern IOMMU drivers which support PASID-granular DMA address
translation. Currently visible usage scenarios include (but not limited):

 - SVA (Shared Virtual Address)
 - kernel DMA with PASID
 - hardware-assist mediated device

This adds a pair of common domain ops for this purpose and adds helpers
to attach/detach a domain to/from a {device, PASID}. Some buses, like
PCI, route packets without considering the PASID value. Thus a DMA target
address with PASID might be treated as P2P if the address falls into the
MMIO BAR of other devices in the group. To make things simple, these
interfaces only apply to devices belonging to the singleton groups, and
the singleton is immutable in fabric i.e. not affected by hotplug.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h | 21 ++++++++++
 drivers/iommu/iommu.c | 95 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 36f43af0af53..fe7d9ee2bc2b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -262,6 +262,8 @@ struct iommu_ops {
  * struct iommu_domain_ops - domain specific operations
  * @attach_dev: attach an iommu domain to a device
  * @detach_dev: detach an iommu domain from a device
+ * @attach_dev_pasid: attach an iommu domain to a pasid of device
+ * @detach_dev_pasid: detach an iommu domain from a pasid of device
  * @map: map a physically contiguous memory region to an iommu domain
  * @map_pages: map a physically contiguous set of pages of the same size to
  *             an iommu domain.
@@ -279,6 +281,10 @@ struct iommu_ops {
 struct iommu_domain_ops {
 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
 	void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
+	int (*attach_dev_pasid)(struct iommu_domain *domain,
+				struct device *dev, ioasid_t pasid);
+	void (*detach_dev_pasid)(struct iommu_domain *domain,
+				 struct device *dev, ioasid_t pasid);
 
 	int (*map)(struct iommu_domain *domain, unsigned long iova,
 		   phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
@@ -672,6 +678,10 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner);
 void iommu_group_release_dma_owner(struct iommu_group *group);
 bool iommu_group_dma_owner_claimed(struct iommu_group *group);
 
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+			      struct device *dev, ioasid_t pasid);
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+			       struct device *dev, ioasid_t pasid);
 #else /* CONFIG_IOMMU_API */
 
 struct iommu_ops {};
@@ -1040,6 +1050,17 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 {
 	return false;
 }
+
+static inline int iommu_attach_device_pasid(struct iommu_domain *domain,
+					    struct device *dev, ioasid_t pasid)
+{
+	return -ENODEV;
+}
+
+static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
+					     struct device *dev, ioasid_t pasid)
+{
+}
 #endif /* CONFIG_IOMMU_API */
 
 /**
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0c42ece25854..c6fdc0067d76 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -38,6 +38,7 @@ struct iommu_group {
 	struct kobject kobj;
 	struct kobject *devices_kobj;
 	struct list_head devices;
+	struct xarray pasid_array;
 	struct mutex mutex;
 	void *iommu_data;
 	void (*iommu_data_release)(void *iommu_data);
@@ -630,6 +631,7 @@ struct iommu_group *iommu_group_alloc(void)
 	mutex_init(&group->mutex);
 	INIT_LIST_HEAD(&group->devices);
 	INIT_LIST_HEAD(&group->entry);
+	xa_init(&group->pasid_array);
 
 	ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
 	if (ret < 0) {
@@ -3167,3 +3169,96 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group)
 	return user;
 }
 EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed);
+
+static int has_pci_alias(struct pci_dev *pdev, u16 alias, void *opaque)
+{
+	return (pdev != opaque) ? -EEXIST : 0;
+}
+
+/*
+ * Use standard PCI bus topology, isolation features, and DMA
+ * alias quirks to check the immutable singleton attribute. If
+ * the device came from DT, assume it is static and then
+ * singleton can know from the device count in the group.
+ */
+static bool device_group_immutable_singleton(struct device *dev)
+{
+	struct iommu_group *group = iommu_group_get(dev);
+	int count;
+
+	if (!group)
+		return false;
+
+	mutex_lock(&group->mutex);
+	count = iommu_group_device_count(group);
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	if (count != 1)
+		return false;
+
+	if (dev_is_pci(dev)) {
+		struct pci_dev *pdev = to_pci_dev(dev);
+
+		/*
+		 * The device could be considered to be fully isolated if
+		 * all devices on the path from the device to the host-PCI
+		 * bridge are protected from peer-to-peer DMA by ACS.
+		 */
+		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
+			return false;
+
+		/* Filter out devices which has any alias device. */
+		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
+			return false;
+
+		return true;
+	}
+
+	/*
+	 * If the device came from DT, assume it is static and then
+	 * singleton can know from the device count in the group.
+	 */
+	return is_of_node(dev_fwnode(dev));
+}
+
+int iommu_attach_device_pasid(struct iommu_domain *domain,
+			      struct device *dev, ioasid_t pasid)
+{
+	struct iommu_group *group;
+	int ret = -EINVAL;
+	void *curr;
+
+	if (!domain->ops->attach_dev_pasid)
+		return -EINVAL;
+
+	if (!device_group_immutable_singleton(dev))
+		return -EINVAL;
+
+	group = iommu_group_get(dev);
+	mutex_lock(&group->mutex);
+	curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
+	if (curr)
+		goto out_unlock;
+	ret = domain->ops->attach_dev_pasid(domain, dev, pasid);
+	if (ret)
+		xa_erase(&group->pasid_array, pasid);
+out_unlock:
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	return ret;
+}
+
+void iommu_detach_device_pasid(struct iommu_domain *domain,
+			       struct device *dev, ioasid_t pasid)
+{
+	struct iommu_group *group = iommu_group_get(dev);
+
+	mutex_lock(&group->mutex);
+	domain->ops->detach_dev_pasid(domain, dev, pasid);
+	xa_erase(&group->pasid_array, pasid);
+	mutex_unlock(&group->mutex);
+
+	iommu_group_put(group);
+}
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 04/12] iommu/sva: Basic data structures for SVA

[Lu Baolu]

Use below data structures for SVA implementation in the IOMMU core:

- struct iommu_sva_ioas
  Represent the I/O address space shared with an application CPU address
  space. This structure has a 1:1 relationship with an mm_struct. It
  grabs a "mm->mm_count" refcount during creation and drop it on release.

- struct iommu_domain (IOMMU_DOMAIN_SVA type)
  Represent a hardware pagetable that the IOMMU hardware could use for
  SVA translation. Multiple iommu domains could be bound with an SVA ioas
  and each grabs a refcount from ioas in order to make sure ioas could
  only be freed after all domains have been unbound.

- struct iommu_sva
  Represent a bond relationship between an SVA ioas and an iommu domain.
  If a bond already exists, it's reused and a reference is taken.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         | 14 +++++++++++++-
 drivers/iommu/iommu-sva-lib.h |  1 +
 drivers/iommu/iommu-sva-lib.c | 18 ++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fe7d9ee2bc2b..14c3b2197b35 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,7 @@ struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
+struct iommu_sva_ioas;
 
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
@@ -64,6 +65,9 @@ struct iommu_domain_geometry {
 #define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity mapped   */
 #define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses flush queue    */
 
+#define __IOMMU_DOMAIN_SHARED	(1U << 4)  /* Page table shared from CPU  */
+#define __IOMMU_DOMAIN_HOST_VA	(1U << 5)  /* Host CPU virtual address */
+
 /*
  * This are the possible domain-types
  *
@@ -86,6 +90,8 @@ struct iommu_domain_geometry {
 #define IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING |	\
 				 __IOMMU_DOMAIN_DMA_API |	\
 				 __IOMMU_DOMAIN_DMA_FQ)
+#define IOMMU_DOMAIN_SVA	(__IOMMU_DOMAIN_SHARED |	\
+				 __IOMMU_DOMAIN_HOST_VA)
 
 struct iommu_domain {
 	unsigned type;
@@ -95,6 +101,7 @@ struct iommu_domain {
 	void *handler_token;
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
+	struct iommu_sva_ioas *sva_ioas;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
@@ -622,7 +629,12 @@ struct iommu_fwspec {
  * struct iommu_sva - handle to a device-mm bond
  */
 struct iommu_sva {
-	struct device			*dev;
+	struct device		*dev;
+	struct iommu_sva_ioas	*sva_ioas;
+	struct iommu_domain	*domain;
+	/* Link to sva ioas's bonds list */
+	struct list_head	node;
+	refcount_t		users;
 };
 
 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 8909ea1094e3..9c5e108e2c8a 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -10,6 +10,7 @@
 
 int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
 struct mm_struct *iommu_sva_find(ioasid_t pasid);
+struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
 /* I/O Page fault */
 struct device;
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 106506143896..d524a402be3b 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -3,6 +3,8 @@
  * Helpers for IOMMU drivers implementing SVA
  */
 #include <linux/mutex.h>
+#include <linux/iommu.h>
+#include <linux/slab.h>
 #include <linux/sched/mm.h>
 
 #include "iommu-sva-lib.h"
@@ -10,6 +12,22 @@
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
 
+struct iommu_sva_ioas {
+	struct mm_struct *mm;
+	ioasid_t pasid;
+
+	/* Counter of domains attached to this ioas. */
+	refcount_t users;
+
+	/* All bindings are linked here. */
+	struct list_head bonds;
+};
+
+struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain)
+{
+	return domain->sva_ioas->mm;
+}
+
 /**
  * iommu_sva_alloc_pasid - Allocate a PASID for the mm
  * @mm: the mm
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 04/12] iommu/sva: Basic data structures for SVA

[Lu Baolu]

Use below data structures for SVA implementation in the IOMMU core:

- struct iommu_sva_ioas
  Represent the I/O address space shared with an application CPU address
  space. This structure has a 1:1 relationship with an mm_struct. It
  grabs a "mm->mm_count" refcount during creation and drop it on release.

- struct iommu_domain (IOMMU_DOMAIN_SVA type)
  Represent a hardware pagetable that the IOMMU hardware could use for
  SVA translation. Multiple iommu domains could be bound with an SVA ioas
  and each grabs a refcount from ioas in order to make sure ioas could
  only be freed after all domains have been unbound.

- struct iommu_sva
  Represent a bond relationship between an SVA ioas and an iommu domain.
  If a bond already exists, it's reused and a reference is taken.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         | 14 +++++++++++++-
 drivers/iommu/iommu-sva-lib.h |  1 +
 drivers/iommu/iommu-sva-lib.c | 18 ++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fe7d9ee2bc2b..14c3b2197b35 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,7 @@ struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
+struct iommu_sva_ioas;
 
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
@@ -64,6 +65,9 @@ struct iommu_domain_geometry {
 #define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity mapped   */
 #define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses flush queue    */
 
+#define __IOMMU_DOMAIN_SHARED	(1U << 4)  /* Page table shared from CPU  */
+#define __IOMMU_DOMAIN_HOST_VA	(1U << 5)  /* Host CPU virtual address */
+
 /*
  * This are the possible domain-types
  *
@@ -86,6 +90,8 @@ struct iommu_domain_geometry {
 #define IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING |	\
 				 __IOMMU_DOMAIN_DMA_API |	\
 				 __IOMMU_DOMAIN_DMA_FQ)
+#define IOMMU_DOMAIN_SVA	(__IOMMU_DOMAIN_SHARED |	\
+				 __IOMMU_DOMAIN_HOST_VA)
 
 struct iommu_domain {
 	unsigned type;
@@ -95,6 +101,7 @@ struct iommu_domain {
 	void *handler_token;
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
+	struct iommu_sva_ioas *sva_ioas;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
@@ -622,7 +629,12 @@ struct iommu_fwspec {
  * struct iommu_sva - handle to a device-mm bond
  */
 struct iommu_sva {
-	struct device			*dev;
+	struct device		*dev;
+	struct iommu_sva_ioas	*sva_ioas;
+	struct iommu_domain	*domain;
+	/* Link to sva ioas's bonds list */
+	struct list_head	node;
+	refcount_t		users;
 };
 
 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 8909ea1094e3..9c5e108e2c8a 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -10,6 +10,7 @@
 
 int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
 struct mm_struct *iommu_sva_find(ioasid_t pasid);
+struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
 /* I/O Page fault */
 struct device;
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 106506143896..d524a402be3b 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -3,6 +3,8 @@
  * Helpers for IOMMU drivers implementing SVA
  */
 #include <linux/mutex.h>
+#include <linux/iommu.h>
+#include <linux/slab.h>
 #include <linux/sched/mm.h>
 
 #include "iommu-sva-lib.h"
@@ -10,6 +12,22 @@
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
 
+struct iommu_sva_ioas {
+	struct mm_struct *mm;
+	ioasid_t pasid;
+
+	/* Counter of domains attached to this ioas. */
+	refcount_t users;
+
+	/* All bindings are linked here. */
+	struct list_head bonds;
+};
+
+struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain)
+{
+	return domain->sva_ioas->mm;
+}
+
 /**
  * iommu_sva_alloc_pasid - Allocate a PASID for the mm
  * @mm: the mm
-- 
2.25.1

[PATCH v4 05/12] iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support

[Lu Baolu]

The current kernel DMA with PASID support is based on the SVA with a flag
SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel memory address
space to a PASID of the device. The device driver programs the device with
kernel virtual address (KVA) for DMA access. There have been security and
functional issues with this approach:

- The lack of IOTLB synchronization upon kernel page table updates.
  (vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.)
- Other than slight more protection, using kernel virtual address (KVA)
  has little advantage over physical address. There are also no use
  cases yet where DMA engines need kernel virtual addresses for in-kernel
  DMA.

This removes SVM_FLAG_SUPERVISOR_MODE support in the Intel IOMMU driver.
The device driver is suggested to handle kernel DMA with PASID through
the kernel DMA APIs.

Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/svm.c | 53 +++++++++------------------------------
 1 file changed, 12 insertions(+), 41 deletions(-)

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 23a38763c1d1..4c283a250541 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -313,8 +313,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
 	return 0;
 }
 
-static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm,
-				 unsigned int flags)
+static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm)
 {
 	ioasid_t max_pasid = dev_is_pci(dev) ?
 			pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id;
@@ -324,8 +323,7 @@ static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm,
 
 static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 					   struct device *dev,
-					   struct mm_struct *mm,
-					   unsigned int flags)
+					   struct mm_struct *mm)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	unsigned long iflags, sflags;
@@ -341,22 +339,18 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 
 		svm->pasid = mm->pasid;
 		svm->mm = mm;
-		svm->flags = flags;
 		INIT_LIST_HEAD_RCU(&svm->devs);
 
-		if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) {
-			svm->notifier.ops = &intel_mmuops;
-			ret = mmu_notifier_register(&svm->notifier, mm);
-			if (ret) {
-				kfree(svm);
-				return ERR_PTR(ret);
-			}
+		svm->notifier.ops = &intel_mmuops;
+		ret = mmu_notifier_register(&svm->notifier, mm);
+		if (ret) {
+			kfree(svm);
+			return ERR_PTR(ret);
 		}
 
 		ret = pasid_private_add(svm->pasid, svm);
 		if (ret) {
-			if (svm->notifier.ops)
-				mmu_notifier_unregister(&svm->notifier, mm);
+			mmu_notifier_unregister(&svm->notifier, mm);
 			kfree(svm);
 			return ERR_PTR(ret);
 		}
@@ -391,9 +385,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 	}
 
 	/* Setup the pasid table: */
-	sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ?
-			PASID_FLAG_SUPERVISOR_MODE : 0;
-	sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
+	sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
 	spin_lock_irqsave(&iommu->lock, iflags);
 	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid,
 					    FLPT_DEFAULT_DID, sflags);
@@ -410,8 +402,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 	kfree(sdev);
 free_svm:
 	if (list_empty(&svm->devs)) {
-		if (svm->notifier.ops)
-			mmu_notifier_unregister(&svm->notifier, mm);
+		mmu_notifier_unregister(&svm->notifier, mm);
 		pasid_private_remove(mm->pasid);
 		kfree(svm);
 	}
@@ -817,37 +808,17 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
 {
 	struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
-	unsigned int flags = 0;
 	struct iommu_sva *sva;
 	int ret;
 
-	if (drvdata)
-		flags = *(unsigned int *)drvdata;
-
-	if (flags & SVM_FLAG_SUPERVISOR_MODE) {
-		if (!ecap_srs(iommu->ecap)) {
-			dev_err(dev, "%s: Supervisor PASID not supported\n",
-				iommu->name);
-			return ERR_PTR(-EOPNOTSUPP);
-		}
-
-		if (mm) {
-			dev_err(dev, "%s: Supervisor PASID with user provided mm\n",
-				iommu->name);
-			return ERR_PTR(-EINVAL);
-		}
-
-		mm = &init_mm;
-	}
-
 	mutex_lock(&pasid_mutex);
-	ret = intel_svm_alloc_pasid(dev, mm, flags);
+	ret = intel_svm_alloc_pasid(dev, mm);
 	if (ret) {
 		mutex_unlock(&pasid_mutex);
 		return ERR_PTR(ret);
 	}
 
-	sva = intel_svm_bind_mm(iommu, dev, mm, flags);
+	sva = intel_svm_bind_mm(iommu, dev, mm);
 	mutex_unlock(&pasid_mutex);
 
 	return sva;
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 05/12] iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support

[Lu Baolu]

The current kernel DMA with PASID support is based on the SVA with a flag
SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel memory address
space to a PASID of the device. The device driver programs the device with
kernel virtual address (KVA) for DMA access. There have been security and
functional issues with this approach:

- The lack of IOTLB synchronization upon kernel page table updates.
  (vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.)
- Other than slight more protection, using kernel virtual address (KVA)
  has little advantage over physical address. There are also no use
  cases yet where DMA engines need kernel virtual addresses for in-kernel
  DMA.

This removes SVM_FLAG_SUPERVISOR_MODE support in the Intel IOMMU driver.
The device driver is suggested to handle kernel DMA with PASID through
the kernel DMA APIs.

Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/svm.c | 53 +++++++++------------------------------
 1 file changed, 12 insertions(+), 41 deletions(-)

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 23a38763c1d1..4c283a250541 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -313,8 +313,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
 	return 0;
 }
 
-static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm,
-				 unsigned int flags)
+static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm)
 {
 	ioasid_t max_pasid = dev_is_pci(dev) ?
 			pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id;
@@ -324,8 +323,7 @@ static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm,
 
 static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 					   struct device *dev,
-					   struct mm_struct *mm,
-					   unsigned int flags)
+					   struct mm_struct *mm)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	unsigned long iflags, sflags;
@@ -341,22 +339,18 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 
 		svm->pasid = mm->pasid;
 		svm->mm = mm;
-		svm->flags = flags;
 		INIT_LIST_HEAD_RCU(&svm->devs);
 
-		if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) {
-			svm->notifier.ops = &intel_mmuops;
-			ret = mmu_notifier_register(&svm->notifier, mm);
-			if (ret) {
-				kfree(svm);
-				return ERR_PTR(ret);
-			}
+		svm->notifier.ops = &intel_mmuops;
+		ret = mmu_notifier_register(&svm->notifier, mm);
+		if (ret) {
+			kfree(svm);
+			return ERR_PTR(ret);
 		}
 
 		ret = pasid_private_add(svm->pasid, svm);
 		if (ret) {
-			if (svm->notifier.ops)
-				mmu_notifier_unregister(&svm->notifier, mm);
+			mmu_notifier_unregister(&svm->notifier, mm);
 			kfree(svm);
 			return ERR_PTR(ret);
 		}
@@ -391,9 +385,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 	}
 
 	/* Setup the pasid table: */
-	sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ?
-			PASID_FLAG_SUPERVISOR_MODE : 0;
-	sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
+	sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
 	spin_lock_irqsave(&iommu->lock, iflags);
 	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid,
 					    FLPT_DEFAULT_DID, sflags);
@@ -410,8 +402,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 	kfree(sdev);
 free_svm:
 	if (list_empty(&svm->devs)) {
-		if (svm->notifier.ops)
-			mmu_notifier_unregister(&svm->notifier, mm);
+		mmu_notifier_unregister(&svm->notifier, mm);
 		pasid_private_remove(mm->pasid);
 		kfree(svm);
 	}
@@ -817,37 +808,17 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
 {
 	struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
-	unsigned int flags = 0;
 	struct iommu_sva *sva;
 	int ret;
 
-	if (drvdata)
-		flags = *(unsigned int *)drvdata;
-
-	if (flags & SVM_FLAG_SUPERVISOR_MODE) {
-		if (!ecap_srs(iommu->ecap)) {
-			dev_err(dev, "%s: Supervisor PASID not supported\n",
-				iommu->name);
-			return ERR_PTR(-EOPNOTSUPP);
-		}
-
-		if (mm) {
-			dev_err(dev, "%s: Supervisor PASID with user provided mm\n",
-				iommu->name);
-			return ERR_PTR(-EINVAL);
-		}
-
-		mm = &init_mm;
-	}
-
 	mutex_lock(&pasid_mutex);
-	ret = intel_svm_alloc_pasid(dev, mm, flags);
+	ret = intel_svm_alloc_pasid(dev, mm);
 	if (ret) {
 		mutex_unlock(&pasid_mutex);
 		return ERR_PTR(ret);
 	}
 
-	sva = intel_svm_bind_mm(iommu, dev, mm, flags);
+	sva = intel_svm_bind_mm(iommu, dev, mm);
 	mutex_unlock(&pasid_mutex);
 
 	return sva;
-- 
2.25.1

[PATCH v4 06/12] iommu/vt-d: Add SVA domain support

[Lu Baolu]

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/intel-iommu.h |  1 +
 drivers/iommu/intel/iommu.c | 10 ++++++++++
 drivers/iommu/intel/svm.c   | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 2f9891cb3d00..c14283137fb5 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -744,6 +744,7 @@ void intel_svm_unbind(struct iommu_sva *handle);
 u32 intel_svm_get_pasid(struct iommu_sva *handle);
 int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg);
+extern const struct iommu_domain_ops intel_svm_domain_ops;
 
 struct intel_svm_dev {
 	struct list_head list;
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ffad7f8f2d73..9c2714ba04ff 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4324,6 +4324,16 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 		return domain;
 	case IOMMU_DOMAIN_IDENTITY:
 		return &si_domain->domain;
+#ifdef CONFIG_INTEL_IOMMU_SVM
+	case IOMMU_DOMAIN_SVA:
+		dmar_domain = alloc_domain(type);
+		if (!dmar_domain)
+			return NULL;
+		domain = &dmar_domain->domain;
+		domain->ops = &intel_svm_domain_ops;
+
+		return domain;
+#endif /* CONFIG_INTEL_IOMMU_SVM */
 	default:
 		return NULL;
 	}
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 4c283a250541..251a3a65d77f 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -927,3 +927,40 @@ int intel_svm_page_response(struct device *dev,
 	mutex_unlock(&pasid_mutex);
 	return ret;
 }
+
+static int intel_svm_attach_dev_pasid(struct iommu_domain *domain,
+				      struct device *dev, ioasid_t pasid)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+	struct intel_iommu *iommu = info->iommu;
+	struct iommu_sva *sva;
+	int ret = 0;
+
+	mutex_lock(&pasid_mutex);
+	sva = intel_svm_bind_mm(iommu, dev, mm);
+	if (IS_ERR(sva))
+		ret = PTR_ERR(sva);
+	mutex_unlock(&pasid_mutex);
+
+	return ret;
+}
+
+static void intel_svm_detach_dev_pasid(struct iommu_domain *domain,
+				       struct device *dev, ioasid_t pasid)
+{
+	mutex_lock(&pasid_mutex);
+	intel_svm_unbind_mm(dev, pasid);
+	mutex_unlock(&pasid_mutex);
+}
+
+static void intel_svm_domain_free(struct iommu_domain *domain)
+{
+	kfree(to_dmar_domain(domain));
+}
+
+const struct iommu_domain_ops intel_svm_domain_ops = {
+	.attach_dev_pasid	= intel_svm_attach_dev_pasid,
+	.detach_dev_pasid	= intel_svm_detach_dev_pasid,
+	.free			= intel_svm_domain_free,
+};
-- 
2.25.1

[PATCH v4 06/12] iommu/vt-d: Add SVA domain support

[Lu Baolu]

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/intel-iommu.h |  1 +
 drivers/iommu/intel/iommu.c | 10 ++++++++++
 drivers/iommu/intel/svm.c   | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 2f9891cb3d00..c14283137fb5 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -744,6 +744,7 @@ void intel_svm_unbind(struct iommu_sva *handle);
 u32 intel_svm_get_pasid(struct iommu_sva *handle);
 int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg);
+extern const struct iommu_domain_ops intel_svm_domain_ops;
 
 struct intel_svm_dev {
 	struct list_head list;
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ffad7f8f2d73..9c2714ba04ff 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4324,6 +4324,16 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 		return domain;
 	case IOMMU_DOMAIN_IDENTITY:
 		return &si_domain->domain;
+#ifdef CONFIG_INTEL_IOMMU_SVM
+	case IOMMU_DOMAIN_SVA:
+		dmar_domain = alloc_domain(type);
+		if (!dmar_domain)
+			return NULL;
+		domain = &dmar_domain->domain;
+		domain->ops = &intel_svm_domain_ops;
+
+		return domain;
+#endif /* CONFIG_INTEL_IOMMU_SVM */
 	default:
 		return NULL;
 	}
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 4c283a250541..251a3a65d77f 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -927,3 +927,40 @@ int intel_svm_page_response(struct device *dev,
 	mutex_unlock(&pasid_mutex);
 	return ret;
 }
+
+static int intel_svm_attach_dev_pasid(struct iommu_domain *domain,
+				      struct device *dev, ioasid_t pasid)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+	struct intel_iommu *iommu = info->iommu;
+	struct iommu_sva *sva;
+	int ret = 0;
+
+	mutex_lock(&pasid_mutex);
+	sva = intel_svm_bind_mm(iommu, dev, mm);
+	if (IS_ERR(sva))
+		ret = PTR_ERR(sva);
+	mutex_unlock(&pasid_mutex);
+
+	return ret;
+}
+
+static void intel_svm_detach_dev_pasid(struct iommu_domain *domain,
+				       struct device *dev, ioasid_t pasid)
+{
+	mutex_lock(&pasid_mutex);
+	intel_svm_unbind_mm(dev, pasid);
+	mutex_unlock(&pasid_mutex);
+}
+
+static void intel_svm_domain_free(struct iommu_domain *domain)
+{
+	kfree(to_dmar_domain(domain));
+}
+
+const struct iommu_domain_ops intel_svm_domain_ops = {
+	.attach_dev_pasid	= intel_svm_attach_dev_pasid,
+	.detach_dev_pasid	= intel_svm_detach_dev_pasid,
+	.free			= intel_svm_domain_free,
+};
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 07/12] arm-smmu-v3/sva: Add SVA domain support

[Lu Baolu]

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   | 14 +++++++
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 42 +++++++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 21 ++++++++++
 3 files changed, 77 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index cd48590ada30..7631c00fdcbd 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -759,6 +759,10 @@ struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm,
 void arm_smmu_sva_unbind(struct iommu_sva *handle);
 u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id);
+void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id);
 #else /* CONFIG_ARM_SMMU_V3_SVA */
 static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
@@ -804,5 +808,15 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
 }
 
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
+
+static inline int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+						struct device *dev, ioasid_t id)
+{
+	return -ENODEV;
+}
+
+static inline void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+						 struct device *dev,
+						 ioasid_t id) {}
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
 #endif /* _ARM_SMMU_V3_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 22ddd05bbdcd..ce229820086d 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
@@ -534,3 +534,45 @@ void arm_smmu_sva_notifier_synchronize(void)
 	 */
 	mmu_notifier_synchronize();
 }
+
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id)
+{
+	int ret = 0;
+	struct iommu_sva *handle;
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+
+	if (domain->type != IOMMU_DOMAIN_SVA || !mm)
+		return -EINVAL;
+
+	mutex_lock(&sva_lock);
+	handle = __arm_smmu_sva_bind(dev, mm);
+	if (IS_ERR(handle))
+		ret = PTR_ERR(handle);
+	mutex_unlock(&sva_lock);
+
+	return ret;
+}
+
+void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id)
+{
+	struct arm_smmu_bond *bond = NULL, *t;
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+
+	mutex_lock(&sva_lock);
+	list_for_each_entry(t, &master->bonds, list) {
+		if (t->mm == mm) {
+			bond = t;
+			break;
+		}
+	}
+
+	if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) {
+		list_del(&bond->list);
+		arm_smmu_mmu_notifier_put(bond->smmu_mn);
+		kfree(bond);
+	}
+	mutex_unlock(&sva_lock);
+}
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 afc63fce6107..bd80de0bad98 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1995,10 +1995,31 @@ static bool arm_smmu_capable(enum iommu_cap cap)
 	}
 }
 
+static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
+{
+	kfree(domain);
+}
+
+static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
+	.attach_dev_pasid	= arm_smmu_sva_attach_dev_pasid,
+	.detach_dev_pasid	= arm_smmu_sva_detach_dev_pasid,
+	.free			= arm_smmu_sva_domain_free,
+};
+
 static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 {
 	struct arm_smmu_domain *smmu_domain;
 
+	if (type == IOMMU_DOMAIN_SVA) {
+		struct iommu_domain *domain;
+
+		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+		if (domain)
+			domain->ops = &arm_smmu_sva_domain_ops;
+
+		return domain;
+	}
+
 	if (type != IOMMU_DOMAIN_UNMANAGED &&
 	    type != IOMMU_DOMAIN_DMA &&
 	    type != IOMMU_DOMAIN_DMA_FQ &&
-- 
2.25.1

[PATCH v4 07/12] arm-smmu-v3/sva: Add SVA domain support

[Lu Baolu]

Add support for SVA domain allocation and provide an SVA-specific
iommu_domain_ops.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   | 14 +++++++
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 42 +++++++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 21 ++++++++++
 3 files changed, 77 insertions(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index cd48590ada30..7631c00fdcbd 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -759,6 +759,10 @@ struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm,
 void arm_smmu_sva_unbind(struct iommu_sva *handle);
 u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id);
+void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id);
 #else /* CONFIG_ARM_SMMU_V3_SVA */
 static inline bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
@@ -804,5 +808,15 @@ static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
 }
 
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
+
+static inline int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+						struct device *dev, ioasid_t id)
+{
+	return -ENODEV;
+}
+
+static inline void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+						 struct device *dev,
+						 ioasid_t id) {}
 #endif /* CONFIG_ARM_SMMU_V3_SVA */
 #endif /* _ARM_SMMU_V3_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 22ddd05bbdcd..ce229820086d 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
@@ -534,3 +534,45 @@ void arm_smmu_sva_notifier_synchronize(void)
 	 */
 	mmu_notifier_synchronize();
 }
+
+int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
+				  struct device *dev, ioasid_t id)
+{
+	int ret = 0;
+	struct iommu_sva *handle;
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+
+	if (domain->type != IOMMU_DOMAIN_SVA || !mm)
+		return -EINVAL;
+
+	mutex_lock(&sva_lock);
+	handle = __arm_smmu_sva_bind(dev, mm);
+	if (IS_ERR(handle))
+		ret = PTR_ERR(handle);
+	mutex_unlock(&sva_lock);
+
+	return ret;
+}
+
+void arm_smmu_sva_detach_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t id)
+{
+	struct arm_smmu_bond *bond = NULL, *t;
+	struct mm_struct *mm = iommu_sva_domain_mm(domain);
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+
+	mutex_lock(&sva_lock);
+	list_for_each_entry(t, &master->bonds, list) {
+		if (t->mm == mm) {
+			bond = t;
+			break;
+		}
+	}
+
+	if (!WARN_ON(!bond) && refcount_dec_and_test(&bond->refs)) {
+		list_del(&bond->list);
+		arm_smmu_mmu_notifier_put(bond->smmu_mn);
+		kfree(bond);
+	}
+	mutex_unlock(&sva_lock);
+}
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 afc63fce6107..bd80de0bad98 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1995,10 +1995,31 @@ static bool arm_smmu_capable(enum iommu_cap cap)
 	}
 }
 
+static void arm_smmu_sva_domain_free(struct iommu_domain *domain)
+{
+	kfree(domain);
+}
+
+static const struct iommu_domain_ops arm_smmu_sva_domain_ops = {
+	.attach_dev_pasid	= arm_smmu_sva_attach_dev_pasid,
+	.detach_dev_pasid	= arm_smmu_sva_detach_dev_pasid,
+	.free			= arm_smmu_sva_domain_free,
+};
+
 static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
 {
 	struct arm_smmu_domain *smmu_domain;
 
+	if (type == IOMMU_DOMAIN_SVA) {
+		struct iommu_domain *domain;
+
+		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+		if (domain)
+			domain->ops = &arm_smmu_sva_domain_ops;
+
+		return domain;
+	}
+
 	if (type != IOMMU_DOMAIN_UNMANAGED &&
 	    type != IOMMU_DOMAIN_DMA &&
 	    type != IOMMU_DOMAIN_DMA_FQ &&
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 08/12] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces

[Lu Baolu]

The existing iommu SVA interfaces are implemented by calling the SVA
specific iommu ops provided by the IOMMU drivers. There's no need for
any SVA specific ops in iommu_ops vector anymore as we can achieve
this through the generic attach/detach_dev_pasid domain ops.

This refactors the IOMMU SVA interfaces implementation by using the
attach/detach_pasid_dev ops and align them with the concept of the
iommu domain. Put the new SVA code in the sva related file in order
to make it self-contained.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         |  44 ++++----
 drivers/iommu/iommu-sva-lib.h |   5 +
 drivers/iommu/iommu-sva-lib.c | 196 ++++++++++++++++++++++++++++++++++
 drivers/iommu/iommu.c         |  95 +---------------
 4 files changed, 227 insertions(+), 113 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 14c3b2197b35..2a2d17431826 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -677,12 +677,6 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
 bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
 
-struct iommu_sva *iommu_sva_bind_device(struct device *dev,
-					struct mm_struct *mm,
-					void *drvdata);
-void iommu_sva_unbind_device(struct iommu_sva *handle);
-u32 iommu_sva_get_pasid(struct iommu_sva *handle);
-
 int iommu_device_use_default_domain(struct device *dev);
 void iommu_device_unuse_default_domain(struct device *dev);
 
@@ -1019,21 +1013,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
 	return -ENODEV;
 }
 
-static inline struct iommu_sva *
-iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	return NULL;
-}
-
-static inline void iommu_sva_unbind_device(struct iommu_sva *handle)
-{
-}
-
-static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
-{
-	return IOMMU_PASID_INVALID;
-}
-
 static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
 {
 	return NULL;
@@ -1075,6 +1054,29 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
 }
 #endif /* CONFIG_IOMMU_API */
 
+#ifdef CONFIG_IOMMU_SVA
+struct iommu_sva *iommu_sva_bind_device(struct device *dev,
+					struct mm_struct *mm,
+					void *drvdata);
+void iommu_sva_unbind_device(struct iommu_sva *handle);
+u32 iommu_sva_get_pasid(struct iommu_sva *handle);
+#else /* CONFIG_IOMMU_SVA */
+static inline struct iommu_sva *
+iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
+{
+	return NULL;
+}
+
+static inline void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+}
+
+static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	return IOMMU_PASID_INVALID;
+}
+#endif /* CONFIG_IOMMU_SVA */
+
 /**
  * iommu_map_sgtable - Map the given buffer to the IOMMU domain
  * @domain:	The IOMMU domain to perform the mapping
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 9c5e108e2c8a..724af2226581 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -27,6 +27,7 @@ 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 iommu_sva_ioas_put(struct iommu_sva_ioas *ioas);
 
 #else /* CONFIG_IOMMU_SVA */
 static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
@@ -64,5 +65,9 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
 {
 	return -ENODEV;
 }
+
+static inline void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
+{
+}
 #endif /* CONFIG_IOMMU_SVA */
 #endif /* _IOMMU_SVA_LIB_H */
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index d524a402be3b..7439f046d2ab 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -11,6 +11,7 @@
 
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
+static DEFINE_XARRAY_ALLOC(iommu_sva_ioas_array);
 
 struct iommu_sva_ioas {
 	struct mm_struct *mm;
@@ -87,3 +88,198 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid)
 	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
 }
 EXPORT_SYMBOL_GPL(iommu_sva_find);
+
+/*
+ * Get or put an ioas for a shared memory.
+ */
+static struct iommu_sva_ioas *iommu_sva_ioas_get(struct mm_struct *mm,
+						 ioasid_t pasid)
+{
+	struct iommu_sva_ioas *ioas;
+	int ret;
+
+	ioas = xa_load(&iommu_sva_ioas_array, pasid);
+	if (ioas) {
+		if (WARN_ON(ioas->mm != mm))
+			return ERR_PTR(-EINVAL);
+		refcount_inc(&ioas->users);
+		return ioas;
+	}
+
+	ioas = kzalloc(sizeof(*ioas), GFP_KERNEL);
+	if (!ioas)
+		return ERR_PTR(-ENOMEM);
+
+	ioas->mm = mm;
+	ioas->pasid = pasid;
+	refcount_set(&ioas->users, 1);
+	INIT_LIST_HEAD(&ioas->bonds);
+	ret = xa_err(xa_store(&iommu_sva_ioas_array, pasid, ioas, GFP_KERNEL));
+	if (ret) {
+		kfree(ioas);
+		return ERR_PTR(ret);
+	}
+
+	mmgrab(mm);
+
+	return ioas;
+}
+
+void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
+{
+	if (!ioas)
+		return;
+
+	if (refcount_dec_and_test(&ioas->users)) {
+		WARN_ON(!list_empty(&ioas->bonds));
+		xa_erase(&iommu_sva_ioas_array, ioas->pasid);
+		mmdrop(ioas->mm);
+		kfree(ioas);
+	}
+}
+
+/*
+ * IOMMU SVA driver-oriented interfaces
+ */
+static struct iommu_domain *
+iommu_sva_alloc_domain(struct device *dev, struct iommu_sva_ioas *ioas)
+{
+	struct bus_type *bus = dev->bus;
+	struct iommu_domain *domain;
+
+	if (!bus || !bus->iommu_ops)
+		return NULL;
+
+	domain = bus->iommu_ops->domain_alloc(IOMMU_DOMAIN_SVA);
+	if (!domain)
+		return NULL;
+
+	/* The caller must hold a reference to ioas. */
+	domain->sva_ioas = ioas;
+	domain->type = IOMMU_DOMAIN_SVA;
+
+	return domain;
+}
+
+/**
+ * iommu_sva_bind_device() - Bind a process address space to a device
+ * @dev: the device
+ * @mm: the mm to bind, caller must hold a reference to it
+ * @drvdata: opaque data pointer to pass to bind callback
+ *
+ * Create a bond between device and address space, allowing the device to access
+ * the mm using the returned PASID. If a bond already exists between @device and
+ * @mm, it is returned and an additional reference is taken. Caller must call
+ * iommu_sva_unbind_device() to release each reference.
+ *
+ * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
+ * initialize the required SVA features.
+ *
+ * On error, returns an ERR_PTR value.
+ */
+struct iommu_sva *
+iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
+{
+	int ret = -EINVAL;
+	struct iommu_sva *handle;
+	struct iommu_domain *domain;
+	struct iommu_sva_ioas *ioas;
+
+	/*
+	 * TODO: Remove the drvdata parameter after kernel PASID support is
+	 * enabled for the idxd driver.
+	 */
+	if (drvdata)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	/* Allocate mm->pasid if necessary. */
+	ret = iommu_sva_alloc_pasid(mm, 1, (1U << dev->iommu->pasid_bits) - 1);
+	if (ret)
+		return ERR_PTR(ret);
+
+	mutex_lock(&iommu_sva_lock);
+	ioas = iommu_sva_ioas_get(mm, mm->pasid);
+	if (IS_ERR(ioas)) {
+		ret = PTR_ERR(ioas);
+		goto out_unlock;
+	}
+
+	/* Search for an existing bond. */
+	list_for_each_entry(handle, &ioas->bonds, node) {
+		if (handle->dev == dev) {
+			refcount_inc(&handle->users);
+			/* No new bond, drop the counter. */
+			iommu_sva_ioas_put(ioas);
+			goto out_success;
+		}
+	}
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (!handle) {
+		ret = -ENOMEM;
+		goto out_put_ioas;
+	}
+
+	/* The reference to ioas will be kept until domain free. */
+	domain = iommu_sva_alloc_domain(dev, ioas);
+	if (!domain) {
+		ret = -ENODEV;
+		goto out_free_handle;
+	}
+
+	ret = iommu_attach_device_pasid(domain, dev, mm->pasid);
+	if (ret)
+		goto out_free_domain;
+
+	handle->dev = dev;
+	handle->domain = domain;
+	handle->sva_ioas = ioas;
+	refcount_set(&handle->users, 1);
+	list_add_tail(&handle->node, &ioas->bonds);
+
+out_success:
+	mutex_unlock(&iommu_sva_lock);
+	return handle;
+
+out_free_domain:
+	domain->ops->free(domain);
+out_free_handle:
+	kfree(handle);
+out_put_ioas:
+	iommu_sva_ioas_put(ioas);
+out_unlock:
+	mutex_unlock(&iommu_sva_lock);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
+
+/**
+ * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
+ * @handle: the handle returned by iommu_sva_bind_device()
+ *
+ * Put reference to a bond between device and address space. The device should
+ * not be issuing any more transaction for this PASID. All outstanding page
+ * requests for this PASID must have been flushed to the IOMMU.
+ */
+void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+	struct device *dev = handle->dev;
+	struct iommu_domain *domain = handle->domain;
+	struct iommu_sva_ioas *ioas = handle->sva_ioas;
+
+	mutex_lock(&iommu_sva_lock);
+	if (refcount_dec_and_test(&handle->users)) {
+		list_del(&handle->node);
+		iommu_detach_device_pasid(domain, dev, ioas->pasid);
+		iommu_domain_free(domain);
+		kfree(handle);
+	}
+	mutex_unlock(&iommu_sva_lock);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
+
+u32 iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	return handle->sva_ioas->pasid;
+}
+EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c6fdc0067d76..7ed0a61351a5 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -27,6 +27,8 @@
 #include <linux/cc_platform.h>
 #include <trace/events/iommu.h>
 
+#include "iommu-sva-lib.h"
+
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
 
@@ -1905,6 +1907,7 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 void iommu_domain_free(struct iommu_domain *domain)
 {
 	iommu_put_dma_cookie(domain);
+	iommu_sva_ioas_put(domain->sva_ioas);
 	domain->ops->free(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
@@ -2708,98 +2711,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
 }
 EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
 
-/**
- * iommu_sva_bind_device() - Bind a process address space to a device
- * @dev: the device
- * @mm: the mm to bind, caller must hold a reference to it
- * @drvdata: opaque data pointer to pass to bind callback
- *
- * Create a bond between device and address space, allowing the device to access
- * the mm using the returned PASID. If a bond already exists between @device and
- * @mm, it is returned and an additional reference is taken. Caller must call
- * iommu_sva_unbind_device() to release each reference.
- *
- * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
- * initialize the required SVA features.
- *
- * On error, returns an ERR_PTR value.
- */
-struct iommu_sva *
-iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct iommu_group *group;
-	struct iommu_sva *handle = ERR_PTR(-EINVAL);
-	const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-	if (!ops->sva_bind)
-		return ERR_PTR(-ENODEV);
-
-	group = iommu_group_get(dev);
-	if (!group)
-		return ERR_PTR(-ENODEV);
-
-	/* Ensure device count and domain don't change while we're binding */
-	mutex_lock(&group->mutex);
-
-	/*
-	 * To keep things simple, SVA currently doesn't support IOMMU groups
-	 * with more than one device. Existing SVA-capable systems are not
-	 * affected by the problems that required IOMMU groups (lack of ACS
-	 * isolation, device ID aliasing and other hardware issues).
-	 */
-	if (iommu_group_device_count(group) != 1)
-		goto out_unlock;
-
-	handle = ops->sva_bind(dev, mm, drvdata);
-
-out_unlock:
-	mutex_unlock(&group->mutex);
-	iommu_group_put(group);
-
-	return handle;
-}
-EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
-
-/**
- * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
- * @handle: the handle returned by iommu_sva_bind_device()
- *
- * Put reference to a bond between device and address space. The device should
- * not be issuing any more transaction for this PASID. All outstanding page
- * requests for this PASID must have been flushed to the IOMMU.
- */
-void iommu_sva_unbind_device(struct iommu_sva *handle)
-{
-	struct iommu_group *group;
-	struct device *dev = handle->dev;
-	const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-	if (!ops->sva_unbind)
-		return;
-
-	group = iommu_group_get(dev);
-	if (!group)
-		return;
-
-	mutex_lock(&group->mutex);
-	ops->sva_unbind(handle);
-	mutex_unlock(&group->mutex);
-
-	iommu_group_put(group);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
-
-u32 iommu_sva_get_pasid(struct iommu_sva *handle)
-{
-	const struct iommu_ops *ops = dev_iommu_ops(handle->dev);
-
-	if (!ops->sva_get_pasid)
-		return IOMMU_PASID_INVALID;
-
-	return ops->sva_get_pasid(handle);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
-
 /*
  * Changes the default domain of an iommu group that has *only* one device
  *
-- 
2.25.1

[PATCH v4 08/12] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces

[Lu Baolu]

The existing iommu SVA interfaces are implemented by calling the SVA
specific iommu ops provided by the IOMMU drivers. There's no need for
any SVA specific ops in iommu_ops vector anymore as we can achieve
this through the generic attach/detach_dev_pasid domain ops.

This refactors the IOMMU SVA interfaces implementation by using the
attach/detach_pasid_dev ops and align them with the concept of the
iommu domain. Put the new SVA code in the sva related file in order
to make it self-contained.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         |  44 ++++----
 drivers/iommu/iommu-sva-lib.h |   5 +
 drivers/iommu/iommu-sva-lib.c | 196 ++++++++++++++++++++++++++++++++++
 drivers/iommu/iommu.c         |  95 +---------------
 4 files changed, 227 insertions(+), 113 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 14c3b2197b35..2a2d17431826 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -677,12 +677,6 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
 bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
 
-struct iommu_sva *iommu_sva_bind_device(struct device *dev,
-					struct mm_struct *mm,
-					void *drvdata);
-void iommu_sva_unbind_device(struct iommu_sva *handle);
-u32 iommu_sva_get_pasid(struct iommu_sva *handle);
-
 int iommu_device_use_default_domain(struct device *dev);
 void iommu_device_unuse_default_domain(struct device *dev);
 
@@ -1019,21 +1013,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
 	return -ENODEV;
 }
 
-static inline struct iommu_sva *
-iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	return NULL;
-}
-
-static inline void iommu_sva_unbind_device(struct iommu_sva *handle)
-{
-}
-
-static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
-{
-	return IOMMU_PASID_INVALID;
-}
-
 static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
 {
 	return NULL;
@@ -1075,6 +1054,29 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
 }
 #endif /* CONFIG_IOMMU_API */
 
+#ifdef CONFIG_IOMMU_SVA
+struct iommu_sva *iommu_sva_bind_device(struct device *dev,
+					struct mm_struct *mm,
+					void *drvdata);
+void iommu_sva_unbind_device(struct iommu_sva *handle);
+u32 iommu_sva_get_pasid(struct iommu_sva *handle);
+#else /* CONFIG_IOMMU_SVA */
+static inline struct iommu_sva *
+iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
+{
+	return NULL;
+}
+
+static inline void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+}
+
+static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	return IOMMU_PASID_INVALID;
+}
+#endif /* CONFIG_IOMMU_SVA */
+
 /**
  * iommu_map_sgtable - Map the given buffer to the IOMMU domain
  * @domain:	The IOMMU domain to perform the mapping
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 9c5e108e2c8a..724af2226581 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -27,6 +27,7 @@ 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 iommu_sva_ioas_put(struct iommu_sva_ioas *ioas);
 
 #else /* CONFIG_IOMMU_SVA */
 static inline int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)
@@ -64,5 +65,9 @@ static inline int iopf_queue_discard_partial(struct iopf_queue *queue)
 {
 	return -ENODEV;
 }
+
+static inline void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
+{
+}
 #endif /* CONFIG_IOMMU_SVA */
 #endif /* _IOMMU_SVA_LIB_H */
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index d524a402be3b..7439f046d2ab 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -11,6 +11,7 @@
 
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
+static DEFINE_XARRAY_ALLOC(iommu_sva_ioas_array);
 
 struct iommu_sva_ioas {
 	struct mm_struct *mm;
@@ -87,3 +88,198 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid)
 	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
 }
 EXPORT_SYMBOL_GPL(iommu_sva_find);
+
+/*
+ * Get or put an ioas for a shared memory.
+ */
+static struct iommu_sva_ioas *iommu_sva_ioas_get(struct mm_struct *mm,
+						 ioasid_t pasid)
+{
+	struct iommu_sva_ioas *ioas;
+	int ret;
+
+	ioas = xa_load(&iommu_sva_ioas_array, pasid);
+	if (ioas) {
+		if (WARN_ON(ioas->mm != mm))
+			return ERR_PTR(-EINVAL);
+		refcount_inc(&ioas->users);
+		return ioas;
+	}
+
+	ioas = kzalloc(sizeof(*ioas), GFP_KERNEL);
+	if (!ioas)
+		return ERR_PTR(-ENOMEM);
+
+	ioas->mm = mm;
+	ioas->pasid = pasid;
+	refcount_set(&ioas->users, 1);
+	INIT_LIST_HEAD(&ioas->bonds);
+	ret = xa_err(xa_store(&iommu_sva_ioas_array, pasid, ioas, GFP_KERNEL));
+	if (ret) {
+		kfree(ioas);
+		return ERR_PTR(ret);
+	}
+
+	mmgrab(mm);
+
+	return ioas;
+}
+
+void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
+{
+	if (!ioas)
+		return;
+
+	if (refcount_dec_and_test(&ioas->users)) {
+		WARN_ON(!list_empty(&ioas->bonds));
+		xa_erase(&iommu_sva_ioas_array, ioas->pasid);
+		mmdrop(ioas->mm);
+		kfree(ioas);
+	}
+}
+
+/*
+ * IOMMU SVA driver-oriented interfaces
+ */
+static struct iommu_domain *
+iommu_sva_alloc_domain(struct device *dev, struct iommu_sva_ioas *ioas)
+{
+	struct bus_type *bus = dev->bus;
+	struct iommu_domain *domain;
+
+	if (!bus || !bus->iommu_ops)
+		return NULL;
+
+	domain = bus->iommu_ops->domain_alloc(IOMMU_DOMAIN_SVA);
+	if (!domain)
+		return NULL;
+
+	/* The caller must hold a reference to ioas. */
+	domain->sva_ioas = ioas;
+	domain->type = IOMMU_DOMAIN_SVA;
+
+	return domain;
+}
+
+/**
+ * iommu_sva_bind_device() - Bind a process address space to a device
+ * @dev: the device
+ * @mm: the mm to bind, caller must hold a reference to it
+ * @drvdata: opaque data pointer to pass to bind callback
+ *
+ * Create a bond between device and address space, allowing the device to access
+ * the mm using the returned PASID. If a bond already exists between @device and
+ * @mm, it is returned and an additional reference is taken. Caller must call
+ * iommu_sva_unbind_device() to release each reference.
+ *
+ * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
+ * initialize the required SVA features.
+ *
+ * On error, returns an ERR_PTR value.
+ */
+struct iommu_sva *
+iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
+{
+	int ret = -EINVAL;
+	struct iommu_sva *handle;
+	struct iommu_domain *domain;
+	struct iommu_sva_ioas *ioas;
+
+	/*
+	 * TODO: Remove the drvdata parameter after kernel PASID support is
+	 * enabled for the idxd driver.
+	 */
+	if (drvdata)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	/* Allocate mm->pasid if necessary. */
+	ret = iommu_sva_alloc_pasid(mm, 1, (1U << dev->iommu->pasid_bits) - 1);
+	if (ret)
+		return ERR_PTR(ret);
+
+	mutex_lock(&iommu_sva_lock);
+	ioas = iommu_sva_ioas_get(mm, mm->pasid);
+	if (IS_ERR(ioas)) {
+		ret = PTR_ERR(ioas);
+		goto out_unlock;
+	}
+
+	/* Search for an existing bond. */
+	list_for_each_entry(handle, &ioas->bonds, node) {
+		if (handle->dev == dev) {
+			refcount_inc(&handle->users);
+			/* No new bond, drop the counter. */
+			iommu_sva_ioas_put(ioas);
+			goto out_success;
+		}
+	}
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (!handle) {
+		ret = -ENOMEM;
+		goto out_put_ioas;
+	}
+
+	/* The reference to ioas will be kept until domain free. */
+	domain = iommu_sva_alloc_domain(dev, ioas);
+	if (!domain) {
+		ret = -ENODEV;
+		goto out_free_handle;
+	}
+
+	ret = iommu_attach_device_pasid(domain, dev, mm->pasid);
+	if (ret)
+		goto out_free_domain;
+
+	handle->dev = dev;
+	handle->domain = domain;
+	handle->sva_ioas = ioas;
+	refcount_set(&handle->users, 1);
+	list_add_tail(&handle->node, &ioas->bonds);
+
+out_success:
+	mutex_unlock(&iommu_sva_lock);
+	return handle;
+
+out_free_domain:
+	domain->ops->free(domain);
+out_free_handle:
+	kfree(handle);
+out_put_ioas:
+	iommu_sva_ioas_put(ioas);
+out_unlock:
+	mutex_unlock(&iommu_sva_lock);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
+
+/**
+ * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
+ * @handle: the handle returned by iommu_sva_bind_device()
+ *
+ * Put reference to a bond between device and address space. The device should
+ * not be issuing any more transaction for this PASID. All outstanding page
+ * requests for this PASID must have been flushed to the IOMMU.
+ */
+void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+	struct device *dev = handle->dev;
+	struct iommu_domain *domain = handle->domain;
+	struct iommu_sva_ioas *ioas = handle->sva_ioas;
+
+	mutex_lock(&iommu_sva_lock);
+	if (refcount_dec_and_test(&handle->users)) {
+		list_del(&handle->node);
+		iommu_detach_device_pasid(domain, dev, ioas->pasid);
+		iommu_domain_free(domain);
+		kfree(handle);
+	}
+	mutex_unlock(&iommu_sva_lock);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
+
+u32 iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	return handle->sva_ioas->pasid;
+}
+EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index c6fdc0067d76..7ed0a61351a5 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -27,6 +27,8 @@
 #include <linux/cc_platform.h>
 #include <trace/events/iommu.h>
 
+#include "iommu-sva-lib.h"
+
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
 
@@ -1905,6 +1907,7 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 void iommu_domain_free(struct iommu_domain *domain)
 {
 	iommu_put_dma_cookie(domain);
+	iommu_sva_ioas_put(domain->sva_ioas);
 	domain->ops->free(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
@@ -2708,98 +2711,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
 }
 EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
 
-/**
- * iommu_sva_bind_device() - Bind a process address space to a device
- * @dev: the device
- * @mm: the mm to bind, caller must hold a reference to it
- * @drvdata: opaque data pointer to pass to bind callback
- *
- * Create a bond between device and address space, allowing the device to access
- * the mm using the returned PASID. If a bond already exists between @device and
- * @mm, it is returned and an additional reference is taken. Caller must call
- * iommu_sva_unbind_device() to release each reference.
- *
- * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to
- * initialize the required SVA features.
- *
- * On error, returns an ERR_PTR value.
- */
-struct iommu_sva *
-iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct iommu_group *group;
-	struct iommu_sva *handle = ERR_PTR(-EINVAL);
-	const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-	if (!ops->sva_bind)
-		return ERR_PTR(-ENODEV);
-
-	group = iommu_group_get(dev);
-	if (!group)
-		return ERR_PTR(-ENODEV);
-
-	/* Ensure device count and domain don't change while we're binding */
-	mutex_lock(&group->mutex);
-
-	/*
-	 * To keep things simple, SVA currently doesn't support IOMMU groups
-	 * with more than one device. Existing SVA-capable systems are not
-	 * affected by the problems that required IOMMU groups (lack of ACS
-	 * isolation, device ID aliasing and other hardware issues).
-	 */
-	if (iommu_group_device_count(group) != 1)
-		goto out_unlock;
-
-	handle = ops->sva_bind(dev, mm, drvdata);
-
-out_unlock:
-	mutex_unlock(&group->mutex);
-	iommu_group_put(group);
-
-	return handle;
-}
-EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
-
-/**
- * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
- * @handle: the handle returned by iommu_sva_bind_device()
- *
- * Put reference to a bond between device and address space. The device should
- * not be issuing any more transaction for this PASID. All outstanding page
- * requests for this PASID must have been flushed to the IOMMU.
- */
-void iommu_sva_unbind_device(struct iommu_sva *handle)
-{
-	struct iommu_group *group;
-	struct device *dev = handle->dev;
-	const struct iommu_ops *ops = dev_iommu_ops(dev);
-
-	if (!ops->sva_unbind)
-		return;
-
-	group = iommu_group_get(dev);
-	if (!group)
-		return;
-
-	mutex_lock(&group->mutex);
-	ops->sva_unbind(handle);
-	mutex_unlock(&group->mutex);
-
-	iommu_group_put(group);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
-
-u32 iommu_sva_get_pasid(struct iommu_sva *handle)
-{
-	const struct iommu_ops *ops = dev_iommu_ops(handle->dev);
-
-	if (!ops->sva_get_pasid)
-		return IOMMU_PASID_INVALID;
-
-	return ops->sva_get_pasid(handle);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
-
 /*
  * Changes the default domain of an iommu group that has *only* one device
  *
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 09/12] iommu: Remove SVA related callbacks from iommu ops

[Lu Baolu]

These ops'es have been replaced with the dev_attach/detach_pasid domain
ops'es. There's no need for them anymore. Remove them to avoid dead
code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/intel-iommu.h                   |  4 --
 include/linux/iommu.h                         |  8 ---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   | 17 -------
 drivers/iommu/iommu-sva-lib.h                 |  1 -
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 41 ----------------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  3 --
 drivers/iommu/intel/iommu.c                   |  3 --
 drivers/iommu/intel/svm.c                     | 49 -------------------
 drivers/iommu/iommu-sva-lib.c                 |  4 +-
 9 files changed, 2 insertions(+), 128 deletions(-)

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index c14283137fb5..7ce12590ce0f 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -738,10 +738,6 @@ struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);
 extern void intel_svm_check(struct intel_iommu *iommu);
 extern int intel_svm_enable_prq(struct intel_iommu *iommu);
 extern int intel_svm_finish_prq(struct intel_iommu *iommu);
-struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm,
-				 void *drvdata);
-void intel_svm_unbind(struct iommu_sva *handle);
-u32 intel_svm_get_pasid(struct iommu_sva *handle);
 int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg);
 extern const struct iommu_domain_ops intel_svm_domain_ops;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2a2d17431826..57650b773f3f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -213,9 +213,6 @@ struct iommu_iotlb_gather {
  * @dev_has/enable/disable_feat: per device entries to check/enable/disable
  *                               iommu specific features.
  * @dev_feat_enabled: check enabled feature
- * @sva_bind: Bind process address space to device
- * @sva_unbind: Unbind process address space from device
- * @sva_get_pasid: Get PASID associated to a SVA handle
  * @page_response: handle page request response
  * @def_domain_type: device default domain type, return value:
  *		- IOMMU_DOMAIN_IDENTITY: must use an identity domain
@@ -249,11 +246,6 @@ struct iommu_ops {
 	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
 
-	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
-				      void *drvdata);
-	void (*sva_unbind)(struct iommu_sva *handle);
-	u32 (*sva_get_pasid)(struct iommu_sva *handle);
-
 	int (*page_response)(struct device *dev,
 			     struct iommu_fault_event *evt,
 			     struct iommu_page_response *msg);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 7631c00fdcbd..2513309ec0db 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -754,10 +754,6 @@ bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master);
 int arm_smmu_master_enable_sva(struct arm_smmu_master *master);
 int arm_smmu_master_disable_sva(struct arm_smmu_master *master);
 bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master);
-struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm,
-				    void *drvdata);
-void arm_smmu_sva_unbind(struct iommu_sva *handle);
-u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
 int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
 				  struct device *dev, ioasid_t id);
@@ -794,19 +790,6 @@ static inline bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master
 	return false;
 }
 
-static inline struct iommu_sva *
-arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline void arm_smmu_sva_unbind(struct iommu_sva *handle) {}
-
-static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
-{
-	return IOMMU_PASID_INVALID;
-}
-
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
 
 static inline int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 724af2226581..0f33472e5212 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -8,7 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
 struct mm_struct *iommu_sva_find(ioasid_t pasid);
 struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
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 ce229820086d..5591321f9e11 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
@@ -328,11 +328,6 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	if (!bond)
 		return ERR_PTR(-ENOMEM);
 
-	/* Allocate a PASID for this mm if necessary */
-	ret = iommu_sva_alloc_pasid(mm, 1, (1U << master->ssid_bits) - 1);
-	if (ret)
-		goto err_free_bond;
-
 	bond->mm = mm;
 	bond->sva.dev = dev;
 	refcount_set(&bond->refs, 1);
@@ -351,42 +346,6 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	return ERR_PTR(ret);
 }
 
-struct iommu_sva *
-arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct iommu_sva *handle;
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-
-	if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
-		return ERR_PTR(-EINVAL);
-
-	mutex_lock(&sva_lock);
-	handle = __arm_smmu_sva_bind(dev, mm);
-	mutex_unlock(&sva_lock);
-	return handle;
-}
-
-void arm_smmu_sva_unbind(struct iommu_sva *handle)
-{
-	struct arm_smmu_bond *bond = sva_to_bond(handle);
-
-	mutex_lock(&sva_lock);
-	if (refcount_dec_and_test(&bond->refs)) {
-		list_del(&bond->list);
-		arm_smmu_mmu_notifier_put(bond->smmu_mn);
-		kfree(bond);
-	}
-	mutex_unlock(&sva_lock);
-}
-
-u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
-{
-	struct arm_smmu_bond *bond = sva_to_bond(handle);
-
-	return bond->mm->pasid;
-}
-
 bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
 	unsigned long reg, fld;
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 bd80de0bad98..543d3ef1c102 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2875,9 +2875,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.dev_feat_enabled	= arm_smmu_dev_feature_enabled,
 	.dev_enable_feat	= arm_smmu_dev_enable_feature,
 	.dev_disable_feat	= arm_smmu_dev_disable_feature,
-	.sva_bind		= arm_smmu_sva_bind,
-	.sva_unbind		= arm_smmu_sva_unbind,
-	.sva_get_pasid		= arm_smmu_sva_get_pasid,
 	.page_response		= arm_smmu_page_response,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 	.owner			= THIS_MODULE,
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9c2714ba04ff..3164bd5a3572 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4896,9 +4896,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.def_domain_type	= device_def_domain_type,
 	.pgsize_bitmap		= SZ_4K,
 #ifdef CONFIG_INTEL_IOMMU_SVM
-	.sva_bind		= intel_svm_bind,
-	.sva_unbind		= intel_svm_unbind,
-	.sva_get_pasid		= intel_svm_get_pasid,
 	.page_response		= intel_svm_page_response,
 #endif
 	.default_domain_ops = &(const struct iommu_domain_ops) {
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 251a3a65d77f..61155f1cb985 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -313,14 +313,6 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
 	return 0;
 }
 
-static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm)
-{
-	ioasid_t max_pasid = dev_is_pci(dev) ?
-			pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id;
-
-	return iommu_sva_alloc_pasid(mm, PASID_MIN, max_pasid - 1);
-}
-
 static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 					   struct device *dev,
 					   struct mm_struct *mm)
@@ -805,47 +797,6 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 	return IRQ_RETVAL(handled);
 }
 
-struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
-	struct iommu_sva *sva;
-	int ret;
-
-	mutex_lock(&pasid_mutex);
-	ret = intel_svm_alloc_pasid(dev, mm);
-	if (ret) {
-		mutex_unlock(&pasid_mutex);
-		return ERR_PTR(ret);
-	}
-
-	sva = intel_svm_bind_mm(iommu, dev, mm);
-	mutex_unlock(&pasid_mutex);
-
-	return sva;
-}
-
-void intel_svm_unbind(struct iommu_sva *sva)
-{
-	struct intel_svm_dev *sdev = to_intel_svm_dev(sva);
-
-	mutex_lock(&pasid_mutex);
-	intel_svm_unbind_mm(sdev->dev, sdev->pasid);
-	mutex_unlock(&pasid_mutex);
-}
-
-u32 intel_svm_get_pasid(struct iommu_sva *sva)
-{
-	struct intel_svm_dev *sdev;
-	u32 pasid;
-
-	mutex_lock(&pasid_mutex);
-	sdev = to_intel_svm_dev(sva);
-	pasid = sdev->pasid;
-	mutex_unlock(&pasid_mutex);
-
-	return pasid;
-}
-
 int intel_svm_page_response(struct device *dev,
 			    struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg)
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 7439f046d2ab..e90d53436a22 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -41,7 +41,8 @@ struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain)
  *
  * Returns 0 on success and < 0 on error.
  */
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
+static int iommu_sva_alloc_pasid(struct mm_struct *mm,
+				 ioasid_t min, ioasid_t max)
 {
 	int ret = 0;
 	ioasid_t pasid;
@@ -67,7 +68,6 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 	mutex_unlock(&iommu_sva_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
 
 /* ioasid_find getter() requires a void * argument */
 static bool __mmget_not_zero(void *mm)
-- 
2.25.1

[PATCH v4 09/12] iommu: Remove SVA related callbacks from iommu ops

[Lu Baolu]

These ops'es have been replaced with the dev_attach/detach_pasid domain
ops'es. There's no need for them anymore. Remove them to avoid dead
code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/intel-iommu.h                   |  4 --
 include/linux/iommu.h                         |  8 ---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   | 17 -------
 drivers/iommu/iommu-sva-lib.h                 |  1 -
 .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 41 ----------------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   |  3 --
 drivers/iommu/intel/iommu.c                   |  3 --
 drivers/iommu/intel/svm.c                     | 49 -------------------
 drivers/iommu/iommu-sva-lib.c                 |  4 +-
 9 files changed, 2 insertions(+), 128 deletions(-)

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index c14283137fb5..7ce12590ce0f 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -738,10 +738,6 @@ struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);
 extern void intel_svm_check(struct intel_iommu *iommu);
 extern int intel_svm_enable_prq(struct intel_iommu *iommu);
 extern int intel_svm_finish_prq(struct intel_iommu *iommu);
-struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm,
-				 void *drvdata);
-void intel_svm_unbind(struct iommu_sva *handle);
-u32 intel_svm_get_pasid(struct iommu_sva *handle);
 int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg);
 extern const struct iommu_domain_ops intel_svm_domain_ops;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2a2d17431826..57650b773f3f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -213,9 +213,6 @@ struct iommu_iotlb_gather {
  * @dev_has/enable/disable_feat: per device entries to check/enable/disable
  *                               iommu specific features.
  * @dev_feat_enabled: check enabled feature
- * @sva_bind: Bind process address space to device
- * @sva_unbind: Unbind process address space from device
- * @sva_get_pasid: Get PASID associated to a SVA handle
  * @page_response: handle page request response
  * @def_domain_type: device default domain type, return value:
  *		- IOMMU_DOMAIN_IDENTITY: must use an identity domain
@@ -249,11 +246,6 @@ struct iommu_ops {
 	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
 
-	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
-				      void *drvdata);
-	void (*sva_unbind)(struct iommu_sva *handle);
-	u32 (*sva_get_pasid)(struct iommu_sva *handle);
-
 	int (*page_response)(struct device *dev,
 			     struct iommu_fault_event *evt,
 			     struct iommu_page_response *msg);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 7631c00fdcbd..2513309ec0db 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -754,10 +754,6 @@ bool arm_smmu_master_sva_enabled(struct arm_smmu_master *master);
 int arm_smmu_master_enable_sva(struct arm_smmu_master *master);
 int arm_smmu_master_disable_sva(struct arm_smmu_master *master);
 bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master);
-struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm,
-				    void *drvdata);
-void arm_smmu_sva_unbind(struct iommu_sva *handle);
-u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle);
 void arm_smmu_sva_notifier_synchronize(void);
 int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
 				  struct device *dev, ioasid_t id);
@@ -794,19 +790,6 @@ static inline bool arm_smmu_master_iopf_supported(struct arm_smmu_master *master
 	return false;
 }
 
-static inline struct iommu_sva *
-arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline void arm_smmu_sva_unbind(struct iommu_sva *handle) {}
-
-static inline u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
-{
-	return IOMMU_PASID_INVALID;
-}
-
 static inline void arm_smmu_sva_notifier_synchronize(void) {}
 
 static inline int arm_smmu_sva_attach_dev_pasid(struct iommu_domain *domain,
diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 724af2226581..0f33472e5212 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -8,7 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
 struct mm_struct *iommu_sva_find(ioasid_t pasid);
 struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
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 ce229820086d..5591321f9e11 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
@@ -328,11 +328,6 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	if (!bond)
 		return ERR_PTR(-ENOMEM);
 
-	/* Allocate a PASID for this mm if necessary */
-	ret = iommu_sva_alloc_pasid(mm, 1, (1U << master->ssid_bits) - 1);
-	if (ret)
-		goto err_free_bond;
-
 	bond->mm = mm;
 	bond->sva.dev = dev;
 	refcount_set(&bond->refs, 1);
@@ -351,42 +346,6 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
 	return ERR_PTR(ret);
 }
 
-struct iommu_sva *
-arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct iommu_sva *handle;
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-
-	if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
-		return ERR_PTR(-EINVAL);
-
-	mutex_lock(&sva_lock);
-	handle = __arm_smmu_sva_bind(dev, mm);
-	mutex_unlock(&sva_lock);
-	return handle;
-}
-
-void arm_smmu_sva_unbind(struct iommu_sva *handle)
-{
-	struct arm_smmu_bond *bond = sva_to_bond(handle);
-
-	mutex_lock(&sva_lock);
-	if (refcount_dec_and_test(&bond->refs)) {
-		list_del(&bond->list);
-		arm_smmu_mmu_notifier_put(bond->smmu_mn);
-		kfree(bond);
-	}
-	mutex_unlock(&sva_lock);
-}
-
-u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle)
-{
-	struct arm_smmu_bond *bond = sva_to_bond(handle);
-
-	return bond->mm->pasid;
-}
-
 bool arm_smmu_sva_supported(struct arm_smmu_device *smmu)
 {
 	unsigned long reg, fld;
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 bd80de0bad98..543d3ef1c102 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2875,9 +2875,6 @@ static struct iommu_ops arm_smmu_ops = {
 	.dev_feat_enabled	= arm_smmu_dev_feature_enabled,
 	.dev_enable_feat	= arm_smmu_dev_enable_feature,
 	.dev_disable_feat	= arm_smmu_dev_disable_feature,
-	.sva_bind		= arm_smmu_sva_bind,
-	.sva_unbind		= arm_smmu_sva_unbind,
-	.sva_get_pasid		= arm_smmu_sva_get_pasid,
 	.page_response		= arm_smmu_page_response,
 	.pgsize_bitmap		= -1UL, /* Restricted during device attach */
 	.owner			= THIS_MODULE,
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9c2714ba04ff..3164bd5a3572 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4896,9 +4896,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.def_domain_type	= device_def_domain_type,
 	.pgsize_bitmap		= SZ_4K,
 #ifdef CONFIG_INTEL_IOMMU_SVM
-	.sva_bind		= intel_svm_bind,
-	.sva_unbind		= intel_svm_unbind,
-	.sva_get_pasid		= intel_svm_get_pasid,
 	.page_response		= intel_svm_page_response,
 #endif
 	.default_domain_ops = &(const struct iommu_domain_ops) {
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 251a3a65d77f..61155f1cb985 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -313,14 +313,6 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
 	return 0;
 }
 
-static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm)
-{
-	ioasid_t max_pasid = dev_is_pci(dev) ?
-			pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id;
-
-	return iommu_sva_alloc_pasid(mm, PASID_MIN, max_pasid - 1);
-}
-
 static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 					   struct device *dev,
 					   struct mm_struct *mm)
@@ -805,47 +797,6 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 	return IRQ_RETVAL(handled);
 }
 
-struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
-{
-	struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
-	struct iommu_sva *sva;
-	int ret;
-
-	mutex_lock(&pasid_mutex);
-	ret = intel_svm_alloc_pasid(dev, mm);
-	if (ret) {
-		mutex_unlock(&pasid_mutex);
-		return ERR_PTR(ret);
-	}
-
-	sva = intel_svm_bind_mm(iommu, dev, mm);
-	mutex_unlock(&pasid_mutex);
-
-	return sva;
-}
-
-void intel_svm_unbind(struct iommu_sva *sva)
-{
-	struct intel_svm_dev *sdev = to_intel_svm_dev(sva);
-
-	mutex_lock(&pasid_mutex);
-	intel_svm_unbind_mm(sdev->dev, sdev->pasid);
-	mutex_unlock(&pasid_mutex);
-}
-
-u32 intel_svm_get_pasid(struct iommu_sva *sva)
-{
-	struct intel_svm_dev *sdev;
-	u32 pasid;
-
-	mutex_lock(&pasid_mutex);
-	sdev = to_intel_svm_dev(sva);
-	pasid = sdev->pasid;
-	mutex_unlock(&pasid_mutex);
-
-	return pasid;
-}
-
 int intel_svm_page_response(struct device *dev,
 			    struct iommu_fault_event *evt,
 			    struct iommu_page_response *msg)
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 7439f046d2ab..e90d53436a22 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -41,7 +41,8 @@ struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain)
  *
  * Returns 0 on success and < 0 on error.
  */
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
+static int iommu_sva_alloc_pasid(struct mm_struct *mm,
+				 ioasid_t min, ioasid_t max)
 {
 	int ret = 0;
 	ioasid_t pasid;
@@ -67,7 +68,6 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 	mutex_unlock(&iommu_sva_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
 
 /* ioasid_find getter() requires a void * argument */
 static bool __mmget_not_zero(void *mm)
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Lu Baolu]

This adds some mechanisms around the iommu_domain so that the I/O page
fault handling framework could route a page fault to the domain and
call the fault handler from it.

It includes:

- A reference counter for the iommu domain. The page fault handler is
  a different context from the bind()/unbind() thread. A reference
  counter is added to struct iommu_domain so that the life cycle of
  the iommu_domain could be synced between different threads.

- A pointer to the page fault handler and its private data. The fault
  handler will be called with the private data as a parameter once a
  page fault is routed to the domain. Any kernel component which owns
  an iommu domain could install handler and its parameter so that the
  page fault could be further routed or handled.

This also prepares the SVA implementation to be the first consumer of
the per-domain page fault handling model.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         | 18 ++++++++++
 drivers/iommu/iommu-sva-lib.c | 68 ++++++++++++++++++++++++++++++++++-
 drivers/iommu/iommu.c         | 29 +++++++++++++++
 3 files changed, 114 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 57650b773f3f..4278a6310a7b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -102,6 +102,10 @@ struct iommu_domain {
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
 	struct iommu_sva_ioas *sva_ioas;
+	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
+						      void *data);
+	void *fault_data;
+	refcount_t async_users;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
@@ -680,6 +684,14 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 			      struct device *dev, ioasid_t pasid);
 void iommu_detach_device_pasid(struct iommu_domain *domain,
 			       struct device *dev, ioasid_t pasid);
+struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid);
+
+static inline void iommu_domain_put_async(struct iommu_domain *domain)
+{
+	if (refcount_dec_and_test(&domain->async_users))
+		iommu_domain_free(domain);
+}
 #else /* CONFIG_IOMMU_API */
 
 struct iommu_ops {};
@@ -1044,6 +1056,12 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
 					     struct device *dev, ioasid_t pasid)
 {
 }
+
+static inline struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
+{
+	return NULL;
+}
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_SVA
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index e90d53436a22..1024c61519dc 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -138,6 +138,69 @@ void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
 	}
 }
 
+/*
+ * I/O page fault handler for SVA
+ *
+ * Copied from io-pgfault.c with mmget_not_zero() added before
+ * mmap_read_lock().
+ */
+static enum iommu_page_response_code
+iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
+{
+	vm_fault_t ret;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	unsigned int access_flags = 0;
+	struct iommu_domain *domain = data;
+	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;
+
+	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
+		return status;
+
+	mm = iommu_sva_domain_mm(domain);
+	if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm))
+		return status;
+
+	mmap_read_lock(mm);
+
+	vma = find_extend_vma(mm, prm->addr);
+	if (!vma)
+		/* Unmapped area */
+		goto out_put_mm;
+
+	if (prm->perm & IOMMU_FAULT_PERM_READ)
+		access_flags |= VM_READ;
+
+	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
+		access_flags |= VM_WRITE;
+		fault_flags |= FAULT_FLAG_WRITE;
+	}
+
+	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
+		access_flags |= VM_EXEC;
+		fault_flags |= FAULT_FLAG_INSTRUCTION;
+	}
+
+	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
+		fault_flags |= FAULT_FLAG_USER;
+
+	if (access_flags & ~vma->vm_flags)
+		/* Access fault */
+		goto out_put_mm;
+
+	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
+	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
+		IOMMU_PAGE_RESP_SUCCESS;
+
+out_put_mm:
+	mmap_read_unlock(mm);
+	mmput(mm);
+
+	return status;
+}
+
 /*
  * IOMMU SVA driver-oriented interfaces
  */
@@ -157,6 +220,9 @@ iommu_sva_alloc_domain(struct device *dev, struct iommu_sva_ioas *ioas)
 	/* The caller must hold a reference to ioas. */
 	domain->sva_ioas = ioas;
 	domain->type = IOMMU_DOMAIN_SVA;
+	domain->iopf_handler = iommu_sva_handle_iopf;
+	domain->fault_data = domain;
+	refcount_set(&domain->async_users, 1);
 
 	return domain;
 }
@@ -271,7 +337,7 @@ void iommu_sva_unbind_device(struct iommu_sva *handle)
 	if (refcount_dec_and_test(&handle->users)) {
 		list_del(&handle->node);
 		iommu_detach_device_pasid(domain, dev, ioas->pasid);
-		iommu_domain_free(domain);
+		iommu_domain_put_async(domain);
 		kfree(handle);
 	}
 	mutex_unlock(&iommu_sva_lock);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7ed0a61351a5..f12c7851d16d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3173,3 +3173,32 @@ void iommu_detach_device_pasid(struct iommu_domain *domain,
 
 	iommu_group_put(group);
 }
+
+/*
+ * Get the attached domain for asynchronous usage, for example the I/O
+ * page fault handling framework. The caller get a reference counter
+ * of the domain automatically on a successful return and should put
+ * it with iommu_domain_put() after usage.
+ */
+struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
+{
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+
+	if (!pasid_valid(pasid))
+		return NULL;
+
+	group = iommu_group_get(dev);
+	if (!group)
+		return NULL;
+
+	mutex_lock(&group->mutex);
+	domain = xa_load(&group->pasid_array, pasid);
+	if (domain)
+		refcount_inc(&domain->async_users);
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	return domain;
+}
-- 
2.25.1

[PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Lu Baolu]

This adds some mechanisms around the iommu_domain so that the I/O page
fault handling framework could route a page fault to the domain and
call the fault handler from it.

It includes:

- A reference counter for the iommu domain. The page fault handler is
  a different context from the bind()/unbind() thread. A reference
  counter is added to struct iommu_domain so that the life cycle of
  the iommu_domain could be synced between different threads.

- A pointer to the page fault handler and its private data. The fault
  handler will be called with the private data as a parameter once a
  page fault is routed to the domain. Any kernel component which owns
  an iommu domain could install handler and its parameter so that the
  page fault could be further routed or handled.

This also prepares the SVA implementation to be the first consumer of
the per-domain page fault handling model.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h         | 18 ++++++++++
 drivers/iommu/iommu-sva-lib.c | 68 ++++++++++++++++++++++++++++++++++-
 drivers/iommu/iommu.c         | 29 +++++++++++++++
 3 files changed, 114 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 57650b773f3f..4278a6310a7b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -102,6 +102,10 @@ struct iommu_domain {
 	struct iommu_domain_geometry geometry;
 	struct iommu_dma_cookie *iova_cookie;
 	struct iommu_sva_ioas *sva_ioas;
+	enum iommu_page_response_code (*iopf_handler)(struct iommu_fault *fault,
+						      void *data);
+	void *fault_data;
+	refcount_t async_users;
 };
 
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
@@ -680,6 +684,14 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 			      struct device *dev, ioasid_t pasid);
 void iommu_detach_device_pasid(struct iommu_domain *domain,
 			       struct device *dev, ioasid_t pasid);
+struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid);
+
+static inline void iommu_domain_put_async(struct iommu_domain *domain)
+{
+	if (refcount_dec_and_test(&domain->async_users))
+		iommu_domain_free(domain);
+}
 #else /* CONFIG_IOMMU_API */
 
 struct iommu_ops {};
@@ -1044,6 +1056,12 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain,
 					     struct device *dev, ioasid_t pasid)
 {
 }
+
+static inline struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
+{
+	return NULL;
+}
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_SVA
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index e90d53436a22..1024c61519dc 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -138,6 +138,69 @@ void iommu_sva_ioas_put(struct iommu_sva_ioas *ioas)
 	}
 }
 
+/*
+ * I/O page fault handler for SVA
+ *
+ * Copied from io-pgfault.c with mmget_not_zero() added before
+ * mmap_read_lock().
+ */
+static enum iommu_page_response_code
+iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
+{
+	vm_fault_t ret;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	unsigned int access_flags = 0;
+	struct iommu_domain *domain = data;
+	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;
+
+	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
+		return status;
+
+	mm = iommu_sva_domain_mm(domain);
+	if (IS_ERR_OR_NULL(mm) || !mmget_not_zero(mm))
+		return status;
+
+	mmap_read_lock(mm);
+
+	vma = find_extend_vma(mm, prm->addr);
+	if (!vma)
+		/* Unmapped area */
+		goto out_put_mm;
+
+	if (prm->perm & IOMMU_FAULT_PERM_READ)
+		access_flags |= VM_READ;
+
+	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
+		access_flags |= VM_WRITE;
+		fault_flags |= FAULT_FLAG_WRITE;
+	}
+
+	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
+		access_flags |= VM_EXEC;
+		fault_flags |= FAULT_FLAG_INSTRUCTION;
+	}
+
+	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
+		fault_flags |= FAULT_FLAG_USER;
+
+	if (access_flags & ~vma->vm_flags)
+		/* Access fault */
+		goto out_put_mm;
+
+	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
+	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
+		IOMMU_PAGE_RESP_SUCCESS;
+
+out_put_mm:
+	mmap_read_unlock(mm);
+	mmput(mm);
+
+	return status;
+}
+
 /*
  * IOMMU SVA driver-oriented interfaces
  */
@@ -157,6 +220,9 @@ iommu_sva_alloc_domain(struct device *dev, struct iommu_sva_ioas *ioas)
 	/* The caller must hold a reference to ioas. */
 	domain->sva_ioas = ioas;
 	domain->type = IOMMU_DOMAIN_SVA;
+	domain->iopf_handler = iommu_sva_handle_iopf;
+	domain->fault_data = domain;
+	refcount_set(&domain->async_users, 1);
 
 	return domain;
 }
@@ -271,7 +337,7 @@ void iommu_sva_unbind_device(struct iommu_sva *handle)
 	if (refcount_dec_and_test(&handle->users)) {
 		list_del(&handle->node);
 		iommu_detach_device_pasid(domain, dev, ioas->pasid);
-		iommu_domain_free(domain);
+		iommu_domain_put_async(domain);
 		kfree(handle);
 	}
 	mutex_unlock(&iommu_sva_lock);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7ed0a61351a5..f12c7851d16d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3173,3 +3173,32 @@ void iommu_detach_device_pasid(struct iommu_domain *domain,
 
 	iommu_group_put(group);
 }
+
+/*
+ * Get the attached domain for asynchronous usage, for example the I/O
+ * page fault handling framework. The caller get a reference counter
+ * of the domain automatically on a successful return and should put
+ * it with iommu_domain_put() after usage.
+ */
+struct iommu_domain *
+iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
+{
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+
+	if (!pasid_valid(pasid))
+		return NULL;
+
+	group = iommu_group_get(dev);
+	if (!group)
+		return NULL;
+
+	mutex_lock(&group->mutex);
+	domain = xa_load(&group->pasid_array, pasid);
+	if (domain)
+		refcount_inc(&domain->async_users);
+	mutex_unlock(&group->mutex);
+	iommu_group_put(group);
+
+	return domain;
+}
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Lu Baolu]

Tweak the I/O page fault handling framework to route the page faults to
the domain and call the page fault handler retrieved from the domain.
This makes the I/O page fault handling framework possible to serve more
usage scenarios as long as they have an IOMMU domain and install a page
fault handler in it. Some unused functions are also removed to avoid
dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/iommu-sva-lib.h |  1 -
 drivers/iommu/io-pgfault.c    | 69 ++++++-----------------------------
 drivers/iommu/iommu-sva-lib.c | 20 ----------
 3 files changed, 12 insertions(+), 78 deletions(-)

diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 0f33472e5212..90d4bd3a61b1 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -8,7 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-struct mm_struct *iommu_sva_find(ioasid_t pasid);
 struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
 /* I/O Page fault */
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 1df8c1dcae77..fc1b2bdeedf8 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -69,62 +69,6 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 	return iommu_page_response(dev, &resp);
 }
 
-static enum iommu_page_response_code
-iopf_handle_single(struct iopf_fault *iopf)
-{
-	vm_fault_t ret;
-	struct mm_struct *mm;
-	struct vm_area_struct *vma;
-	unsigned int access_flags = 0;
-	unsigned int fault_flags = FAULT_FLAG_REMOTE;
-	struct iommu_fault_page_request *prm = &iopf->fault.prm;
-	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
-
-	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
-		return status;
-
-	mm = iommu_sva_find(prm->pasid);
-	if (IS_ERR_OR_NULL(mm))
-		return status;
-
-	mmap_read_lock(mm);
-
-	vma = find_extend_vma(mm, prm->addr);
-	if (!vma)
-		/* Unmapped area */
-		goto out_put_mm;
-
-	if (prm->perm & IOMMU_FAULT_PERM_READ)
-		access_flags |= VM_READ;
-
-	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
-		access_flags |= VM_WRITE;
-		fault_flags |= FAULT_FLAG_WRITE;
-	}
-
-	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
-		access_flags |= VM_EXEC;
-		fault_flags |= FAULT_FLAG_INSTRUCTION;
-	}
-
-	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
-		fault_flags |= FAULT_FLAG_USER;
-
-	if (access_flags & ~vma->vm_flags)
-		/* Access fault */
-		goto out_put_mm;
-
-	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
-	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
-		IOMMU_PAGE_RESP_SUCCESS;
-
-out_put_mm:
-	mmap_read_unlock(mm);
-	mmput(mm);
-
-	return status;
-}
-
 static void iopf_handle_group(struct work_struct *work)
 {
 	struct iopf_group *group;
@@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
 	group = container_of(work, struct iopf_group, work);
 
 	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+		struct iommu_domain *domain;
+
+		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
+				iopf->fault.prm.pasid);
+		if (!domain || !domain->iopf_handler)
+			status = IOMMU_PAGE_RESP_INVALID;
+
 		/*
 		 * 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 = iopf_handle_single(iopf);
+			status = domain->iopf_handler(&iopf->fault,
+						      domain->fault_data);
+
+		if (domain)
+			iommu_domain_put_async(domain);
 
 		if (!(iopf->fault.prm.flags &
 		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 1024c61519dc..d84cffaeb331 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -69,26 +69,6 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm,
 	return ret;
 }
 
-/* ioasid_find getter() requires a void * argument */
-static bool __mmget_not_zero(void *mm)
-{
-	return mmget_not_zero(mm);
-}
-
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */
-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_find);
-
 /*
  * Get or put an ioas for a shared memory.
  */
-- 
2.25.1

[PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Lu Baolu]

Tweak the I/O page fault handling framework to route the page faults to
the domain and call the page fault handler retrieved from the domain.
This makes the I/O page fault handling framework possible to serve more
usage scenarios as long as they have an IOMMU domain and install a page
fault handler in it. Some unused functions are also removed to avoid
dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/iommu-sva-lib.h |  1 -
 drivers/iommu/io-pgfault.c    | 69 ++++++-----------------------------
 drivers/iommu/iommu-sva-lib.c | 20 ----------
 3 files changed, 12 insertions(+), 78 deletions(-)

diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h
index 0f33472e5212..90d4bd3a61b1 100644
--- a/drivers/iommu/iommu-sva-lib.h
+++ b/drivers/iommu/iommu-sva-lib.h
@@ -8,7 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-struct mm_struct *iommu_sva_find(ioasid_t pasid);
 struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain);
 
 /* I/O Page fault */
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 1df8c1dcae77..fc1b2bdeedf8 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -69,62 +69,6 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 	return iommu_page_response(dev, &resp);
 }
 
-static enum iommu_page_response_code
-iopf_handle_single(struct iopf_fault *iopf)
-{
-	vm_fault_t ret;
-	struct mm_struct *mm;
-	struct vm_area_struct *vma;
-	unsigned int access_flags = 0;
-	unsigned int fault_flags = FAULT_FLAG_REMOTE;
-	struct iommu_fault_page_request *prm = &iopf->fault.prm;
-	enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
-
-	if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
-		return status;
-
-	mm = iommu_sva_find(prm->pasid);
-	if (IS_ERR_OR_NULL(mm))
-		return status;
-
-	mmap_read_lock(mm);
-
-	vma = find_extend_vma(mm, prm->addr);
-	if (!vma)
-		/* Unmapped area */
-		goto out_put_mm;
-
-	if (prm->perm & IOMMU_FAULT_PERM_READ)
-		access_flags |= VM_READ;
-
-	if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
-		access_flags |= VM_WRITE;
-		fault_flags |= FAULT_FLAG_WRITE;
-	}
-
-	if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
-		access_flags |= VM_EXEC;
-		fault_flags |= FAULT_FLAG_INSTRUCTION;
-	}
-
-	if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
-		fault_flags |= FAULT_FLAG_USER;
-
-	if (access_flags & ~vma->vm_flags)
-		/* Access fault */
-		goto out_put_mm;
-
-	ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
-	status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
-		IOMMU_PAGE_RESP_SUCCESS;
-
-out_put_mm:
-	mmap_read_unlock(mm);
-	mmput(mm);
-
-	return status;
-}
-
 static void iopf_handle_group(struct work_struct *work)
 {
 	struct iopf_group *group;
@@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
 	group = container_of(work, struct iopf_group, work);
 
 	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+		struct iommu_domain *domain;
+
+		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
+				iopf->fault.prm.pasid);
+		if (!domain || !domain->iopf_handler)
+			status = IOMMU_PAGE_RESP_INVALID;
+
 		/*
 		 * 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 = iopf_handle_single(iopf);
+			status = domain->iopf_handler(&iopf->fault,
+						      domain->fault_data);
+
+		if (domain)
+			iommu_domain_put_async(domain);
 
 		if (!(iopf->fault.prm.flags &
 		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c
index 1024c61519dc..d84cffaeb331 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva-lib.c
@@ -69,26 +69,6 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm,
 	return ret;
 }
 
-/* ioasid_find getter() requires a void * argument */
-static bool __mmget_not_zero(void *mm)
-{
-	return mmget_not_zero(mm);
-}
-
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */
-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
-}
-EXPORT_SYMBOL_GPL(iommu_sva_find);
-
 /*
  * Get or put an ioas for a shared memory.
  */
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH v4 12/12] iommu: Rename iommu-sva-lib.{c,h}

[Lu Baolu]

Rename iommu-sva-lib.c[h] to iommu-sva.c[h] as it contains all code
for SVA implementation in iommu core.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/{iommu-sva-lib.h => iommu-sva.h}  | 0
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c     | 2 +-
 drivers/iommu/intel/iommu.c                     | 2 +-
 drivers/iommu/intel/svm.c                       | 2 +-
 drivers/iommu/io-pgfault.c                      | 2 +-
 drivers/iommu/{iommu-sva-lib.c => iommu-sva.c}  | 2 +-
 drivers/iommu/iommu.c                           | 2 +-
 drivers/iommu/Makefile                          | 2 +-
 9 files changed, 8 insertions(+), 8 deletions(-)
 rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (100%)
 rename drivers/iommu/{iommu-sva-lib.c => iommu-sva.c} (99%)

diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva.h
similarity index 100%
rename from drivers/iommu/iommu-sva-lib.h
rename to drivers/iommu/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 5591321f9e11..a13543aa9df4 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
@@ -9,7 +9,7 @@
 #include <linux/slab.h>
 
 #include "arm-smmu-v3.h"
-#include "../../iommu-sva-lib.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 543d3ef1c102..ca2bd17eec41 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -31,7 +31,7 @@
 #include <linux/amba/bus.h>
 
 #include "arm-smmu-v3.h"
-#include "../../iommu-sva-lib.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 3164bd5a3572..d3dbef5b74a7 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -27,7 +27,7 @@
 #include <linux/tboot.h>
 
 #include "../irq_remapping.h"
-#include "../iommu-sva-lib.h"
+#include "../iommu-sva.h"
 #include "pasid.h"
 #include "cap_audit.h"
 
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 61155f1cb985..166d1af2bda4 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -25,7 +25,7 @@
 
 #include "pasid.h"
 #include "perf.h"
-#include "../iommu-sva-lib.h"
+#include "../iommu-sva.h"
 
 static irqreturn_t prq_event_thread(int irq, void *d);
 static void intel_svm_drain_prq(struct device *dev, u32 pasid);
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index fc1b2bdeedf8..d337165f3707 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -11,7 +11,7 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 /**
  * struct iopf_queue - IO Page Fault queue
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva.c
similarity index 99%
rename from drivers/iommu/iommu-sva-lib.c
rename to drivers/iommu/iommu-sva.c
index d84cffaeb331..7647b4938c99 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva.c
@@ -7,7 +7,7 @@
 #include <linux/slab.h>
 #include <linux/sched/mm.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f12c7851d16d..18758cbf1e4a 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -27,7 +27,7 @@
 #include <linux/cc_platform.h>
 #include <trace/events/iommu.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 44475a9b3eea..c1763476162b 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -27,6 +27,6 @@ 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-$(CONFIG_IOMMU_SVA) += iommu-sva-lib.o io-pgfault.o
+obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o io-pgfault.o
 obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
 obj-$(CONFIG_APPLE_DART) += apple-dart.o
-- 
2.25.1

[PATCH v4 12/12] iommu: Rename iommu-sva-lib.{c,h}

[Lu Baolu]

Rename iommu-sva-lib.c[h] to iommu-sva.c[h] as it contains all code
for SVA implementation in iommu core.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/{iommu-sva-lib.h => iommu-sva.h}  | 0
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 2 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c     | 2 +-
 drivers/iommu/intel/iommu.c                     | 2 +-
 drivers/iommu/intel/svm.c                       | 2 +-
 drivers/iommu/io-pgfault.c                      | 2 +-
 drivers/iommu/{iommu-sva-lib.c => iommu-sva.c}  | 2 +-
 drivers/iommu/iommu.c                           | 2 +-
 drivers/iommu/Makefile                          | 2 +-
 9 files changed, 8 insertions(+), 8 deletions(-)
 rename drivers/iommu/{iommu-sva-lib.h => iommu-sva.h} (100%)
 rename drivers/iommu/{iommu-sva-lib.c => iommu-sva.c} (99%)

diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva.h
similarity index 100%
rename from drivers/iommu/iommu-sva-lib.h
rename to drivers/iommu/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 5591321f9e11..a13543aa9df4 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
@@ -9,7 +9,7 @@
 #include <linux/slab.h>
 
 #include "arm-smmu-v3.h"
-#include "../../iommu-sva-lib.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 543d3ef1c102..ca2bd17eec41 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -31,7 +31,7 @@
 #include <linux/amba/bus.h>
 
 #include "arm-smmu-v3.h"
-#include "../../iommu-sva-lib.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 3164bd5a3572..d3dbef5b74a7 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -27,7 +27,7 @@
 #include <linux/tboot.h>
 
 #include "../irq_remapping.h"
-#include "../iommu-sva-lib.h"
+#include "../iommu-sva.h"
 #include "pasid.h"
 #include "cap_audit.h"
 
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 61155f1cb985..166d1af2bda4 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -25,7 +25,7 @@
 
 #include "pasid.h"
 #include "perf.h"
-#include "../iommu-sva-lib.h"
+#include "../iommu-sva.h"
 
 static irqreturn_t prq_event_thread(int irq, void *d);
 static void intel_svm_drain_prq(struct device *dev, u32 pasid);
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index fc1b2bdeedf8..d337165f3707 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -11,7 +11,7 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 /**
  * struct iopf_queue - IO Page Fault queue
diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva.c
similarity index 99%
rename from drivers/iommu/iommu-sva-lib.c
rename to drivers/iommu/iommu-sva.c
index d84cffaeb331..7647b4938c99 100644
--- a/drivers/iommu/iommu-sva-lib.c
+++ b/drivers/iommu/iommu-sva.c
@@ -7,7 +7,7 @@
 #include <linux/slab.h>
 #include <linux/sched/mm.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
 static DECLARE_IOASID_SET(iommu_sva_pasid);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f12c7851d16d..18758cbf1e4a 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -27,7 +27,7 @@
 #include <linux/cc_platform.h>
 #include <trace/events/iommu.h>
 
-#include "iommu-sva-lib.h"
+#include "iommu-sva.h"
 
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 44475a9b3eea..c1763476162b 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -27,6 +27,6 @@ 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-$(CONFIG_IOMMU_SVA) += iommu-sva-lib.o io-pgfault.o
+obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o io-pgfault.o
 obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
 obj-$(CONFIG_APPLE_DART) += apple-dart.o
-- 
2.25.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Jean-Philippe Brucker]

Hi Baolu,

On Thu, Apr 21, 2022 at 01:21:19PM +0800, Lu Baolu wrote:
> +/*
> + * Get the attached domain for asynchronous usage, for example the I/O
> + * page fault handling framework. The caller get a reference counter
> + * of the domain automatically on a successful return and should put
> + * it with iommu_domain_put() after usage.
> + */
> +struct iommu_domain *
> +iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
> +{
> +	struct iommu_domain *domain;
> +	struct iommu_group *group;
> +
> +	if (!pasid_valid(pasid))
> +		return NULL;
> +
> +	group = iommu_group_get(dev);
> +	if (!group)
> +		return NULL;
> +
> +	mutex_lock(&group->mutex);

There is a possible deadlock between unbind() and the fault handler:

 unbind()                            iopf_handle_group()
  mutex_lock(&group->mutex)
  iommu_detach_device_pasid()
   iopf_queue_flush_dev()             iommu_get_domain_for_dev_pasid_async()
    ... waits for IOPF work            mutex_lock(&group->mutex)

I was wrong in my previous review: we do have a guarantee that the SVA
domain does not go away during IOPF handling, because unbind() waits for
pending faults with iopf_queue_flush_dev() before freeing the domain (or
for Arm stall, knows that there are no pending faults). So we can just get
rid of domain->async_users and the group->mutex in IOPF, I think?

Thanks,
Jean

> +	domain = xa_load(&group->pasid_array, pasid);
> +	if (domain)
> +		refcount_inc(&domain->async_users);
> +	mutex_unlock(&group->mutex);
> +	iommu_group_put(group);
> +
> +	return domain;
> +}
> -- 
> 2.25.1
> 

Re: [PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Jean-Philippe Brucker]

Hi Baolu,

On Thu, Apr 21, 2022 at 01:21:19PM +0800, Lu Baolu wrote:
> +/*
> + * Get the attached domain for asynchronous usage, for example the I/O
> + * page fault handling framework. The caller get a reference counter
> + * of the domain automatically on a successful return and should put
> + * it with iommu_domain_put() after usage.
> + */
> +struct iommu_domain *
> +iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
> +{
> +	struct iommu_domain *domain;
> +	struct iommu_group *group;
> +
> +	if (!pasid_valid(pasid))
> +		return NULL;
> +
> +	group = iommu_group_get(dev);
> +	if (!group)
> +		return NULL;
> +
> +	mutex_lock(&group->mutex);

There is a possible deadlock between unbind() and the fault handler:

 unbind()                            iopf_handle_group()
  mutex_lock(&group->mutex)
  iommu_detach_device_pasid()
   iopf_queue_flush_dev()             iommu_get_domain_for_dev_pasid_async()
    ... waits for IOPF work            mutex_lock(&group->mutex)

I was wrong in my previous review: we do have a guarantee that the SVA
domain does not go away during IOPF handling, because unbind() waits for
pending faults with iopf_queue_flush_dev() before freeing the domain (or
for Arm stall, knows that there are no pending faults). So we can just get
rid of domain->async_users and the group->mutex in IOPF, I think?

Thanks,
Jean

> +	domain = xa_load(&group->pasid_array, pasid);
> +	if (domain)
> +		refcount_inc(&domain->async_users);
> +	mutex_unlock(&group->mutex);
> +	iommu_group_put(group);
> +
> +	return domain;
> +}
> -- 
> 2.25.1
> 
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Jean-Philippe Brucker]

On Thu, Apr 21, 2022 at 01:21:12PM +0800, Lu Baolu wrote:
> Attaching an IOMMU domain to a PASID of a device is a generic operation
> for modern IOMMU drivers which support PASID-granular DMA address
> translation. Currently visible usage scenarios include (but not limited):
> 
>  - SVA (Shared Virtual Address)
>  - kernel DMA with PASID
>  - hardware-assist mediated device
> 
> This adds a pair of common domain ops for this purpose and adds helpers
> to attach/detach a domain to/from a {device, PASID}. Some buses, like
> PCI, route packets without considering the PASID value. Thus a DMA target
> address with PASID might be treated as P2P if the address falls into the
> MMIO BAR of other devices in the group. To make things simple, these
> interfaces only apply to devices belonging to the singleton groups, and
> the singleton is immutable in fabric i.e. not affected by hotplug.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
[...]
> +/*
> + * Use standard PCI bus topology, isolation features, and DMA
> + * alias quirks to check the immutable singleton attribute. If
> + * the device came from DT, assume it is static and then
> + * singleton can know from the device count in the group.
> + */
> +static bool device_group_immutable_singleton(struct device *dev)
> +{
> +	struct iommu_group *group = iommu_group_get(dev);
> +	int count;
> +
> +	if (!group)
> +		return false;
> +
> +	mutex_lock(&group->mutex);
> +	count = iommu_group_device_count(group);
> +	mutex_unlock(&group->mutex);
> +	iommu_group_put(group);
> +
> +	if (count != 1)
> +		return false;
> +
> +	if (dev_is_pci(dev)) {
> +		struct pci_dev *pdev = to_pci_dev(dev);
> +
> +		/*
> +		 * The device could be considered to be fully isolated if
> +		 * all devices on the path from the device to the host-PCI
> +		 * bridge are protected from peer-to-peer DMA by ACS.
> +		 */
> +		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
> +			return false;
> +
> +		/* Filter out devices which has any alias device. */
> +		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
> +			return false;

Aren't aliases already added to the group by pci_device_group()?  If so
it's part of the count check above

> +
> +		return true;
> +	}
> +
> +	/*
> +	 * If the device came from DT, assume it is static and then
> +	 * singleton can know from the device count in the group.
> +	 */
> +	return is_of_node(dev_fwnode(dev));

I don't think DT is relevant here because a platform device enumerated
through ACPI will also have its own group. It should be safe to stick to
what the IOMMU drivers declare with their device_group() callback. Except
for PCI those groups should be immutable so we can return true here.

Thanks,
Jean

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Jean-Philippe Brucker]

On Thu, Apr 21, 2022 at 01:21:12PM +0800, Lu Baolu wrote:
> Attaching an IOMMU domain to a PASID of a device is a generic operation
> for modern IOMMU drivers which support PASID-granular DMA address
> translation. Currently visible usage scenarios include (but not limited):
> 
>  - SVA (Shared Virtual Address)
>  - kernel DMA with PASID
>  - hardware-assist mediated device
> 
> This adds a pair of common domain ops for this purpose and adds helpers
> to attach/detach a domain to/from a {device, PASID}. Some buses, like
> PCI, route packets without considering the PASID value. Thus a DMA target
> address with PASID might be treated as P2P if the address falls into the
> MMIO BAR of other devices in the group. To make things simple, these
> interfaces only apply to devices belonging to the singleton groups, and
> the singleton is immutable in fabric i.e. not affected by hotplug.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
[...]
> +/*
> + * Use standard PCI bus topology, isolation features, and DMA
> + * alias quirks to check the immutable singleton attribute. If
> + * the device came from DT, assume it is static and then
> + * singleton can know from the device count in the group.
> + */
> +static bool device_group_immutable_singleton(struct device *dev)
> +{
> +	struct iommu_group *group = iommu_group_get(dev);
> +	int count;
> +
> +	if (!group)
> +		return false;
> +
> +	mutex_lock(&group->mutex);
> +	count = iommu_group_device_count(group);
> +	mutex_unlock(&group->mutex);
> +	iommu_group_put(group);
> +
> +	if (count != 1)
> +		return false;
> +
> +	if (dev_is_pci(dev)) {
> +		struct pci_dev *pdev = to_pci_dev(dev);
> +
> +		/*
> +		 * The device could be considered to be fully isolated if
> +		 * all devices on the path from the device to the host-PCI
> +		 * bridge are protected from peer-to-peer DMA by ACS.
> +		 */
> +		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
> +			return false;
> +
> +		/* Filter out devices which has any alias device. */
> +		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
> +			return false;

Aren't aliases already added to the group by pci_device_group()?  If so
it's part of the count check above

> +
> +		return true;
> +	}
> +
> +	/*
> +	 * If the device came from DT, assume it is static and then
> +	 * singleton can know from the device count in the group.
> +	 */
> +	return is_of_node(dev_fwnode(dev));

I don't think DT is relevant here because a platform device enumerated
through ACPI will also have its own group. It should be safe to stick to
what the IOMMU drivers declare with their device_group() callback. Except
for PCI those groups should be immutable so we can return true here.

Thanks,
Jean

Re: [PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Jean-Philippe Brucker]

On Thu, Apr 21, 2022 at 01:21:20PM +0800, Lu Baolu wrote:
>  static void iopf_handle_group(struct work_struct *work)
>  {
>  	struct iopf_group *group;
> @@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
>  	group = container_of(work, struct iopf_group, work);
>  
>  	list_for_each_entry_safe(iopf, next, &group->faults, list) {
> +		struct iommu_domain *domain;
> +
> +		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
> +				iopf->fault.prm.pasid);

Reading the PCIe spec again (v6.0 10.4.1.1 PASID Usage), all faults within
the group have the same PASID so we could move the domain fetch out of the
loop. It does deviate from the old behavior, though, so we could change
it later.

Thanks,
Jean

> +		if (!domain || !domain->iopf_handler)
> +			status = IOMMU_PAGE_RESP_INVALID;
> +
>  		/*
>  		 * 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 = iopf_handle_single(iopf);
> +			status = domain->iopf_handler(&iopf->fault,
> +						      domain->fault_data);
> +
> +		if (domain)
> +			iommu_domain_put_async(domain);
>  
>  		if (!(iopf->fault.prm.flags &
>  		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))

Re: [PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Jean-Philippe Brucker]

On Thu, Apr 21, 2022 at 01:21:20PM +0800, Lu Baolu wrote:
>  static void iopf_handle_group(struct work_struct *work)
>  {
>  	struct iopf_group *group;
> @@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
>  	group = container_of(work, struct iopf_group, work);
>  
>  	list_for_each_entry_safe(iopf, next, &group->faults, list) {
> +		struct iommu_domain *domain;
> +
> +		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
> +				iopf->fault.prm.pasid);

Reading the PCIe spec again (v6.0 10.4.1.1 PASID Usage), all faults within
the group have the same PASID so we could move the domain fetch out of the
loop. It does deviate from the old behavior, though, so we could change
it later.

Thanks,
Jean

> +		if (!domain || !domain->iopf_handler)
> +			status = IOMMU_PAGE_RESP_INVALID;
> +
>  		/*
>  		 * 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 = iopf_handle_single(iopf);
> +			status = domain->iopf_handler(&iopf->fault,
> +						      domain->fault_data);
> +
> +		if (domain)
> +			iommu_domain_put_async(domain);
>  
>  		if (!(iopf->fault.prm.flags &
>  		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Baolu Lu]

Hi Jean,

On 2022/4/28 22:47, Jean-Philippe Brucker wrote:
> Hi Baolu,
> 
> On Thu, Apr 21, 2022 at 01:21:19PM +0800, Lu Baolu wrote:
>> +/*
>> + * Get the attached domain for asynchronous usage, for example the I/O
>> + * page fault handling framework. The caller get a reference counter
>> + * of the domain automatically on a successful return and should put
>> + * it with iommu_domain_put() after usage.
>> + */
>> +struct iommu_domain *
>> +iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
>> +{
>> +	struct iommu_domain *domain;
>> +	struct iommu_group *group;
>> +
>> +	if (!pasid_valid(pasid))
>> +		return NULL;
>> +
>> +	group = iommu_group_get(dev);
>> +	if (!group)
>> +		return NULL;
>> +
>> +	mutex_lock(&group->mutex);
> 
> There is a possible deadlock between unbind() and the fault handler:
> 
>   unbind()                            iopf_handle_group()
>    mutex_lock(&group->mutex)
>    iommu_detach_device_pasid()
>     iopf_queue_flush_dev()             iommu_get_domain_for_dev_pasid_async()
>      ... waits for IOPF work            mutex_lock(&group->mutex)
> 

Yes, really.

> I was wrong in my previous review: we do have a guarantee that the SVA
> domain does not go away during IOPF handling, because unbind() waits for
> pending faults with iopf_queue_flush_dev() before freeing the domain (or
> for Arm stall, knows that there are no pending faults). So we can just get
> rid of domain->async_users and the group->mutex in IOPF, I think?

Agreed with you. The Intel code does the same thing in its unbind().

Thus, the sva domain's life cycle has already synchronized with IOPF
handling, there's no need for domain->async.

I will drop it in the next version. Thanks you!

Best regards,
baolu

Re: [PATCH v4 10/12] iommu: Prepare IOMMU domain for IOPF

[Baolu Lu]

Hi Jean,

On 2022/4/28 22:47, Jean-Philippe Brucker wrote:
> Hi Baolu,
> 
> On Thu, Apr 21, 2022 at 01:21:19PM +0800, Lu Baolu wrote:
>> +/*
>> + * Get the attached domain for asynchronous usage, for example the I/O
>> + * page fault handling framework. The caller get a reference counter
>> + * of the domain automatically on a successful return and should put
>> + * it with iommu_domain_put() after usage.
>> + */
>> +struct iommu_domain *
>> +iommu_get_domain_for_dev_pasid_async(struct device *dev, ioasid_t pasid)
>> +{
>> +	struct iommu_domain *domain;
>> +	struct iommu_group *group;
>> +
>> +	if (!pasid_valid(pasid))
>> +		return NULL;
>> +
>> +	group = iommu_group_get(dev);
>> +	if (!group)
>> +		return NULL;
>> +
>> +	mutex_lock(&group->mutex);
> 
> There is a possible deadlock between unbind() and the fault handler:
> 
>   unbind()                            iopf_handle_group()
>    mutex_lock(&group->mutex)
>    iommu_detach_device_pasid()
>     iopf_queue_flush_dev()             iommu_get_domain_for_dev_pasid_async()
>      ... waits for IOPF work            mutex_lock(&group->mutex)
> 

Yes, really.

> I was wrong in my previous review: we do have a guarantee that the SVA
> domain does not go away during IOPF handling, because unbind() waits for
> pending faults with iopf_queue_flush_dev() before freeing the domain (or
> for Arm stall, knows that there are no pending faults). So we can just get
> rid of domain->async_users and the group->mutex in IOPF, I think?

Agreed with you. The Intel code does the same thing in its unbind().

Thus, the sva domain's life cycle has already synchronized with IOPF
handling, there's no need for domain->async.

I will drop it in the next version. Thanks you!

Best regards,
baolu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Baolu Lu]

On 2022/4/28 22:53, Jean-Philippe Brucker wrote:
> On Thu, Apr 21, 2022 at 01:21:12PM +0800, Lu Baolu wrote:
>> Attaching an IOMMU domain to a PASID of a device is a generic operation
>> for modern IOMMU drivers which support PASID-granular DMA address
>> translation. Currently visible usage scenarios include (but not limited):
>>
>>   - SVA (Shared Virtual Address)
>>   - kernel DMA with PASID
>>   - hardware-assist mediated device
>>
>> This adds a pair of common domain ops for this purpose and adds helpers
>> to attach/detach a domain to/from a {device, PASID}. Some buses, like
>> PCI, route packets without considering the PASID value. Thus a DMA target
>> address with PASID might be treated as P2P if the address falls into the
>> MMIO BAR of other devices in the group. To make things simple, these
>> interfaces only apply to devices belonging to the singleton groups, and
>> the singleton is immutable in fabric i.e. not affected by hotplug.
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> [...]
>> +/*
>> + * Use standard PCI bus topology, isolation features, and DMA
>> + * alias quirks to check the immutable singleton attribute. If
>> + * the device came from DT, assume it is static and then
>> + * singleton can know from the device count in the group.
>> + */
>> +static bool device_group_immutable_singleton(struct device *dev)
>> +{
>> +	struct iommu_group *group = iommu_group_get(dev);
>> +	int count;
>> +
>> +	if (!group)
>> +		return false;
>> +
>> +	mutex_lock(&group->mutex);
>> +	count = iommu_group_device_count(group);
>> +	mutex_unlock(&group->mutex);
>> +	iommu_group_put(group);
>> +
>> +	if (count != 1)
>> +		return false;
>> +
>> +	if (dev_is_pci(dev)) {
>> +		struct pci_dev *pdev = to_pci_dev(dev);
>> +
>> +		/*
>> +		 * The device could be considered to be fully isolated if
>> +		 * all devices on the path from the device to the host-PCI
>> +		 * bridge are protected from peer-to-peer DMA by ACS.
>> +		 */
>> +		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
>> +			return false;
>> +
>> +		/* Filter out devices which has any alias device. */
>> +		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
>> +			return false;
> 
> Aren't aliases already added to the group by pci_device_group()?  If so
> it's part of the count check above

You are right. pci_device_group() has already covered pci aliases.

> 
>> +
>> +		return true;
>> +	}
>> +
>> +	/*
>> +	 * If the device came from DT, assume it is static and then
>> +	 * singleton can know from the device count in the group.
>> +	 */
>> +	return is_of_node(dev_fwnode(dev));
> 
> I don't think DT is relevant here because a platform device enumerated
> through ACPI will also have its own group. It should be safe to stick to
> what the IOMMU drivers declare with their device_group() callback. Except
> for PCI those groups should be immutable so we can return true here.

Fair enough. My code is too restrict. The group singleton is immutable
as long as the fabric is static or ACS (or similar) technology is
implemented. Currently we only need to care about PCI as far as I can
see.

> Thanks,
> Jean
> 

Best regards,
baolu

Re: [PATCH v4 03/12] iommu: Add attach/detach_dev_pasid domain ops

[Baolu Lu]

On 2022/4/28 22:53, Jean-Philippe Brucker wrote:
> On Thu, Apr 21, 2022 at 01:21:12PM +0800, Lu Baolu wrote:
>> Attaching an IOMMU domain to a PASID of a device is a generic operation
>> for modern IOMMU drivers which support PASID-granular DMA address
>> translation. Currently visible usage scenarios include (but not limited):
>>
>>   - SVA (Shared Virtual Address)
>>   - kernel DMA with PASID
>>   - hardware-assist mediated device
>>
>> This adds a pair of common domain ops for this purpose and adds helpers
>> to attach/detach a domain to/from a {device, PASID}. Some buses, like
>> PCI, route packets without considering the PASID value. Thus a DMA target
>> address with PASID might be treated as P2P if the address falls into the
>> MMIO BAR of other devices in the group. To make things simple, these
>> interfaces only apply to devices belonging to the singleton groups, and
>> the singleton is immutable in fabric i.e. not affected by hotplug.
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> [...]
>> +/*
>> + * Use standard PCI bus topology, isolation features, and DMA
>> + * alias quirks to check the immutable singleton attribute. If
>> + * the device came from DT, assume it is static and then
>> + * singleton can know from the device count in the group.
>> + */
>> +static bool device_group_immutable_singleton(struct device *dev)
>> +{
>> +	struct iommu_group *group = iommu_group_get(dev);
>> +	int count;
>> +
>> +	if (!group)
>> +		return false;
>> +
>> +	mutex_lock(&group->mutex);
>> +	count = iommu_group_device_count(group);
>> +	mutex_unlock(&group->mutex);
>> +	iommu_group_put(group);
>> +
>> +	if (count != 1)
>> +		return false;
>> +
>> +	if (dev_is_pci(dev)) {
>> +		struct pci_dev *pdev = to_pci_dev(dev);
>> +
>> +		/*
>> +		 * The device could be considered to be fully isolated if
>> +		 * all devices on the path from the device to the host-PCI
>> +		 * bridge are protected from peer-to-peer DMA by ACS.
>> +		 */
>> +		if (!pci_acs_path_enabled(pdev, NULL, REQ_ACS_FLAGS))
>> +			return false;
>> +
>> +		/* Filter out devices which has any alias device. */
>> +		if (pci_for_each_dma_alias(pdev, has_pci_alias, pdev))
>> +			return false;
> 
> Aren't aliases already added to the group by pci_device_group()?  If so
> it's part of the count check above

You are right. pci_device_group() has already covered pci aliases.

> 
>> +
>> +		return true;
>> +	}
>> +
>> +	/*
>> +	 * If the device came from DT, assume it is static and then
>> +	 * singleton can know from the device count in the group.
>> +	 */
>> +	return is_of_node(dev_fwnode(dev));
> 
> I don't think DT is relevant here because a platform device enumerated
> through ACPI will also have its own group. It should be safe to stick to
> what the IOMMU drivers declare with their device_group() callback. Except
> for PCI those groups should be immutable so we can return true here.

Fair enough. My code is too restrict. The group singleton is immutable
as long as the fabric is static or ACS (or similar) technology is
implemented. Currently we only need to care about PCI as far as I can
see.

> Thanks,
> Jean
> 

Best regards,
baolu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Re: [PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Baolu Lu]

On 2022/4/28 22:57, Jean-Philippe Brucker wrote:
> On Thu, Apr 21, 2022 at 01:21:20PM +0800, Lu Baolu wrote:
>>   static void iopf_handle_group(struct work_struct *work)
>>   {
>>   	struct iopf_group *group;
>> @@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
>>   	group = container_of(work, struct iopf_group, work);
>>   
>>   	list_for_each_entry_safe(iopf, next, &group->faults, list) {
>> +		struct iommu_domain *domain;
>> +
>> +		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
>> +				iopf->fault.prm.pasid);
> Reading the PCIe spec again (v6.0 10.4.1.1 PASID Usage), all faults within
> the group have the same PASID so we could move the domain fetch out of the
> loop. It does deviate from the old behavior, though, so we could change
> it later.

Perhaps we can add a pasid member in the struct iopf_group and do a
sanity check when a new iopf is added to the group? Here, we just fetch
the domain with group->pasid.

Best regards,
baolu

Re: [PATCH v4 11/12] iommu: Per-domain I/O page fault handling

[Baolu Lu]

On 2022/4/28 22:57, Jean-Philippe Brucker wrote:
> On Thu, Apr 21, 2022 at 01:21:20PM +0800, Lu Baolu wrote:
>>   static void iopf_handle_group(struct work_struct *work)
>>   {
>>   	struct iopf_group *group;
>> @@ -134,12 +78,23 @@ static void iopf_handle_group(struct work_struct *work)
>>   	group = container_of(work, struct iopf_group, work);
>>   
>>   	list_for_each_entry_safe(iopf, next, &group->faults, list) {
>> +		struct iommu_domain *domain;
>> +
>> +		domain = iommu_get_domain_for_dev_pasid_async(group->dev,
>> +				iopf->fault.prm.pasid);
> Reading the PCIe spec again (v6.0 10.4.1.1 PASID Usage), all faults within
> the group have the same PASID so we could move the domain fetch out of the
> loop. It does deviate from the old behavior, though, so we could change
> it later.

Perhaps we can add a pasid member in the struct iopf_group and do a
sanity check when a new iopf is added to the group? Here, we just fetch
the domain with group->pasid.

Best regards,
baolu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu