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[PATCH v5 00/17] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions

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  [PATCH v5 00/17] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions Eric Auger <eric.auger@redhat.com> - 2017-01-04 14:50 +0100
    [PATCH v5 02/17] iommu: Rename iommu_dm_regions into iommu_resv_regions Eric Auger <eric.auger@redhat.com> - 2017-01-04 14:50 +0100
    [PATCH v5 04/17] iommu: iommu_alloc_resv_region Eric Auger <eric.auger@redhat.com> - 2017-01-04 14:50 +0100
    [PATCH v5 15/17] vfio/type1: Allow transparent MSI IOVA allocation Eric Auger <eric.auger@redhat.com> - 2017-01-04 14:50 +0100

#1550819 — [PATCH v5 00/17] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions

Following LPC discussions, we now report reserved regions through
iommu-group sysfs reserved_regions attribute file.

Reserved regions are populated through the IOMMU get_resv_region
callback (former get_dm_regions), now implemented by amd-iommu,
intel-iommu and arm-smmu:
- the intel-iommu reports the [0xfee00000 - 0xfeefffff] MSI window
  as an IOMMU_RESV_NOMAP reserved region.
- the amd-iommu reports device direct mapped regions, the MSI region
  and HT regions.
- the arm-smmu reports the MSI window (arbitrarily located at
  0x8000000 and 1MB large).

Unsafe interrupt assignment is tested by enumerating all MSI irq
domains and checking MSI remapping is supported in the above hierarchy.
This check is done in case we detect the iommu translates MSI
(an IOMMU_RESV_MSI window exists). Otherwise the IRQ remapping
capability is checked at IOMMU level. Obviously this is a defensive
IRQ safety assessment: Assuming there are several MSI controllers
in the system and at least one does not implement IRQ remapping,
the assignment will be considered as unsafe (even if this controller
is not acessible from the assigned devices).

The series integrates a not officially posted patch from Robin:
"iommu/dma: Allow MSI-only cookies".

Best Regards

Eric

Git: complete series available at
https://github.com/eauger/linux/tree/v4.10-rc2-reserved-v5

History:

RFCv4 -> PATCHv5
- fix IRQ security assessment by looking at irq domain parents
- check DOMAIN_BUS_FSL_MC_MSI irq domains
- AMD MSI and HT regions are exposed in iommu group sysfs

RFCv3 -> RFCv4:
- arm-smmu driver does not register PCI host bridge windows as
  reserved regions anymore
- Implement reserved region get/put callbacks also in arm-smmuv3
- take the iommu_group lock on iommu_get_group_resv_regions
- add a type field in iommu_resv_region instead of using prot
- init the region list_head in iommu_alloc_resv_region, also
  add type parameter
- iommu_insert_resv_region manage overlaps and sort reserved
  windows
- address IRQ safety assessment by enumerating all the MSI irq
  domains and checking the MSI_REMAP flag
- update Documentation/ABI/testing/sysfs-kernel-iommu_groups

RFC v2 -> v3:
- switch to an iommu-group sysfs API
- use new dummy allocator provided by Robin
- dummy allocator initialized by vfio-iommu-type1 after enumerating
  the reserved regions
- at the moment ARM MSI base address/size is left unchanged compared
  to v2
- we currently report reserved regions and not usable IOVA regions as
  requested by Alex

RFC v1 -> v2:
- fix intel_add_reserved_regions
- add mutex lock/unlock in vfio_iommu_type1


Eric Auger (17):
  iommu/dma: Allow MSI-only cookies
  iommu: Rename iommu_dm_regions into iommu_resv_regions
  iommu: Add a new type field in iommu_resv_region
  iommu: iommu_alloc_resv_region
  iommu: Only map direct mapped regions
  iommu: iommu_get_group_resv_regions
  iommu: Implement reserved_regions iommu-group sysfs file
  iommu/vt-d: Implement reserved region get/put callbacks
  iommu/amd: Declare MSI and HT regions as reserved IOVA regions
  iommu/arm-smmu: Implement reserved region get/put callbacks
  iommu/arm-smmu-v3: Implement reserved region get/put callbacks
  irqdomain: Add IRQ_DOMAIN_FLAG_MSI_REMAP value
  irqdomain: irq_domain_check_msi_remap
  irqchip/gicv3-its: Sets IRQ_DOMAIN_FLAG_MSI_REMAP
  vfio/type1: Allow transparent MSI IOVA allocation
  vfio/type1: Check MSI remapping at irq domain level
  iommu/arm-smmu: Do not advertise IOMMU_CAP_INTR_REMAP anymore

 drivers/iommu/amd_iommu.c        |  54 +++++++++-----
 drivers/iommu/arm-smmu-v3.c      |  30 +++++++-
 drivers/iommu/arm-smmu.c         |  30 +++++++-
 drivers/iommu/dma-iommu.c        | 116 ++++++++++++++++++++++++------
 drivers/iommu/intel-iommu.c      |  50 +++++++++----
 drivers/iommu/iommu.c            | 152 ++++++++++++++++++++++++++++++++++++---
 drivers/irqchip/irq-gic-v3-its.c |   1 +
 drivers/vfio/vfio_iommu_type1.c  |  34 ++++++++-
 include/linux/dma-iommu.h        |   7 ++
 include/linux/iommu.h            |  46 ++++++++----
 include/linux/irqdomain.h        |   4 ++
 kernel/irq/irqdomain.c           |  41 +++++++++++
 12 files changed, 481 insertions(+), 84 deletions(-)

-- 
1.9.1

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#1550820 — [PATCH v5 02/17] iommu: Rename iommu_dm_regions into iommu_resv_regions

We want to extend the callbacks used for dm regions and
use them for reserved regions. Reserved regions can be
- directly mapped regions
- regions that cannot be iommu mapped (PCI host bridge windows, ...)
- MSI regions (because they belong to another address space or because
  they are not translated by the IOMMU and need special handling)

So let's rename the struct and also the callbacks.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>

---

v3 -> v4:
- add Robin's A-b
---
 drivers/iommu/amd_iommu.c | 20 ++++++++++----------
 drivers/iommu/iommu.c     | 22 +++++++++++-----------
 include/linux/iommu.h     | 29 +++++++++++++++--------------
 3 files changed, 36 insertions(+), 35 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 019e027..04334eb 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3161,8 +3161,8 @@ static bool amd_iommu_capable(enum iommu_cap cap)
 	return false;
 }
 
-static void amd_iommu_get_dm_regions(struct device *dev,
-				     struct list_head *head)
+static void amd_iommu_get_resv_regions(struct device *dev,
+				       struct list_head *head)
 {
 	struct unity_map_entry *entry;
 	int devid;
@@ -3172,7 +3172,7 @@ static void amd_iommu_get_dm_regions(struct device *dev,
 		return;
 
 	list_for_each_entry(entry, &amd_iommu_unity_map, list) {
-		struct iommu_dm_region *region;
+		struct iommu_resv_region *region;
 
 		if (devid < entry->devid_start || devid > entry->devid_end)
 			continue;
@@ -3195,18 +3195,18 @@ static void amd_iommu_get_dm_regions(struct device *dev,
 	}
 }
 
-static void amd_iommu_put_dm_regions(struct device *dev,
+static void amd_iommu_put_resv_regions(struct device *dev,
 				     struct list_head *head)
 {
-	struct iommu_dm_region *entry, *next;
+	struct iommu_resv_region *entry, *next;
 
 	list_for_each_entry_safe(entry, next, head, list)
 		kfree(entry);
 }
 
-static void amd_iommu_apply_dm_region(struct device *dev,
+static void amd_iommu_apply_resv_region(struct device *dev,
 				      struct iommu_domain *domain,
-				      struct iommu_dm_region *region)
+				      struct iommu_resv_region *region)
 {
 	struct dma_ops_domain *dma_dom = to_dma_ops_domain(to_pdomain(domain));
 	unsigned long start, end;
@@ -3230,9 +3230,9 @@ static void amd_iommu_apply_dm_region(struct device *dev,
 	.add_device = amd_iommu_add_device,
 	.remove_device = amd_iommu_remove_device,
 	.device_group = amd_iommu_device_group,
-	.get_dm_regions = amd_iommu_get_dm_regions,
-	.put_dm_regions = amd_iommu_put_dm_regions,
-	.apply_dm_region = amd_iommu_apply_dm_region,
+	.get_resv_regions = amd_iommu_get_resv_regions,
+	.put_resv_regions = amd_iommu_put_resv_regions,
+	.apply_resv_region = amd_iommu_apply_resv_region,
 	.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
 };
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index dbe7f65..1cee5c3 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -318,7 +318,7 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
 					      struct device *dev)
 {
 	struct iommu_domain *domain = group->default_domain;
-	struct iommu_dm_region *entry;
+	struct iommu_resv_region *entry;
 	struct list_head mappings;
 	unsigned long pg_size;
 	int ret = 0;
@@ -331,14 +331,14 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
 	pg_size = 1UL << __ffs(domain->pgsize_bitmap);
 	INIT_LIST_HEAD(&mappings);
 
-	iommu_get_dm_regions(dev, &mappings);
+	iommu_get_resv_regions(dev, &mappings);
 
 	/* We need to consider overlapping regions for different devices */
 	list_for_each_entry(entry, &mappings, list) {
 		dma_addr_t start, end, addr;
 
-		if (domain->ops->apply_dm_region)
-			domain->ops->apply_dm_region(dev, domain, entry);
+		if (domain->ops->apply_resv_region)
+			domain->ops->apply_resv_region(dev, domain, entry);
 
 		start = ALIGN(entry->start, pg_size);
 		end   = ALIGN(entry->start + entry->length, pg_size);
@@ -358,7 +358,7 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
 	}
 
 out:
-	iommu_put_dm_regions(dev, &mappings);
+	iommu_put_resv_regions(dev, &mappings);
 
 	return ret;
 }
@@ -1559,20 +1559,20 @@ int iommu_domain_set_attr(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_domain_set_attr);
 
-void iommu_get_dm_regions(struct device *dev, struct list_head *list)
+void iommu_get_resv_regions(struct device *dev, struct list_head *list)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-	if (ops && ops->get_dm_regions)
-		ops->get_dm_regions(dev, list);
+	if (ops && ops->get_resv_regions)
+		ops->get_resv_regions(dev, list);
 }
 
-void iommu_put_dm_regions(struct device *dev, struct list_head *list)
+void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 {
 	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
-	if (ops && ops->put_dm_regions)
-		ops->put_dm_regions(dev, list);
+	if (ops && ops->put_resv_regions)
+		ops->put_resv_regions(dev, list);
 }
 
 /* Request that a device is direct mapped by the IOMMU */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0ff5111..bfecb8b 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -118,13 +118,13 @@ enum iommu_attr {
 };
 
 /**
- * struct iommu_dm_region - descriptor for a direct mapped memory region
+ * struct iommu_resv_region - descriptor for a reserved memory region
  * @list: Linked list pointers
  * @start: System physical start address of the region
  * @length: Length of the region in bytes
  * @prot: IOMMU Protection flags (READ/WRITE/...)
  */
-struct iommu_dm_region {
+struct iommu_resv_region {
 	struct list_head	list;
 	phys_addr_t		start;
 	size_t			length;
@@ -150,9 +150,9 @@ struct iommu_dm_region {
  * @device_group: find iommu group for a particular device
  * @domain_get_attr: Query domain attributes
  * @domain_set_attr: Change domain attributes
- * @get_dm_regions: Request list of direct mapping requirements for a device
- * @put_dm_regions: Free list of direct mapping requirements for a device
- * @apply_dm_region: Temporary helper call-back for iova reserved ranges
+ * @get_resv_regions: Request list of reserved regions for a device
+ * @put_resv_regions: Free list of reserved regions for a device
+ * @apply_resv_region: Temporary helper call-back for iova reserved ranges
  * @domain_window_enable: Configure and enable a particular window for a domain
  * @domain_window_disable: Disable a particular window for a domain
  * @domain_set_windows: Set the number of windows for a domain
@@ -184,11 +184,12 @@ struct iommu_ops {
 	int (*domain_set_attr)(struct iommu_domain *domain,
 			       enum iommu_attr attr, void *data);
 
-	/* Request/Free a list of direct mapping requirements for a device */
-	void (*get_dm_regions)(struct device *dev, struct list_head *list);
-	void (*put_dm_regions)(struct device *dev, struct list_head *list);
-	void (*apply_dm_region)(struct device *dev, struct iommu_domain *domain,
-				struct iommu_dm_region *region);
+	/* Request/Free a list of reserved regions for a device */
+	void (*get_resv_regions)(struct device *dev, struct list_head *list);
+	void (*put_resv_regions)(struct device *dev, struct list_head *list);
+	void (*apply_resv_region)(struct device *dev,
+				  struct iommu_domain *domain,
+				  struct iommu_resv_region *region);
 
 	/* Window handling functions */
 	int (*domain_window_enable)(struct iommu_domain *domain, u32 wnd_nr,
@@ -233,8 +234,8 @@ extern size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long io
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
 
-extern void iommu_get_dm_regions(struct device *dev, struct list_head *list);
-extern void iommu_put_dm_regions(struct device *dev, struct list_head *list);
+extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
+extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
 
 extern int iommu_attach_group(struct iommu_domain *domain,
@@ -443,12 +444,12 @@ static inline void iommu_set_fault_handler(struct iommu_domain *domain,
 {
 }
 
-static inline void iommu_get_dm_regions(struct device *dev,
+static inline void iommu_get_resv_regions(struct device *dev,
 					struct list_head *list)
 {
 }
 
-static inline void iommu_put_dm_regions(struct device *dev,
+static inline void iommu_put_resv_regions(struct device *dev,
 					struct list_head *list)
 {
 }
-- 
1.9.1

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#1550821 — [PATCH v5 04/17] iommu: iommu_alloc_resv_region

Introduce a new helper serving the purpose to allocate a reserved
region. This will be used in iommu driver implementing reserved
region callbacks.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v3 -> v4:
- add INIT_LIST_HEAD(&region->list)
- use int for prot param and add int type param
- remove implementation outside of CONFIG_IOMMU_API
---
 drivers/iommu/iommu.c | 18 ++++++++++++++++++
 include/linux/iommu.h |  2 ++
 2 files changed, 20 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 1cee5c3..927878d 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1575,6 +1575,24 @@ void iommu_put_resv_regions(struct device *dev, struct list_head *list)
 		ops->put_resv_regions(dev, list);
 }
 
+struct iommu_resv_region *iommu_alloc_resv_region(phys_addr_t start,
+						  size_t length,
+						  int prot, int type)
+{
+	struct iommu_resv_region *region;
+
+	region = kzalloc(sizeof(*region), GFP_KERNEL);
+	if (!region)
+		return NULL;
+
+	INIT_LIST_HEAD(&region->list);
+	region->start = start;
+	region->length = length;
+	region->prot = prot;
+	region->type = type;
+	return region;
+}
+
 /* Request that a device is direct mapped by the IOMMU */
 int iommu_request_dm_for_dev(struct device *dev)
 {
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9128a8d..e97a877 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -244,6 +244,8 @@ extern void iommu_set_fault_handler(struct iommu_domain *domain,
 extern void iommu_get_resv_regions(struct device *dev, struct list_head *list);
 extern void iommu_put_resv_regions(struct device *dev, struct list_head *list);
 extern int iommu_request_dm_for_dev(struct device *dev);
+extern struct iommu_resv_region *
+iommu_alloc_resv_region(phys_addr_t start, size_t length, int prot, int type);
 
 extern int iommu_attach_group(struct iommu_domain *domain,
 			      struct iommu_group *group);
-- 
1.9.1

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#1550825 — [PATCH v5 15/17] vfio/type1: Allow transparent MSI IOVA allocation

When attaching a group to the container, check the group's
reserved regions and test whether the IOMMU translates MSI
transactions. If yes, we initialize an IOVA allocator through
the iommu_get_msi_cookie API. This will allow the MSI IOVAs
to be transparently allocated on MSI controller's compose().

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v3 -> v4:
- test region's type: IOMMU_RESV_MSI
- restructure the code to prepare for safety assessment
- reword title
---
 drivers/vfio/vfio_iommu_type1.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index f3726ba..b473ef80 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -39,6 +39,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/mdev.h>
 #include <linux/notifier.h>
+#include <linux/dma-iommu.h>
 
 #define DRIVER_VERSION  "0.2"
 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
@@ -1177,6 +1178,28 @@ static struct vfio_group *find_iommu_group(struct vfio_domain *domain,
 	return NULL;
 }
 
+static bool vfio_iommu_has_resv_msi(struct iommu_group *group,
+				    phys_addr_t *base)
+{
+	struct list_head group_resv_regions;
+	struct iommu_resv_region *region, *next;
+	bool ret = false;
+
+	INIT_LIST_HEAD(&group_resv_regions);
+	iommu_get_group_resv_regions(group, &group_resv_regions);
+	list_for_each_entry(region, &group_resv_regions, list) {
+		if (region->type & IOMMU_RESV_MSI) {
+			*base = region->start;
+			ret = true;
+			goto out;
+		}
+	}
+out:
+	list_for_each_entry_safe(region, next, &group_resv_regions, list)
+		kfree(region);
+	return ret;
+}
+
 static int vfio_iommu_type1_attach_group(void *iommu_data,
 					 struct iommu_group *iommu_group)
 {
@@ -1185,6 +1208,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	struct vfio_domain *domain, *d;
 	struct bus_type *bus = NULL, *mdev_bus;
 	int ret;
+	bool resv_msi;
+	phys_addr_t resv_msi_base;
 
 	mutex_lock(&iommu->lock);
 
@@ -1254,6 +1279,8 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	if (ret)
 		goto out_domain;
 
+	resv_msi = vfio_iommu_has_resv_msi(iommu_group, &resv_msi_base);
+
 	INIT_LIST_HEAD(&domain->group_list);
 	list_add(&group->next, &domain->group_list);
 
@@ -1300,6 +1327,9 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	if (ret)
 		goto out_detach;
 
+	if (resv_msi && iommu_get_msi_cookie(domain->domain, resv_msi_base))
+		goto out_detach;
+
 	list_add(&domain->next, &iommu->domain_list);
 
 	mutex_unlock(&iommu->lock);
-- 
1.9.1

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