[RFC v3 0/7] Add multiple address spaces support to VDUSE

[RFC v3 0/7] Add multiple address spaces support to VDUSE

[Eugenio Pérez]

When used by vhost-vDPA bus driver for VM, the control virtqueue
should be shadowed via userspace VMM (QEMU) instead of being assigned
directly to Guest. This is because QEMU needs to know the device state
in order to start and stop device correctly (e.g for Live Migration).

This requies to isolate the memory mapping for control virtqueue
presented by vhost-vDPA to prevent guest from accessing it directly.

This series add support to multiple address spaces in VDUSE device
allowing selective virtqueue isolation through address space IDs (ASID).

The VDUSE device needs to report:
* Number of virtqueue groups
* Association of each vq group with each virtqueue
* Number of address spaces supported.

Then, the vDPA driver can modify the ASID assigned to each VQ group to
isolate the memory AS.  This aligns VDUSE with gq}vdpa_sim and nvidia
mlx5 devices which already support ASID.

This helps to isolate the environments for the virtqueues that will not
be assigned directly. E.g in the case of virtio-net, the control
virtqueue will not be assigned directly to guest.

This is still a RFC as it depends on the series that reworks the virtio mapping
API:
https://lore.kernel.org/all/20250813054831.25865-1-jasowang@redhat.com/

As some changes has been requested to it, these will need to be applied here
too.

Also, to be able to test this patch, the user needs to manually revert
56e71885b034 ("vduse: Temporarily fail if control queue feature requested").

RFC: Not tested, just sent to justify the use of generic tokens in Jason's DMA
rework.

v3:
* Increase VDUSE_MAX_VQ_GROUPS to 0xffff (Jason). It was set to a lower
  value to reduce memory consumption, but vqs are already limited to
  that value and userspace VDUSE is able to allocate that many vqs.  Also, it's
  a dynamic array now.  Same with ASID.
* Move the valid vq groups range check to vduse_validate_config.
* Embed vduse_iotlb_entry into vduse_iotlb_entry_v2.
* Use of array_index_nospec in VDUSE device ioctls.
* Move the umem mutex to asid struct so there is no contention between
  ASIDs.
* Remove the descs vq group capability as it will not be used and we can
  add it on top.
* Do not ask for vq groups in number of vq groups < 2.
* Remove TODO about merging VDUSE_IOTLB_GET_FD ioctl with
  VDUSE_IOTLB_GET_INFO.

v2:
* Cache group information in kernel, as we need to provide the vq map
  tokens properly.
* Add descs vq group to optimize SVQ forwarding and support indirect
  descriptors out of the box.
* Make iotlb entry the last one of vduse_iotlb_entry_v2 so the first
  part of the struct is the same.
* Fixes detected testing with OVS+VDUSE.

Eugenio Pérez (7):
  vduse: add v1 API definition
  vduse: add vq group support
  vdpa: change map_token from void * to an empty struct
  vduse: return internal vq group struct as map token
  vduse: create vduse_as to make it an array
  vduse: add vq group asid support
  vduse: bump version number

 drivers/vdpa/vdpa_user/vduse_dev.c | 439 ++++++++++++++++++++++-------
 drivers/virtio/virtio_ring.c       |   6 +-
 include/linux/virtio.h             |   8 +-
 include/linux/virtio_config.h      |  34 ++-
 include/uapi/linux/vduse.h         |  73 ++++-
 5 files changed, 438 insertions(+), 122 deletions(-)

-- 
2.50.1

[RFC v3 1/7] vduse: add v1 API definition

[Eugenio Pérez]

This allows the kernel to detect whether the userspace VDUSE device
supports the VQ group and ASID features.  VDUSE devices that don't set
the V1 API will not receive the new messages, and vdpa device will be
created with only one vq group and asid.

The next patches implement the new feature incrementally, only enabling
the VDUSE device to set the V1 API version by the end of the series.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/uapi/linux/vduse.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index 68a627d04afa..9a56d0416bfe 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -10,6 +10,10 @@
 
 #define VDUSE_API_VERSION	0
 
+/* VQ groups and ASID support */
+
+#define VDUSE_API_VERSION_1	1
+
 /*
  * Get the version of VDUSE API that kernel supported (VDUSE_API_VERSION).
  * This is used for future extension.
-- 
2.50.1

[RFC v3 2/7] vduse: add vq group support

[Eugenio Pérez]

This allows sepparate the different virtqueues in groups that shares the
same address space.  Asking the VDUSE device for the groups of the vq at
the beginning as they're needed for the DMA API.

Allocating 3 vq groups as net is the device that need the most groups:
* Dataplane (guest passthrough)
* CVQ
* Shadowed vrings.

Future versions of the series can include dynamic allocation of the
groups array so VDUSE can declare more groups.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
v3:
* Increase VDUSE_MAX_VQ_GROUPS to 0xffff (Jason). It was set to a lower
  value to reduce memory consumption, but vqs are already limited to
  that value and userspace VDUSE is able to allocate that many vqs.
* Remove the descs vq group capability as it will not be used and we can
  add it on top.
* Do not ask for vq groups in number of vq groups < 2.
* Move the valid vq groups range check to vduse_validate_config.

v2:
* Cache group information in kernel, as we need to provide the vq map
  tokens properly.
* Add descs vq group to optimize SVQ forwarding and support indirect
  descriptors out of the box.
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 53 ++++++++++++++++++++++++++++--
 include/uapi/linux/vduse.h         | 21 +++++++++++-
 2 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 3260edefdf0d..e42d14888ca2 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -58,6 +58,7 @@ struct vduse_virtqueue {
 	struct vdpa_vq_state state;
 	bool ready;
 	bool kicked;
+	u32 vq_group;
 	spinlock_t kick_lock;
 	spinlock_t irq_lock;
 	struct eventfd_ctx *kickfd;
@@ -115,6 +116,7 @@ struct vduse_dev {
 	u8 status;
 	u32 vq_num;
 	u32 vq_align;
+	u32 ngroups;
 	struct vduse_umem *umem;
 	struct mutex mem_lock;
 	unsigned int bounce_size;
@@ -593,6 +595,13 @@ static int vduse_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 idx,
 	return 0;
 }
 
+static u32 vduse_get_vq_group(struct vdpa_device *vdpa, u16 idx)
+{
+	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+
+	return dev->vqs[idx]->vq_group;
+}
+
 static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx,
 				struct vdpa_vq_state *state)
 {
@@ -679,13 +688,42 @@ static u8 vduse_vdpa_get_status(struct vdpa_device *vdpa)
 	return dev->status;
 }
 
+static int vduse_fill_vq_groups(struct vduse_dev *dev)
+{
+	/* All vqs and descs must be in vq group 0 if ngroups < 2 */
+	if (dev->ngroups < 2)
+		return 0;
+
+	for (int i = 0; i < dev->vdev->vdpa.nvqs; ++i) {
+		struct vduse_dev_msg msg = { 0 };
+		int ret;
+
+		msg.req.type = VDUSE_GET_VQ_GROUP;
+		msg.req.vq_group.index = i;
+		ret = vduse_dev_msg_sync(dev, &msg);
+		if (ret)
+			return ret;
+
+		dev->vqs[i]->vq_group = msg.resp.vq_group.group;
+	}
+
+	return 0;
+}
+
 static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
 {
 	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+	u8 previous_status = dev->status;
 
 	if (vduse_dev_set_status(dev, status))
 		return;
 
+	if ((dev->status ^ previous_status) &
+	     BIT_ULL(VIRTIO_CONFIG_S_FEATURES_OK) &&
+	    status & (1ULL << VIRTIO_CONFIG_S_FEATURES_OK))
+		if (vduse_fill_vq_groups(dev))
+			return;
+
 	dev->status = status;
 }
 
@@ -790,6 +828,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
 	.set_vq_cb		= vduse_vdpa_set_vq_cb,
 	.set_vq_num             = vduse_vdpa_set_vq_num,
 	.get_vq_size		= vduse_vdpa_get_vq_size,
+	.get_vq_group		= vduse_get_vq_group,
 	.set_vq_ready		= vduse_vdpa_set_vq_ready,
 	.get_vq_ready		= vduse_vdpa_get_vq_ready,
 	.set_vq_state		= vduse_vdpa_set_vq_state,
@@ -1738,12 +1777,19 @@ static bool features_is_valid(struct vduse_dev_config *config)
 	return true;
 }
 
-static bool vduse_validate_config(struct vduse_dev_config *config)
+static bool vduse_validate_config(struct vduse_dev_config *config,
+				  u64 api_version)
 {
 	if (!is_mem_zero((const char *)config->reserved,
 			 sizeof(config->reserved)))
 		return false;
 
+	if (api_version < VDUSE_API_VERSION_1 && config->ngroups)
+		return false;
+
+	if (api_version >= VDUSE_API_VERSION_1 && config->ngroups > 0xffff)
+		return false;
+
 	if (config->vq_align > PAGE_SIZE)
 		return false;
 
@@ -1859,6 +1905,7 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 	dev->device_features = config->features;
 	dev->device_id = config->device_id;
 	dev->vendor_id = config->vendor_id;
+	dev->ngroups = (dev->api_version < 1) ? 1 : (config->ngroups ?: 1);
 	dev->name = kstrdup(config->name, GFP_KERNEL);
 	if (!dev->name)
 		goto err_str;
@@ -1937,7 +1984,7 @@ static long vduse_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		ret = -EINVAL;
-		if (vduse_validate_config(&config) == false)
+		if (!vduse_validate_config(&config, control->api_version))
 			break;
 
 		buf = vmemdup_user(argp + size, config.config_size);
@@ -2018,7 +2065,7 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
 
 	vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
 				 &vduse_vdpa_config_ops, &vduse_map_ops,
-				 1, 1, name, true);
+				 dev->ngroups, 1, name, true);
 	if (IS_ERR(vdev))
 		return PTR_ERR(vdev);
 
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index 9a56d0416bfe..b1c0e47d71fb 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -31,6 +31,7 @@
  * @features: virtio features
  * @vq_num: the number of virtqueues
  * @vq_align: the allocation alignment of virtqueue's metadata
+ * @ngroups: number of vq groups that VDUSE device declares
  * @reserved: for future use, needs to be initialized to zero
  * @config_size: the size of the configuration space
  * @config: the buffer of the configuration space
@@ -45,7 +46,8 @@ struct vduse_dev_config {
 	__u64 features;
 	__u32 vq_num;
 	__u32 vq_align;
-	__u32 reserved[13];
+	__u32 ngroups; /* if VDUSE_API_VERSION >= 1 */
+	__u32 reserved[12];
 	__u32 config_size;
 	__u8 config[];
 };
@@ -160,6 +162,16 @@ struct vduse_vq_state_packed {
 	__u16 last_used_idx;
 };
 
+/**
+ * struct vduse_vq_group - virtqueue group
+ * @index: Index of the virtqueue
+ * @group: Virtqueue group
+ */
+struct vduse_vq_group {
+	__u32 index;
+	__u32 group;
+};
+
 /**
  * struct vduse_vq_info - information of a virtqueue
  * @index: virtqueue index
@@ -274,6 +286,7 @@ enum vduse_req_type {
 	VDUSE_GET_VQ_STATE,
 	VDUSE_SET_STATUS,
 	VDUSE_UPDATE_IOTLB,
+	VDUSE_GET_VQ_GROUP,
 };
 
 /**
@@ -316,6 +329,7 @@ struct vduse_iova_range {
  * @vq_state: virtqueue state, only index field is available
  * @s: device status
  * @iova: IOVA range for updating
+ * @vq_group: virtqueue group of a virtqueue
  * @padding: padding
  *
  * Structure used by read(2) on /dev/vduse/$NAME.
@@ -328,6 +342,8 @@ struct vduse_dev_request {
 		struct vduse_vq_state vq_state;
 		struct vduse_dev_status s;
 		struct vduse_iova_range iova;
+		/* Only if vduse api version >= 1 */;
+		struct vduse_vq_group vq_group;
 		__u32 padding[32];
 	};
 };
@@ -338,6 +354,7 @@ struct vduse_dev_request {
  * @result: the result of request
  * @reserved: for future use, needs to be initialized to zero
  * @vq_state: virtqueue state
+ * @vq_group: virtqueue group of a virtqueue
  * @padding: padding
  *
  * Structure used by write(2) on /dev/vduse/$NAME.
@@ -350,6 +367,8 @@ struct vduse_dev_response {
 	__u32 reserved[4];
 	union {
 		struct vduse_vq_state vq_state;
+		/* Only if vduse api version >= 1 */
+		struct vduse_vq_group vq_group;
 		__u32 padding[32];
 	};
 };
-- 
2.50.1

[RFC v3 3/7] vdpa: change map_token from void * to an empty struct

[Eugenio Pérez]

Proposal to make it type safe, never casting to void, but allow the
backend to use whatever struct it needs.

Next patches will move the token from a domain to a custom struct.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 drivers/vdpa/vdpa_user/iova_domain.h |  1 +
 drivers/vdpa/vdpa_user/vduse_dev.c   | 60 ++++++++++++++++------------
 drivers/virtio/virtio_ring.c         |  6 ++-
 include/linux/virtio.h               |  8 +++-
 include/linux/virtio_config.h        | 34 +++++++++-------
 5 files changed, 67 insertions(+), 42 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/iova_domain.h b/drivers/vdpa/vdpa_user/iova_domain.h
index 1f3c30be272a..c0f97dfaf94f 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.h
+++ b/drivers/vdpa/vdpa_user/iova_domain.h
@@ -26,6 +26,7 @@ struct vduse_bounce_map {
 };
 
 struct vduse_iova_domain {
+	struct vring_mapping_opaque token;
 	struct iova_domain stream_iovad;
 	struct iova_domain consistent_iovad;
 	struct vduse_bounce_map *bounce_maps;
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index e42d14888ca2..e3c8fc1aa446 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -164,6 +164,11 @@ static inline struct vduse_dev *dev_to_vduse(struct device *dev)
 	return vdpa_to_vduse(vdpa);
 }
 
+static struct vduse_iova_domain *vduse_token_to_domain(struct vring_mapping_opaque *token)
+{
+	return container_of(token, struct vduse_iova_domain, token);
+}
+
 static struct vduse_dev_msg *vduse_find_msg(struct list_head *head,
 					    uint32_t request_id)
 {
@@ -854,47 +859,50 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
 	.free			= vduse_vdpa_free,
 };
 
-static void vduse_dev_sync_single_for_device(void *token,
+static void vduse_dev_sync_single_for_device(struct vring_mapping_opaque *token,
 					     dma_addr_t dma_addr, size_t size,
 					     enum dma_data_direction dir)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	vduse_domain_sync_single_for_device(domain, dma_addr, size, dir);
 }
 
-static void vduse_dev_sync_single_for_cpu(void *token,
-					     dma_addr_t dma_addr, size_t size,
-					     enum dma_data_direction dir)
+static void vduse_dev_sync_single_for_cpu(struct vring_mapping_opaque *token,
+					  dma_addr_t dma_addr, size_t size,
+					  enum dma_data_direction dir)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	vduse_domain_sync_single_for_cpu(domain, dma_addr, size, dir);
 }
 
-static dma_addr_t vduse_dev_map_page(void *token, struct page *page,
+static dma_addr_t vduse_dev_map_page(struct vring_mapping_opaque *token,
+				     struct page *page,
 				     unsigned long offset, size_t size,
 				     enum dma_data_direction dir,
 				     unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
 }
 
-static void vduse_dev_unmap_page(void *token, dma_addr_t dma_addr,
-				size_t size, enum dma_data_direction dir,
-				unsigned long attrs)
+static void vduse_dev_unmap_page(struct vring_mapping_opaque *token,
+				 dma_addr_t dma_addr, size_t size,
+				 enum dma_data_direction dir,
+				 unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
 }
 
-static void *vduse_dev_alloc_coherent(void *token, size_t size,
-				      dma_addr_t *dma_addr, gfp_t flag)
+static void *vduse_dev_alloc_coherent(struct vring_mapping_opaque *token,
+				      size_t size, dma_addr_t *dma_addr,
+				      gfp_t flag)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 	unsigned long iova;
 	void *addr;
 
@@ -909,32 +917,34 @@ static void *vduse_dev_alloc_coherent(void *token, size_t size,
 	return addr;
 }
 
-static void vduse_dev_free_coherent(void *token, size_t size,
-				    void *vaddr, dma_addr_t dma_addr,
-				    unsigned long attrs)
+static void vduse_dev_free_coherent(struct vring_mapping_opaque *token,
+				    size_t size, void *vaddr,
+				    dma_addr_t dma_addr, unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
 }
 
-static bool vduse_dev_need_sync(void *token, dma_addr_t dma_addr)
+static bool vduse_dev_need_sync(struct vring_mapping_opaque *token,
+				dma_addr_t dma_addr)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	return dma_addr < domain->bounce_size;
 }
 
-static int vduse_dev_mapping_error(void *token, dma_addr_t dma_addr)
+static int vduse_dev_mapping_error(struct vring_mapping_opaque *token,
+				   dma_addr_t dma_addr)
 {
 	if (unlikely(dma_addr == DMA_MAPPING_ERROR))
 		return -ENOMEM;
 	return 0;
 }
 
-static size_t vduse_dev_max_mapping_size(void *token)
+static size_t vduse_dev_max_mapping_size(struct vring_mapping_opaque *token)
 {
-	struct vduse_iova_domain *domain = token;
+	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
 
 	return domain->bounce_size;
 }
@@ -2103,7 +2113,7 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 		return -ENOMEM;
 	}
 
-	dev->vdev->vdpa.mapping_token.token = dev->domain;
+	dev->vdev->vdpa.mapping_token.token = &dev->domain->token;
 	ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num);
 	if (ret) {
 		put_device(&dev->vdev->vdpa.dev);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index fc0f5faa8523..4fc588458b23 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -349,8 +349,12 @@ size_t virtio_max_dma_size(const struct virtio_device *vdev)
 
 	if (vring_use_map_api(vdev)) {
 		if (vdev->map)
+			/*
+			 * TODO we should be able to get the token here, not
+			 * cast to void
+			 */
 			max_segment_size =
-				vdev->map->max_mapping_size(vdev->dev.parent);
+				vdev->map->max_mapping_size((void *)vdev->dev.parent);
 		else
 			max_segment_size =
 				dma_max_mapping_size(vdev->dev.parent);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index ceca93348aed..c446c511b8c1 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -40,11 +40,17 @@ struct virtqueue {
 	void *priv;
 };
 
+/*
+ * Base struct for the transport specific token used for doing map.
+ * It allows to convert between the transport specific type to the mapping
+ * token with a valud type always.
+ */
+struct vring_mapping_opaque {};
 union vring_mapping_token {
 	/* Device that performs DMA */
 	struct device *dma_dev;
 	/* Transport specific token used for doing map */
-	void *token;
+	struct vring_mapping_opaque *token;
 };
 
 int virtqueue_add_outbuf(struct virtqueue *vq,
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4566ac87feb7..02d98fb1309c 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -191,24 +191,28 @@ struct virtio_config_ops {
  *      Returns: the maximum buffer size that can be mapped
  */
 struct virtio_map_ops {
-	dma_addr_t (*map_page)(void *token, struct page *page,
-			       unsigned long offset, size_t size,
-			       enum dma_data_direction dir, unsigned long attrs);
-	void (*unmap_page)(void *token, dma_addr_t map_handle,
-			   size_t size, enum dma_data_direction dir,
-			   unsigned long attrs);
-	void (*sync_single_for_cpu)(void *token, dma_addr_t map_handle,
-				    size_t size, enum dma_data_direction dir);
-	void (*sync_single_for_device)(void *token,
+	dma_addr_t (*map_page)(struct vring_mapping_opaque *token,
+			       struct page *page, unsigned long offset,
+			       size_t size, enum dma_data_direction dir,
+			       unsigned long attrs);
+	void (*unmap_page)(struct vring_mapping_opaque *token,
+			   dma_addr_t map_handle, size_t size,
+			   enum dma_data_direction dir, unsigned long attrs);
+	void (*sync_single_for_cpu)(struct vring_mapping_opaque *token,
+				    dma_addr_t map_handle, size_t size,
+				    enum dma_data_direction dir);
+	void (*sync_single_for_device)(struct vring_mapping_opaque *token,
 				       dma_addr_t map_handle, size_t size,
 				       enum dma_data_direction dir);
-	void *(*alloc)(void *token, size_t size,
+	void *(*alloc)(struct vring_mapping_opaque *token, size_t size,
 		       dma_addr_t *map_handle, gfp_t gfp);
-	void (*free)(void *token, size_t size, void *vaddr,
-		     dma_addr_t map_handle, unsigned long attrs);
-	bool (*need_sync)(void *token, dma_addr_t map_handle);
-	int (*mapping_error)(void *token, dma_addr_t map_handle);
-	size_t (*max_mapping_size)(void *token);
+	void (*free)(struct vring_mapping_opaque *token, size_t size,
+		     void *vaddr, dma_addr_t map_handle, unsigned long attrs);
+	bool (*need_sync)(struct vring_mapping_opaque *token,
+			  dma_addr_t map_handle);
+	int (*mapping_error)(struct vring_mapping_opaque *token,
+			     dma_addr_t map_handle);
+	size_t (*max_mapping_size)(struct vring_mapping_opaque *token);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
-- 
2.50.1

[RFC v3 4/7] vduse: return internal vq group struct as map token

[Eugenio Pérez]

Return the internal struct that represents the vq group as virtqueue map
token, instead of the device.  This allows the map functions to access
the information per group.

At this moment all the virtqueues share the same vq group, that only
can point to ASID 0.  This change prepares the infrastructure for actual
per-group address space handling

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
v3:
* Make the vq groups a dynamic array to support an arbitrary number of
  them.
---
 drivers/vdpa/vdpa_user/iova_domain.h |  1 -
 drivers/vdpa/vdpa_user/vduse_dev.c   | 65 +++++++++++++++++++++++-----
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/iova_domain.h b/drivers/vdpa/vdpa_user/iova_domain.h
index c0f97dfaf94f..1f3c30be272a 100644
--- a/drivers/vdpa/vdpa_user/iova_domain.h
+++ b/drivers/vdpa/vdpa_user/iova_domain.h
@@ -26,7 +26,6 @@ struct vduse_bounce_map {
 };
 
 struct vduse_iova_domain {
-	struct vring_mapping_opaque token;
 	struct iova_domain stream_iovad;
 	struct iova_domain consistent_iovad;
 	struct vduse_bounce_map *bounce_maps;
diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index e3c8fc1aa446..45b188dc2659 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -84,6 +84,11 @@ struct vduse_umem {
 	struct mm_struct *mm;
 };
 
+struct vduse_vq_group_int {
+	struct vring_mapping_opaque token;
+	struct vduse_dev *dev;
+};
+
 struct vduse_dev {
 	struct vduse_vdpa *vdev;
 	struct device *dev;
@@ -118,6 +123,7 @@ struct vduse_dev {
 	u32 vq_align;
 	u32 ngroups;
 	struct vduse_umem *umem;
+	struct vduse_vq_group_int *groups;
 	struct mutex mem_lock;
 	unsigned int bounce_size;
 	struct mutex domain_lock;
@@ -164,9 +170,9 @@ static inline struct vduse_dev *dev_to_vduse(struct device *dev)
 	return vdpa_to_vduse(vdpa);
 }
 
-static struct vduse_iova_domain *vduse_token_to_domain(struct vring_mapping_opaque *token)
+static struct vduse_vq_group_int *vduse_token_to_vq_group(struct vring_mapping_opaque *token)
 {
-	return container_of(token, struct vduse_iova_domain, token);
+	return container_of(token, struct vduse_vq_group_int, token);
 }
 
 static struct vduse_dev_msg *vduse_find_msg(struct list_head *head,
@@ -607,6 +613,16 @@ static u32 vduse_get_vq_group(struct vdpa_device *vdpa, u16 idx)
 	return dev->vqs[idx]->vq_group;
 }
 
+static union vring_mapping_token vduse_get_vq_mapping_token(struct vdpa_device *vdpa,
+							    u16 idx)
+{
+	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+	u32 vq_group = dev->vqs[idx]->vq_group;
+	union vring_mapping_token ret = { .token = &dev->groups[vq_group].token };
+
+	return ret;
+}
+
 static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx,
 				struct vdpa_vq_state *state)
 {
@@ -856,6 +872,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
 	.get_vq_affinity	= vduse_vdpa_get_vq_affinity,
 	.reset			= vduse_vdpa_reset,
 	.set_map		= vduse_vdpa_set_map,
+	.get_vq_mapping_token	= vduse_get_vq_mapping_token,
 	.free			= vduse_vdpa_free,
 };
 
@@ -863,7 +880,9 @@ static void vduse_dev_sync_single_for_device(struct vring_mapping_opaque *token,
 					     dma_addr_t dma_addr, size_t size,
 					     enum dma_data_direction dir)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	vduse_domain_sync_single_for_device(domain, dma_addr, size, dir);
 }
@@ -872,7 +891,9 @@ static void vduse_dev_sync_single_for_cpu(struct vring_mapping_opaque *token,
 					  dma_addr_t dma_addr, size_t size,
 					  enum dma_data_direction dir)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	vduse_domain_sync_single_for_cpu(domain, dma_addr, size, dir);
 }
@@ -883,7 +904,9 @@ static dma_addr_t vduse_dev_map_page(struct vring_mapping_opaque *token,
 				     enum dma_data_direction dir,
 				     unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
 }
@@ -893,7 +916,9 @@ static void vduse_dev_unmap_page(struct vring_mapping_opaque *token,
 				 enum dma_data_direction dir,
 				 unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
 }
@@ -902,7 +927,9 @@ static void *vduse_dev_alloc_coherent(struct vring_mapping_opaque *token,
 				      size_t size, dma_addr_t *dma_addr,
 				      gfp_t flag)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 	unsigned long iova;
 	void *addr;
 
@@ -921,7 +948,9 @@ static void vduse_dev_free_coherent(struct vring_mapping_opaque *token,
 				    size_t size, void *vaddr,
 				    dma_addr_t dma_addr, unsigned long attrs)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
 }
@@ -929,7 +958,9 @@ static void vduse_dev_free_coherent(struct vring_mapping_opaque *token,
 static bool vduse_dev_need_sync(struct vring_mapping_opaque *token,
 				dma_addr_t dma_addr)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	return dma_addr < domain->bounce_size;
 }
@@ -944,7 +975,9 @@ static int vduse_dev_mapping_error(struct vring_mapping_opaque *token,
 
 static size_t vduse_dev_max_mapping_size(struct vring_mapping_opaque *token)
 {
-	struct vduse_iova_domain *domain = vduse_token_to_domain(token);
+	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
+	struct vduse_dev *vdev = group->dev;
+	struct vduse_iova_domain *domain = vdev->domain;
 
 	return domain->bounce_size;
 }
@@ -1750,6 +1783,7 @@ static int vduse_destroy_dev(char *name)
 	if (dev->domain)
 		vduse_domain_destroy(dev->domain);
 	kfree(dev->name);
+	kfree(dev->groups);
 	vduse_dev_destroy(dev);
 	module_put(THIS_MODULE);
 
@@ -1915,7 +1949,15 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 	dev->device_features = config->features;
 	dev->device_id = config->device_id;
 	dev->vendor_id = config->vendor_id;
+
 	dev->ngroups = (dev->api_version < 1) ? 1 : (config->ngroups ?: 1);
+	dev->groups = kcalloc(dev->ngroups, sizeof(dev->groups[0]),
+			      GFP_KERNEL);
+	if (!dev->groups)
+		goto err_vq_groups;
+	for (u32 i = 0; i < dev->ngroups; ++i)
+		dev->groups[i].dev = dev;
+
 	dev->name = kstrdup(config->name, GFP_KERNEL);
 	if (!dev->name)
 		goto err_str;
@@ -1952,6 +1994,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 err_idr:
 	kfree(dev->name);
 err_str:
+	kfree(dev->groups);
+err_vq_groups:
 	vduse_dev_destroy(dev);
 err:
 	return ret;
@@ -2113,7 +2157,6 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 		return -ENOMEM;
 	}
 
-	dev->vdev->vdpa.mapping_token.token = &dev->domain->token;
 	ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num);
 	if (ret) {
 		put_device(&dev->vdev->vdpa.dev);
-- 
2.50.1

[RFC v3 5/7] vduse: create vduse_as to make it an array

[Eugenio Pérez]

This is a first step so we can make more than one different address
spaces.  No change on the colde flow intended.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 115 +++++++++++++++--------------
 1 file changed, 59 insertions(+), 56 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 45b188dc2659..561aab048d1a 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -84,6 +84,12 @@ struct vduse_umem {
 	struct mm_struct *mm;
 };
 
+struct vduse_as {
+	struct vduse_iova_domain *domain;
+	struct vduse_umem *umem;
+	struct mutex mem_lock;
+};
+
 struct vduse_vq_group_int {
 	struct vring_mapping_opaque token;
 	struct vduse_dev *dev;
@@ -93,8 +99,7 @@ struct vduse_dev {
 	struct vduse_vdpa *vdev;
 	struct device *dev;
 	struct vduse_virtqueue **vqs;
-	struct vduse_iova_domain *domain;
-	struct vduse_iova_domain *dom;
+	struct vduse_as as;
 	char *name;
 	struct mutex lock;
 	spinlock_t msg_lock;
@@ -122,9 +127,7 @@ struct vduse_dev {
 	u32 vq_num;
 	u32 vq_align;
 	u32 ngroups;
-	struct vduse_umem *umem;
 	struct vduse_vq_group_int *groups;
-	struct mutex mem_lock;
 	unsigned int bounce_size;
 	struct mutex domain_lock;
 };
@@ -444,7 +447,7 @@ static __poll_t vduse_dev_poll(struct file *file, poll_table *wait)
 static void vduse_dev_reset(struct vduse_dev *dev)
 {
 	int i;
-	struct vduse_iova_domain *domain = dev->domain;
+	struct vduse_iova_domain *domain = dev->as.domain;
 
 	/* The coherent mappings are handled in vduse_dev_free_coherent() */
 	if (domain && domain->bounce_map)
@@ -823,13 +826,13 @@ static int vduse_vdpa_set_map(struct vdpa_device *vdpa,
 	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
 	int ret;
 
-	ret = vduse_domain_set_map(dev->domain, iotlb);
+	ret = vduse_domain_set_map(dev->as.domain, iotlb);
 	if (ret)
 		return ret;
 
 	ret = vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX);
 	if (ret) {
-		vduse_domain_clear_map(dev->domain, iotlb);
+		vduse_domain_clear_map(dev->as.domain, iotlb);
 		return ret;
 	}
 
@@ -882,7 +885,7 @@ static void vduse_dev_sync_single_for_device(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	vduse_domain_sync_single_for_device(domain, dma_addr, size, dir);
 }
@@ -893,7 +896,7 @@ static void vduse_dev_sync_single_for_cpu(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	vduse_domain_sync_single_for_cpu(domain, dma_addr, size, dir);
 }
@@ -906,7 +909,7 @@ static dma_addr_t vduse_dev_map_page(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
 }
@@ -918,7 +921,7 @@ static void vduse_dev_unmap_page(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
 }
@@ -929,7 +932,7 @@ static void *vduse_dev_alloc_coherent(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 	unsigned long iova;
 	void *addr;
 
@@ -950,7 +953,7 @@ static void vduse_dev_free_coherent(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
 }
@@ -960,7 +963,7 @@ static bool vduse_dev_need_sync(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	return dma_addr < domain->bounce_size;
 }
@@ -977,7 +980,7 @@ static size_t vduse_dev_max_mapping_size(struct vring_mapping_opaque *token)
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->domain;
+	struct vduse_iova_domain *domain = vdev->as.domain;
 
 	return domain->bounce_size;
 }
@@ -1124,29 +1127,29 @@ static int vduse_dev_dereg_umem(struct vduse_dev *dev,
 {
 	int ret;
 
-	mutex_lock(&dev->mem_lock);
+	mutex_lock(&dev->as.mem_lock);
 	ret = -ENOENT;
-	if (!dev->umem)
+	if (!dev->as.umem)
 		goto unlock;
 
 	ret = -EINVAL;
-	if (!dev->domain)
+	if (!dev->as.domain)
 		goto unlock;
 
-	if (dev->umem->iova != iova || size != dev->domain->bounce_size)
+	if (dev->as.umem->iova != iova || size != dev->as.domain->bounce_size)
 		goto unlock;
 
-	vduse_domain_remove_user_bounce_pages(dev->domain);
-	unpin_user_pages_dirty_lock(dev->umem->pages,
-				    dev->umem->npages, true);
-	atomic64_sub(dev->umem->npages, &dev->umem->mm->pinned_vm);
-	mmdrop(dev->umem->mm);
-	vfree(dev->umem->pages);
-	kfree(dev->umem);
-	dev->umem = NULL;
+	vduse_domain_remove_user_bounce_pages(dev->as.domain);
+	unpin_user_pages_dirty_lock(dev->as.umem->pages,
+				    dev->as.umem->npages, true);
+	atomic64_sub(dev->as.umem->npages, &dev->as.umem->mm->pinned_vm);
+	mmdrop(dev->as.umem->mm);
+	vfree(dev->as.umem->pages);
+	kfree(dev->as.umem);
+	dev->as.umem = NULL;
 	ret = 0;
 unlock:
-	mutex_unlock(&dev->mem_lock);
+	mutex_unlock(&dev->as.mem_lock);
 	return ret;
 }
 
@@ -1159,14 +1162,14 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 	unsigned long npages, lock_limit;
 	int ret;
 
-	if (!dev->domain || !dev->domain->bounce_map ||
-	    size != dev->domain->bounce_size ||
+	if (!dev->as.domain || !dev->as.domain->bounce_map ||
+	    size != dev->as.domain->bounce_size ||
 	    iova != 0 || uaddr & ~PAGE_MASK)
 		return -EINVAL;
 
-	mutex_lock(&dev->mem_lock);
+	mutex_lock(&dev->as.mem_lock);
 	ret = -EEXIST;
-	if (dev->umem)
+	if (dev->as.umem)
 		goto unlock;
 
 	ret = -ENOMEM;
@@ -1190,7 +1193,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 		goto out;
 	}
 
-	ret = vduse_domain_add_user_bounce_pages(dev->domain,
+	ret = vduse_domain_add_user_bounce_pages(dev->as.domain,
 						 page_list, pinned);
 	if (ret)
 		goto out;
@@ -1203,7 +1206,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 	umem->mm = current->mm;
 	mmgrab(current->mm);
 
-	dev->umem = umem;
+	dev->as.umem = umem;
 out:
 	if (ret && pinned > 0)
 		unpin_user_pages(page_list, pinned);
@@ -1214,7 +1217,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 		vfree(page_list);
 		kfree(umem);
 	}
-	mutex_unlock(&dev->mem_lock);
+	mutex_unlock(&dev->as.mem_lock);
 	return ret;
 }
 
@@ -1260,12 +1263,12 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		mutex_lock(&dev->domain_lock);
-		if (!dev->domain) {
+		if (!dev->as.domain) {
 			mutex_unlock(&dev->domain_lock);
 			break;
 		}
-		spin_lock(&dev->domain->iotlb_lock);
-		map = vhost_iotlb_itree_first(dev->domain->iotlb,
+		spin_lock(&dev->as.domain->iotlb_lock);
+		map = vhost_iotlb_itree_first(dev->as.domain->iotlb,
 					      entry.start, entry.last);
 		if (map) {
 			map_file = (struct vdpa_map_file *)map->opaque;
@@ -1275,7 +1278,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			entry.last = map->last;
 			entry.perm = map->perm;
 		}
-		spin_unlock(&dev->domain->iotlb_lock);
+		spin_unlock(&dev->as.domain->iotlb_lock);
 		mutex_unlock(&dev->domain_lock);
 		ret = -EINVAL;
 		if (!f)
@@ -1469,22 +1472,22 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		mutex_lock(&dev->domain_lock);
-		if (!dev->domain) {
+		if (!dev->as.domain) {
 			mutex_unlock(&dev->domain_lock);
 			break;
 		}
-		spin_lock(&dev->domain->iotlb_lock);
-		map = vhost_iotlb_itree_first(dev->domain->iotlb,
+		spin_lock(&dev->as.domain->iotlb_lock);
+		map = vhost_iotlb_itree_first(dev->as.domain->iotlb,
 					      info.start, info.last);
 		if (map) {
 			info.start = map->start;
 			info.last = map->last;
 			info.capability = 0;
-			if (dev->domain->bounce_map && map->start == 0 &&
-			    map->last == dev->domain->bounce_size - 1)
+			if (dev->as.domain->bounce_map && map->start == 0 &&
+			    map->last == dev->as.domain->bounce_size - 1)
 				info.capability |= VDUSE_IOVA_CAP_UMEM;
 		}
-		spin_unlock(&dev->domain->iotlb_lock);
+		spin_unlock(&dev->as.domain->iotlb_lock);
 		mutex_unlock(&dev->domain_lock);
 		if (!map)
 			break;
@@ -1509,8 +1512,8 @@ static int vduse_dev_release(struct inode *inode, struct file *file)
 	struct vduse_dev *dev = file->private_data;
 
 	mutex_lock(&dev->domain_lock);
-	if (dev->domain)
-		vduse_dev_dereg_umem(dev, 0, dev->domain->bounce_size);
+	if (dev->as.domain)
+		vduse_dev_dereg_umem(dev, 0, dev->as.domain->bounce_size);
 	mutex_unlock(&dev->domain_lock);
 	spin_lock(&dev->msg_lock);
 	/* Make sure the inflight messages can processed after reconncection */
@@ -1729,7 +1732,7 @@ static struct vduse_dev *vduse_dev_create(void)
 		return NULL;
 
 	mutex_init(&dev->lock);
-	mutex_init(&dev->mem_lock);
+	mutex_init(&dev->as.mem_lock);
 	mutex_init(&dev->domain_lock);
 	spin_lock_init(&dev->msg_lock);
 	INIT_LIST_HEAD(&dev->send_list);
@@ -1780,8 +1783,8 @@ static int vduse_destroy_dev(char *name)
 	idr_remove(&vduse_idr, dev->minor);
 	kvfree(dev->config);
 	vduse_dev_deinit_vqs(dev);
-	if (dev->domain)
-		vduse_domain_destroy(dev->domain);
+	if (dev->as.domain)
+		vduse_domain_destroy(dev->as.domain);
 	kfree(dev->name);
 	kfree(dev->groups);
 	vduse_dev_destroy(dev);
@@ -1897,7 +1900,7 @@ static ssize_t bounce_size_store(struct device *device,
 
 	ret = -EPERM;
 	mutex_lock(&dev->domain_lock);
-	if (dev->domain)
+	if (dev->as.domain)
 		goto unlock;
 
 	ret = kstrtouint(buf, 10, &bounce_size);
@@ -2148,11 +2151,11 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 		return ret;
 
 	mutex_lock(&dev->domain_lock);
-	if (!dev->domain)
-		dev->domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1,
+	if (!dev->as.domain)
+		dev->as.domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1,
 						  dev->bounce_size);
 	mutex_unlock(&dev->domain_lock);
-	if (!dev->domain) {
+	if (!dev->as.domain) {
 		put_device(&dev->vdev->vdpa.dev);
 		return -ENOMEM;
 	}
@@ -2161,8 +2164,8 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 	if (ret) {
 		put_device(&dev->vdev->vdpa.dev);
 		mutex_lock(&dev->domain_lock);
-		vduse_domain_destroy(dev->domain);
-		dev->domain = NULL;
+		vduse_domain_destroy(dev->as.domain);
+		dev->as.domain = NULL;
 		mutex_unlock(&dev->domain_lock);
 		return ret;
 	}
-- 
2.50.1

[RFC v3 6/7] vduse: add vq group asid support

[Eugenio Pérez]

Add support for assigning Address Space Identifiers (ASIDs) to each VQ
group.  This enables mapping each group into a distinct memory space.

Now that the driver can change ASID in the middle of operation, the
domain that each vq address point is also protected by domain_lock.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
v3:
* Increase VDUSE_MAX_VQ_GROUPS to 0xffff (Jason). It was set to a lower
  value to reduce memory consumption, but vqs are already limited to
  that value and userspace VDUSE is able to allocate that many vqs.
* Remove TODO about merging VDUSE_IOTLB_GET_FD ioctl with
  VDUSE_IOTLB_GET_INFO.
* Use of array_index_nospec in VDUSE device ioctls.
* Embed vduse_iotlb_entry into vduse_iotlb_entry_v2.
* Move the umem mutex to asid struct so there is no contention between
  ASIDs.

v2:
* Make iotlb entry the last one of vduse_iotlb_entry_v2 so the first
  part of the struct is the same.
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 290 +++++++++++++++++++++--------
 include/uapi/linux/vduse.h         |  52 +++++-
 2 files changed, 259 insertions(+), 83 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 561aab048d1a..de9550fd1cc8 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -92,6 +92,7 @@ struct vduse_as {
 
 struct vduse_vq_group_int {
 	struct vring_mapping_opaque token;
+	struct vduse_iova_domain *domain;
 	struct vduse_dev *dev;
 };
 
@@ -99,7 +100,7 @@ struct vduse_dev {
 	struct vduse_vdpa *vdev;
 	struct device *dev;
 	struct vduse_virtqueue **vqs;
-	struct vduse_as as;
+	struct vduse_as *as;
 	char *name;
 	struct mutex lock;
 	spinlock_t msg_lock;
@@ -127,6 +128,7 @@ struct vduse_dev {
 	u32 vq_num;
 	u32 vq_align;
 	u32 ngroups;
+	u32 nas;
 	struct vduse_vq_group_int *groups;
 	unsigned int bounce_size;
 	struct mutex domain_lock;
@@ -322,7 +324,7 @@ static int vduse_dev_set_status(struct vduse_dev *dev, u8 status)
 	return vduse_dev_msg_sync(dev, &msg);
 }
 
-static int vduse_dev_update_iotlb(struct vduse_dev *dev,
+static int vduse_dev_update_iotlb(struct vduse_dev *dev, u32 asid,
 				  u64 start, u64 last)
 {
 	struct vduse_dev_msg msg = { 0 };
@@ -331,8 +333,14 @@ static int vduse_dev_update_iotlb(struct vduse_dev *dev,
 		return -EINVAL;
 
 	msg.req.type = VDUSE_UPDATE_IOTLB;
-	msg.req.iova.start = start;
-	msg.req.iova.last = last;
+	if (dev->api_version < VDUSE_API_VERSION_1) {
+		msg.req.iova.start = start;
+		msg.req.iova.last = last;
+	} else {
+		msg.req.iova_v2.start = start;
+		msg.req.iova_v2.last = last;
+		msg.req.iova_v2.asid = asid;
+	}
 
 	return vduse_dev_msg_sync(dev, &msg);
 }
@@ -444,14 +452,28 @@ static __poll_t vduse_dev_poll(struct file *file, poll_table *wait)
 	return mask;
 }
 
+/* Force set the asid to a vq group without a message to the VDUSE device */
+static void vduse_set_group_asid_nomsg(struct vduse_dev *dev,
+				       unsigned int group, unsigned int asid)
+{
+	guard(mutex)(&dev->domain_lock);
+	dev->groups[group].domain = dev->as[asid].domain;
+}
+
 static void vduse_dev_reset(struct vduse_dev *dev)
 {
 	int i;
-	struct vduse_iova_domain *domain = dev->as.domain;
 
 	/* The coherent mappings are handled in vduse_dev_free_coherent() */
-	if (domain && domain->bounce_map)
-		vduse_domain_reset_bounce_map(domain);
+	for (i = 0; i < dev->nas; i++) {
+		struct vduse_iova_domain *domain = dev->as[i].domain;
+
+		if (domain && domain->bounce_map)
+			vduse_domain_reset_bounce_map(domain);
+	}
+
+	for (i = 0; i < dev->ngroups; i++)
+		vduse_set_group_asid_nomsg(dev, i, 0);
 
 	down_write(&dev->rwsem);
 
@@ -626,6 +648,29 @@ static union vring_mapping_token vduse_get_vq_mapping_token(struct vdpa_device *
 	return ret;
 }
 
+static int vduse_set_group_asid(struct vdpa_device *vdpa, unsigned int group,
+				unsigned int asid)
+{
+	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
+	struct vduse_dev_msg msg = { 0 };
+	int r;
+
+	if (dev->api_version < VDUSE_API_VERSION_1 ||
+	    group >= dev->ngroups || asid >= dev->nas)
+		return -EINVAL;
+
+	msg.req.type = VDUSE_SET_VQ_GROUP_ASID;
+	msg.req.vq_group_asid.group = group;
+	msg.req.vq_group_asid.asid = asid;
+
+	r = vduse_dev_msg_sync(dev, &msg);
+	if (r < 0)
+		return r;
+
+	vduse_set_group_asid_nomsg(dev, group, asid);
+	return 0;
+}
+
 static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx,
 				struct vdpa_vq_state *state)
 {
@@ -826,13 +871,13 @@ static int vduse_vdpa_set_map(struct vdpa_device *vdpa,
 	struct vduse_dev *dev = vdpa_to_vduse(vdpa);
 	int ret;
 
-	ret = vduse_domain_set_map(dev->as.domain, iotlb);
+	ret = vduse_domain_set_map(dev->as[asid].domain, iotlb);
 	if (ret)
 		return ret;
 
-	ret = vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX);
+	ret = vduse_dev_update_iotlb(dev, asid, 0ULL, ULLONG_MAX);
 	if (ret) {
-		vduse_domain_clear_map(dev->as.domain, iotlb);
+		vduse_domain_clear_map(dev->as[asid].domain, iotlb);
 		return ret;
 	}
 
@@ -875,6 +920,7 @@ static const struct vdpa_config_ops vduse_vdpa_config_ops = {
 	.get_vq_affinity	= vduse_vdpa_get_vq_affinity,
 	.reset			= vduse_vdpa_reset,
 	.set_map		= vduse_vdpa_set_map,
+	.set_group_asid		= vduse_set_group_asid,
 	.get_vq_mapping_token	= vduse_get_vq_mapping_token,
 	.free			= vduse_vdpa_free,
 };
@@ -885,8 +931,10 @@ static void vduse_dev_sync_single_for_device(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	vduse_domain_sync_single_for_device(domain, dma_addr, size, dir);
 }
 
@@ -896,8 +944,10 @@ static void vduse_dev_sync_single_for_cpu(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	vduse_domain_sync_single_for_cpu(domain, dma_addr, size, dir);
 }
 
@@ -909,8 +959,10 @@ static dma_addr_t vduse_dev_map_page(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
 }
 
@@ -921,8 +973,10 @@ static void vduse_dev_unmap_page(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
 }
 
@@ -932,11 +986,13 @@ static void *vduse_dev_alloc_coherent(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 	unsigned long iova;
 	void *addr;
 
 	*dma_addr = DMA_MAPPING_ERROR;
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	addr = vduse_domain_alloc_coherent(domain, size,
 					   (dma_addr_t *)&iova, flag);
 	if (!addr)
@@ -953,8 +1009,10 @@ static void vduse_dev_free_coherent(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
 }
 
@@ -963,8 +1021,10 @@ static bool vduse_dev_need_sync(struct vring_mapping_opaque *token,
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	return dma_addr < domain->bounce_size;
 }
 
@@ -980,8 +1040,10 @@ static size_t vduse_dev_max_mapping_size(struct vring_mapping_opaque *token)
 {
 	struct vduse_vq_group_int *group = vduse_token_to_vq_group(token);
 	struct vduse_dev *vdev = group->dev;
-	struct vduse_iova_domain *domain = vdev->as.domain;
+	struct vduse_iova_domain *domain;
 
+	guard(mutex)(&vdev->domain_lock);
+	domain = group->domain;
 	return domain->bounce_size;
 }
 
@@ -1122,39 +1184,40 @@ static int vduse_dev_queue_irq_work(struct vduse_dev *dev,
 	return ret;
 }
 
-static int vduse_dev_dereg_umem(struct vduse_dev *dev,
+static int vduse_dev_dereg_umem(struct vduse_dev *dev, u32 asid,
 				u64 iova, u64 size)
 {
 	int ret;
 
-	mutex_lock(&dev->as.mem_lock);
+	mutex_lock(&dev->as[asid].mem_lock);
 	ret = -ENOENT;
-	if (!dev->as.umem)
+	if (!dev->as[asid].umem)
 		goto unlock;
 
 	ret = -EINVAL;
-	if (!dev->as.domain)
+	if (!dev->as[asid].domain)
 		goto unlock;
 
-	if (dev->as.umem->iova != iova || size != dev->as.domain->bounce_size)
+	if (dev->as[asid].umem->iova != iova ||
+	    size != dev->as[asid].domain->bounce_size)
 		goto unlock;
 
-	vduse_domain_remove_user_bounce_pages(dev->as.domain);
-	unpin_user_pages_dirty_lock(dev->as.umem->pages,
-				    dev->as.umem->npages, true);
-	atomic64_sub(dev->as.umem->npages, &dev->as.umem->mm->pinned_vm);
-	mmdrop(dev->as.umem->mm);
-	vfree(dev->as.umem->pages);
-	kfree(dev->as.umem);
-	dev->as.umem = NULL;
+	vduse_domain_remove_user_bounce_pages(dev->as[asid].domain);
+	unpin_user_pages_dirty_lock(dev->as[asid].umem->pages,
+				    dev->as[asid].umem->npages, true);
+	atomic64_sub(dev->as[asid].umem->npages, &dev->as[asid].umem->mm->pinned_vm);
+	mmdrop(dev->as[asid].umem->mm);
+	vfree(dev->as[asid].umem->pages);
+	kfree(dev->as[asid].umem);
+	dev->as[asid].umem = NULL;
 	ret = 0;
 unlock:
-	mutex_unlock(&dev->as.mem_lock);
+	mutex_unlock(&dev->as[asid].mem_lock);
 	return ret;
 }
 
 static int vduse_dev_reg_umem(struct vduse_dev *dev,
-			      u64 iova, u64 uaddr, u64 size)
+			      u32 asid, u64 iova, u64 uaddr, u64 size)
 {
 	struct page **page_list = NULL;
 	struct vduse_umem *umem = NULL;
@@ -1162,14 +1225,14 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 	unsigned long npages, lock_limit;
 	int ret;
 
-	if (!dev->as.domain || !dev->as.domain->bounce_map ||
-	    size != dev->as.domain->bounce_size ||
+	if (!dev->as[asid].domain || !dev->as[asid].domain->bounce_map ||
+	    size != dev->as[asid].domain->bounce_size ||
 	    iova != 0 || uaddr & ~PAGE_MASK)
 		return -EINVAL;
 
-	mutex_lock(&dev->as.mem_lock);
+	mutex_lock(&dev->as[asid].mem_lock);
 	ret = -EEXIST;
-	if (dev->as.umem)
+	if (dev->as[asid].umem)
 		goto unlock;
 
 	ret = -ENOMEM;
@@ -1193,7 +1256,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 		goto out;
 	}
 
-	ret = vduse_domain_add_user_bounce_pages(dev->as.domain,
+	ret = vduse_domain_add_user_bounce_pages(dev->as[asid].domain,
 						 page_list, pinned);
 	if (ret)
 		goto out;
@@ -1206,7 +1269,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 	umem->mm = current->mm;
 	mmgrab(current->mm);
 
-	dev->as.umem = umem;
+	dev->as[asid].umem = umem;
 out:
 	if (ret && pinned > 0)
 		unpin_user_pages(page_list, pinned);
@@ -1217,7 +1280,7 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
 		vfree(page_list);
 		kfree(umem);
 	}
-	mutex_unlock(&dev->as.mem_lock);
+	mutex_unlock(&dev->as[asid].mem_lock);
 	return ret;
 }
 
@@ -1249,47 +1312,66 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 
 	switch (cmd) {
 	case VDUSE_IOTLB_GET_FD: {
-		struct vduse_iotlb_entry entry;
+		struct vduse_iotlb_entry_v2 entry;
 		struct vhost_iotlb_map *map;
 		struct vdpa_map_file *map_file;
 		struct file *f = NULL;
+		u32 asid;
 
 		ret = -EFAULT;
-		if (copy_from_user(&entry, argp, sizeof(entry)))
-			break;
+		if (dev->api_version >= VDUSE_API_VERSION_1) {
+			if (copy_from_user(&entry, argp, sizeof(entry)))
+				break;
+		} else {
+			entry.asid = 0;
+			if (copy_from_user(&entry.v1, argp,
+					   sizeof(entry.v1)))
+				break;
+		}
 
 		ret = -EINVAL;
-		if (entry.start > entry.last)
+		if (entry.v1.start > entry.v1.last)
+			break;
+
+		if (entry.asid >= dev->nas)
 			break;
 
 		mutex_lock(&dev->domain_lock);
-		if (!dev->as.domain) {
+		asid = array_index_nospec(entry.asid, dev->nas);
+		if (!dev->as[asid].domain) {
 			mutex_unlock(&dev->domain_lock);
 			break;
 		}
-		spin_lock(&dev->as.domain->iotlb_lock);
-		map = vhost_iotlb_itree_first(dev->as.domain->iotlb,
-					      entry.start, entry.last);
+		spin_lock(&dev->as[asid].domain->iotlb_lock);
+		map = vhost_iotlb_itree_first(dev->as[asid].domain->iotlb,
+					      entry.v1.start, entry.v1.last);
 		if (map) {
 			map_file = (struct vdpa_map_file *)map->opaque;
 			f = get_file(map_file->file);
-			entry.offset = map_file->offset;
-			entry.start = map->start;
-			entry.last = map->last;
-			entry.perm = map->perm;
+			entry.v1.offset = map_file->offset;
+			entry.v1.start = map->start;
+			entry.v1.last = map->last;
+			entry.v1.perm = map->perm;
 		}
-		spin_unlock(&dev->as.domain->iotlb_lock);
+		spin_unlock(&dev->as[asid].domain->iotlb_lock);
 		mutex_unlock(&dev->domain_lock);
 		ret = -EINVAL;
 		if (!f)
 			break;
 
 		ret = -EFAULT;
-		if (copy_to_user(argp, &entry, sizeof(entry))) {
+		if (dev->api_version >= VDUSE_API_VERSION_1)
+			ret = copy_to_user(argp, &entry,
+					   sizeof(entry));
+		else
+			ret = copy_to_user(argp, &entry.v1,
+					   sizeof(entry.v1));
+
+		if (ret) {
 			fput(f);
 			break;
 		}
-		ret = receive_fd(f, NULL, perm_to_file_flags(entry.perm));
+		ret = receive_fd(f, NULL, perm_to_file_flags(entry.v1.perm));
 		fput(f);
 		break;
 	}
@@ -1422,6 +1504,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 	}
 	case VDUSE_IOTLB_REG_UMEM: {
 		struct vduse_iova_umem umem;
+		u32 asid;
 
 		ret = -EFAULT;
 		if (copy_from_user(&umem, argp, sizeof(umem)))
@@ -1429,17 +1512,21 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 
 		ret = -EINVAL;
 		if (!is_mem_zero((const char *)umem.reserved,
-				 sizeof(umem.reserved)))
+				 sizeof(umem.reserved)) ||
+		    (dev->api_version < VDUSE_API_VERSION_1 &&
+		     umem.asid != 0) || umem.asid >= dev->nas)
 			break;
 
 		mutex_lock(&dev->domain_lock);
-		ret = vduse_dev_reg_umem(dev, umem.iova,
+		asid = array_index_nospec(umem.asid, dev->nas);
+		ret = vduse_dev_reg_umem(dev, asid, umem.iova,
 					 umem.uaddr, umem.size);
 		mutex_unlock(&dev->domain_lock);
 		break;
 	}
 	case VDUSE_IOTLB_DEREG_UMEM: {
 		struct vduse_iova_umem umem;
+		u32 asid;
 
 		ret = -EFAULT;
 		if (copy_from_user(&umem, argp, sizeof(umem)))
@@ -1447,10 +1534,15 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 
 		ret = -EINVAL;
 		if (!is_mem_zero((const char *)umem.reserved,
-				 sizeof(umem.reserved)))
+				 sizeof(umem.reserved)) ||
+		    (dev->api_version < VDUSE_API_VERSION_1 &&
+		     umem.asid != 0) ||
+		     umem.asid >= dev->nas)
 			break;
+
 		mutex_lock(&dev->domain_lock);
-		ret = vduse_dev_dereg_umem(dev, umem.iova,
+		asid = array_index_nospec(umem.asid, dev->nas);
+		ret = vduse_dev_dereg_umem(dev, asid, umem.iova,
 					   umem.size);
 		mutex_unlock(&dev->domain_lock);
 		break;
@@ -1458,6 +1550,7 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 	case VDUSE_IOTLB_GET_INFO: {
 		struct vduse_iova_info info;
 		struct vhost_iotlb_map *map;
+		u32 asid;
 
 		ret = -EFAULT;
 		if (copy_from_user(&info, argp, sizeof(info)))
@@ -1471,23 +1564,31 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 				 sizeof(info.reserved)))
 			break;
 
+		if (dev->api_version < VDUSE_API_VERSION_1) {
+			if (info.asid)
+				break;
+		} else if (info.asid >= dev->nas)
+			break;
+
 		mutex_lock(&dev->domain_lock);
-		if (!dev->as.domain) {
+		asid = array_index_nospec(info.asid, dev->nas);
+		if (!dev->as[asid].domain) {
 			mutex_unlock(&dev->domain_lock);
 			break;
 		}
-		spin_lock(&dev->as.domain->iotlb_lock);
-		map = vhost_iotlb_itree_first(dev->as.domain->iotlb,
+		spin_lock(&dev->as[asid].domain->iotlb_lock);
+		map = vhost_iotlb_itree_first(dev->as[asid].domain->iotlb,
 					      info.start, info.last);
 		if (map) {
 			info.start = map->start;
 			info.last = map->last;
 			info.capability = 0;
-			if (dev->as.domain->bounce_map && map->start == 0 &&
-			    map->last == dev->as.domain->bounce_size - 1)
+			if (dev->as[asid].domain->bounce_map &&
+			    map->start == 0 &&
+			    map->last == dev->as[asid].domain->bounce_size - 1)
 				info.capability |= VDUSE_IOVA_CAP_UMEM;
 		}
-		spin_unlock(&dev->as.domain->iotlb_lock);
+		spin_unlock(&dev->as[asid].domain->iotlb_lock);
 		mutex_unlock(&dev->domain_lock);
 		if (!map)
 			break;
@@ -1512,8 +1613,10 @@ static int vduse_dev_release(struct inode *inode, struct file *file)
 	struct vduse_dev *dev = file->private_data;
 
 	mutex_lock(&dev->domain_lock);
-	if (dev->as.domain)
-		vduse_dev_dereg_umem(dev, 0, dev->as.domain->bounce_size);
+	for (int i = 0; i < dev->nas; i++)
+		if (dev->as[i].domain)
+			vduse_dev_dereg_umem(dev, i, 0,
+					     dev->as[i].domain->bounce_size);
 	mutex_unlock(&dev->domain_lock);
 	spin_lock(&dev->msg_lock);
 	/* Make sure the inflight messages can processed after reconncection */
@@ -1732,7 +1835,6 @@ static struct vduse_dev *vduse_dev_create(void)
 		return NULL;
 
 	mutex_init(&dev->lock);
-	mutex_init(&dev->as.mem_lock);
 	mutex_init(&dev->domain_lock);
 	spin_lock_init(&dev->msg_lock);
 	INIT_LIST_HEAD(&dev->send_list);
@@ -1783,8 +1885,11 @@ static int vduse_destroy_dev(char *name)
 	idr_remove(&vduse_idr, dev->minor);
 	kvfree(dev->config);
 	vduse_dev_deinit_vqs(dev);
-	if (dev->as.domain)
-		vduse_domain_destroy(dev->as.domain);
+	for (int i = 0; i < dev->nas; i++) {
+		if (dev->as[i].domain)
+			vduse_domain_destroy(dev->as[i].domain);
+	}
+	kfree(dev->as);
 	kfree(dev->name);
 	kfree(dev->groups);
 	vduse_dev_destroy(dev);
@@ -1831,12 +1936,16 @@ static bool vduse_validate_config(struct vduse_dev_config *config,
 			 sizeof(config->reserved)))
 		return false;
 
-	if (api_version < VDUSE_API_VERSION_1 && config->ngroups)
+	if (api_version < VDUSE_API_VERSION_1 &&
+	    (config->ngroups || config->nas))
 		return false;
 
 	if (api_version >= VDUSE_API_VERSION_1 && config->ngroups > 0xffff)
 		return false;
 
+	if (api_version >= VDUSE_API_VERSION_1 && config->nas > 0xffff)
+		return false;
+
 	if (config->vq_align > PAGE_SIZE)
 		return false;
 
@@ -1900,7 +2009,8 @@ static ssize_t bounce_size_store(struct device *device,
 
 	ret = -EPERM;
 	mutex_lock(&dev->domain_lock);
-	if (dev->as.domain)
+	/* Assuming that if the first domain is allocated, all are allocated */
+	if (dev->as[0].domain)
 		goto unlock;
 
 	ret = kstrtouint(buf, 10, &bounce_size);
@@ -1961,6 +2071,13 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 	for (u32 i = 0; i < dev->ngroups; ++i)
 		dev->groups[i].dev = dev;
 
+	dev->nas = (dev->api_version < 1) ? 1 : (config->nas ?: 1);
+	dev->as = kcalloc(dev->nas, sizeof(dev->as[0]), GFP_KERNEL);
+	if (!dev->as)
+		goto err_as;
+	for (int i = 0; i < dev->nas; i++)
+		mutex_init(&dev->as[i].mem_lock);
+
 	dev->name = kstrdup(config->name, GFP_KERNEL);
 	if (!dev->name)
 		goto err_str;
@@ -1997,6 +2114,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 err_idr:
 	kfree(dev->name);
 err_str:
+	kfree(dev->as);
+err_as:
 	kfree(dev->groups);
 err_vq_groups:
 	vduse_dev_destroy(dev);
@@ -2122,7 +2241,7 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
 
 	vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
 				 &vduse_vdpa_config_ops, &vduse_map_ops,
-				 dev->ngroups, 1, name, true);
+				 dev->ngroups, dev->nas, name, true);
 	if (IS_ERR(vdev))
 		return PTR_ERR(vdev);
 
@@ -2151,11 +2270,20 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 		return ret;
 
 	mutex_lock(&dev->domain_lock);
-	if (!dev->as.domain)
-		dev->as.domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1,
-						  dev->bounce_size);
+	ret = 0;
+
+	for (int i = 0; i < dev->nas; ++i) {
+		dev->as[i].domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1,
+							dev->bounce_size);
+		if (!dev->as[i].domain) {
+			ret = -ENOMEM;
+			for (int j = 0; j < i; ++j)
+				vduse_domain_destroy(dev->as[j].domain);
+		}
+	}
+
 	mutex_unlock(&dev->domain_lock);
-	if (!dev->as.domain) {
+	if (ret == -ENOMEM) {
 		put_device(&dev->vdev->vdpa.dev);
 		return -ENOMEM;
 	}
@@ -2164,8 +2292,12 @@ static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
 	if (ret) {
 		put_device(&dev->vdev->vdpa.dev);
 		mutex_lock(&dev->domain_lock);
-		vduse_domain_destroy(dev->as.domain);
-		dev->as.domain = NULL;
+		for (int i = 0; i < dev->nas; i++) {
+			if (dev->as[i].domain) {
+				vduse_domain_destroy(dev->as[i].domain);
+				dev->as[i].domain = NULL;
+			}
+		}
 		mutex_unlock(&dev->domain_lock);
 		return ret;
 	}
diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index b1c0e47d71fb..54da965a65dc 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -47,7 +47,8 @@ struct vduse_dev_config {
 	__u32 vq_num;
 	__u32 vq_align;
 	__u32 ngroups; /* if VDUSE_API_VERSION >= 1 */
-	__u32 reserved[12];
+	__u32 nas; /* if VDUSE_API_VERSION >= 1 */
+	__u32 reserved[11];
 	__u32 config_size;
 	__u8 config[];
 };
@@ -82,6 +83,18 @@ struct vduse_iotlb_entry {
 	__u8 perm;
 };
 
+/**
+ * struct vduse_iotlb_entry_v2 - entry of IOTLB to describe one IOVA region in an ASID
+ * @v1: the original vduse_iotlb_entry
+ * @asid: address space ID of the IOVA region
+ *
+ * Structure used by VDUSE_IOTLB_GET_FD ioctl to find an overlapped IOVA region.
+ */
+struct vduse_iotlb_entry_v2 {
+	struct vduse_iotlb_entry v1;
+	__u32 asid;
+};
+
 /*
  * Find the first IOVA region that overlaps with the range [start, last]
  * and return the corresponding file descriptor. Return -EINVAL means the
@@ -172,6 +185,16 @@ struct vduse_vq_group {
 	__u32 group;
 };
 
+/**
+ * struct vduse_vq_group - virtqueue group
+ @ @group: Index of the virtqueue group
+ * @asid: Address space ID of the group
+ */
+struct vduse_vq_group_asid {
+	__u32 group;
+	__u32 asid;
+};
+
 /**
  * struct vduse_vq_info - information of a virtqueue
  * @index: virtqueue index
@@ -231,6 +254,7 @@ struct vduse_vq_eventfd {
  * @uaddr: start address of userspace memory, it must be aligned to page size
  * @iova: start of the IOVA region
  * @size: size of the IOVA region
+ * @asid: Address space ID of the IOVA region
  * @reserved: for future use, needs to be initialized to zero
  *
  * Structure used by VDUSE_IOTLB_REG_UMEM and VDUSE_IOTLB_DEREG_UMEM
@@ -240,7 +264,8 @@ struct vduse_iova_umem {
 	__u64 uaddr;
 	__u64 iova;
 	__u64 size;
-	__u64 reserved[3];
+	__u32 asid;
+	__u32 reserved[5];
 };
 
 /* Register userspace memory for IOVA regions */
@@ -254,6 +279,7 @@ struct vduse_iova_umem {
  * @start: start of the IOVA region
  * @last: last of the IOVA region
  * @capability: capability of the IOVA regsion
+ * @asid: Address space ID of the IOVA region, only if device API version >= 1
  * @reserved: for future use, needs to be initialized to zero
  *
  * Structure used by VDUSE_IOTLB_GET_INFO ioctl to get information of
@@ -264,7 +290,8 @@ struct vduse_iova_info {
 	__u64 last;
 #define VDUSE_IOVA_CAP_UMEM (1 << 0)
 	__u64 capability;
-	__u64 reserved[3];
+	__u32 asid; /* Only if device API version >= 1 */
+	__u32 reserved[5];
 };
 
 /*
@@ -287,6 +314,7 @@ enum vduse_req_type {
 	VDUSE_SET_STATUS,
 	VDUSE_UPDATE_IOTLB,
 	VDUSE_GET_VQ_GROUP,
+	VDUSE_SET_VQ_GROUP_ASID,
 };
 
 /**
@@ -321,6 +349,18 @@ struct vduse_iova_range {
 	__u64 last;
 };
 
+/**
+ * struct vduse_iova_range - IOVA range [start, last] if API_VERSION >= 1
+ * @start: start of the IOVA range
+ * @last: last of the IOVA range
+ * @asid: address space ID of the IOVA range
+ */
+struct vduse_iova_range_v2 {
+	__u64 start;
+	__u64 last;
+	__u32 asid;
+};
+
 /**
  * struct vduse_dev_request - control request
  * @type: request type
@@ -330,6 +370,8 @@ struct vduse_iova_range {
  * @s: device status
  * @iova: IOVA range for updating
  * @vq_group: virtqueue group of a virtqueue
+ * @iova_v2: IOVA range for updating if API_VERSION >= 1
+ * @vq_group_asid: ASID of a virtqueue group
  * @padding: padding
  *
  * Structure used by read(2) on /dev/vduse/$NAME.
@@ -342,8 +384,10 @@ struct vduse_dev_request {
 		struct vduse_vq_state vq_state;
 		struct vduse_dev_status s;
 		struct vduse_iova_range iova;
-		/* Only if vduse api version >= 1 */;
+		/* Following members only if vduse api version >= 1 */;
 		struct vduse_vq_group vq_group;
+		struct vduse_iova_range_v2 iova_v2;
+		struct vduse_vq_group_asid vq_group_asid;
 		__u32 padding[32];
 	};
 };
-- 
2.50.1

[RFC v3 7/7] vduse: bump version number

[Eugenio Pérez]

Finalize the series by advertising VDUSE API v1 support to userspace.

Now that all required infrastructure for v1 (ASIDs, VQ groups,
update_iotlb_v2) is in place, VDUSE devices can opt in to the new
features.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index de9550fd1cc8..dbabb1e527bf 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -2143,7 +2143,7 @@ static long vduse_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		ret = -EINVAL;
-		if (api_version > VDUSE_API_VERSION)
+		if (api_version > VDUSE_API_VERSION_1)
 			break;
 
 		ret = 0;
@@ -2210,7 +2210,7 @@ static int vduse_open(struct inode *inode, struct file *file)
 	if (!control)
 		return -ENOMEM;
 
-	control->api_version = VDUSE_API_VERSION;
+	control->api_version = VDUSE_API_VERSION_1;
 	file->private_data = control;
 
 	return 0;
-- 
2.50.1