vdpa: multiple address spaces support

This patches introduces the multiple address spaces support for vDPA
device. This idea is to identify a specific address space via an
dedicated identifier - ASID.

During vDPA device allocation, vDPA device driver needs to report the
number of address spaces supported by the device then the DMA mapping
ops of the vDPA device needs to be extended to support ASID.

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

As a start, simply claim 1 virtqueue groups and 1 address spaces for
all vDPA devices. And vhost-vDPA will simply reject the device with
more than 1 virtqueue groups or address spaces.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-7-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index e4e53574183e..1515748e84ff 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -69,6 +69,8 @@ struct vdpa_mgmt_dev;
  * @cf_lock: Protects get and set access to configuration layout.
  * @index: device index
  * @features_valid: were features initialized? for legacy guests
+ * @ngroups: the number of virtqueue groups
+ * @nas: the number of address spaces
  * @use_va: indicate whether virtual address must be used by this device
  * @nvqs: maximum number of supported virtqueues
  * @mdev: management device pointer; caller must setup when registering device as part
@@ -86,6 +88,7 @@ struct vdpa_device {
 	u32 nvqs;
 	struct vdpa_mgmt_dev *mdev;
 	unsigned int ngroups;
+	unsigned int nas;
 };
 
 /**
@@ -241,6 +244,7 @@ struct vdpa_map_file {
  *				Needed for device that using device
  *				specific DMA translation (on-chip IOMMU)
  *				@vdev: vdpa device
+ *				@asid: address space identifier
  *				@iotlb: vhost memory mapping to be
  *				used by the vDPA
  *				Returns integer: success (0) or error (< 0)
@@ -249,6 +253,7 @@ struct vdpa_map_file {
  *				specific DMA translation (on-chip IOMMU)
  *				and preferring incremental map.
  *				@vdev: vdpa device
+ *				@asid: address space identifier
  *				@iova: iova to be mapped
  *				@size: size of the area
  *				@pa: physical address for the map
@@ -260,6 +265,7 @@ struct vdpa_map_file {
  *				specific DMA translation (on-chip IOMMU)
  *				and preferring incremental unmap.
  *				@vdev: vdpa device
+ *				@asid: address space identifier
  *				@iova: iova to be unmapped
  *				@size: size of the area
  *				Returns integer: success (0) or error (< 0)
@@ -313,10 +319,12 @@ struct vdpa_config_ops {
 	struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
 
 	/* DMA ops */
-	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
-	int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
-		       u64 pa, u32 perm, void *opaque);
-	int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
+	int (*set_map)(struct vdpa_device *vdev, unsigned int asid,
+		       struct vhost_iotlb *iotlb);
+	int (*dma_map)(struct vdpa_device *vdev, unsigned int asid,
+		       u64 iova, u64 size, u64 pa, u32 perm, void *opaque);
+	int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
+			 u64 iova, u64 size);
 
 	/* Free device resources */
 	void (*free)(struct vdpa_device *vdev);
@@ -324,7 +332,7 @@ struct vdpa_config_ops {
 
 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 					const struct vdpa_config_ops *config,
-					unsigned int ngroups,
+					unsigned int ngroups, unsigned int nas,
 					size_t size, const char *name,
 					bool use_va);
 
@@ -336,17 +344,19 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
  * @parent: the parent device
  * @config: the bus operations that is supported by this device
  * @ngroups: the number of virtqueue groups supported by this device
+ * @nas: the number of address spaces
  * @name: name of the vdpa device
  * @use_va: indicate whether virtual address must be used by this device
  *
  * Return allocated data structure or ERR_PTR upon error
  */
-#define vdpa_alloc_device(dev_struct, member, parent, config, ngroups, name, use_va)   \
+#define vdpa_alloc_device(dev_struct, member, parent, config, ngroups, nas, \
+			  name, use_va) \
 			  container_of((__vdpa_alloc_device( \
-				       parent, config, ngroups, \
-				       sizeof(dev_struct) + \
+				       parent, config, ngroups, nas, \
+				       (sizeof(dev_struct) + \
 				       BUILD_BUG_ON_ZERO(offsetof( \
-				       dev_struct, member)), name, use_va)), \
+				       dev_struct, member))), name, use_va)), \
 				       dev_struct, member)
 
 int vdpa_register_device(struct vdpa_device *vdev, u32 nvqs);