Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:

 - in-order support in virtio core

 - multiple address space support in vduse

 - fixes, cleanups all over the place, notably dma alignment fixes for
   non-cache-coherent systems

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (59 commits)
  vduse: avoid adding implicit padding
  vhost: fix caching attributes of MMIO regions by setting them explicitly
  vdpa/mlx5: update MAC address handling in mlx5_vdpa_set_attr()
  vdpa/mlx5: reuse common function for MAC address updates
  vdpa/mlx5: update mlx_features with driver state check
  crypto: virtio: Replace package id with numa node id
  crypto: virtio: Remove duplicated virtqueue_kick in virtio_crypto_skcipher_crypt_req
  crypto: virtio: Add spinlock protection with virtqueue notification
  Documentation: Add documentation for VDUSE Address Space IDs
  vduse: bump version number
  vduse: add vq group asid support
  vduse: merge tree search logic of IOTLB_GET_FD and IOTLB_GET_INFO ioctls
  vduse: take out allocations from vduse_dev_alloc_coherent
  vduse: remove unused vaddr parameter of vduse_domain_free_coherent
  vduse: refactor vdpa_dev_add for goto err handling
  vhost: forbid change vq groups ASID if DRIVER_OK is set
  vdpa: document set_group_asid thread safety
  vduse: return internal vq group struct as map token
  vduse: add vq group support
  vduse: add v1 API definition
  ...

1 files changed, 53 insertions, 0 deletions

diff --git a/Documentation/userspace-api/vduse.rst b/Documentation/userspace-api/vduse.rst
index bdb880e01132..81479d47c8b9 100644
--- a/Documentation/userspace-api/vduse.rst
+++ b/Documentation/userspace-api/vduse.rst
@@ -230,4 +230,57 @@ able to start the dataplane processing as follows:
 5. Inject an interrupt for specific virtqueue with the VDUSE_INJECT_VQ_IRQ ioctl
    after the used ring is filled.
 
+Enabling ASID (API version 1)
+------------------------------
+
+VDUSE supports per-address-space identifiers (ASIDs) starting with API
+version 1. Set it up with ioctl(VDUSE_SET_API_VERSION) on `/dev/vduse/control`
+and pass `VDUSE_API_VERSION_1` before creating a new VDUSE instance with
+ioctl(VDUSE_CREATE_DEV).
+
+Afterwards, you can use the member asid of ioctl(VDUSE_VQ_SETUP) argument to
+select the address space of the IOTLB you are querying.  The driver could
+change the address space of any virtqueue group by using the
+VDUSE_SET_VQ_GROUP_ASID VDUSE message type, and the VDUSE instance needs to
+reply with VDUSE_REQ_RESULT_OK if it was possible to change it.
+
+Similarly, you can use ioctl(VDUSE_IOTLB_GET_FD2) to obtain the file descriptor
+describing an IOVA region of a specific ASID. Example usage:
+
+.. code-block:: c
+
+	static void *iova_to_va(int dev_fd, uint32_t asid, uint64_t iova,
+	                        uint64_t *len)
+	{
+		int fd;
+		void *addr;
+		size_t size;
+		struct vduse_iotlb_entry_v2 entry = { 0 };
+
+		entry.v1.start = iova;
+		entry.v1.last = iova;
+		entry.asid = asid;
+
+		fd = ioctl(dev_fd, VDUSE_IOTLB_GET_FD2, &entry);
+		if (fd < 0)
+			return NULL;
+
+		size = entry.v1.last - entry.v1.start + 1;
+		*len = entry.v1.last - iova + 1;
+		addr = mmap(0, size, perm_to_prot(entry.v1.perm), MAP_SHARED,
+			    fd, entry.v1.offset);
+		close(fd);
+		if (addr == MAP_FAILED)
+			return NULL;
+
+		/*
+		 * Using some data structures such as linked list to store
+		 * the iotlb mapping. The munmap(2) should be called for the
+		 * cached mapping when the corresponding VDUSE_UPDATE_IOTLB
+		 * message is received or the device is reset.
+		 */
+
+		return addr + iova - entry.v1.start;
+	}
+
 For more details on the uAPI, please see include/uapi/linux/vduse.h.