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

Pull virtio updates from Michael Tsirkin:

 - vhost can now support legacy threading if enabled in Kconfig

 - vsock memory allocation strategies for large buffers have been
   improved, reducing pressure on kmalloc

 - vhost now supports the in-order feature. guest bits missed the merge
   window.

 - fixes, cleanups all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (30 commits)
  vsock/virtio: Allocate nonlinear SKBs for handling large transmit buffers
  vsock/virtio: Rename virtio_vsock_skb_rx_put()
  vhost/vsock: Allocate nonlinear SKBs for handling large receive buffers
  vsock/virtio: Move SKB allocation lower-bound check to callers
  vsock/virtio: Rename virtio_vsock_alloc_skb()
  vsock/virtio: Resize receive buffers so that each SKB fits in a 4K page
  vsock/virtio: Move length check to callers of virtio_vsock_skb_rx_put()
  vsock/virtio: Validate length in packet header before skb_put()
  vhost/vsock: Avoid allocating arbitrarily-sized SKBs
  vhost_net: basic in_order support
  vhost: basic in order support
  vhost: fail early when __vhost_add_used() fails
  vhost: Reintroduce kthread API and add mode selection
  vdpa: Fix IDR memory leak in VDUSE module exit
  vdpa/mlx5: Fix release of uninitialized resources on error path
  vhost-scsi: Fix check for inline_sg_cnt exceeding preallocated limit
  virtio: virtio_dma_buf: fix missing parameter documentation
  vhost: Fix typos
  vhost: vringh: Remove unused functions
  vhost: vringh: Remove unused iotlb functions
  ...

1 files changed, 28 insertions, 0 deletions

diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index d6ad01fbb8d2..283348b64af9 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -242,4 +242,32 @@
 #define VHOST_SET_FEATURES_ARRAY _IOW(VHOST_VIRTIO, 0x83, \
 				       struct vhost_features_array)
 
+/* fork_owner values for vhost */
+#define VHOST_FORK_OWNER_KTHREAD 0
+#define VHOST_FORK_OWNER_TASK 1
+
+/**
+ * VHOST_SET_FORK_FROM_OWNER - Set the fork_owner flag for the vhost device,
+ * This ioctl must called before VHOST_SET_OWNER.
+ * Only available when CONFIG_VHOST_ENABLE_FORK_OWNER_CONTROL=y
+ *
+ * @param fork_owner: An 8-bit value that determines the vhost thread mode
+ *
+ * When fork_owner is set to VHOST_FORK_OWNER_TASK(default value):
+ *   - Vhost will create vhost worker as tasks forked from the owner,
+ *     inheriting all of the owner's attributes.
+ *
+ * When fork_owner is set to VHOST_FORK_OWNER_KTHREAD:
+ *   - Vhost will create vhost workers as kernel threads.
+ */
+#define VHOST_SET_FORK_FROM_OWNER _IOW(VHOST_VIRTIO, 0x83, __u8)
+
+/**
+ * VHOST_GET_FORK_OWNER - Get the current fork_owner flag for the vhost device.
+ * Only available when CONFIG_VHOST_ENABLE_FORK_OWNER_CONTROL=y
+ *
+ * @return: An 8-bit value indicating the current thread mode.
+ */
+#define VHOST_GET_FORK_FROM_OWNER _IOR(VHOST_VIRTIO, 0x84, __u8)
+
 #endif