Merge tag 'virtio-fs-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse virtio-fs support from Miklos Szeredi:
 "Virtio-fs allows exporting directory trees on the host and mounting
  them in guest(s).

  This isn't actually a new filesystem, but a glue layer between the
  fuse filesystem and a virtio based back-end.

  It's similar in functionality to the existing virtio-9p solution, but
  significantly faster in benchmarks and has better POSIX compliance.
  Further permformance improvements can be achieved by sharing the page
  cache between host and guest, allowing for faster I/O and reduced
  memory use.

  Kata Containers have been including the out-of-tree virtio-fs (with
  the shared page cache patches as well) since version 1.7 as an
  experimental feature. They have been active in development and plan to
  switch from virtio-9p to virtio-fs as their default solution. There
  has been interest from other sources as well.

  The userspace infrastructure is slated to be merged into qemu once the
  kernel part hits mainline.

  This was developed by Vivek Goyal, Dave Gilbert and Stefan Hajnoczi"

* tag 'virtio-fs-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  virtio-fs: add virtiofs filesystem
  virtio-fs: add Documentation/filesystems/virtiofs.rst
  fuse: reserve values for mapping protocol

3 files changed, 27 insertions, 1 deletions

diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
index df2e12fb3381..802b0377a49e 100644
--- a/include/uapi/linux/fuse.h
+++ b/include/uapi/linux/fuse.h
@@ -133,6 +133,8 @@
  *
  *  7.31
  *  - add FUSE_WRITE_KILL_PRIV flag
+ *  - add FUSE_SETUPMAPPING and FUSE_REMOVEMAPPING
+ *  - add map_alignment to fuse_init_out, add FUSE_MAP_ALIGNMENT flag
  */
 
 #ifndef _LINUX_FUSE_H
@@ -274,6 +276,7 @@ struct fuse_file_lock {
  * FUSE_CACHE_SYMLINKS: cache READLINK responses
  * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
  * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
+ * FUSE_MAP_ALIGNMENT: map_alignment field is valid
  */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -301,6 +304,7 @@ struct fuse_file_lock {
 #define FUSE_CACHE_SYMLINKS	(1 << 23)
 #define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
 #define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
+#define FUSE_MAP_ALIGNMENT	(1 << 26)
 
 /**
  * CUSE INIT request/reply flags
@@ -422,6 +426,8 @@ enum fuse_opcode {
 	FUSE_RENAME2		= 45,
 	FUSE_LSEEK		= 46,
 	FUSE_COPY_FILE_RANGE	= 47,
+	FUSE_SETUPMAPPING	= 48,
+	FUSE_REMOVEMAPPING	= 49,
 
 	/* CUSE specific operations */
 	CUSE_INIT		= 4096,
@@ -656,7 +662,7 @@ struct fuse_init_out {
 	uint32_t	max_write;
 	uint32_t	time_gran;
 	uint16_t	max_pages;
-	uint16_t	padding;
+	uint16_t	map_alignment;
 	uint32_t	unused[8];
 };
 
diff --git a/include/uapi/linux/virtio_fs.h b/include/uapi/linux/virtio_fs.h
new file mode 100644
index 000000000000..b02eb2ac3d99
--- /dev/null
+++ b/include/uapi/linux/virtio_fs.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+
+#ifndef _UAPI_LINUX_VIRTIO_FS_H
+#define _UAPI_LINUX_VIRTIO_FS_H
+
+#include <linux/types.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_types.h>
+
+struct virtio_fs_config {
+	/* Filesystem name (UTF-8, not NUL-terminated, padded with NULs) */
+	__u8 tag[36];
+
+	/* Number of request queues */
+	__u32 num_request_queues;
+} __attribute__((packed));
+
+#endif /* _UAPI_LINUX_VIRTIO_FS_H */
diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h
index 348fd0176f75..585e07b27333 100644
--- a/include/uapi/linux/virtio_ids.h
+++ b/include/uapi/linux/virtio_ids.h
@@ -44,6 +44,7 @@
 #define VIRTIO_ID_VSOCK        19 /* virtio vsock transport */
 #define VIRTIO_ID_CRYPTO       20 /* virtio crypto */
 #define VIRTIO_ID_IOMMU        23 /* virtio IOMMU */
+#define VIRTIO_ID_FS           26 /* virtio filesystem */
 #define VIRTIO_ID_PMEM         27 /* virtio pmem */
 
 #endif /* _LINUX_VIRTIO_IDS_H */