qemu-options.hx: Update virtfs command documentation

Clarify the virtfs option better
Updates from:Sripathi Kodi <sripathik@in.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

1 files changed, 69 insertions, 50 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index 20fd7b506..518a1f190 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -522,43 +522,61 @@ possible drivers and properties, use @code{-device ?} and
 @code{-device @var{driver},?}.
 ETEXI
 
+DEFHEADING()
+
 DEFHEADING(File system options:)
 
 DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
-    "-fsdev local,id=id,path=path,security_model=[mapped|passthrough|none]\n"
+    "-fsdev fsdriver,id=id,path=path,security_model=[mapped|passthrough|none]\n"
     "       [,writeout=immediate]\n",
     QEMU_ARCH_ALL)
 
 STEXI
 
-The general form of a File system device option is:
-@table @option
-
-@item -fsdev @var{fstype} ,id=@var{id} [,@var{options}]
+@item -fsdev @var{fsdriver},id=@var{id},path=@var{path},security_model=@var{security_model}[,writeout=@var{writeout}]
 @findex -fsdev
-Fstype is one of:
-@option{local},
-The specific Fstype will determine the applicable options.
-
-Options to each backend are described below.
-
-@item -fsdev local ,id=@var{id} ,path=@var{path} ,security_model=@var{security_model}[,writeout=@var{writeout}]
-
-Create a file-system-"device" for local-filesystem.
-
-@option{local} is only available on Linux.
-
-@option{path} specifies the path to be exported. @option{path} is required.
-
-@option{security_model} specifies the security model to be followed.
-@option{security_model} is required.
-
-@option{writeout} specifies whether to skip the host page cache.
-@option{writeout} is an optional argument.
+Define a new file system device. Valid options are:
+@table @option
+@item @var{fsdriver}
+This option specifies the fs driver backend to use.
+Currently "local" and "handle" file system drivers are supported.
+@item id=@var{id}
+Specifies identifier for this device
+@item path=@var{path}
+Specifies the export path for the file system device. Files under
+this path will be available to the 9p client on the guest.
+@item security_model=@var{security_model}
+Specifies the security model to be used for this export path.
+Supported security models are "passthrough", "mapped" and "none".
+In "passthrough" security model, files are stored using the same
+credentials as they are created on the guest. This requires qemu
+to run as root. In "mapped" security model, some of the file
+attributes like uid, gid, mode bits and link target are stored as
+file attributes. Directories exported by this security model cannot
+interact with other unix tools. "none" security model is same as
+passthrough except the sever won't report failures if it fails to
+set file attributes like ownership.
+@item writeout=@var{writeout}
+This is an optional argument. The only supported value is "immediate".
+This means that host page cache will be used to read and write data but
+write notification will be sent to the guest only when the data has been
+reported as written by the storage subsystem.
+@end table
 
+-fsdev option is used along with -device driver "virtio-9p-pci".
+@item -device virtio-9p-pci,fsdev=@var{id},mount_tag=@var{mount_tag}
+Options for virtio-9p-pci driver are:
+@table @option
+@item fsdev=@var{id}
+Specifies the id value specified along with -fsdev option
+@item mount_tag=@var{mount_tag}
+Specifies the tag name to be used by the guest to mount this export point
 @end table
+
 ETEXI
 
+DEFHEADING()
+
 DEFHEADING(Virtual File system pass-through options:)
 
 DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
@@ -568,34 +586,35 @@ DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
 
 STEXI
 
-The general form of a Virtual File system pass-through option is:
-@table @option
-
-@item -virtfs @var{fstype} [,@var{options}]
+@item -virtfs @var{fsdriver},path=@var{path},mount_tag=@var{mount_tag},security_model=@var{security_model}[,writeout=@var{writeout}]
 @findex -virtfs
-Fstype is one of:
-@option{local},
-The specific Fstype will determine the applicable options.
-
-Options to each backend are described below.
-
-@item -virtfs local ,path=@var{path} ,mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}]
-
-Create a Virtual file-system-pass through for local-filesystem.
-
-@option{local} is only available on Linux.
-
-@option{path} specifies the path to be exported. @option{path} is required.
-
-@option{security_model} specifies the security model to be followed.
-@option{security_model} is required.
-
-@option{mount_tag} specifies the tag with which the exported file is mounted.
-@option{mount_tag} is required.
-
-@option{writeout} specifies whether to skip the host page cache.
-@option{writeout} is an optional argument.
 
+The general form of a Virtual File system pass-through options are:
+@table @option
+@item @var{fsdriver}
+This option specifies the fs driver backend to use.
+Currently "local" and "handle" file system drivers are supported.
+@item id=@var{id}
+Specifies identifier for this device
+@item path=@var{path}
+Specifies the export path for the file system device. Files under
+this path will be available to the 9p client on the guest.
+@item security_model=@var{security_model}
+Specifies the security model to be used for this export path.
+Supported security models are "passthrough", "mapped" and "none".
+In "passthrough" security model, files are stored using the same
+credentials as they are created on the guest. This requires qemu
+to run as root. In "mapped" security model, some of the file
+attributes like uid, gid, mode bits and link target are stored as
+file attributes. Directories exported by this security model cannot
+interact with other unix tools. "none" security model is same as
+passthrough except the sever won't report failures if it fails to
+set file attributes like ownership.
+@item writeout=@var{writeout}
+This is an optional argument. The only supported value is "immediate".
+This means that host page cache will be used to read and write data but
+write notification will be sent to the guest only when the data has been
+reported as written by the storage subsystem.
 @end table
 ETEXI