virtio-9p: Create a syntactic shortcut for the file-system pass-thru

Currently the commandline to create a virtual-filesystem pass-through between
the guest and the host is as follows:
#qemu -fsdev fstype,id=ID,path=path/to/share \
      -device virtio-9p-pci,fsdev=ID,mount_tag=tag \

This patch provides a syntactic short-cut to achieve the same as follows:
#qemu -virtfs fstype,path=path/to/share,mount_tag=tag

This will be internally expanded as:
#qemu -fsdev fstype,id=tag,path=path/to/share, \
      -device virtio-9p-pci,fsdev=tag,mount_tag=tag \

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/qemu-options.hx b/qemu-options.hx
index e754ba116b..12f6b5179d 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -510,6 +510,41 @@ Create a file-system-"device" for local-filesystem.
 ETEXI
 #endif
 
+#ifdef CONFIG_LINUX
+DEFHEADING(Virtual File system pass-through options:)
+
+DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
+    "-virtfs local,path=path,mount_tag=tag\n",
+    QEMU_ARCH_ALL)
+
+STEXI
+
+The general form of a Virtual File system pass-through option is:
+@table @option
+
+@item -virtfs @var{fstype} [,@var{options}]
+@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}
+
+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{mount_tag} specifies the tag with which the exported file is mounted.
+@option{mount_tag} is required.
+
+@end table
+ETEXI
+#endif
+
 DEFHEADING()
 
 DEF("name", HAS_ARG, QEMU_OPTION_name,