diff options
Diffstat (limited to 'qemu-options.hx')
| -rw-r--r-- | qemu-options.hx | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/qemu-options.hx b/qemu-options.hx index 2a04ca6ac5..793d70ff93 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1339,7 +1339,7 @@ ETEXI DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, "-virtfs local,path=path,mount_tag=tag,security_model=mapped-xattr|mapped-file|passthrough|none\n" - " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n" + " [,id=id][,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode][,multidevs=remap|forbid|warn]\n" "-virtfs proxy,mount_tag=tag,socket=socket[,id=id][,writeout=immediate][,readonly]\n" "-virtfs proxy,mount_tag=tag,sock_fd=sock_fd[,id=id][,writeout=immediate][,readonly]\n" "-virtfs synth,mount_tag=tag[,id=id][,readonly]\n", @@ -1347,7 +1347,7 @@ DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs, STEXI -@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}] +@item -virtfs local,path=@var{path},mount_tag=@var{mount_tag} ,security_model=@var{security_model}[,writeout=@var{writeout}][,readonly] [,fmode=@var{fmode}][,dmode=@var{dmode}][,multidevs=@var{multidevs}] @itemx -virtfs proxy,socket=@var{socket},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] @itemx -virtfs proxy,sock_fd=@var{sock_fd},mount_tag=@var{mount_tag} [,writeout=@var{writeout}][,readonly] @itemx -virtfs synth,mount_tag=@var{mount_tag} @@ -1403,6 +1403,28 @@ Specifies the default mode for newly created directories on the host. Works only with security models "mapped-xattr" and "mapped-file". @item mount_tag=@var{mount_tag} Specifies the tag name to be used by the guest to mount this export point. +@item multidevs=@var{multidevs} +Specifies how to deal with multiple devices being shared with a 9p export. +Supported behaviours are either "remap", "forbid" or "warn". The latter is +the default behaviour on which virtfs 9p expects only one device to be +shared with the same export, and if more than one device is shared and +accessed via the same 9p export then only a warning message is logged +(once) by qemu on host side. In order to avoid file ID collisions on guest +you should either create a separate virtfs export for each device to be +shared with guests (recommended way) or you might use "remap" instead which +allows you to share multiple devices with only one export instead, which is +achieved by remapping the original inode numbers from host to guest in a +way that would prevent such collisions. Remapping inodes in such use cases +is required because the original device IDs from host are never passed and +exposed on guest. Instead all files of an export shared with virtfs always +share the same device id on guest. So two files with identical inode +numbers but from actually different devices on host would otherwise cause a +file ID collision and hence potential misbehaviours on guest. "forbid" on +the other hand assumes like "warn" that only one device is shared by the +same export, however it will not only log a warning message but also +deny access to additional devices on guest. Note though that "forbid" does +currently not block all possible file access operations (e.g. readdir() +would still return entries from other devices). @end table ETEXI |