Re: [Qemu-devel] [PATCH v2 2/2] virtfs: Fix documentation of -fsdev and -virtfs

[Greg Kurz]

On Mon, 13 May 2019 12:34:10 +0200
Greg Kurz <address@hidden> wrote:

> This fixes several things:
> - add "id" description to -virtfs documentation
> - split the description into several lines in both usage and documentation
>   for accurateness and clarity
> - add documentation and usage of the synth fsdriver
> - add "throttling.*" description to -fsdev local
> - add some missing periods
> - add proper reference to the virtfs-proxy-helper(1) manual page
> - document that the virtio device may be either virtio-9p-pci, virtio-9p-ccw
>   or virtio-9p-device, depending on the machine type
> 
> Buglink: https://bugs.launchpad.net/qemu/+bug/1581976
> Signed-off-by: Greg Kurz <address@hidden>
> ---
> v2: - mention virtfs-proxy-helper(1) change in the changelog
>     - mention virtio-9p-ccw and virtio-9p-device
> ---

Thomas,

Unless you (or anyone else) have some objections, I intend to apply this patch
and issue a pull request in a near future.

Cheers,

--
Greg

>  qemu-options.hx |   93 
> +++++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 66 insertions(+), 27 deletions(-)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 03c50ba0f0b2..fa705b63b157 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -1232,26 +1232,35 @@ the write back by pressing @key{C-a s} 
> (@pxref{disk_images}).
>  ETEXI
>  
>  DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
> -    "-fsdev 
> fsdriver,id=id[,path=path,][security_model={mapped-xattr|mapped-file|passthrough|none}]\n"
> -    " 
> [,writeout=immediate][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n"
> +    "-fsdev 
> local,id=id,path=path,security_model=mapped-xattr|mapped-file|passthrough|none\n"
> +    " [,writeout=immediate][,readonly][,fmode=fmode][,dmode=dmode]\n"
>      " 
> [[,throttling.bps-total=b]|[[,throttling.bps-read=r][,throttling.bps-write=w]]]\n"
>      " 
> [[,throttling.iops-total=i]|[[,throttling.iops-read=r][,throttling.iops-write=w]]]\n"
>      " 
> [[,throttling.bps-total-max=bm]|[[,throttling.bps-read-max=rm][,throttling.bps-write-max=wm]]]\n"
>      " 
> [[,throttling.iops-total-max=im]|[[,throttling.iops-read-max=irm][,throttling.iops-write-max=iwm]]]\n"
> -    " [[,throttling.iops-size=is]]\n",
> +    " [[,throttling.iops-size=is]]\n"
> +    "-fsdev proxy,id=id,socket=socket[,writeout=immediate][,readonly]\n"
> +    "-fsdev proxy,id=id,sock_fd=sock_fd[,writeout=immediate][,readonly]\n"
> +    "-fsdev synth,id=id\n",
>      QEMU_ARCH_ALL)
>  
>  STEXI
>  
> address@hidden -fsdev 
> @var{fsdriver},address@hidden,address@hidden,address@hidden,address@hidden,readonly][,address@hidden|address@hidden,address@hidden,address@hidden
> address@hidden -fsdev local,address@hidden,address@hidden,address@hidden 
> [,address@hidden,readonly][,address@hidden,address@hidden 
> [,address@hidden@var{value}[,address@hidden@var{value}[,...]]]
> address@hidden -fsdev 
> proxy,address@hidden,address@hidden,address@hidden,readonly]
> address@hidden -fsdev 
> proxy,address@hidden,address@hidden,address@hidden,readonly]
> address@hidden -fsdev synth,address@hidden,readonly]
>  @findex -fsdev
>  Define a new file system device. Valid options are:
>  @table @option
> address@hidden @var{fsdriver}
> -This option specifies the fs driver backend to use.
> -Currently "local" and "proxy" file system drivers are supported.
> address@hidden local
> +Accesses to the filesystem are done by QEMU.
> address@hidden proxy
> +Accesses to the filesystem are done by virtfs-proxy-helper(1).
> address@hidden synth
> +Synthetic filesystem, only used by QTests.
>  @item address@hidden
> -Specifies identifier for this device
> +Specifies identifier for this device.
>  @item address@hidden
>  Specifies the export path for the file system device. Files under
>  this path will be available to the 9p client on the guest.
> @@ -1279,48 +1288,76 @@ Enables exporting 9p share as a readonly mount for 
> guests. By default
>  read-write access is given.
>  @item address@hidden
>  Enables proxy filesystem driver to use passed socket file for communicating
> -with virtfs-proxy-helper
> +with virtfs-proxy-helper(1).
>  @item address@hidden
>  Enables proxy filesystem driver to use passed socket descriptor for
> -communicating with virtfs-proxy-helper. Usually a helper like libvirt
> -will create socketpair and pass one of the fds as sock_fd
> +communicating with virtfs-proxy-helper(1). Usually a helper like libvirt
> +will create socketpair and pass one of the fds as sock_fd.
>  @item address@hidden
>  Specifies the default mode for newly created files on the host. Works only
>  with security models "mapped-xattr" and "mapped-file".
>  @item address@hidden
>  Specifies the default mode for newly created directories on the host. Works
>  only with security models "mapped-xattr" and "mapped-file".
> address@hidden address@hidden,address@hidden,address@hidden
> +Specify bandwidth throttling limits in bytes per second, either for all 
> request
> +types or for reads or writes only.
> address@hidden address@hidden,address@hidden,address@hidden
> +Specify bursts in bytes per second, either for all request types or for reads
> +or writes only.  Bursts allow the guest I/O to spike above the limit
> +temporarily.
> address@hidden address@hidden,address@hidden, address@hidden
> +Specify request rate limits in requests per second, either for all request
> +types or for reads or writes only.
> address@hidden address@hidden,address@hidden, address@hidden
> +Specify bursts in requests per second, either for all request types or for 
> reads
> +or writes only.  Bursts allow the guest I/O to spike above the limit 
> temporarily.
> address@hidden address@hidden
> +Let every @var{is} bytes of a request count as a new request for iops
> +throttling purposes.
>  @end table
>  
> --fsdev option is used along with -device driver "virtio-9p-pci".
> address@hidden -device virtio-9p-pci,address@hidden,address@hidden
> -Options for virtio-9p-pci driver are:
> +-fsdev option is used along with -device driver "virtio-9p-...".
> address@hidden -device address@hidden,address@hidden,address@hidden
> +Options for virtio-9p-... driver are:
>  @table @option
> address@hidden @var{type}
> +Specifies the variant to be used. Supported values are "pci", "ccw" or 
> "device",
> +depending on the machine type.
>  @item address@hidden
> -Specifies the id value specified along with -fsdev option
> +Specifies the id value specified along with -fsdev option.
>  @item address@hidden
> -Specifies the tag name to be used by the guest to mount this export point
> +Specifies the tag name to be used by the guest to mount this export point.
>  @end table
>  
>  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][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]\n",
> +    "-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"
> +    "-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",
>      QEMU_ARCH_ALL)
>  
>  STEXI
>  
> address@hidden -virtfs 
> @var{fsdriver}[,address@hidden,address@hidden,address@hidden,address@hidden,readonly][,address@hidden|address@hidden,address@hidden,address@hidden
> address@hidden -virtfs local,address@hidden,address@hidden 
> ,address@hidden,address@hidden,readonly] [,address@hidden,address@hidden
> address@hidden -virtfs proxy,address@hidden,address@hidden 
> [,address@hidden,readonly]
> address@hidden -virtfs proxy,address@hidden,address@hidden 
> [,address@hidden,readonly]
> address@hidden -virtfs synth,address@hidden
>  @findex -virtfs
>  
> -The general form of a Virtual File system pass-through options are:
> +Define a new filesystem device and expose it to the guest using a 
> virtio-9p-device. The general form of a Virtual File system pass-through 
> options are:
>  @table @option
> address@hidden @var{fsdriver}
> -This option specifies the fs driver backend to use.
> -Currently "local" and "proxy" file system drivers are supported.
> address@hidden local
> +Accesses to the filesystem are done by QEMU.
> address@hidden proxy
> +Accesses to the filesystem are done by virtfs-proxy-helper(1).
> address@hidden synth
> +Synthetic filesystem, only used by QTests.
>  @item address@hidden
> -Specifies identifier for this device
> +Specifies identifier for the filesystem device
>  @item address@hidden
>  Specifies the export path for the file system device. Files under
>  this path will be available to the 9p client on the guest.
> @@ -1348,17 +1385,19 @@ Enables exporting 9p share as a readonly mount for 
> guests. By default
>  read-write access is given.
>  @item address@hidden
>  Enables proxy filesystem driver to use passed socket file for
> -communicating with virtfs-proxy-helper. Usually a helper like libvirt
> -will create socketpair and pass one of the fds as sock_fd
> +communicating with virtfs-proxy-helper(1). Usually a helper like libvirt
> +will create socketpair and pass one of the fds as sock_fd.
>  @item sock_fd
>  Enables proxy filesystem driver to use passed 'sock_fd' as the socket
> -descriptor for interfacing with virtfs-proxy-helper
> +descriptor for interfacing with virtfs-proxy-helper(1).
>  @item address@hidden
>  Specifies the default mode for newly created files on the host. Works only
>  with security models "mapped-xattr" and "mapped-file".
>  @item address@hidden
>  Specifies the default mode for newly created directories on the host. Works
>  only with security models "mapped-xattr" and "mapped-file".
> address@hidden address@hidden
> +Specifies the tag name to be used by the guest to mount this export point.
>  @end table
>  ETEXI
>  
>