On 09/22/2016 10:42 AM, Kevin Wolf wrote:
> This adds documentation for the -blockdev options that apply to all
> nodes independent of the block driver used.
> 
> All options that are shared by -blockdev and -drive are now explained in
> the section for -blockdev. The documentation of -drive mentions that all
> -blockdev options are accepted as well.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  qemu-options.hx | 98 ++++++++++++++++++++++++++++++++++++++++-----------------
>  1 file changed, 69 insertions(+), 29 deletions(-)
> 

>  @item cache=@var{cache}
> -@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data.
> +@var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough"
> +and controls how the host cache is used to access block data. This is a
> +shortcut that sets the @option{cache.direct} and @option{cache.no-flush}
> +options (as in @option{-blockdev}), and additionally @option{cache.writeback},
> +which provides a default for the @option{write-cache} option of block guest
> +devices (as in @option{-device}). The modes correspond to the following
> +settings:
> +
> +@c Our texi2pod.pl script doesn't support @multitable, so fall back to using
> +@c plain ASCII art (well, UTF-8 art really). This looks okay both in the manpage
> +@c and the HTML output.
> +@example
> +@             │ cache.writeback   cache.direct   cache.no-flush
> +─────────────┼─────────────────────────────────────────────────
> +writeback    │ on                off            off
> +none         │ on                on             off
> +writethrough │ off               off            off
> +directsync   │ off               on             off
> +unsafe       │ on                off            on
> +@end example

Nice table.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org