Re: [Qemu-devel] [PATCH for-2.10] qemu-options: Document the -drive locking parameter.

From: "Richard W.M. Jones" <rjones@redhat.com>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: kwolf@redhat.com, famz@redhat.com, qemu-trivial@nongnu.org,
	mjt@tls.msk.ru, qemu-devel@nongnu.org, armbru@redhat.com
Subject: Re: [Qemu-devel] [PATCH for-2.10] qemu-options: Document the -drive locking parameter.
Date: Wed, 6 Sep 2017 10:04:24 +0100	[thread overview]
Message-ID: <20170906090424.GA18719@redhat.com> (raw)
In-Reply-To: <20170906085902.GH15510@redhat.com>

On Wed, Sep 06, 2017 at 09:59:02AM +0100, Daniel P. Berrange wrote:
> The 2.10 versio nis already released. Did you mean that you wanted
> this in the stable branch ?  If so, then CC qemu-stable@nongnu.org
> 
> On Wed, Sep 06, 2017 at 09:50:06AM +0100, Richard W.M. Jones wrote:
> > Commit 16b48d5d66d2 ("file-posix: Add 'locking' option") added this
> > option, but as it was not documented in the -help output it was not
> > easily possible to tell if a particular qemu binary supports it.
> 
> NB, nothing should be parsing -help output to look for features
> anymore. Is there really no other way to detect this feature ?

It can be found from monitor output, but parsing -help output really
is easier in some cases.  In any case it's good to document it for end users.

Rich.

> > Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
> > ---
> >  qemu-options.hx | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/qemu-options.hx b/qemu-options.hx
> > index 9f6e2adfff..f8f95eb498 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -796,7 +796,7 @@ DEF("drive", HAS_ARG, QEMU_OPTION_drive,
> >      "       [,cache=writethrough|writeback|none|directsync|unsafe][,format=f]\n"
> >      "       [,serial=s][,addr=A][,rerror=ignore|stop|report]\n"
> >      "       [,werror=ignore|stop|report|enospc][,id=name][,aio=threads|native]\n"
> > -    "       [,readonly=on|off][,copy-on-read=on|off]\n"
> > +    "       [,readonly=on|off][,copy-on-read=on|off][,locking=off|auto|on]\n"
> >      "       [,discard=ignore|unmap][,detect-zeroes=on|off|unmap]\n"
> >      "       [[,bps=b]|[[,bps_rd=r][,bps_wr=w]]]\n"
> >      "       [[,iops=i]|[[,iops_rd=r][,iops_wr=w]]]\n"
> 
> Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
> 
> Regards,
> Daniel
> -- 
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v