[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] Raise 9pfs mount_tag limit from 32 to 255 bytes
From: |
Daniel P. Berrange |
Subject: |
Re: [Qemu-devel] [PATCH] Raise 9pfs mount_tag limit from 32 to 255 bytes |
Date: |
Fri, 7 Oct 2011 10:27:56 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Sep 29, 2011 at 04:22:16PM +0100, Daniel P. Berrange wrote:
> On Thu, Sep 29, 2011 at 08:23:49PM +0530, Aneesh Kumar K.V wrote:
> > On Thu, 29 Sep 2011 11:34:21 +0100, "Daniel P. Berrange" <address@hidden>
> > wrote:
> > > From: "Daniel P. Berrange" <address@hidden>
> > >
> > > The Linux guest kernel does not appear to have a problem handling
> > > a mount_tag larger than 32 bytes. Increase the limit to 255 bytes,
> > > though perhaps it can be made larger still, or not limited at all ?
> > >
> > > Tested with a 3.0.4 kernel and a mount_tag 255 bytes in length.
> > >
> > > * hw/9pfs/virtio-9p.h: Change MAX_TAG_LEN to 255
> >
> >
> > mount_tag is passed via pci config space, do we want to have 255 bytes
> > out of that for device identification.
>
> How big is the config space available for each 9pfs device and what
> other info does it need to keep there ?
Does anyone have an clear answer for this ?
I've done some tests with ever larger mount tags, and managed to increase
the MAX_TAG_LEN value to 1023 before I started getting guest failures.
So if the config space is really 1023 bytes in size, it doesn't seem too
unrealistic to allow 255 bytes of it for the mount_tag, or at the very
least increase it from 32 to 128 ?
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
- Re: [Qemu-devel] [PATCH] Raise 9pfs mount_tag limit from 32 to 255 bytes,
Daniel P. Berrange <=