From: Derek Murray <Derek.Murray@cl.cam.ac.uk>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Eduardo Habkost <ehabkost@redhat.com>,
Juan Quintela <quintela@redhat.com>,
"Stephen C. Tweedie" <sct@redhat.com>,
Jan Beulich <jbeulich@novell.com>,
Glauber de Oliveira Costa <gcosta@redhat.com>,
Chris Wright <chrisw@sous-sol.org>,
"virtualization@lists.osdl.org" <virtualization@lists.osdl.org>
Subject: Re: Re: Next steps with pv_ops for Xen
Date: Mon, 03 Dec 2007 13:19:08 +0000 [thread overview]
Message-ID: <4754024C.7020905@cl.cam.ac.uk> (raw)
In-Reply-To: <4753FC6A.4020601@redhat.com>
I take the blame for that one. I added the hook because, if a process
were to die whilst holding one or more grants, there were no hooks that
would make it possible to carry out the grant-unmap. All existing hooks
on either the device or the VMA were called *after* the PTEs were cleared.
It gets better, though. The same hook is used in the version of blktap
in linux-2.6.18-xen (not, as far as I can see, in the sparse tree for
xen-3.1-testing):
http://xenbits.xensource.com/linux-2.6.18-xen.hg?file/fd879c0688bf/drivers/xen/blktap/blktap.c
Reverting back to the old (hookless) behaviour would be a retrograde
step IMHO.
Cheers,
Derek Murray.
Gerd Hoffmann wrote:
> Stephen C. Tweedie wrote:
>> Hi all,
>>
>> driver domains
>
> Looked at the gntdev (grant table mappings for user space) driver,
> noticed that one is not self-contained. It needs a hook for page unmapping:
>
> http://xenbits.xensource.com/xen-3.1-testing.hg?rev/7180d2e61f92
> plus an s/ptep_get_and_clear_full/zap_pte/ fixup a few changesets
> later.
>
> Upstreaming that one could become *uhm* intresting. Nevertheless the
> gntdev functionality is quite useful for writing pure userspace
> backend drivers ...
>
> cheers,
> Gerd
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
next prev parent reply other threads:[~2007-12-03 13:19 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-21 22:05 Next steps with pv_ops for Xen Stephen C. Tweedie
2007-11-21 23:12 ` Jeremy Fitzhardinge
2007-11-26 14:02 ` Juan Quintela
2007-11-26 18:52 ` Jeremy Fitzhardinge
2007-11-27 8:30 ` Jan Beulich
2007-11-27 17:00 ` Jeremy Fitzhardinge
2007-11-27 17:14 ` Jan Beulich
2007-11-27 17:15 ` Stephen C. Tweedie
2007-12-03 12:54 ` Gerd Hoffmann
2007-12-03 13:19 ` Derek Murray [this message]
2007-12-03 14:16 ` Gerd Hoffmann
2007-12-03 14:51 ` Derek Murray
2007-12-03 17:18 ` Mark Williamson
2007-12-03 18:36 ` D.G. Murray
2007-12-03 19:08 ` Mark Williamson
2007-12-04 9:35 ` tgh
2007-12-05 3:42 ` Mark Williamson
2007-12-06 15:21 ` Gerd Hoffmann
2007-12-06 15:32 ` Derek Murray
2007-12-06 15:55 ` Gerd Hoffmann
2007-12-21 12:58 ` Gerd Hoffmann
2007-12-03 20:38 ` Gerd Hoffmann
2007-12-04 9:40 ` Derek Murray
2007-12-04 12:01 ` Gerd Hoffmann
2007-12-04 12:39 ` Stephen C. Tweedie
2007-12-04 19:58 ` Gerd Hoffmann
2007-12-05 11:48 ` Derek Murray
2007-12-05 14:12 ` Gerd Hoffmann
2007-12-05 14:22 ` Keir Fraser
2007-12-05 14:30 ` Derek Murray
2007-12-05 16:58 ` Keir Fraser
2007-12-05 17:17 ` Derek Murray
2007-12-05 17:22 ` Keir Fraser
2007-12-05 17:48 ` Derek Murray
2007-12-05 17:59 ` Keir Fraser
2007-12-05 18:15 ` Derek Murray
2007-12-12 8:27 ` Isaku Yamahata
2007-12-12 8:39 ` Keir Fraser
2007-12-12 8:44 ` Isaku Yamahata
2007-12-05 20:06 ` Gerd Hoffmann
2007-12-05 18:12 ` Jeremy Fitzhardinge
2007-12-05 18:29 ` Derek Murray
2007-12-05 20:15 ` Jeremy Fitzhardinge
2007-12-05 20:35 ` Geoffrey Lefebvre
2007-12-06 10:15 ` Gerd Hoffmann
2007-12-05 20:44 ` Keir Fraser
2007-12-06 10:00 ` Derek Murray
2007-12-06 19:55 ` [Xen-devel] " Jeremy Fitzhardinge
2007-12-05 13:19 ` Derek Murray
2007-12-04 21:08 ` Ian Main
2007-12-05 10:03 ` Gerd Hoffmann
2007-12-05 12:51 ` Gerd Hoffmann
2007-12-05 10:11 ` Derek Murray
2007-12-04 20:59 ` Ian Main
2007-12-05 11:54 ` Derek Murray
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