From: Pawel Moll <pawel.moll@arm.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH] virtio-spec: Define virtio-mmio registers as LE
Date: Wed, 06 Mar 2013 15:10:15 +0000 [thread overview]
Message-ID: <1362582615.3105.45.camel@hornet> (raw)
In-Reply-To: <87fw0ad7sr.fsf@rustcorp.com.au>
On Tue, 2013-03-05 at 00:11 +0000, Rusty Russell wrote:
> Pawel Moll <pawel.moll@arm.com> writes:
> > On Fri, 2013-03-01 at 11:21 +0000, Marc Zyngier wrote:
> >> > Having said that, Rusty was contemplating enforcing LE config space in
> >> > the new PCI layout...
> >>
> >> I wouldn't complain about that, and would like to see a similar thing on
> >> MMIO.
> >
> > Wherever PCI goes, MMIO follows :-)
>
> Yes, but if you switch from 'guest-endian' to 'little-endian' how will
> you tell? For PCI, we'd detect it by using the new layout.
The version register/value. At some point of time there will be a
new(ish) MMIO layout anyway to deal with 64-bit addresses, replacing the
ring page number with two 32-bit hi/lo physical address registers. This
was discussed not long after the driver got merged...
> I'd rather you specify MMIO as little endian, and we fix the kernel
> config accessors to be endian aware (ie. 8, 16, 32, 64-bit accessors).
> Since noone BE is using MMIO right now, it's safe...
That's absolutely fine with me, however I don't see anything I could do
in the virtio_mmio driver and spec - the virtio_config_ops specifies
get/set as void * operations and I simply do byte-by-byte copy. Have I
missed some config/endianess/PCI related discussion?
Paweł
next prev parent reply other threads:[~2013-03-06 15:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-13 14:25 [RFC PATCH] virt_mmio: fix signature checking for BE guests Marc Zyngier
2013-02-13 15:08 ` Pawel Moll
2013-02-13 15:28 ` Marc Zyngier
2013-02-13 15:46 ` Pawel Moll
2013-02-13 16:40 ` Marc Zyngier
2013-02-13 16:53 ` Michael S. Tsirkin
2013-02-13 17:04 ` Marc Zyngier
2013-02-14 0:22 ` Rusty Russell
2013-02-14 10:54 ` [PATCH] virtio-spec: Define virtio-mmio registers as LE Pawel Moll
2013-02-15 3:57 ` Rusty Russell
2013-03-01 10:41 ` Marc Zyngier
2013-03-01 10:50 ` Pawel Moll
2013-03-01 11:21 ` Marc Zyngier
2013-03-01 12:37 ` Pawel Moll
2013-03-01 13:16 ` Marc Zyngier
2013-03-05 0:11 ` Rusty Russell
2013-03-06 15:10 ` Pawel Moll [this message]
2013-03-07 6:36 ` Rusty Russell
2013-02-15 0:07 ` [RFC PATCH] virt_mmio: fix signature checking for BE guests Benjamin Herrenschmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1362582615.3105.45.camel@hornet \
--to=pawel.moll@arm.com \
--cc=Marc.Zyngier@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mst@redhat.com \
--cc=rusty@rustcorp.com.au \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).