From: Alexander Graf <agraf@suse.de>
To: Ondrej Zajicek <santiago@crfreenet.org>
Cc: linux-fbdev-devel@lists.sourceforge.net,
qemu-devel <qemu-devel@nongnu.org>,
Anthony Liguori <anthony@codemonkey.ws>,
kvm list <kvm@vger.kernel.org>
Subject: Re: [Linux-fbdev-devel] [PATCH] Add VirtIO Frame Buffer Support
Date: Tue, 3 Nov 2009 00:24:15 +0100 [thread overview]
Message-ID: <5B01907D-86BE-4693-81BA-23CB81B8B047@suse.de> (raw)
In-Reply-To: <D295329B-4DE0-4935-8C6B-D45042E72826@suse.de>
On 02.11.2009, at 23:42, Alexander Graf wrote:
>
> Am 02.11.2009 um 23:32 schrieb Ondrej Zajicek
> <santiago@crfreenet.org>:
>
>> On Mon, Nov 02, 2009 at 11:09:19PM +0100, Alexander Graf wrote:
>>> When we want to create a full VirtIO based machine, we're still
>>> missing
>>> graphics output. Fortunately, Linux provides us with most of the
>>> frameworks
>>> to render text and everything, we only need to implement a
>>> transport.
>>>
>>> So this is a frame buffer backend written for VirtIO. Using this
>>> and my
>>> patch to qemu, you can use paravirtualized graphics.
>>
>> Just a note: it might be useful to allow paravirtualized graphics to
>> handle text mode. In that case, it can be done in fbdev layer using
>> tileblit operations.
>
> Is there any real driver implementing this already? I'd prefer to copy
> from working code instead of writing my own :-).
>
> Also, we still need to keep the local frame buffer copy in sync so we
> can mmap and read from it, right? So it's not really worth it
> probably...
But then again we could just try to be closer to a real graphics card.
What if we'd set up a memory region on the host that is basically our
graphics frame buffer? For S390 we could just append the graphics
memory to the guest's memory.
We could use that as backing buffer in the qemu graphics frontend and
as frame buffer in the Linux fbdev layer, similar to what real
graphics cards set up.
Then we could send all those fancy commands that we have already over
to the host, that renders them and thanks to the mapping have a
consistent frame buffer we can mmap. It'd even simplify the deferred
IO stuff, making it basically a notify that something changed, but the
changes already being written to the frame buffer.
On sync we'd just have to make sure the virtio buffer was processed
completely.
That would get rid of all sys_* calls, a lot of copying and the
duplicate frame buffer we have right now. Wow.
Alex
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de>
To: Ondrej Zajicek <santiago@crfreenet.org>
Cc: linux-fbdev-devel@lists.sourceforge.net,
qemu-devel <qemu-devel@nongnu.org>,
kvm list <kvm@vger.kernel.org>
Subject: [Qemu-devel] Re: [Linux-fbdev-devel] [PATCH] Add VirtIO Frame Buffer Support
Date: Tue, 3 Nov 2009 00:24:15 +0100 [thread overview]
Message-ID: <5B01907D-86BE-4693-81BA-23CB81B8B047@suse.de> (raw)
In-Reply-To: <D295329B-4DE0-4935-8C6B-D45042E72826@suse.de>
On 02.11.2009, at 23:42, Alexander Graf wrote:
>
> Am 02.11.2009 um 23:32 schrieb Ondrej Zajicek
> <santiago@crfreenet.org>:
>
>> On Mon, Nov 02, 2009 at 11:09:19PM +0100, Alexander Graf wrote:
>>> When we want to create a full VirtIO based machine, we're still
>>> missing
>>> graphics output. Fortunately, Linux provides us with most of the
>>> frameworks
>>> to render text and everything, we only need to implement a
>>> transport.
>>>
>>> So this is a frame buffer backend written for VirtIO. Using this
>>> and my
>>> patch to qemu, you can use paravirtualized graphics.
>>
>> Just a note: it might be useful to allow paravirtualized graphics to
>> handle text mode. In that case, it can be done in fbdev layer using
>> tileblit operations.
>
> Is there any real driver implementing this already? I'd prefer to copy
> from working code instead of writing my own :-).
>
> Also, we still need to keep the local frame buffer copy in sync so we
> can mmap and read from it, right? So it's not really worth it
> probably...
But then again we could just try to be closer to a real graphics card.
What if we'd set up a memory region on the host that is basically our
graphics frame buffer? For S390 we could just append the graphics
memory to the guest's memory.
We could use that as backing buffer in the qemu graphics frontend and
as frame buffer in the Linux fbdev layer, similar to what real
graphics cards set up.
Then we could send all those fancy commands that we have already over
to the host, that renders them and thanks to the mapping have a
consistent frame buffer we can mmap. It'd even simplify the deferred
IO stuff, making it basically a notify that something changed, but the
changes already being written to the frame buffer.
On sync we'd just have to make sure the virtio buffer was processed
completely.
That would get rid of all sys_* calls, a lot of copying and the
duplicate frame buffer we have right now. Wow.
Alex
next prev parent reply other threads:[~2009-11-02 23:24 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-02 22:09 [PATCH] Add VirtIO Frame Buffer Support Alexander Graf
2009-11-02 22:09 ` [Qemu-devel] " Alexander Graf
2009-11-02 22:32 ` Ondrej Zajicek
2009-11-02 22:42 ` Alexander Graf
2009-11-02 23:24 ` Alexander Graf [this message]
2009-11-02 23:24 ` [Qemu-devel] Re: [Linux-fbdev-devel] " Alexander Graf
2009-11-02 23:57 ` Ondrej Zajicek
2009-11-02 23:57 ` [Qemu-devel] Re: [Linux-fbdev-devel] " Ondrej Zajicek
2009-11-02 23:59 ` Alexander Graf
2009-11-02 23:59 ` [Qemu-devel] " Alexander Graf
2009-11-02 23:51 ` Ondrej Zajicek
2009-11-02 23:53 ` Alexander Graf
2009-11-02 23:58 ` Ondrej Zajicek
2009-11-03 6:21 ` Avi Kivity
2009-11-03 6:21 ` [Qemu-devel] " Avi Kivity
2009-11-03 6:22 ` Alexander Graf
2009-11-03 6:22 ` [Qemu-devel] " Alexander Graf
2009-11-03 6:24 ` Avi Kivity
2009-11-03 6:24 ` [Qemu-devel] " Avi Kivity
2009-11-03 6:27 ` Alexander Graf
2009-11-03 6:27 ` [Qemu-devel] " Alexander Graf
2009-11-03 6:34 ` Avi Kivity
2009-11-03 6:34 ` [Qemu-devel] " Avi Kivity
2009-11-03 6:39 ` Alexander Graf
2009-11-03 6:39 ` [Qemu-devel] " Alexander Graf
2009-11-03 7:43 ` Avi Kivity
2009-11-03 7:43 ` [Qemu-devel] " Avi Kivity
2009-11-03 7:50 ` Alexander Graf
2009-11-03 7:50 ` [Qemu-devel] " Alexander Graf
2009-11-03 8:20 ` Avi Kivity
2009-11-03 8:20 ` [Qemu-devel] " Avi Kivity
2009-11-03 8:26 ` Alexander Graf
2009-11-03 8:26 ` [Qemu-devel] " Alexander Graf
2009-11-03 8:53 ` Avi Kivity
2009-11-03 8:53 ` [Qemu-devel] " Avi Kivity
2009-11-03 15:14 ` Anthony Liguori
2009-11-03 15:14 ` [Qemu-devel] " Anthony Liguori
2009-11-03 15:57 ` Avi Kivity
2009-11-03 15:57 ` [Qemu-devel] " Avi Kivity
2009-11-03 11:25 ` Vincent Hanquez
2009-11-03 11:25 ` Vincent Hanquez
2009-11-03 9:38 ` Avi Kivity
2009-11-03 9:38 ` Avi Kivity
2009-11-03 15:29 ` Ondrej Zajicek
2009-11-03 15:29 ` [Linux-fbdev-devel] " Ondrej Zajicek
2009-11-03 16:05 ` Avi Kivity
2009-11-03 16:05 ` Avi Kivity
2009-11-03 16:53 ` Ondrej Zajicek
2009-11-03 16:53 ` Ondrej Zajicek
2009-11-03 17:33 ` [Linux-fbdev-devel] " Paolo Bonzini
2009-11-03 17:33 ` [Linux-fbdev-devel] [Qemu-devel] " Paolo Bonzini
2009-11-03 17:33 ` [Linux-fbdev-devel] " Paolo Bonzini
2009-11-04 16:09 ` [Qemu-devel] " Vincent Hanquez
2009-11-04 16:35 ` Anthony Liguori
2009-11-04 16:35 ` Anthony Liguori
2009-11-05 9:04 ` Avi Kivity
2009-11-08 4:43 ` Thomas Fjellstrom
2009-11-06 2:39 ` Jamie Lokier
2009-11-06 2:39 ` Jamie Lokier
2009-11-06 3:05 ` Anthony Liguori
2009-11-06 3:05 ` Anthony Liguori
2009-11-05 11:36 ` Michael S. Tsirkin
2009-11-05 11:36 ` Michael S. Tsirkin
2009-11-05 11:36 ` [Qemu-devel] " Michael S. Tsirkin
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=5B01907D-86BE-4693-81BA-23CB81B8B047@suse.de \
--to=agraf@suse.de \
--cc=anthony@codemonkey.ws \
--cc=kvm@vger.kernel.org \
--cc=linux-fbdev-devel@lists.sourceforge.net \
--cc=qemu-devel@nongnu.org \
--cc=santiago@crfreenet.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.