On 3/23/22 4:17 AM, Daniel P. Berrangé wrote:
On Wed, Mar 23, 2022 at 12:01:19PM +0400, Marc-André Lureau wrote:
Hi
On Wed, Mar 23, 2022 at 12:47 AM Jonathon Jongsma <jjong...@redhat.com> wrote:
This patch series enables support for the qemu-vdagent character device which
enables copy/paste support between guest and client when using vnc graphics.
The guest must be configured with something like the following:
<channel type='qemu-vdagent'>
<source clipboard='on' mouse='on'/>
<target type='virtio' name='com.redhat.spice.0'/>
</channel>
Copy/paste sync requires a vnc client that has support for copy/paste commands.
Currently virt-viewer does not work, but the version of tigervnc provided by
fedora (executable name 'vncviewer') does work.
More details about this device on Gerd's blog:
https://www.kraxel.org/blog/2021/05/qemu-cut-paste/
OPEN QUESTIONS:
- I'm not fully convinced that the `<source>` element is the right place for
the new `clipboard` / `mouse` configuration options, but I'm not sure that
adding a new xml element to the `<channel>` is the right approach either.
Suggestions welcome.
I am not convinced <channel> is appropriate either for -chardev
qemu-vdagent. That's why in my dbus display series it's an
implementation detail
(https://patchew.org/Libvirt/20211222194345.766352-1-marcandre.lur...@redhat.com/20211222194345.766352-13-marcandre.lur...@redhat.com/),
and it's not exposed to the domain XML directly. However I realize
that my approach is probably broken, as it looks like I totally missed
the associated virtserialport! :)
As you say "source" is strange to put those extra channel options too.
And the only really valid associated device is a virtserialport of
name "com.redhat.spice.0", so what's the point in exposing that detail
to the user?
You could say the same thing about the normal spice vdagent, right? And
we allow the user to specify a different virtio name for the spicevmc
channel. spice-vdagent does offer a --virtio-serial-port-path option
that can be used to connect to a different name within the guest, after all.
At the QEMU level we have one serial port with chardv
-chardev qemu-vdagent,id=ch1,name=vdagent,clipboard=on
-device virtio-serial-pci \
-device virtserialport,chardev=ch1,id=ch1,name=com.redhat.spice.0
but IIUC, we can have multiple frontends - ie both VNC and DBus
display, and in that case the clipboard=on property on the
chardev will apply to both VNC & DBus displays. We can't
control clipboard independantly for the displays, so it is
right to put the control in the XML for the <channel> for
both VNC and DBus.
In addition to <channel>, there are several other xml elements that
essentially map to a qemu character device: <serial>, <console>, etc.
Would it make more sense to introduce a new element like this for the
qemu-vdagent? This might make it easier to introduce new configuration
options that wouldn't really fit in the general <channel>. For example,
something like:
<qemuvdagent>
<clipboard copypaste="yes"/>
<target type='virtio' name='com.redhat.spice.0'/>
</qemuvdagent>
Jonathon
