On Wed, Mar 23, 2022 at 09:44:53AM -0500, Jonathon Jongsma wrote: > 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 <jjongsma@xxxxxxxxxx> 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.lureau@xxxxxxxxxx/20211222194345.766352-13-marcandre.lureau@xxxxxxxxxx/), > > > 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> The devices in libvirt represent the guest exposed devics, and that's still a virtio-serial port, so <channel> is the right place. The chardev is merely a backend and doesn't need it own top level XML element. This does mean yuo can use qemu-vgagent chardev with any of serial, parallel, channel, etc but that's harmless from libvirt's POV. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
