On Thu, 18 Apr 2013 06:10:19 -0600 Eric Blake <ebl...@redhat.com> wrote:
> On 04/18/2013 03:01 AM, Gerd Hoffmann wrote: > > Hi, > > > > This patch qom-ifies the QemuConsoles and adds an new, optional > > parameter to the screendump command to specify the device you > > want dump from. > > > > Question for the QOM guys: where in the tree should the QemuConsoles > > show up? I can't find anything in the tree doing this. I've placed > > them below /backend. See patch #2. Ok? Better suggestions? > > > > Question for the libvirt guys: Is it ok for libvirt to just extend the > > existing screendump command? Can libvirt figure there is a new > > (optional) parameter? See patch #5. > > The existing libvirt API is: > > char * > virDomainScreenshot(virDomainPtr domain, > virStreamPtr stream, > unsigned int screen, > unsigned int flags) > > which uses the screen argument to distinguish both between devices and > heads on a given device: > > * The screen ID is the sequential number of screen. In case of multiple > * graphics cards, heads are enumerated before devices, e.g. having > * two graphics cards, both with four heads, screen ID 5 addresses > * the second head on the second card. > > So yes, I think libvirt will be able to drive the new command by knowing > how many heads appear per device, then passing in the appropriate named > device to the QMP command. And yes, I'll review patch 5 regarding > interface design. We can extend screendump on HMP, but the general rule for QMP is to add a new command instead so that clients don't have to play tricks like Eric is suggesting :) Is there any big issue with adding a new command?
