Hi On Mon, Jan 23, 2017 at 4:04 PM Gerd Hoffmann <kra...@redhat.com> wrote:
> Hi, > > > > If you only ref, you could have the image being modified while it is > > being saved asynchronously, this could result in tearing artefacts, > > no? > > Yes, but you have that problem _anyway_. screendump qmp command can run > in parallel to guest vcpu, so it can race with guest display updates > today. Assuming they happen as simple framebuffer writes and therefore > don't involve vmexit + grabbing big qemu lock. > Agreed, fwiw, I implemented a coroutine-based ppm_save in the qapi-async branch: https://github.com/elmarco/qemu/commit/6f45a28ce737eab1d0ce4639f7b015a51a43674c btw, is it supported to reenter the main_loop in hmp_screendump_sync() (Paolo)? (the alternative is probably to block hmp until the async command is finished. This would eventually be interesting if more qmp commands used from hmp are converted to be async) -- Marc-André Lureau
