Package: qemu-system
Version: 1:3.1+dfsg-4
Severity: normal
Dear Maintainer,
after upgrading to qemu 3.1 from stretch [from qemu 2.8 -- mjt], I found
that both linux and windows guests, when using the qxl device, do not
come back from deep power save.
That is, when I run either a standard ubuntu 17.10 or windows 10 (with
qxl-dod driver), then by default they switch off the screen after a while,
which results in black screen in qemu, as expected.
If one moves the mouse or presses a key shortly after this, the screen comes
back.
If I let the systems idle for longer (say, half an hour), then they seem
to go into a deeper powersave, and pressing a key or moving the mouse does
NOT restore the screen - it stays black.
When the vm is in this state, I have not found a way to get the display
back, the only way that works is to quit qemu and start it again (meaning
boot the guest again in a new qemu instance, I have not tried to
suspend/resume a vm).
I have verified that mouse inputs and keypresses are registered correctly
by the guest in this state, so I assume it does try to switch on the
virtual monitor.
Since this happens with both linux and windows guests, this looks like a
bug in qemu's display code to me.