Finding a minimal case did shed some light on this. Using QEMU's native graphics window, this works fine:
$ /usr/bin/qemu-system-x86_64 \ -m 1G \ -blockdev raw,node-name=install_iso,read-only=on,file.driver=file,file.filename=/mnt/losable/ISOs/archlinux-2019.09.01-x86_64.iso \ -device ide-cd,drive=install_iso,bus=ide.0,bootindex=0 But, introducing spice reproduces the problem: $ /usr/bin/qemu-system-x86_64 \ -m 1G \ -blockdev raw,node-name=install_iso,read-only=on,file.driver=file,file.filename=/mnt/losable/ISOs/archlinux-2019.09.01-x86_64.iso \ -spice unix,addr=/tmp/spice.qxl.sock,disable-ticketing \ -device ide-cd,drive=install_iso,bus=ide.0,bootindex=0 \ -vga qxl $ remote-viewer "spice+unix:///tmp/spice.qxl.sock" I've been running remote-viewer (from virt-viewer package) since around March 13, version 8.0 since then. It's only when upgrading QEMU from 4.0.0 to 4.1.0 that introduces the problem. Running remote-viewer this way also shows that it outputs these, right when KMS changes resolution: (remote-viewer:15090): GLib-GObject-WARNING **: 23:56:03.914: value "64" of type 'gint' is invalid or out of range for property 'desktop-width' of type 'gint' (remote-viewer:15090): GLib-GObject-WARNING **: 23:56:03.915: value "64" of type 'gint' is invalid or out of range for property 'desktop-height' of type 'gint' When downgrading to QEMU 4.0.0, remote-viewer STILL outputs these lines regarding desktop-width and height, when KMS changes resolution. In case it helps, below are spice-debug logs from remote-viewer. I've included the whole log, but also added a bunch of spacing and a header showing the second worth of output correlating with the KMS resolution change. QEMU 4.0.0 without the bug: http://ix.io/1USn QEMU 4.1.0 with the bug: http://ix.io/1USo So, it's always possible the fix might need to be in remote-viewer, but at minimum, the case it would need to handle properly wasn't being given to it until QEMU 4.1.0. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1843151 Title: Regression: QEMU 4.1.0 qxl and KMS resoluiton only 4x10 Status in QEMU: New Bug description: Host is Arch Linux. linux 5.2.13, qemu 4.1.0. virt-viewer 8.0. Guest is Arch Linux Sept 2019 ISO. linux 5.2.11. Have replicated this both on a system using amdgpu and one using integrated ASPEED graphics. Downgrading from 4.1.0 to 4.0.0 works as usual, see: https://www.youtube.com/watch?v=NyMdcYwOCvY Going back to 4.1.0 reproduces, see: https://www.youtube.com/watch?v=H3nGG2Mk6i0 4.1.0 displays fine until KMS kicks in. Using 4.1.0 with virtio-vga doesn't cause this. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1843151/+subscriptions
