I am not sure if this due to qemu or xen (or both), but if I try booting a xen pv guest with graphics using /usr/bin/qemu-system-i386 I either get a crash with sdl or a failure to produce graphics with vnc. The sdl crash (with qemu-system-x86-2.6.0-3.fc24.x86_64) has backtrace #0 0x000056408e9f9e6e in sdl_display_init (ds=<optimized out>, full_screen=0, no_frame=<optimized out>) at ui/sdl2.c:822 #1 0x000056408e793136 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4571 where the qemu command line was /usr/bin/qemu-system-i386 -xen-domid 2 -chardev socket,id=libxl-cmd,path=/var/run/xen/qmp-libxl-2,server,nowait -no-shutdown -mon chardev=libxl-cmd,mode=control -chardev socket,id=libxenstat-cmd,path=/var/run/xen/qmp-libxenstat-2,server,nowait -mon chardev=libxenstat-cmd,mode=control -nodefaults -xen-attach -name f24test -vnc 127.0.0.1:0,to=99 -display none -sdl -machine xenpv -m 1024 and the command line for vnc was /usr/bin/qemu-system-i386 -xen-domid 4 -chardev socket,id=libxl-cmd,path=/var/run/xen/qmp-libxl-4,server,nowait -no-shutdown -mon chardev=libxl-cmd,mode=control -chardev socket,id=libxenstat-cmd,path=/var/run/xen/qmp-libxenstat-4,server,nowait -mon chardev=libxenstat-cmd,mode=control -nodefaults -xen-attach -name f24test -vnc 127.0.0.1:0,to=99 -display none -machine xenpv -m 1024
There's some weirdness here. The command line has both '-display none' and -vnc/-sdl, which seems odd, but I don't think it's the root issue. Maybe just a xen buglet The root issue is that -nodefaults sets -vga none, which explains the lack of output for -vnc, and is tickling the sdl crash. So let's use this to track the sdl crasher, but maybe you need a xen bug if the lack of video hardware is unexpected
Patch posted: http://lists.nongnu.org/archive/html/qemu-devel/2016-05/msg05735.html
qemu-2.6.0-4.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-a80eab65ba
qemu-2.6.0-4.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-a80eab65ba
qemu-2.6.0-4.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.