With the same Ubuntu 12.04.5 host (qemu-kvm 1.0+noroms-0ubuntu14.21) I got the following test results.
For Ubuntu 12.04.5 LTS i386 guest I got:
* without "-vga" I got screen corruption (see comment 64)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 14.04.2 LTS i386 guest I got:
* without "-vga" I got screen corruption (Unity looks better, but others - not)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 14.10 i386 guest I got:
* without "-vga" I got screen corruption (Unity looks better, but others - not)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 15.04 beta2 i386 guest I got:
* without "-vga" it does not boot to Unity session (see bug 1437740)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
So I suggest you to add simple "boot livecd/liveusb in kvm" test to livecd/liveusb testing procedure.
Ubuntu should not use "cirrus" driver while being guest, it should use "vesa".
Thank you!
With the same Ubuntu 12.04.5 host (qemu-kvm 1.0+noroms- 0ubuntu14. 21) I got the following test results.
For Ubuntu 12.04.5 LTS i386 guest I got:
* without "-vga" I got screen corruption (see comment 64)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 14.04.2 LTS i386 guest I got:
* without "-vga" I got screen corruption (Unity looks better, but others - not)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 14.10 i386 guest I got:
* without "-vga" I got screen corruption (Unity looks better, but others - not)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
For Ubuntu 15.04 beta2 i386 guest I got:
* without "-vga" it does not boot to Unity session (see bug 1437740)
* with "-vga std" and "-vga vmware" it works as expected
* with "-vga qxl" QEMU boots to its console
With "-vga wmvare" I always got the highest screen resolution. /docs.google. com/spreadsheet s/d/1WsjQ8nz3b6 dhYGdM3xxkdxZHp 27j9ggvrRPcZbm9 Cao/edit? usp=sharing ).
I summarized test results in Google Docs table ( see https:/
So I suggest you to add simple "boot livecd/liveusb in kvm" test to livecd/liveusb testing procedure.
Ubuntu should not use "cirrus" driver while being guest, it should use "vesa".
Thank you!