Comment 65 for bug 1080674

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.
I summarized test results in Google Docs table ( see https://docs.google.com/spreadsheets/d/1WsjQ8nz3b6dhYGdM3xxkdxZHp27j9ggvrRPcZbm9Cao/edit?usp=sharing ).

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!