* Gerd Hoffmann ([email protected]) wrote: > Hi, > > > virt-manager/libvirt seems to default to 9 MByte of Vram for cirrus, > > so this would break a lot of setups. > > It wouldn't. libvirt sticks that into the xml, but it doesn't set any > qemu parameters. The libvirt parameter actually predates the qemu > property for setting the size.
Yeuch messy. > > Looking at datasheets on the web seems to say the chips actually went > > down to 1 MB or less. > > I have my doubts we emulate that correctly (register telling the guest > how much memory is actually there etc.). Also it is pretty much useless > these days, even the 4MB imply serious constrains when FullHD displays > are commonplace. Newer cirrus drivers such as the kernel's drm driver > are specifically written to qemu's cirrus cards, I have my doubs that > they are prepared to handle 1MB cirrus cards correctly. > > Bottom line: Allowing less than 4MB is asking for trouble for no good > reason ;) OK, so checking for 4MB/8MB/16MB is probably safe, and it also would have the benefit of shouting if someone fixed libvirt and it started trying to configure a 9MB version. Dave -- Dr. David Alan Gilbert / [email protected] / Manchester, UK
