On 03/18/2014 03:59 PM, Serge Hallyn wrote:
Hi,
In order to migrate a VM from an older system with qemu-kvm to a newer one with qemu, the newer qemu needs to be told to use the same vga ram size as qemu-kvm used, 8M.
virsh domxml-from-native suggests that the way to specify a 8mb cirrus vga ram size would be to add
<qemu:commandline> <qemu:arg value='-global'/> <qemu:arg value='cirrus-vga.vgamem_mb=8'/> </qemu:commandline>
This points out a weakness in our code - <qemu:commandline> is intentionally unsupported, which means our XML needs an actual parameter for this, rather than forcing you back to qemu:commandline. Or maybe we already have the parameter, in which case the bug is in the domxml-from-native code for not recognizing this particular usage of command line arguments. But a quick grep for vgamem_mb doesn't have any hits in current src/qemu/qemu_command.c, so it looks like we don't support it yet.
However whenever I edit a .xml to add this, it disappears.
When outputting <qemu:commandline> in domxml-from-native, you must also output the xmlns directive that enables its use. domxml-from-native is correctly doing it, but doing it at the very first <domain> which is quite some distance away, so you probably missed that key point. See http://libvirt.org/drvqemu.html#qemucommand
Am I doing something silly?
You're forgetting <domain type='qemu' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org