On Fri, Mar 25, 2011 at 07:47:45PM +0100, Philipp Hahn wrote:

If a domain is initially created without a <vidoe> device but with other devices (like <interface>), PCI device slots normally reserved for hardcoded devices (host bridge, IDE controller, video) get assigned to these. If than later on a <video> device is added without removing the already assigned <addresse>s, the re-definition fails in qemuAssignDevicePCISlots() with the error message "Primary video card must have PCI address 0:0:2.0"

To simplify editing existing domains just reserve the first three slots for internal usage by setting qemuDomainPCIAddressSet.nextslot = 3.

Signed-off-by: Philipp Hahn <hahn@univention.de>

The motivation for this patch is ok, but the impl isn't quite robust enough. When nextslot gets to 31, libvirt resets it back to 0 and starts searching again (in case there are now gaps from unplugged devices). So when this happens, it'll pick up slot 2 again. In qemuAssignDevicePCISlots() we do this if (!reservedIDE && qemuDomainPCIAddressReserveSlot(addrs, 1) < 0) goto error; To ensure the PIIX is always reserved, even if no IDE disks are present. I think we can just do the same with VGA but with s/1/2/ in the slot number.

--- src/qemu/qemu_command.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index c63de09..c359fd0 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -733,6 +733,9 @@ qemuDomainAssignPCIAddresses(virDomainDefPtr def) if (!(addrs = qemuDomainPCIAddressSetCreate(def))) goto cleanup;

+ /* reserve first 3 slots for hardcoded devices */ + addrs->nextslot = 3; + if (qemuAssignDevicePCISlots(def, addrs) < 0) goto cleanup; }

Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|