What's the status of the SATA controller migration bug? Are the patches for it expected to be in 2.4? Looks like they didn't make it into 2.3. Since you last wrote, if the SATA controller patches aren't in yet, is there any new way to avoid the SATA controller device, if you have no SATA devices? Thank you. === REPLYING TO === On 02/23/2015 02:26 PM, Thomas Stein wrote: Yep. You have described the situation perfectly. Here are my notes from libvirt commit c27b0bb171d9bdac10a93492a2a99eaa22746694, which fixed the handling of "default" devices in the Q35 machinetype: sata - a q35 machine always has a sata controller implicitly added at slot 0x1F, function 2. There is no way to avoid this controller, so we always add it. Note that the xml2xml tests for the pcie-root and q35 cases were changed to use DO_TEST_DIFFERENT() so that we can check for the sata controller being automatically added. This is especially important because we can't check for it in the xml2argv output (it has no effect on that output since it's an implicit device). So basically when you specify a q35 machinetype, you get a SATA controller at 00:1f.2 even though you have added no commandline args to ask for it. And unlike the default network device (which libvirt can eliminate by adding "-net none" to the qemu commandline), there is no way to avoid this device. And it is also true that any machine with a SATA controller can't be migrated because of problems with the driver. I just talked to the person responsible for fixing these bugs in qemu, and he said that the patches will go upstream "soon", and that he hopes they will be in qemu 2.3. In the meantime, the only way to avoid this problem is to switch to an i440fx-based machinetype (this will require removing all the pci controllers from your config as well as removing all <address type='pci' .../> elements within all devices in the domain; libvirt will then reassign PCI addresses in the guest appropriate to the new machine type. IMPORTANT: If the guest is running MS Windows, this may require a new "activation"; best to keep a copy of the old config and an image of the disk just in case there are problems!)