On Thu, Jan 16, 2020 at 01:13:38PM +0000, Richard W.M. Jones wrote:
On Thu, Jan 16, 2020 at 12:41:37PM +0100, Peter Krempa wrote:
When parsing legacy NBD backing file strings such as 'nbd:unix:/tmp/sock:exportname=/' we'd fail to set the transport to VIR_STORAGE_NET_HOST_TRANS_UNIX. This started to be a problem once we actually started to generate config of the backing store on the command line with -blockdev as the JSON code would try to format it as TCP and fail with:
internal error: argument key 'host' must not have null value
Set the type properly and add a test.
This bug was found by the libguestfs test suite in:
The bug was found by Ming Xie of the virt-v2v QE team.
The patch itself looks fine as far as I can tell. But I'm having real problems actually testing it. Can you suggest any way to test libvirt parsing these URIs?
My current method (which doesn't work for reasons that I don't understand) is:
(1) Compile libvirt from source.
(2) Run ./run src/libvirtd &
(3) Create an NBD server + overlay file:
rm /tmp/sock nbdkit -U /tmp/sock memory 1G qemu-img create -f qcow2 overlay.qcow2 -b nbd:unix:/tmp/sock:exportname=/ -F raw
(4) Try to boot a libvirt guest using the overlay:
virt-install --import --name test --disk path=overlay.qcow2,format=raw --memory 1024
But for some reason libvirt just ignores the overlay:
2020-01-16 13:00:44.980+0000: 2378711: warning : virStorageBackendVolOpen:1527 : ignoring missing file 'nbd:unix:/tmp/sock'
I verified that the overlay works in programs like qemu-img so it doesn't seem to be a problem with the overlay itself.
The problem was too old qemu. With qemu 4.2 I can verify that the patch is working, so: Tested-by: Richard W.M. Jones <rjones@redhat.com> Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top