On 10/21/2016 08:22 AM, Peter Krempa wrote:
static struct virQEMUCapsStringFlags virQEMUCapsQMPSchemaQueries[] = { - { "bogus/path/to/satisfy/compiler", 0 }, + { "blockdev-add/arg-type/options/+gluster/debug-level", QEMU_CAPS_GLUSTER_DEBUG_LEVEL},
Okay, I see how you plan to use this.
BIG WARNING FLAG - in qemu 2.7, blockdev-add is unstable (it should have been named x-blockdev-add; but we goofed); but you can use the existence of x-blockdev-del as a witness that blockdev-add is incomplete.
In qemu 2.8, we are taking advantage of the fact that 2.7 wasn't complete in order to get rid of the 'options' nesting layer; the plan is to also rename x-blockdev-add at the same time. Which means this probe, as written, will only succeed for 2.7.
So. Should I add both? One with the "options" indirection and one without? Since there is no other way to access the structure than via blockdev-add and I really don't want to add a version check I see it as the only option.
Qemu 2.8 isn't released yet. We tend to only commit into libvirt support for released qemu. So I think I'm okay with using this patch as-is (it will detect support for 2.7); then a followup patch once 2.8 is actually released and we've tested that we can still detect the capability with the new-and-improved blockdev-add and corresponding second query addition at that time. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org