On 03/12/2014 09:04 AM, Martin Kletzander wrote:
On Thu, Mar 06, 2014 at 09:35:47AM +0000, qiaonuohan@cn.fujitsu.com wrote:
--memory-only option is introduced without compression supported. Therefore, this is a freature regression of virsh dump. Now qemu has support dumping memory
s/freature/feature/
but I would not use the word "regression" since that never worked. Also it would help mentioning the commit ID or a version it got included in qemu. On that note, is there a possibility of of introspection of that feature, so we can gracefully error out in case older qemu is used?
Yes - qemu 2.0 is adding 'query-dump-guest-memory-capability', which can be used for two purposes: 1. if this command exists, 'dump-guest-memory' supports the new optional 'format' argument; and 2. calling this command will return a list of WHICH formats are supported by the given qemu binary (since configure-time choices can disable some of the formats from actually working). So you need to have a patch that modifies src/qemu/qemu_capabilities.[ch] to do the probing and set capability bits, so that we can gracefully error out when talking to a too-old qemu, or requesting a format that was not compiled in to a new qemu.
Looking at the rest, I rather fixed what I wanted to change in my repo and here's the diff I'd squash in. Let me know if you're OK with that. I'll still want an ACK from someone in order to push that, though. And feel free to ask about that changes as well.
I suppose the capability detection could be done as an add-on patch, but I'm personally thinking it's better to hold off on this series until ALL the work is done, so we don't forget to do the capability detection work. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org