Re: [libvirt] [PATCH v5 1/3] add new virDomainCoreDumpWithFormat API

On 03/12/2014 09:04 AM, Martin Kletzander wrote: > On Thu, Mar 06, 2014 at 09:35:47AM +0000, qiaonuohan(a)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.