Re: [libvirt] [PATCH v3 2/4] qemu: add dtb capability
On 02/27/2013 09:56 AM, Eric Blake wrote:
> @@ -944,6 +945,8 @@ virQEMUCapsComputeCmdFlags(const char *help,
> }
> if (strstr(help, "-uuid"))
> virQEMUCapsSet(qemuCaps, QEMU_CAPS_UUID);
> + if (strstr(help, "-dtb"))
> + virQEMUCapsSet(qemuCaps, QEMU_CAPS_DTB);
This won't work. -dtb did not exist prior to qemu 1.2, and for all qemu
newer than 1.2, we do NOT scrape '-help' output; instead, we use QMP
query commands. You need to figure out the corresponding QMP command
that we can use to tell when dtb support exists in qemu.
I stand (slightly) corrected: it looks like -dtb was added in qemu 1.1
(qemu commit 379b5c7), which means we DO need -help scraping for that
version of qemu. Then, since it predates when QMP queries are reliable,
you can get away with blindly setting QEMU_CAPS_DTB when targetting a
qemu new enough to support QMP queries without actually having to query
for it. But it's still something to be fixed before this patch is ready :)
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
Attachments:
- signature.asc (application/pgp-signature — 621 bytes)