On 02/12/2013 01:15 PM, Laine Stump wrote:
virCommand was previously calling virSetUIDGID() to change the uid and gid of the child process, then separately calling virSetCapabilities(). This did not work if the desired uid was != 0, since a setuid to anything other than 0 normally clears all capabilities bits.
The solution is to use the new virSetUIDGIDWithCaps(), sending it the uid, gid, and capabilities bits. This will get the new process setup properly.
Since the static functions virSetCapabilities() and virClearCapabilities are no longer called, they have been removed.
NOTE: When combined with "filecap $path-to-qemu sys_rawio", this patch will make CAP_SYS_RAWIO (which is required for passthrough of generic scsi commands to a guest - see commits e8daeeb, 177db08, 397e6a7, and 74e0349) be retained by qemu when necessary. Apparently that capability has been broken for non-root qemu every since it was
s/every/ever/
originally added. --- Change from V1: s/todo/to do/ in comment
I didn't do anything about issuing a warning if CAPNG isn't present, because we previously haven't done that, and I think it would clutter the log terribly on any platform that didn't have libcapng.
Fair enough. Maybe if there were a way to do a one-shot logging it might be helpful; but as there is no change in logging behavior (not logging either before or after this patch), that could be deferred to a later patch if we ever want it. ACK. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org