Re: [libvirt] [PATCHv5 0/8] bulk stats: QEMU implementation

This patchset enhances the QEMU support for the new bulk stats API to include equivalents of these APIs: virDomainBlockInfo virDomainGetInfo - for balloon stats virDomainGetCPUStats virDomainBlockStatsFlags virDomainInterfaceStats virDomainGetVcpusFlags virDomainGetVcpus This subset of API is the one oVirt relies on. Scale/stress test on an oVirt test environment is in progress. The patchset is organized as follows: - the first patch enhances the internal stats gathering API to accomodate the needs of the groups which extract information using QEMU monitor jobs. - the next five patches implement the bulk stats groups, extracting helpers where do refactoring to extract internal helpers every time it is feasible and convenient. - the seventh patch enhances the virsh domstats command with options to use the new bulk stats. - the last patch enhances the block stats group adding the wr_highest_offset information, needed by oVirt for thin provisioned disks. ChangeLog v5: address reviewer's comment - Eric pointed out a possible flaw in balloon stats if QEMU monitor needs to be queried. A proper fix require further discussion and API changes (possbily just a new flag); However, since the balloon event is available in QEMU >= 1.2, I just dropped the query and relied on the event instead. Support for older QEMUs will be reintroduced, if needed, with following patches. - fix: per-domain monitor check and reporting. (pointed out by Peter) - reset last error when fail silently. (pointed out by Peter)