Re: [libvirt] [PATCH RFC 00/39] qemu: Add support for -blockdev

On Thu, Jul 26, 2018 at 17:04:19 +0800, Fam Zheng wrote: Well the problem is that when using -blockdev with 'query-nodes' false/not present you get a even more useless output: virsh qemu-monitor-command --pretty upstream '{"execute":"query-blockstats","arguments":{"query-nodes":false}}' { "return": [ ], "id": "libvirt-20" } 'query-named-block-nodes' don't provide the 'stats' section either: (other drives snipped) { "iops_rd": 0, "detect_zeroes": "off", "image": { "virtual-size": 520032256, "filename": "/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso", "format": "raw", "actual-size": 520036352, "dirty-flag": false }, "iops_wr": 0, "ro": true, "node-name": "libvirt-7-format", "backing_file_depth": 0, "drv": "raw", "iops": 0, "bps_wr": 0, "write_threshold": 0, "encrypted": false, "bps": 0, "bps_rd": 0, "cache": { "no-flush": false, "direct": false, "writeback": true }, "file": "/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso", "encryption_key_missing": false }, { "iops_rd": 0, "detect_zeroes": "off", "image": { "virtual-size": 520032256, "filename": "/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso", "format": "file", "actual-size": 520036352, "dirty-flag": false }, "iops_wr": 0, "ro": true, "node-name": "libvirt-7-storage", "backing_file_depth": 0, "drv": "file", "iops": 0, "bps_wr": 0, "write_threshold": 0, "encrypted": false, "bps": 0, "bps_rd": 0, "cache": { "no-flush": false, "direct": false, "writeback": true }, "file": "/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso", "encryption_key_missing": false } ], "id": "libvirt-19" } Thus libvirt can't provide the stats it used to with -drive. Since we need to special-case the code for gathering stats for -blockdev it should not be a problem if e.g. query-named-block-nodes reported the stats section along. (perhaps with a boolean flag to do so which also could disable the nesting) In either case we need the stats in the same extent as we had before with -drive and query-blockstats.