Re: [libvirt] [PATCH v3 06/18] blockjob: allow finer bandwidth tuning for query

While reviewing the new virDomainBlockCopy API, Peter Krempa pointed out that our existing design of using MiB/s for block job bandwidth is rather coarse, especially since qemu tracks it in bytes/s; so virDomainBlockCopy only accepts bytes/s. But once the new API is implemented for qemu, we will be in the situation where it is possible to set a value that cannot be accurately reflected back to the user, because the existing virDomainGetBlockJobInfo defaults to the coarser units. Fortunately, we have an escape hatch; and one that has already served us well in the past: we can use the flags argument to specify which scale to use (see virDomainBlockResize for prior art). This patch fixes the query side of the API; made easier by previous patches that split the query side out from the modification code. Later patches will address the virsh interface, as well retrofitting all other blockjob APIs to also accept a flag for toggling bandwidth units. * include/libvirt/libvirt.h.in (_virDomainBlockJobInfo) (VIR_DOMAIN_BLOCK_COPY_BANDWIDTH): Document sizing issues. (virDomainBlockJobInfoFlags): New enum. * src/libvirt.c (virDomainGetBlockJobInfo): Document new flag. * src/qemu/qemu_monitor.h (qemuMonitorBlockJobInfo): Add parameter. * src/qemu/qemu_monitor.c (qemuMonitorBlockJobInfo): Likewise. * src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJobInfo): Likewise. * src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJobInfo) (qemuMonitorJSONGetBlockJobInfoOne): Likewise. Don't scale here. * src/qemu/qemu_migration.c (qemuMigrationDriveMirror): Update callers. * src/qemu/qemu_driver.c (qemuDomainBlockPivot) (qemuDomainBlockJobImpl): Likewise. (qemuDomainGetBlockJobInfo): Likewise, and support new flag. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- include/libvirt/libvirt.h.in | 38 +++++++++++++++++++++++++------------- src/libvirt.c | 8 ++++++-- src/qemu/qemu_driver.c | 20 ++++++++++++++++---- src/qemu/qemu_migration.c | 3 ++- src/qemu/qemu_monitor.c | 8 +++++--- src/qemu/qemu_monitor.h | 3 ++- src/qemu/qemu_monitor_json.c | 19 ++++++++++++------- src/qemu/qemu_monitor_json.h | 3 ++- 8 files changed, 70 insertions(+), 32 deletions(-)