QEMU introduced the dirty page rate limit feature in 7.1.0, see the details in the following link: https://lore.kernel.org/qemu- devel/cover.1656177590.git.huangy81@xxxxxxxxxxxxxxx/ So maybe it's the right time to enable this feature in libvirt and the upper user can play with it, expecting the upper app can use this feature to do a virtual CPU Qos or whatever else. Introduce the virsh API as follows: # virsh limit-dirty-page-rate <domain> [--rate <number>] [--vcpu <number>] [--cancel] Examples: To set the dirty page rate upper limit 60MB/s for all virtual CPUs in c81_node1, use: # virsh limit-dirty-page-rate c81_node1 --rate 60 Set dirty page rate limit 60(MB/s) on all virtual CPUs successfully To set the dirty page rate upper limit 35MB/s for virtual CPU 1 in c81_node1, use: # virsh limit-dirty-page-rate c81_node1 --rate 35 --vcpu 1 Set vcpu[1] dirty page rate upper limit 35(MB/s) successfully Specify the 'cancel' option to do the reverse, the optional option 'vcpu' is used to specify the CPU index to be set. To query the dirty page rate upper limit, use: # virsh vcpuinfo c81_node1 VCPU: 0 CPU: 14 State: running CPU time: 27.1s CPU Affinity: yyyyyyyyyyyyyyyy DirtyRate limit: 60 DirtyRate current: 0 VCPU: 1 CPU: 1 State: running CPU time: 25.1s CPU Affinity: yyyyyyyyyyyyyyyy DirtyRate limit: 35 DirtyRate current: 0 VCPU: 2 CPU: 7 State: running CPU time: 6.0s CPU Affinity: yyyyyyyyyyyyyyyy DirtyRate limit: 60 DirtyRate current: 0 VCPU: 3 CPU: 8 State: running CPU time: 3.5s CPU Affinity: yyyyyyyyyyyyyyyy DirtyRate limit: 60 DirtyRate current: 0 The patch set adds two new APIs to implement a dirty page rate limit: 1. virDomainSetVcpuDirtyLimit, which set virtual CPU dirty page rate limit. virsh command 'limit-dirty-page-rate' correspondingly. 2. virDomainCancelVcpuDirtyLimit, which cancel virtual CPU dirty page rate limit. 'cancel' option was introduced to 'limit-dirty-page-rate' to cancel the limit correspondingly. In addition, function 'qemuMonitorQueryVcpuDirtyLimit' was implemented to query the dirty page rate upper limit, the virsh command 'vcpuinfo' was extended. So that the user can query dirty page rate limit info via 'vcpuinfo'. This series makes the main modifications as follows: - introduce QEMU_CAPS_VCPU_DIRTY_LIMIT capability so that libvirt can probe before using dirty page rate upper limit feature. - implement virsh command 'limit-dirty-page-rate' to set/cancel dirty page rate upper limit. - extend 'vcpuinfo' API so that it can display dirty page rate upper limit. - document dirty page rate limit feature. Please review, and hoping the comments, thanks ! Yong Hyman Huang(黄勇) (11): qemu_capabilities: Introduce QEMU_CAPS_VCPU_DIRTY_LIMIT capability libvirt: Add virDomainSetVcpuDirtyLimit API qemu_driver: Implement qemuDomainSetVcpuDirtyLimit virsh: Introduce limit-dirty-page-rate api qemu_monitor: Implement qemuMonitorQueryVcpuDirtyLimit qemu_driver: Extend qemuDomainGetVcpus virsh: Extend vcpuinfo api libvirt: Add virDomainCancelVcpuDirtyLimit API qemu_driver: Implement qemuDomainCancelVcpuDirtyLimit virsh: Add cancel option of limit-dirty-page-rate api NEWS: Document limit dirty page rate APIs NEWS.rst | 16 ++ include/libvirt/libvirt-domain.h | 22 +++ src/driver-hypervisor.h | 13 ++ src/libvirt-domain.c | 106 ++++++++++++ src/libvirt_public.syms | 6 + src/qemu/qemu_capabilities.c | 2 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_driver.c | 154 ++++++++++++++++++ src/qemu/qemu_monitor.c | 36 ++++ src/qemu/qemu_monitor.h | 26 +++ src/qemu/qemu_monitor_json.c | 150 +++++++++++++++++ src/qemu/qemu_monitor_json.h | 13 ++ src/remote/remote_daemon_dispatch.c | 2 + src/remote/remote_driver.c | 4 + src/remote/remote_protocol.x | 28 +++- src/remote_protocol-structs | 13 ++ .../qemucapabilitiesdata/caps_7.1.0_ppc64.xml | 1 + .../caps_7.1.0_x86_64.xml | 1 + tests/qemucapabilitiesdata/caps_7.2.0_ppc.xml | 1 + .../caps_7.2.0_x86_64+hvf.xml | 1 + .../caps_7.2.0_x86_64.xml | 1 + .../caps_8.0.0_riscv64.xml | 1 + .../caps_8.0.0_x86_64.xml | 1 + .../qemucapabilitiesdata/caps_8.1.0_s390x.xml | 1 + .../caps_8.1.0_x86_64.xml | 1 + tools/virsh-domain.c | 123 ++++++++++++++ 26 files changed, 723 insertions(+), 1 deletion(-) -- 2.38.5
