From: Chun Feng Wu <w...@linux.ibm.com> Hi,
I am thinking to leverage "throttle block filter" in QEMU to support more flexible I/O limits(e.g. tiered I/O groups), one sample provided by QEMU doc is: https://github.com/qemu/qemu/blob/master/docs/throttle.txt "For example, let's say that we have three different drives and we want to set I/O limits for each one of them and an additional set of limits for the combined I/O of all three drives." The implementation idea is to - Define throttle groups(limit) in domain - Define throttle filter to reference throttle group within disk - Within domain disk, throttle filters references multiple throttle groups to form filter chain to apply multiple limits in QEMU like above sample - Add new virsh cmds for throttle group management: throttlegroupset Add or update a throttling group. throttlegroupdel Delete a throttling group. throttlegroupinfo Get a throttling group. throttlegrouplist list all domain throttlegroups - Update "attach-disk" to add one more option "--throttle-groups" to apply throttle filters e.g. "virsh attach-disk $VM_ID ${DISK_PATH}/vm1_disk_2.qcow2 vdd --driver qemu --subdriver qcow2 --targetbus virtio --throttle-groups limit2,limit012" - I chose above semantics as I felt they're appropriate, if there are better ones please kindly suggest. Note, this implementation requires flag "QEMU_CAPS_OBJECT_JSON". >From QMP perspective, the sample flow works this way: - Throttle group creation: virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit0","limits":{"iops-total":200,"iops-read":0,"iops-total-max":200,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit1","limits":{"iops-total":250,"iops-read":0,"iops-total-max":250,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit2","limits":{"iops-total":300,"iops-read":0,"iops-total-max":300,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit012","limits":{"iops-total":400,"iops-read":0,"iops-total-max":400,"iops-total-max-length":1}}}' - Chain up filters during attaching disk to apply two filters(limit0 and limit012): virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments": {"driver":"file","filename":"/virt/disks/vm1_disk_1.qcow2","node-name":"test-3-storage","auto-read-only":true,"discard":"unmap"}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments":{"node-name":"test-4-format","read-only":false,"driver":"qcow2","file":"test-3-storage","backing":null}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments":{"driver":"throttle","node-name":"libvirt-5-filter","throttle-group": "limit0","file":"test-4-format"}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments": {"driver":"throttle","node-name":"libvirt-6-filter","throttle-group":"limit012","file":"libvirt-5-filter"}}' virsh qemu-monitor-command 1 '{"execute": "device_add", "arguments": {"driver":"virtio-blk-pci","scsi":false,"bus":"pci.0","addr":"0x5","drive":"libvirt-6-filter","id":"virtio-disk1"}}' This patchset includes: - Throttle group XML schema definition in patch 1 - Throttle filter XML schema definition in patch 2 - Throttle group struct definition, parsing and formating in patch 3 - Throttle filter struct definition, parsing and formating in patch 4 - New QMP processing to update and get throttle group in patch 5&6 - New API definition and implementation in patch 7 - QEMU driver implementation in patch 8 - Hotplug processing for throttle filters in patch 9 - Extract common iotune validation in patch 10 - qemuProcessLaunch flow implemenation for throttle group in patch 11 - qemuProcessLaunch flow implemenation for throttle filter in patch 12 - Domain XML test for processing throttle groups and filters in patch 13 - Test new implemented driver in patch 14 - New virsh cmd implementation for group in patch 15 - Update Virsh cmd "attach_disk" to include throttle filters in patch 16 v3 changes: - re-org commits by splitting changes containing throttle group and filters - update commits msgs - move schema commits to be the first ones - refactor "diskIoTune" to extract common schema "iotune" - add new tests for throttle groups and filters in qemuxmlconftest - check flag "QEMU_CAPS_OBJECT_JSON" when preparing "-object"(qemu: command: Support throttle groups during qemuProcessLaunch ) or creating throttle group (qemu: Implement qemu driver for throttle API) - when creating throttle group through "object-add" (qemu: Implement qemu driver for throttle API), reuse "qemuMonitorAddObject" to check if "objectAddNoWrap"("props") is requried - remove "virObject parent;" in "_virDomainThrottleFilterDef" in domain_conf.h - remove "virDomainThrottleGroupIndexByName" in both domain_conf.h and domain_conf.c - remove "virDomainThrottleFilterDefNew" in domain_conf.c - update "virDomainThrottleFilterDefFree" to use "g_free" rather than "VIR_FREE" in domain_conf.c - update "virDomainDiskThrottleFilterDefParse" to remove "xmlXPathContextPtr ctx" parameter and check NULL against "filter->group_name" in domain_conf.c - use "virBufferEscapeString" instead of "virBufferAsprintf" in "virDomainDiskDefFormatThrottleFilterChain" - use "group->val > 0" instead of "if (group->val)" in FORMAT_THROTTLE_GROUP - remove NULL check for "group->group_name" since virBufferEscapeString checked NULL already in "virDomainThrottleGroupFormat" - I haven't added new conf module (src/conf/virdomainthrottle.c/h) because "virDomainThrottleGroupDef" is alias of "_virDomainBlockIoTuneInfo", try to avoid circular dependency - remove "NULLSTR" in qemuMonitorUpdateThrottleGroup and qemuMonitorGetThrottleGroup in qemu_monitor.c - refactor "qemuMonitorMakeThrottleGroupLimits" to use virJSONValueObjectAdd in qemu_monitor_json.c - use "g_strdup_printf" to avoid static buffers in "qemuMonitorJSONGetThrottleGroup" - remove virReportError after qemuMonitorJSONGetReply in "qemuMonitorJSONGetThrottleGroup" to avoid overriding error - remove "VIR_DOMAIN_THROTTLE_GROUP" in libvirt/include/libvirt/libvirt-domain.h - update "virDomainGetThrottleGroup" to not first query the number of parameters, - update "remote_domain_get_throttle_group_args" and "remote_domain_get_throttle_group_ret" to remove "nparams" in src/remote_protocol-structs, also updated "remote_domain_get_throttle_group_args" and "remote_domain_get_throttle_group_ret" in src/remote/remote_protocol.x - update parameter "virTypedParameterPtr params" to be "virTypedParameterPtr *params" in "virDrvDomainGetThrottleGroup" in driver-hypervisor.h - update "qemuDomainSetThrottleGroup" to not query number of parameters first - remove wrapper "qemuDomainThrottleGroupByName" and "qemuDomainSetThrottleGroupDefaults" - refactor "qemuDomainSetThrottleGroup" and "qemuDomainSetBlockIoTune" to use common logic - update "qemuDomainDelThrottleGroup" to use VIR_JOB_MODIFY by referencing "qemuDomainHotplugDelIOThread" - check if group is still being used by some filter(qemuDomainCheckThrottleGroupRef) during deletion - replace "ThrottleFilterChain" with "ThrottleFilters" - update "qemuDomainDiskGetTopNodename" to take top throttle node name if disk has throttles, and reuse "qemuDomainDiskGetBackendAlias" in "qemuBuildDiskDeviceProps" to get top node name as "drive" - after enabling throttlerfilter and if disk has throttlefilters, during blockcommit, the top node name is not "libvirt-x-format" anymore, instead, top node name referencies top filter like "libvirt-x-filter" - add check "cdrom device with throttle filters isn't supported" - delete "filternodenameindex" and reuse "nodenameindex" to generate index for throttle nodes - refactor detaching filters by adding "qemuBuildThrottleFiltersDetachPrepareBlockdev" to just build parameters for "blockdev-del" - refactor "testDomainSetBlockIoTune" and "testDomainSetThrottleGroup" to use common logic Any comments/suggestions will be appriciated! Chun Feng Wu (16): schema: Add new domain elements to support multiple throttle groups schema: Add new domain elements to support multiple throttle filters config: Introduce ThrottleGroup and corresponding XML parsing config: Introduce ThrottleFilter and corresponding XML parsing qemu: monitor: Add support for ThrottleGroup operations tests: Test qemuMonitorJSONGetThrottleGroup and qemuMonitorJSONUpdateThrottleGroup remote: New APIs for ThrottleGroup lifecycle management qemu: Implement qemu driver for throttle API qemu: hotplug: Support hot attach and detach block disk along with throttle filters config: validate: Refactor disk iotune validation for reuse qemu: command: Support throttle groups during qemuProcessLaunch qemu: command: Support throttle filters during qemuProcessLaunch qemuxmlconftest: Add 'throttlefilter' tests test_driver: Test throttle group lifecycle APIs virsh: Add support for throttle group operations virsh: Add option "throttle-groups" to "attach_disk" docs/formatdomain.rst | 48 ++ include/libvirt/libvirt-domain.h | 21 + src/conf/domain_conf.c | 376 +++++++++++ src/conf/domain_conf.h | 51 ++ src/conf/domain_validate.c | 118 +++- src/conf/schemas/domaincommon.rng | 293 +++++---- src/conf/virconftypes.h | 4 + src/driver-hypervisor.h | 22 + src/libvirt-domain.c | 196 ++++++ src/libvirt_private.syms | 9 + src/libvirt_public.syms | 7 + src/qemu/qemu_block.c | 131 ++++ src/qemu/qemu_block.h | 53 ++ src/qemu/qemu_command.c | 182 ++++++ src/qemu/qemu_command.h | 12 + src/qemu/qemu_domain.c | 39 +- src/qemu/qemu_domain.h | 8 + src/qemu/qemu_driver.c | 617 +++++++++++++++--- src/qemu/qemu_hotplug.c | 33 + src/qemu/qemu_monitor.c | 34 + src/qemu/qemu_monitor.h | 14 + src/qemu/qemu_monitor_json.c | 150 +++++ src/qemu/qemu_monitor_json.h | 14 + src/remote/remote_daemon_dispatch.c | 44 ++ src/remote/remote_driver.c | 40 ++ src/remote/remote_protocol.x | 48 +- src/remote_protocol-structs | 28 + src/test/test_driver.c | 452 +++++++++---- tests/qemumonitorjsontest.c | 86 +++ .../throttlefilter.x86_64-latest.args | 43 ++ .../throttlefilter.x86_64-latest.xml | 65 ++ tests/qemuxmlconfdata/throttlefilter.xml | 55 ++ tests/qemuxmlconftest.c | 1 + tools/virsh-completer-domain.c | 64 ++ tools/virsh-completer-domain.h | 5 + tools/virsh-domain.c | 453 ++++++++++++- 36 files changed, 3447 insertions(+), 369 deletions(-) create mode 100644 tests/qemuxmlconfdata/throttlefilter.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/throttlefilter.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/throttlefilter.xml -- 2.34.1
