On 12/4/19 3:20 PM, Daniel P. Berrangé wrote:
The virCapsPtr object is a serious source of performance problems for the QEMU driver, because populating it means probing every QEMU system emulator binary installed on the host. This is is crazy because parsing any single XML document only ever needs information about a single QEMU binary. We've already done a great job of untangling stuff with the post-parse and validation functions, but the job was never quite finished. This series tackles the last pieces so that parsing & formatting XML will never use the virCapsPtr object directly. Some of the virt drivers will still use virCapsPtr in their private callbacks, but the QEMU driver will instead use the QEMU emulator capabilities cache directly. The first ten patches are the key bits of work to remove use of the virCapsPtr parameter from domain XML APIs. The next thirteen patches remove the (now unused) virCapsPtr parameter from the domain XML APIs & their callers. The final six patches help various QEMU driver APIs stop relying on the virCapsPtr, so that it is no longer even created at startup. This has a nice benefit on libvirtd startup tie when all 30 QEMU emulators are installed, reducing it from 4 seconds down to a fraction of a second. More work is still needed to follow on from this... A couple of places in the QEMU driver still use virCapsPtr - The virConnectGetVersion API. - The virNodeGetSecurityModel API. - virDomainGetResctrlMonData API. In all cases we just need to move to store the relevant data directly in virQEMUDriverPtr, and not use the virCaps. next, apps can use virDomainGetCapabilities to fetch info about a specific QEMU binary they care about to avoid the cost of the virConnectGetCapabilities API. There are still times when apps need info in virConnectGetCapabilities and this will annoyingly probe all QEMU binaries, even though the app doesn't want the guest info. virConnectGetCapabilities is one of our very early APIs which now flags parameter, so this problem is unfixable in that API. I'm thus included to introduce a new virNodeGetCapabilities that is specifically only returning information about the host hypervisor. Essentially the <capabilities> schema, but only the <host> sub-tree. I do, however, wonder if even this is overkill & we should aim for a much more fine grained way for reporting host capabilities. eg if an app wants the host CPU, do they really want to pay the penality to probe host cache nformation, or NUMA topology and vica-verca. I'm not sure what the right kind of tradeoff here is, whether we should try individual APIs, or have one API and a set of flags to control what info is filled in. Daniel P. Berrangé (30): qemu: cache host arch separately from virCapsPtr qemu: add machines & arch to fake test capabilities cache conf: sanitize virDomainSaveStatus & virDomainSaveConfig APIs conf: sanitize virDomainObjFormat & virDomainDefFormat* APIs conf: pass in default architecture via domain XML options conf: move virt type / os type / arch validation to post-parse conf: don't use passed in caps in post parse method conf: pass netprefix in the domain parser config struct conf: move seclabel validation into post-parse phase conf: pass default sec model in parser config conf: drop virCapsPtr param from assign addresses callback conf: drop virCapsPtr param from basic post parse callback conf: drop virCapsPtr param from post parse data alloc callback conf: drop virCapsPtr param from post parse callback conf: drop virCapsPtr param from device post parse callback conf: drop virCapsPtr param from domain validate callback conf: drop virCapsPtr param from domain formatting APIs conf: drop virCapsPtr param from domain post parse & validate APIs conf: drop virCapsPtr param from domain parse APIs conf: drop virCapsPtr param from domain APIs for copying config conf: drop virCapsPtr param from APIs for saving domains conf: drop virCapsPtr param from domain obj list APIs conf: drop virCapsPtr param from snapshot & checkpoint APIs qemu: drop virCapsPtr param & vars from many APIs conf: move NUMA capabilities into self contained object qemu: use NUMA capabilities object directly conf: make virCPUDef into a ref counted struct qemu: use host CPU object directly qemu: directly create virResctrlInfo ignoring capabilities qemu: stop creating capabilities at driver startup docs/formatdomain.html.in | 6 +- src/bhyve/bhyve_domain.c | 16 +- src/bhyve/bhyve_driver.c | 46 +- src/bhyve/bhyve_process.c | 22 +- src/conf/capabilities.c | 217 +++++--- src/conf/capabilities.h | 34 +- src/conf/checkpoint_conf.c | 21 +- src/conf/checkpoint_conf.h | 2 - src/conf/cpu_conf.c | 29 +- src/conf/cpu_conf.h | 4 + src/conf/domain_conf.c | 404 ++++++-------- src/conf/domain_conf.h | 84 ++- src/conf/snapshot_conf.c | 28 +- src/conf/snapshot_conf.h | 3 - src/conf/virconftypes.h | 3 + src/conf/virdomainobjlist.c | 9 +- src/conf/virdomainobjlist.h | 1 - src/cpu/cpu.c | 3 +- src/cpu/cpu_arm.c | 5 +- src/cpu/cpu_ppc64.c | 3 +- src/cpu/cpu_x86.c | 6 +- src/esx/esx_driver.c | 14 +- src/hyperv/hyperv_driver.c | 1 + src/libvirt_private.syms | 18 +- src/libxl/libxl_capabilities.c | 23 +- src/libxl/libxl_conf.c | 3 +- src/libxl/libxl_conf.h | 2 +- src/libxl/libxl_domain.c | 37 +- src/libxl/libxl_driver.c | 83 ++- src/libxl/libxl_migration.c | 20 +- src/libxl/xen_xl.c | 13 +- src/libxl/xen_xm.c | 2 +- src/lxc/lxc_conf.c | 9 +- src/lxc/lxc_conf.h | 2 +- src/lxc/lxc_controller.c | 44 +- src/lxc/lxc_domain.c | 13 +- src/lxc/lxc_driver.c | 98 ++-- src/lxc/lxc_native.c | 4 +- src/lxc/lxc_process.c | 20 +- src/openvz/openvz_conf.c | 62 ++- src/openvz/openvz_conf.h | 1 + src/openvz/openvz_driver.c | 64 +-- src/phyp/phyp_driver.c | 26 +- src/qemu/qemu_capabilities.c | 176 ++++--- src/qemu/qemu_capabilities.h | 12 +- src/qemu/qemu_capspriv.h | 10 + src/qemu/qemu_checkpoint.c | 32 +- src/qemu/qemu_checkpoint.h | 1 - src/qemu/qemu_command.c | 6 +- src/qemu/qemu_conf.c | 57 +- src/qemu/qemu_conf.h | 18 +- src/qemu/qemu_domain.c | 108 ++-- src/qemu/qemu_domain.h | 1 - src/qemu/qemu_driver.c | 293 ++++------- src/qemu/qemu_hotplug.c | 8 +- src/qemu/qemu_migration.c | 36 +- src/qemu/qemu_migration_cookie.c | 8 +- src/qemu/qemu_process.c | 196 +++---- src/security/virt-aa-helper.c | 2 +- src/test/test_driver.c | 45 +- src/util/virresctrl.h | 2 + src/vbox/vbox_common.c | 16 +- src/vmware/vmware_conf.c | 2 +- src/vmware/vmware_driver.c | 25 +- src/vmx/vmx.c | 23 +- src/vmx/vmx.h | 2 +- src/vz/vz_driver.c | 29 +- tests/Makefile.am | 17 +- tests/bhyveargv2xmltest.c | 2 +- tests/bhyvexml2argvtest.c | 2 +- tests/cputest.c | 11 +- tests/domaincapstest.c | 14 +- tests/domainconftest.c | 2 +- tests/libxlxml2domconfigtest.c | 22 +- tests/lxcconf2xmltest.c | 17 +- tests/lxcxml2xmltest.c | 13 +- tests/openvzutilstest.c | 8 +- tests/qemuagenttest.c | 2 +- tests/qemublocktest.c | 2 +- tests/qemucapabilitiestest.c | 9 +- tests/qemudomaincheckpointxml2xmltest.c | 4 +- tests/qemudomainsnapshotxml2xmltest.c | 4 +- tests/qemuhotplugtest.c | 11 +- tests/qemumemlocktest.c | 6 +- tests/qemusecuritytest.c | 1 - tests/qemuxml2argvtest.c | 35 +- tests/qemuxml2xmltest.c | 4 +- tests/securityselinuxlabeltest.c | 2 +- tests/testutils.c | 39 +- tests/testutils.h | 5 +- tests/testutilslxc.c | 34 +- tests/testutilslxc.h | 4 + tests/testutilsqemu.c | 670 +++++++----------------- tests/testutilsqemu.h | 9 +- tests/testutilsxen.c | 34 +- tests/testutilsxen.h | 9 +- tests/vircaps2xmltest.c | 6 +- tests/vircapstest.c | 11 +- tests/vmx2xmltest.c | 4 +- tests/xlconfigtest.c | 27 +- tests/xmconfigtest.c | 23 +- tests/xml2vmxtest.c | 4 +- 102 files changed, 1687 insertions(+), 1993 deletions(-)
Reviewed-by: Michal Privoznik <mprivozn@xxxxxxxxxx> Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
