See below. What do the more experienced libvirt developers think, is this going in the right direction? Thanks, Tim On Tue, 2022-06-28 at 18:09 +0200, Tim Wiederhake wrote: > libvirt and qemu cpu models are out of sync. libvirt cpu models are > considered static and never changing, whereas qemu cpu models have > changed over time. This leads to problems and confusion for users, > as the cpu models they specify may have different features than what > they expect. > > This series introduces two new APIs to enumerate and retrieve cpu > models dynamically from the hypervisor at runtime, allowing the user > to make use of cpu models from newer hypervisor versions even if > libvirt is not aware of them. > > These two new functions are intended as building blocks onto which > higher-level functionality can be build, e.g. the ability to specify > a hypervisor cpu model directly in a domain xml. With these two > functions alone this has to be done manually for now, i.e. enumerate > the available cpu models, retrieve the cpu description and manually > insert it into the domain xml accordingly: > > $ virsh hypervisor-cpu-models --arch x86_64 > Name Alias > ---------------------------------------------------- > max > host > base > qemu64-v1 > qemu64 qemu64-v1 > qemu32-v1 > qemu32 qemu32-v1 > phenom-v1 > phenom phenom-v1 > (...) > > $ virsh hypervisor-cpu-definition --machine pc --arch x86_64 > qemu64 > <cpu> > <model>qemu64</model> > <feature name='cmov'/> > <feature name='mmx'/> > <feature name='xd'/> > <feature name='x-intel-pt-auto-level'/> > <feature name='kvm_asyncpf'/> > <feature name='kvm-asyncpf'/> > <feature name='legacy-cache'/> > <feature name='vmware-cpuid-freq'/> > <feature name='mce'/> > <feature name='mca'/> > <feature name='msr'/> > <feature name='fxsr'/> > <feature name='cpuid-0xb'/> > <feature name='kvm_pv_eoi'/> > <feature name='pni'/> > <feature name='x2apic'/> > <feature name='i64'/> > <feature name='pae'/> > <feature name='pat'/> > <feature name='sse'/> > <feature name='kvm_nopiodelay'/> > <feature name='kvm-nopiodelay'/> > <feature name='kvmclock-stable-bit'/> > <feature name='hypervisor'/> > <feature name='syscall'/> > <feature name='x-migrate-smi-count'/> > <feature name='full-cpuid-auto-level'/> > <feature name='sse3'/> > <feature name='sse2'/> > <feature name='kvm-pv-eoi'/> > <feature name='cx8'/> > <feature name='pge'/> > <feature name='fill-mtrr-mask'/> > <feature name='cx16'/> > <feature name='de'/> > <feature name='clflush'/> > <feature name='tsc'/> > <feature name='fpu'/> > <feature name='check'/> > <feature name='apic'/> > <feature name='kvm-steal-time'/> > <feature name='kvm_steal_time'/> > <feature name='kvmclock'/> > <feature name='l3-cache'/> > <feature name='nx'/> > <feature name='tcg-cpuid'/> > <feature name='lm'/> > <feature name='pse'/> > <feature name='sep'/> > <feature name='kvm'/> > <feature name='lahf-lm'/> > <feature name='lahf_lm'/> > <feature name='mtrr'/> > <feature name='pse36'/> > </cpu> > > The returned cpu description is currently completely unfiltered, as > can be seen by the duplicate entries differing only in "-" vs. "_" > usage, inclusion of experimental feature flags and generally, flags > that are not recognized by libvirt. One possibility to adress this > would be to extend virQEMUCapsCPUFeatureTranslate. > > Before I continue with this, I would love to hear other people's > thoughts, comments and potential use cases. > > Cheers, > Tim > > Tim Wiederhake (9): > qemuMonitorCPUDefInfo: Add alias > libvirt: introduce virConnectGetHypervisorCPUModelNames public API > remote: Add RPC support for the > virConnectGetHypervisorCPUModelNames > API > qemu: implement virConnectGetHypervisorCPUModelNames API > tools: Report hypervisor cpu model names > libvirt: introduce virConnectGetHypervisorCPUModelDefinition public > API > remote: Add support for the > virConnectGetHypervisorCPUModelDefinition > API > qemu: Implement virConnectGetHypervisorCPUModelDefinition API > tools: Report hypervisor cpu model definitions > > docs/manpages/virsh.rst | 27 ++++++ > include/libvirt/libvirt-host.h | 13 +++ > src/driver-hypervisor.h | 17 ++++ > src/libvirt-host.c | 109 +++++++++++++++++++++++ > src/libvirt_public.syms | 2 + > src/qemu/qemu_driver.c | 105 ++++++++++++++++++++++ > src/qemu/qemu_monitor.c | 2 + > src/qemu/qemu_monitor.h | 1 + > src/qemu/qemu_monitor_json.c | 3 + > src/remote/remote_daemon_dispatch.c | 76 ++++++++++++++++ > src/remote/remote_driver.c | 100 +++++++++++++++++++++ > src/remote/remote_protocol.x | 37 +++++++- > src/remote_protocol-structs | 27 ++++++ > tools/virsh-host.c | 132 > ++++++++++++++++++++++++++++ > 14 files changed, 650 insertions(+), 1 deletion(-) > > -- > 2.31.1 > >
