On Fri, Dec 15, 2023 at 04:12:00PM -0600, Jonathon Jongsma wrote: > As described in detail in the commit "cpu_map: add canonical names to > existing CPU models", the unversioned CPU model names are not > migration-safe. If qemu makes the anticipated changes to CPU alias > mapping, an unversioned CPU model may be represented by different > underlying CPU models on different hosts. To avoid being susceptible to > this issue, use the new 'canonical_name' property of the CPU definition > to always specify a specific versioned CPU model version to qemu rather > than using CPU model aliases. The CPU models *are* migration safe because libvirt /always/ uses the versioned machine type name. > This canonical name is only used in the qemu backend and is not exposed > to the user in anyway. The libvirt CPU configuration will continue to > use existing unversioned model names in the domain xml for continuity. > But internally we will translate these to a specific version. > > Signed-off-by: Jonathon Jongsma <jjongsma@xxxxxxxxxx> > --- > src/qemu/qemu_command.c | 5 ++++- > tests/qemuxml2argvdata/cpu-Haswell-noTSX.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-Haswell.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-Haswell2.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-Haswell3.x86_64-latest.args | 2 +- > .../cpu-Icelake-Server-pconfig.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-cache-disable3.x86_64-latest.args | 2 +- > .../cpu-check-default-partial.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-fallback.x86_64-5.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-fallback.x86_64-8.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-cmt.x86_64-latest.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-4.2.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-5.0.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-5.1.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-5.2.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-6.0.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-6.1.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-6.2.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-7.0.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-7.1.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-7.2.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-8.0.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-8.1.0.args | 2 +- > .../cpu-host-model-fallback-kvm.x86_64-latest.args | 2 +- > .../cpu-host-model-fallback-tcg.x86_64-7.2.0.args | 2 +- > .../cpu-host-model-fallback-tcg.x86_64-8.0.0.args | 2 +- > .../cpu-host-model-fallback-tcg.x86_64-8.1.0.args | 2 +- > .../cpu-host-model-fallback-tcg.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-4.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-5.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-5.1.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-5.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-6.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-6.1.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-6.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-7.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-7.1.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-7.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-8.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-8.1.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-kvm.x86_64-latest.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-4.2.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-5.0.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-5.1.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-5.2.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-6.0.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-6.1.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-6.2.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-7.0.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-7.1.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-7.2.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-8.0.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-8.1.0.args | 2 +- > .../cpu-host-model-nofallback-kvm.x86_64-latest.args | 2 +- > .../cpu-host-model-nofallback-tcg.x86_64-7.2.0.args | 2 +- > .../cpu-host-model-nofallback-tcg.x86_64-8.0.0.args | 2 +- > .../cpu-host-model-nofallback-tcg.x86_64-8.1.0.args | 2 +- > .../cpu-host-model-nofallback-tcg.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-tcg.x86_64-7.2.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-tcg.x86_64-8.0.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-tcg.x86_64-8.1.0.args | 2 +- > tests/qemuxml2argvdata/cpu-host-model-tcg.x86_64-latest.args | 2 +- > .../cpu-host-model-vendor.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-minimum1.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-minimum2.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-nofallback.x86_64-8.0.0.args | 2 +- > .../cpu-phys-bits-emulate2.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-strict1.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-translation.x86_64-latest.args | 2 +- > tests/qemuxml2argvdata/cpu-tsc-frequency.x86_64-latest.args | 2 +- > 70 files changed, 73 insertions(+), 70 deletions(-) > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 54fb8220e8..be9cbe4915 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -6267,7 +6267,10 @@ qemuBuildCpuModelArgStr(virQEMUDriver *driver, > break; > > case VIR_CPU_MODE_CUSTOM: > - virBufferAdd(buf, cpu->model, -1); > + if (cpu->canonical_model) > + virBufferAdd(buf, cpu->canonical_model, -1); > + else > + virBufferAdd(buf, cpu->model, -1); > break; This isn't checking whether QEMU supports the versioned CPU model or not. QEMU has had 'Haswell-noTSX' long before 'Haswell-v2' was added. Can you check what version QEMU introduced CPU versions, and whether that's /equal or older/ than our minimum QEMU version. Assuming it is, then record this in the commit message as justification for why this doesn't break compatibility with launching old QEMU. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| _______________________________________________ Devel mailing list -- devel@xxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxx
