Re: [libvirt] [PATCH v2 0/3] Implement CPU model driver for PowerPC

On 15.10.2012 11:07, Li Zhang wrote: > CPU model driver is to get host's CPU information and it also provides > one mechanism to expose host's CPU information to guests during migration. > > When migrating one guest from one machine to another machine, it will > compare the CPU information. If it is incomptible, it won't start the > guest. > > On x86, it uses CPUID instruction to get information. When migrating > the guest, if the CPU defined in guest XML file is incompatible with > host CPU, cpu-baseline will find out best features to expose to guest. > Refer to > [http://berrange.com/posts/2010/02/15 > /guest-cpu-model-configuration-in-libvirt-with-qemukvm/]. > > On PowerPC, it can get CPU version by mfpvr instruction. So, if PVR is > different from definition in guest XML file by cpu-compare, it will fail > to start guest. The CPU infromation can be got by cpu-baseline. But only > CPU vendor and model can be shown, there are no features as x86. > So on PowrePC, it assumes that migration only occurs between the machines > with the same type CPUs on PowerPC. > > In this driver, there are definitions of models and PVRs for CPUs supported > on PowerPC. The relationship between models and PVRs are as the following: > For one specific CPU model, its PVR is unique. And also for one PVR code, > the PVR code is also unique. > > So from the PVR code of CPU data, it's easy to get model and vendor information. > > It is tested on my Power machine which CPU PVR is Power7_v2.3. > * cap.xml has the same definition as the host. > [root@ltckvmopal2 kvm-test]# /bin/virsh cpu-compare cap.xml > CPU described in cap.xml is identical to host CPU > > [root@ltckvmopal2 kvm-test]# /bin/virsh cpu-baseline cap.xml > <cpu mode='custom' match='exact'> > <model fallback='allow'>POWER7_v2.3</model> > <vendor>IBM</vendor> > </cpu> > > * cap.xml has differnt model as the host. > [root@ltckvmopal2 kvm-test]# /bin/virsh cpu-compare cap.xml > CPU described in cap.xml is incompatible with host CPU > > [root@ltckvmopal2 kvm-test]# /bin/virsh cpu-baseline cap.xml > <cpu mode='custom' match='exact'> > <model fallback='allow'>POWER7_v2.1</model> > <vendor>IBM</vendor> > </cpu> > > *v1 -> v2: > * Fix coding style's problems in several places. > * Replace while with for loop in 2 places according to Michal Privoznik's suggestion. > * Add powerpc.c to po/PORTFILES.in > > Li Zhang (3): > libvirt: Add one file cpu_ppc_data.h to define CPU data for PPC > libvirt: Implement CPU model driver for PowerPC > Doc-fix for PowerPC CPU model driver > > po/POTFILES.in | 1 + > src/cpu/cpu.h | 3 + > src/cpu/cpu_map.xml | 14 ++ > src/cpu/cpu_powerpc.c | 591 ++++++++++++++++++++++++++++++++++++++++++++++-- > src/cpu/cpu_ppc_data.h | 33 +++ > 5 files changed, 624 insertions(+), 18 deletions(-) > create mode 100644 src/cpu/cpu_ppc_data.h > I've reviewed second version too, ACKed all patches, applied small fixed I've found and pushed the whole series. Thanks!

Michal