Hi James, On 11/19/20 4:58 PM, James Morse wrote: > Hi Alex, > > On 27/10/2020 17:26, Alexandru Elisei wrote: >> Detect Statistical Profiling Extension (SPE) support using the cpufeatures >> framework. The presence of SPE is reported via the ARM64_SPE capability. >> >> The feature will be necessary for emulating SPE in KVM, because KVM needs >> that all CPUs have SPE hardware to avoid scheduling a VCPU on a CPU without >> support. For this reason, the feature type ARM64_CPUCAP_SYSTEM_FEATURE has >> been selected to disallow hotplugging a CPU which doesn't support SPE. > Can you mention the existing driver in the commit message? Surprisingly it > doesn't use > cpufeature at all. It looks like arm_spe_pmu_dev_init() goes out of its way > to support > mismatched systems. (otherwise the significance of the new behaviour isn't > clear!) > > I read it as: the host is fine with mismatched systems, and the existing > drivers supports > this. But KVM is not. After this patch you can't make the system mismatched > 'late'.
That was exactly my intention. Certainly, I'll try to make the commit message clearer by mentioning the SPE driver. Thanks, Alex _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
