On Wed, Jun 29, 2022, Jim Mattson wrote: > On Wed, Jun 29, 2022 at 2:06 AM Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote: > > > For PERF_GLOBAL_CTRL errata: > > - We can move the filtering to vmx_vmexit_ctrl()/vmx_vmentry_ctrl() > > preserving the status quo: KVM doesn't use the feature but it is exposed > > to L1 hypervisor (and L1 hypervisor presumably has the same check and > > doesn't use the feature. FWIW, the workaround was added in 2011 and the > > erratas it references appeared in 2010, this means that the affected > > CPUs are quite old, modern proprietary hypervisors won't likely boot > > there). > Sadly, Nehalem and Westmere are well-supported by KVM today, and we > will probably still continue to support them for at least another > decade. They both have EPT, unrestricted guest, and other VT-x2 > features that KVM still considers optional. Nehalem doesn't have unrestricted guest. Nehalem is the only generation with EPT but not unrestricted guest.
