Can rr work if

1. intel hybrid cores on KVM or hyper-v: It seems that PMU won't work if you are in KVM on intel hybrid cores, can anyone confirm that? @rocallahan I learned from your blog that you've built a new computer with an Intel hybrid-core processor.
   [added] I can confirm that PMU doesn't work on Intel hybrid cores in Hyper-V, nor does it work in VMware Workstation even for 11th-gen Intel CPUs that aren't hybrid cores.
2. AMD Zen on hypervisor: the workaround may work on bare mental, but not for hypervisor like hyper-v.
3. You can't get access to PMU: Don't worry, have you noticed rr.soft? I've tested it, and it passed 99% of the tests.

Summary: 1. and 2. , If you are on hypervisor with intel hybrid cores or AMD zen, or you are in VMware Workstation with newer intel cpus, you have trouble running rr.