Hello to all, I am using qemu to set-up a VM on a Sapphire Rapid server. I am running linux kernel 6.6.14 in both guest and host. I enable kvm for the guest and I pass the --cpu host flag to qemu. My understanding is that there is some PEBS virtualization support in place within kvm. However in the above set-up if I try: perf record -e instructions:p ls -- I get back "unchecked MSR access error: WRMSR to 0x3f1 (tried to write 0x0000000000000002)" if I try perf record -e instructions:ppp ls -- I get back that the PMU HW does not support sampling. Also I see in dmesg that in the guest, PEBS has fmt-0 (format) configured while in the host it is fmt-4. In general, I would like to use PEBS within the guest to take a trace of sampled instructions that cause LLC misses. At this point, it is not clear to me if this is even possible. Could you please let me know if I can use PEBS for my purpose at all, and if yes what configuration am I missing? Is there some other VMM that I should be using and not qemu? Thank you very much in advance! Best Regards, Chloe P.S.: PEBS sampling works fine in the host.
