RE: [PATCH v1 00/11] PEBS virtualization enabling via DS

[Kang, Luwei]

> Subject: Re: [PATCH v1 00/11] PEBS virtualization enabling via DS
> 
> > Testing:
> > The guest can use PEBS feature like native. e.g.
> 
> Could you please add example qemu command lines too? That will make it
> much easier for someone to reproduce.

I introduce a new CPU parameter "pebs" to enable PEBS in KVM guest(disabled in default)  
e.g. "qemu-system-x86_64 -enable-kvm -M q35 -cpu Icelake-Server,pmu=true,pebs=true ...."

[PATCH v1 0/3] PEBS virtualization enabling via DS in Qemu
https://lore.kernel.org/qemu-devel/1583490005-27761-1-git-send-email-luwei.kang@xxxxxxxxx/

Thanks,
Luwei Kang

> 
> -Andi
> >
> > # perf record -e instructions:ppp ./br_instr a
> >
> > perf report on guest:
> > # Samples: 2K of event 'instructions:ppp', # Event count (approx.):
> 1473377250
> > # Overhead  Command   Shared Object      Symbol
> >   57.74%  br_instr  br_instr           [.] lfsr_cond
> >   41.40%  br_instr  br_instr           [.] cmp_end
> >    0.21%  br_instr  [kernel.kallsyms]  [k] __lock_acquire
> >
> > perf report on host:
> > # Samples: 2K of event 'instructions:ppp', # Event count (approx.):
> 1462721386
> > # Overhead  Command   Shared Object     Symbol
> >   57.90%  br_instr  br_instr          [.] lfsr_cond
> >   41.95%  br_instr  br_instr          [.] cmp_end
> >    0.05%  br_instr  [kernel.vmlinux]  [k] lock_acquire