Re: GPF in intel_pmu_lbr_reset() with qemu -cpu host

Peter Wu
2014-03-22T22:00:46Z

On Saturday 22 March 2014 14:27:59 Gleb Natapov wrote:
> > but now I have a NULL dereference (in rapl_pmu_init). Previously, when
> > `-cpu SandyBridge` was passed to qemu, it would show this:
> >
> > [ 0.016995] Performance Events: unsupported p6 CPU model 42 no PMU driver, software events only.
> >
> > The same NULL pointer deref would be visible (slightly different
> > addresses, but the Code lines are equal). With `-host`, the NULL deref
> > with `-cpu host` contains:
> >
> > [ 0.016445] Performance Events: 16-deep LBR, IvyBridge events, Intel PMU driver.
> >
> > Full dmesg below.
> >
> I am confused. Do you see crash now with -cpu SandyBridge and -cpu host, or -cpu host only?

The RAPL crash is seen with both SandyBridge and host, I mentioned SB
because that environment should be more constant than "host" (which
depends on the CPU you have on, well, the host).

Peter