On Thu, 2012-10-18 at 16:19 -0700, Andi Kleen wrote: > From: Andi Kleen <a...@linux.intel.com> > > This is not arch perfmon, but older CPUs will just ignore it. This makes > it possible to do at least some TSX measurements from a KVM guest
Please, always CC people who wrote the code as well, in this case that's Gleb. > Cc: a...@redhat.com > v2: Various fixes to address review feedback > Signed-off-by: Andi Kleen <a...@linux.intel.com> > --- > arch/x86/kvm/pmu.c | 15 +++++++++++---- > 1 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c > index cfc258a..81c1632 100644 > --- a/arch/x86/kvm/pmu.c > +++ b/arch/x86/kvm/pmu.c > @@ -173,6 +173,11 @@ static void reprogram_counter(struct kvm_pmc *pmc, u32 > type, > .exclude_kernel = exclude_kernel, > .config = config, > }; > + /* Will be ignored on CPUs that don't support this. */ > + if (intx) > + attr.config |= HSW_INTX; > + if (intx_cp) > + attr.config |= HSW_INTX_CHECKPOINTED; > > attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc); > So I forgot how all this worked, but will the KVM emulation not pass this straight down to the hardware? Don't we have a problem where we're emulating arch perfmon v1 on AMD hardware? On AMD hardware those bits do have meaning. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
