From: Eric Hankland <ehankland@google.com>
To: Wei Wang <wei.w.wang@intel.com>
Cc: pbonzini@redhat.com, rkrcmar@redhat.com,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v1] KVM: x86: PMU Whitelist
Date: Tue, 4 Jun 2019 08:56:36 -0700 [thread overview]
Message-ID: <CAOyeoRW5wx0F=9B24h29KkhUrbaORXVSoJufb4d-XzKiAsz+NQ@mail.gmail.com> (raw)
In-Reply-To: <5CF5F6AE.90706@intel.com>
On Mon, Jun 3, 2019 at 9:37 PM Wei Wang <wei.w.wang@intel.com> wrote:
> So, I'm not sure if "quantifying LLC contention" has been proved to
> be a real issue. If this is considered to be an issue:
>
> - without PMU, we could also write a piece of software to run in the
> guest to quantify that contention (e.g. by analyzing the memory access
> latency). How do you prevent this?
>
> - the same thing could also happen with the L1 cache (e.g. a vCPU
> and a host thread run 2 logical CPUs on the same core). If this is disabled
> as well, we may have very few events usable, and would like to see what you
> have on the whitelist.
Right - I'm aware there are other ways of detecting this - it's still
a class of events that some people don't want to surface. I'll ask if
there are any better examples.
Eric
next prev parent reply other threads:[~2019-06-04 15:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-22 22:23 [PATCH v1] KVM: x86: PMU Whitelist Eric Hankland
2019-05-28 2:01 ` Wei Wang
2019-05-28 18:14 ` Eric Hankland
2019-05-29 7:54 ` Wei Wang
2019-05-29 17:11 ` Eric Hankland
2019-05-31 1:02 ` Wei Wang
2019-05-31 19:59 ` Eric Hankland
2019-06-01 10:55 ` Wei Wang
2019-06-03 17:30 ` Eric Hankland
2019-06-04 4:42 ` Wei Wang
2019-06-04 15:56 ` Eric Hankland [this message]
[not found] ` <CAEU=KTHsVmrAHXUKdHu_OwcrZoy-hgV7pk4UymtchGE5bGdUGA@mail.gmail.com>
2019-06-05 21:35 ` Eric Hankland
2019-06-06 7:36 ` Wei Wang
2019-06-13 17:43 ` Eric Hankland
2019-06-14 9:14 ` Wei Wang
2019-06-14 9:26 ` Wei Wang
2019-06-25 0:32 ` Eric Hankland
2019-06-25 9:12 ` Wei Wang
2019-07-02 17:46 ` Eric Hankland
2019-07-03 9:06 ` Wei Wang
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