From: Andi Kleen <ak@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
eranian@google.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] x86, perf: Support custom test values for extra_regs
Date: Tue, 30 Jun 2015 08:44:51 -0700 [thread overview]
Message-ID: <20150630154451.GA25760@tassilo.jf.intel.com> (raw)
In-Reply-To: <20150630111907.GF3644@twins.programming.kicks-ass.net>
On Tue, Jun 30, 2015 at 01:19:07PM +0200, Peter Zijlstra wrote:
> On Mon, Jun 29, 2015 at 02:22:14PM -0700, Andi Kleen wrote:
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Current kernels always test extra registers at boot with RMW
> > cycle, to catch lying virtual machines.
> >
> > For a new register the standard 0x1ff test value does not work,
> > as 0x1ff is not a valid value and causes an #GP.
> >
> > Add the ability to add custom test values to an extra_reg
> > into the description tables.
>
> Just wondering; is there not a test value that works for all registers?
0x11 will likely work everywhere.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2015-06-30 15:44 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-29 21:22 [PATCH 1/3] x86, perf: Make merge_attr global to use from perf_event_intel Andi Kleen
2015-06-29 21:22 ` [PATCH 2/3] x86, perf: Support custom test values for extra_regs Andi Kleen
2015-06-30 11:19 ` Peter Zijlstra
2015-06-30 15:44 ` Andi Kleen [this message]
2015-06-29 21:22 ` [PATCH 3/3] x86, perf: Add PEBS frontend profiling for Skylake Andi Kleen
2015-07-17 19:47 ` Stephane Eranian
2015-07-17 20:09 ` Andi Kleen
2015-07-17 20:11 ` Thomas Gleixner
2015-07-17 20:33 ` Andi Kleen
2015-07-17 21:01 ` Stephane Eranian
2015-07-17 21:19 ` Andi Kleen
2015-07-17 22:00 ` Stephane Eranian
2015-07-17 23:31 ` Andi Kleen
2015-07-17 23:52 ` Stephane Eranian
2015-07-18 14:23 ` Andi Kleen
2015-07-17 22:16 ` Thomas Gleixner
2015-07-17 20:41 ` Stephane Eranian
2015-07-17 20:52 ` Andi Kleen
2015-07-17 21:05 ` Peter Zijlstra
2015-07-17 21:18 ` Andi Kleen
2015-07-17 22:23 ` Thomas Gleixner
2015-08-04 9:00 ` [tip:perf/core] perf/x86: Make merge_attr() global to use from perf_event_intel tip-bot for Andi Kleen
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