From: David Ahern <dsahern@gmail.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: acme@ghostprotocols.net, linux-kernel@vger.kernel.org,
peterz@infradead.org, Ingo Molnar <mingo@kernel.org>,
Robert Richter <robert.richter@amd.com>,
Gleb Natapov <gleb@redhat.com>, Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 2/3] perf: require exclude_guest to use PEBS - kernel side enforcement
Date: Wed, 12 Sep 2012 22:33:36 -0600 [thread overview]
Message-ID: <50516220.7060507@gmail.com> (raw)
In-Reply-To: <87392mabqn.fsf@sejong.aot.lge.com>
On 9/12/12 8:38 PM, Namhyung Kim wrote:
> Hi David,
>
> On Wed, 12 Sep 2012 09:16:29 -0600, David Ahern wrote:
>> From: Peter Zijlstra <peterz@infradead.org>
>>
>> Per Peter:
>> "Intel PEBS in VT-x context uses the DS address as a guest linear address,
>> even though its programmed by the host as a host linear address. This
>> either results in guest memory corruption and or the hardware faulting and
>> 'crashing' the virtual machine. Therefore we have to disable PEBS on VT-x
>> enter and re-enable on VT-x exit, enforcing a strict exclude_guest.
>>
>> This patch enforces exclude_guest kernel side.
>>
> [snip]
>> @@ -380,6 +383,9 @@ int x86_pmu_hw_config(struct perf_event *event)
>> if (event->attr.precise_ip) {
>> int precise = 0;
>>
>> + if (!event->attr.exclude_guest)
>> + return -EOPNOTSUPP;
>
> I see a whitespace problem here. :)
grr.... an extra freaking tab.
next prev parent reply other threads:[~2012-09-13 4:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-12 15:16 [PATCH 0/3 v2] perf: precise mode and exclude_guest David Ahern
2012-09-12 15:16 ` [PATCH 1/3] perf tool: precise mode requires exclude_guest David Ahern
2012-09-12 17:46 ` Robert Richter
2012-09-12 18:50 ` Arnaldo Carvalho de Melo
2012-09-13 9:13 ` Robert Richter
2012-09-12 15:16 ` [PATCH 2/3] perf: require exclude_guest to use PEBS - kernel side enforcement David Ahern
2012-09-13 2:38 ` Namhyung Kim
2012-09-13 4:33 ` David Ahern [this message]
2012-09-13 4:45 ` Arnaldo Carvalho de Melo
2012-09-12 15:16 ` [PATCH 3/3 v2] perf tool: give user better message if precise is not supported David Ahern
-- strict thread matches above, loose matches on Subject: below --
2012-09-13 20:59 [PATCH 0/3 v3] perf: precise mode and exclude_guest David Ahern
2012-09-13 20:59 ` [PATCH 2/3] perf: require exclude_guest to use PEBS - kernel side enforcement David Ahern
2012-09-10 16:40 [PATCH 0/3] perf: precise mode and exclude_guest David Ahern
2012-09-10 16:40 ` [PATCH 2/3] perf: require exclude_guest to use PEBS - kernel side enforcement David Ahern
2012-09-10 17:24 ` Peter Zijlstra
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