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From: Richard Weinberger <richard@nod.at>
To: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Christoph Hellwig <hch@infradead.org>,
	kernel list <linux-kernel@vger.kernel.org>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	"clementine.maurice@iaik.tugraz.at" 
	<clementine.maurice@iaik.tugraz.at>,
	"moritz.lipp@iaik.tugraz.at" <moritz.lipp@iaik.tugraz.at>,
	Michael Schwarz <michael.schwarz@iaik.tugraz.at>,
	Richard Fellner <richard.fellner@student.tugraz.at>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Ingo Molnar <mingo@kernel.org>,
	"anders.fogh@gdata-adan.de" <anders.fogh@gdata-adan.de>
Subject: Re: [kernel-hardening] Re: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Mon, 8 May 2017 00:02:41 +0200	[thread overview]
Message-ID: <6013bf3f-c3bd-3836-e5e2-ea89cc2e556a@nod.at> (raw)
In-Reply-To: <cc75a38a-4ea6-e300-0370-882dfbfd7a23@iaik.tugraz.at>

Daniel,

Am 07.05.2017 um 23:45 schrieb Daniel Gruss:
>> Just did a quick test on my main KVM host, a 8 core Intel(R) Xeon(R)
>> CPU E3-1240 V2.
>> KVM guests are 4.10 w/o CONFIG_KAISER and kvmconfig without CONFIG_PARAVIRT.
>> Building a defconfig kernel within that guests is about 10% slower
>> when CONFIG_KAISER
>> is enabled.
> 
> Thank you for testing it! :)
> 
>> Is this expected?
> 
> It sounds plausible. First, I would expect any form of virtualization to increase the overhead. Second, for the processor (Ivy Bridge), I would have expected even higher
> performance overheads. KAISER utilizes very recent performance improvements in Intel processors...

Ahh, *very* recent is the keyword then. ;)
I was a bit confused since in your paper the overhead is less than 1%.

What platforms did you test?
i.e. how does it perform on recent AMD systems?

Thanks,
//richard

  reply	other threads:[~2017-05-07 22:02 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-04 10:02 [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode Daniel Gruss
2017-05-04 12:26 ` Daniel Gruss
2017-05-04 15:28 ` [kernel-hardening] " Thomas Garnier
2017-05-05  8:23   ` Daniel Gruss
2017-05-05 15:47     ` Thomas Garnier
2017-05-06  4:02       ` David Gens
2017-05-06  8:38         ` Daniel Gruss
2017-05-08 10:21           ` Mark Rutland
2017-05-08 10:51             ` Daniel Gruss
2017-05-08 13:22               ` Mark Rutland
2017-05-08 13:43                 ` Daniel Gruss
2017-05-08 13:53           ` Daniel Gruss
2017-05-08 14:09             ` Thomas Garnier
2017-05-08 14:19               ` Daniel Gruss
2017-05-08 13:23     ` Daniel Gruss
2017-05-04 15:47 ` Christoph Hellwig
2017-05-05  7:40   ` Daniel Gruss
2017-05-07 20:20     ` [kernel-hardening] " Richard Weinberger
2017-05-07 21:45       ` Daniel Gruss
2017-05-07 22:02         ` Richard Weinberger [this message]
2017-05-07 22:18           ` Daniel Gruss
2017-05-09 14:44             ` [kernel-hardening] Re: [RFC, PATCH] x86_64: KAISER - do not mapkernel " Fogh, Anders
2017-05-09 14:57               ` Richard Weinberger
2017-05-09 15:30                 ` Rik van Riel
2017-10-31 23:28                   ` Dave Hansen
2017-05-05 15:49 ` [kernel-hardening] [RFC, PATCH] x86_64: KAISER - do not map kernel " Jann Horn
2017-05-05 15:53   ` Jann Horn
2017-05-06  8:28     ` Daniel Gruss

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