From: Khalid Aziz <khalid.aziz@oracle.com>
To: Waiman Long <longman@redhat.com>, Ingo Molnar <mingo@kernel.org>
Cc: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de,
keescook@google.com, konrad.wilk@oracle.com,
Juerg Haefliger <juerg.haefliger@canonical.com>,
deepa.srinivasan@oracle.com, chris.hyser@oracle.com,
tyhicks@canonical.com, dwmw@amazon.co.uk,
andrew.cooper3@citrix.com, jcm@redhat.com,
boris.ostrovsky@oracle.com, iommu@lists.linux-foundation.org,
x86@kernel.org, linux-arm-kernel@lists.infradead.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-security-module@vger.kernel.org,
Khalid Aziz <khalid@gonehiking.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Dave Hansen <dave@sr71.net>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Arjan van de Ven <arjan@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [RFC PATCH v9 03/13] mm: Add support for eXclusive Page Frame Ownership (XPFO)
Date: Wed, 1 May 2019 09:18:41 -0600 [thread overview]
Message-ID: <4a47cf86-a05d-3de5-0320-eda06101cc75@oracle.com> (raw)
In-Reply-To: <35c4635e-8214-7dde-b4ec-4cb266b2ea10@redhat.com>
On 5/1/19 8:49 AM, Waiman Long wrote:
> On Wed, Apr 03, 2019 at 11:34:04AM -0600, Khalid Aziz wrote:
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt
> b/Documentation/admin-guide/kernel-parameters.txt
>
>> index 858b6c0b9a15..9b36da94760e 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -2997,6 +2997,12 @@
>>
>> nox2apic [X86-64,APIC] Do not enable x2APIC mode.
>>
>> + noxpfo [XPFO] Disable eXclusive Page Frame Ownership (XPFO)
>> + when CONFIG_XPFO is on. Physical pages mapped into
>> + user applications will also be mapped in the
>> + kernel's address space as if CONFIG_XPFO was not
>> + enabled.
>> +
>> cpu0_hotplug [X86] Turn on CPU0 hotplug feature when
>> CONFIG_BO OTPARAM_HOTPLUG_CPU0 is off.
>> Some features depend on CPU0. Known dependencies are:
>
> Given the big performance impact that XPFO can have. It should be off by
> default when configured. Instead, the xpfo option should be used to
> enable it.
Agreed. I plan to disable it by default in the next version of the
patch. This is likely to end up being a feature for extreme security
conscious folks only, unless I or someone else comes up with further
significant performance boost.
Thanks,
Khalid
prev parent reply other threads:[~2019-05-01 15:22 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1554248001.git.khalid.aziz@oracle.com>
2019-04-04 16:44 ` [RFC PATCH v9 00/13] Add support for eXclusive Page Frame Ownership Nadav Amit
2019-04-04 17:18 ` Khalid Aziz
[not found] ` <f1ac3700970365fb979533294774af0b0dd84b3b.1554248002.git.khalid.aziz@oracle.com>
2019-04-17 16:15 ` [RFC PATCH v9 03/13] mm: Add support for eXclusive Page Frame Ownership (XPFO) Ingo Molnar
2019-04-17 16:49 ` Khalid Aziz
2019-04-17 17:09 ` Ingo Molnar
2019-04-17 17:19 ` Nadav Amit
2019-04-17 17:26 ` Ingo Molnar
2019-04-17 17:44 ` Nadav Amit
2019-04-17 21:19 ` Thomas Gleixner
[not found] ` <CAHk-=wgBMg9P-nYQR2pS0XwVdikPCBqLsMFqR9nk=wSmAd4_5g@mail.gmail.com>
2019-04-17 23:42 ` Thomas Gleixner
2019-04-17 23:52 ` Linus Torvalds
2019-04-18 4:41 ` Andy Lutomirski
2019-04-18 5:41 ` Kees Cook
2019-04-18 14:34 ` Khalid Aziz
2019-04-22 19:30 ` Khalid Aziz
2019-04-22 22:23 ` Kees Cook
2019-04-18 6:14 ` Thomas Gleixner
2019-04-17 17:33 ` Khalid Aziz
2019-04-17 19:49 ` Andy Lutomirski
2019-04-17 19:52 ` Tycho Andersen
2019-04-17 20:12 ` Khalid Aziz
2019-05-01 14:49 ` Waiman Long
2019-05-01 15:18 ` Khalid Aziz [this message]
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