From: Peter Zijlstra <peterz@infradead.org>
To: ira.weiny@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Fenghua Yu <fenghua.yu@intel.com>,
x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org
Subject: Re: [RFC PATCH 04/15] x86/pks: Preserve the PKRS MSR on context switch
Date: Tue, 14 Jul 2020 10:27:01 +0200 [thread overview]
Message-ID: <20200714082701.GO10769@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200714070220.3500839-5-ira.weiny@intel.com>
On Tue, Jul 14, 2020 at 12:02:09AM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> The PKRS MSR is defined as a per-core register. This isolates memory
> access by CPU. Unfortunately, the MSR is not preserved by XSAVE.
> Therefore, We must preserve the protections for individual tasks even if
> they are context switched out and placed on another cpu later.
This is a contradiction and utter trainwreck. We're not going to do more
per-core MSRs and pretend they make sense per-task.
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: ira.weiny@intel.com
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Fenghua Yu <fenghua.yu@intel.com>,
x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org
Subject: Re: [RFC PATCH 04/15] x86/pks: Preserve the PKRS MSR on context switch
Date: Tue, 14 Jul 2020 10:27:01 +0200 [thread overview]
Message-ID: <20200714082701.GO10769@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200714070220.3500839-5-ira.weiny@intel.com>
On Tue, Jul 14, 2020 at 12:02:09AM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> The PKRS MSR is defined as a per-core register. This isolates memory
> access by CPU. Unfortunately, the MSR is not preserved by XSAVE.
> Therefore, We must preserve the protections for individual tasks even if
> they are context switched out and placed on another cpu later.
This is a contradiction and utter trainwreck. We're not going to do more
per-core MSRs and pretend they make sense per-task.
next prev parent reply other threads:[~2020-07-14 8:27 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 7:02 [RFC PATCH 00/15] PKS: Add Protection Keys Supervisor (PKS) support ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 01/15] x86/pkeys: Create pkeys_internal.h ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 02/15] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 03/15] x86/pks: Enable Protection Keys Supervisor (PKS) ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 04/15] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 8:27 ` Peter Zijlstra [this message]
2020-07-14 8:27 ` Peter Zijlstra
2020-07-14 18:53 ` Ira Weiny
2020-07-14 18:53 ` Ira Weiny
2020-07-14 18:56 ` Dave Hansen
2020-07-14 18:56 ` Dave Hansen
2020-07-14 19:05 ` Peter Zijlstra
2020-07-14 19:05 ` Peter Zijlstra
2020-07-14 19:09 ` Ira Weiny
2020-07-14 19:09 ` Ira Weiny
2020-07-16 8:37 ` [x86/pks] 061e3e0b92: leaking-addresses.dmesg.uncheckedMSRaccesserror:WRMSRto0x6e1(triedtowrite0x0000000055555554)atrIP:(write_pkrs+0x15/0x2b) kernel test robot
2020-07-16 8:37 ` kernel test robot
2020-07-14 7:02 ` [RFC PATCH 05/15] x86/pks: Add PKS kernel API ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 06/15] x86/pks: Add a debugfs file for allocated PKS keys ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 07/15] Documentation/pkeys: Update documentation for kernel pkeys ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 08/15] x86/pks: Add PKS Test code ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 09/15] fs/dax: Remove unused size parameter ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 10/15] drivers/dax: Expand lock scope to cover the use of addresses ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 11/15] memremap: Add zone device access protection ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 8:40 ` Peter Zijlstra
2020-07-14 8:40 ` Peter Zijlstra
2020-07-14 19:10 ` Ira Weiny
2020-07-14 19:10 ` Ira Weiny
2020-07-14 19:40 ` Peter Zijlstra
2020-07-14 19:40 ` Peter Zijlstra
2020-07-14 7:02 ` [RFC PATCH 12/15] kmap: Add stray write protection for device pages ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 8:44 ` Peter Zijlstra
2020-07-14 8:44 ` Peter Zijlstra
2020-07-14 19:06 ` Ira Weiny
2020-07-14 19:06 ` Ira Weiny
2020-07-14 19:29 ` Peter Zijlstra
2020-07-14 19:29 ` Peter Zijlstra
2020-07-14 19:42 ` Dave Hansen
2020-07-14 19:42 ` Dave Hansen
2020-07-14 19:49 ` Peter Zijlstra
2020-07-14 19:49 ` Peter Zijlstra
2020-07-14 20:00 ` Ira Weiny
2020-07-14 20:00 ` Ira Weiny
2020-07-14 7:02 ` [RFC PATCH 13/15] dax: Stray write protection for dax_direct_access() ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 14/15] nvdimm/pmem: Stray write protection for pmem->virt_addr ira.weiny
2020-07-14 7:02 ` ira.weiny
2020-07-14 7:02 ` [RFC PATCH 15/15] [dax|pmem]: Enable stray write protection ira.weiny
2020-07-14 7:02 ` ira.weiny
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200714082701.GO10769@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=fenghua.yu@intel.com \
--cc=ira.weiny@intel.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.