From: Fenghua Yu <fenghua.yu@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, H Peter Anvin <hpa@zytor.com>,
Ashok Raj <ashok.raj@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Michael Chan <michael.chan@broadcom.com>,
Ravi V Shankar <ravi.v.shankar@intel.com>,
Ricardo Neri <ricardo.neri@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>
Subject: Re: [PATCH v3 09/10] x86/split_lock: Define #AC for split lock feature
Date: Mon, 4 Feb 2019 11:03:44 -0800 [thread overview]
Message-ID: <20190204190344.GA69898@romley-ivt3.sc.intel.com> (raw)
In-Reply-To: <efd79b59-c3b5-a635-534a-b49596174969@intel.com>
On Mon, Feb 04, 2019 at 11:00:03AM -0800, Dave Hansen wrote:
> On 2/4/19 10:45 AM, Fenghua Yu wrote:
> > On Mon, Feb 04, 2019 at 10:41:40AM -0800, Dave Hansen wrote:
> >> On 2/1/19 9:14 PM, Fenghua Yu wrote:
> >>> --- a/arch/x86/include/asm/cpufeatures.h
> >>> +++ b/arch/x86/include/asm/cpufeatures.h
> >>> @@ -221,6 +221,7 @@
> >>> #define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */
> >>> #define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */
> >>> #define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */
> >>> +#define X86_FEATURE_AC_SPLIT_LOCK ( 7*32+31) /* #AC for split lock */
> >>
> >> The last time this was posted, we (Intel) promised to go get the proper
> >> (CPUID or MSR-based) enumeration of this feature documented. Did we do
> >> that? If so, where is that documentation?
> >
> > As said in the cover patch:
> > "Please note: The feature could be enumerated through
> > MSR IA32_CORE_CAPABILITY (0xCF). But the enumeration is not completely
> > published yet. So this patch set doesn't include the method."
>
> FWIW, I think we (Intel) promised to get this documented _before_ we
> came back asking our intrepid x86 maintainers to accept something like
> setcpuid=. While I generally applaud the post-early-post-often
> attitude, we might have been a bit trigger-happy on this one.
>
> This is awfully crucial information to bury in a massive cover letter,
> especially when the patch description is a rather anemic two lines.
>
Hi, Dave,
I do have two pathes available to enumerate IA32_CORE_CAPABILITY itself
and to enumerate #AC for split lock by bit 5 in the MSR. But because the
enumeration for the MSR is not published, I cannot release the two
patches in this patch set.
Hopefully this patch set without the two enumeration patches is
a meaningful set.
Thanks.
-Fenghua
next prev parent reply other threads:[~2019-02-04 19:09 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-02 5:14 [PATCH v3 00/10] x86/split_lock: Enable #AC exception for split locked accesses Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 01/10] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 02/10] drivers/net/b44: Align pwol_mask to unsigned long for better performance Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 03/10] wlcore: Align reg_ch_conf_pending and tmp_ch_bitmap " Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 04/10] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 05/10] x86/clearcpuid: Support multiple clearcpuid options Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 06/10] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 07/10] Change document for " Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 08/10] x86/setcpuid: Add kernel option setcpuid Fenghua Yu
2019-02-04 17:49 ` Thomas Gleixner
2019-02-04 19:05 ` Dave Hansen
2019-02-04 19:57 ` Borislav Petkov
2019-02-04 20:46 ` Dave Hansen
2019-02-04 21:40 ` Borislav Petkov
2019-02-04 22:14 ` Fenghua Yu
2019-02-05 6:10 ` Borislav Petkov
2019-02-04 23:24 ` Dave Hansen
2019-02-05 6:18 ` Borislav Petkov
2019-02-05 16:46 ` Dave Hansen
2019-02-05 17:09 ` Peter Zijlstra
2019-02-05 8:57 ` Peter Zijlstra
2019-02-05 13:15 ` Peter Zijlstra
2019-02-05 8:48 ` Peter Zijlstra
2019-02-05 15:19 ` Dave Hansen
2019-02-05 15:43 ` Borislav Petkov
2019-02-05 18:26 ` Fenghua Yu
2019-02-05 17:04 ` Peter Zijlstra
2019-02-10 19:20 ` Thomas Gleixner
2019-02-11 19:16 ` Fenghua Yu
2019-02-12 13:37 ` Peter Zijlstra
2019-02-12 13:51 ` Thomas Gleixner
2019-02-12 16:48 ` Peter Zijlstra
2019-02-12 16:50 ` Dave Hansen
2019-02-12 17:52 ` Yu, Fenghua
2019-02-04 21:09 ` Fenghua Yu
2019-02-05 8:51 ` Peter Zijlstra
2019-02-05 15:21 ` Dave Hansen
2019-02-05 15:34 ` Peter Zijlstra
2019-02-02 5:14 ` [PATCH v3 09/10] x86/split_lock: Define #AC for split lock feature Fenghua Yu
2019-02-04 18:41 ` Dave Hansen
2019-02-04 18:45 ` Fenghua Yu
2019-02-04 19:00 ` Dave Hansen
2019-02-04 19:03 ` Fenghua Yu [this message]
2019-02-02 5:14 ` [PATCH v3 10/10] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-02-04 11:00 ` kbuild test robot
2019-02-04 14:43 ` kbuild test robot
2019-02-11 10:53 ` Ingo Molnar
2019-02-11 18:10 ` Fenghua Yu
2019-02-13 8:14 ` Ingo Molnar
2019-02-13 14:37 ` Yu, Fenghua
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=20190204190344.GA69898@romley-ivt3.sc.intel.com \
--to=fenghua.yu@intel.com \
--cc=ashok.raj@intel.com \
--cc=dave.hansen@intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=michael.chan@broadcom.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=ricardo.neri@intel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome