From: Dave Hansen <dave.hansen@intel.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
X86 ML <x86@kernel.org>, "Rafael J . Wysocki" <rjw@rjwysocki.net>,
"H . Peter Anvin" <hpa@zytor.com>,
Tony Luck <tony.luck@intel.com>, Andi Kleen <ak@linux.intel.com>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux ACPI <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH v2] x86: Skip WBINVD instruction for VM guest
Date: Mon, 6 Dec 2021 08:53:50 -0800 [thread overview]
Message-ID: <e84556f2-a724-5f90-d950-b4e017eee989@intel.com> (raw)
In-Reply-To: <CAPcyv4gHK=-gxxYexV8jtycPGE15yDWe7jYutbcqKc-1Zhmx8Q@mail.gmail.com>
On 12/6/21 8:39 AM, Dan Williams wrote:
>> But, the trick is that we need a contract. A contract requires a
>> "meeting of the minds" first.
> The WBINVD requirement in sleep states is about getting cache contents
> out to to power preserved domain before the CPU turns off. The bare
> metal host handles that requirement. The conversation that needs to be
> had is with the ACPI specification committee to clarify that virtual
> machines have no responsibility to flush caches. We can do that as a
> Code First proposal to the ACPI Specification Working Group.
Sounds sane to me. So, we effectively go to the ACPI folks and say that
Linux isn't going to do WBINVD in virtualized environments any more.
That was effectively the approach that the first patch in this thread did:
> https://lore.kernel.org/all/20211116005027.2929297-1-sathyanarayanan.kuppuswamy@linux.intel.com/
Right?
next prev parent reply other threads:[~2021-12-06 17:05 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-16 0:50 [PATCH v1 1/1] x86: Skip WBINVD instruction for VM guest Kuppuswamy Sathyanarayanan
2021-11-16 16:24 ` Borislav Petkov
2021-11-16 16:36 ` Sathyanarayanan Kuppuswamy
2021-11-19 4:03 ` [PATCH v2] " Kuppuswamy Sathyanarayanan
2021-11-25 0:40 ` Thomas Gleixner
2021-12-02 22:21 ` Kirill A. Shutemov
2021-12-02 22:38 ` Dave Hansen
2021-12-02 23:48 ` Thomas Gleixner
2021-12-03 23:49 ` Kirill A. Shutemov
2021-12-04 0:20 ` Dave Hansen
2021-12-04 0:54 ` Kirill A. Shutemov
2021-12-06 15:35 ` Dave Hansen
2021-12-06 16:39 ` Dan Williams
2021-12-06 16:53 ` Dave Hansen [this message]
2021-12-06 17:51 ` Dan Williams
2021-12-04 20:27 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 0/4] ACPI/ACPICA: Only flush caches on S1/S2/S3 and C3 Kirill A. Shutemov
2021-12-06 12:29 ` [PATCH 1/4] ACPICA: Do not flush cache for on entering S4 and S5 Kirill A. Shutemov
2021-12-08 14:58 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 2/4] ACPI: PM: Remove redundant cache flushing Kirill A. Shutemov
2021-12-07 16:35 ` Rafael J. Wysocki
2021-12-09 13:32 ` Kirill A. Shutemov
2021-12-17 18:04 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 3/4] ACPI: processor idle: Only flush cache on entering C3 Kirill A. Shutemov
2021-12-06 15:03 ` Peter Zijlstra
2021-12-08 16:26 ` Rafael J. Wysocki
2021-12-09 13:33 ` Kirill A. Shutemov
2021-12-17 17:58 ` Rafael J. Wysocki
2021-12-06 12:29 ` [PATCH 4/4] ACPI: PM: Avoid cache flush on entering S4 Kirill A. Shutemov
2021-12-08 15:10 ` Rafael J. Wysocki
2021-12-08 16:04 ` Kirill A. Shutemov
2021-12-08 16:16 ` Rafael J. Wysocki
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=e84556f2-a724-5f90-d950-b4e017eee989@intel.com \
--to=dave.hansen@intel.com \
--cc=ak@linux.intel.com \
--cc=bp@alien8.de \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=knsathya@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=rjw@rjwysocki.net \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--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;
as well as URLs for NNTP newsgroup(s).