From: Jim Mattson <jmattson@google.com>
To: Andi Kleen <ak@linux.intel.com>
Cc: "David Dunn" <ddunn@vmware.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
"Arjan van de Ven" <arjan@linux.intel.com>,
"KarimAllah Ahmed" <karahmed@amazon.de>,
"Wilson, Matt" <msw@amazon.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Andrea Arcangeli" <aarcange@redhat.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Ashok Raj" <ashok.raj@intel.com>,
"Asit Mallick" <asit.k.mallick@intel.com>,
"Borislav Petkov" <bp@suse.de>,
"Dan Williams" <dan.j.williams@intel.com>,
"Dave Hansen" <dave.hansen@intel.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"H . Peter Anvin" <hpa@zytor.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Janakarajan Natarajan" <Janakarajan.Natarajan@amd.com>,
"Joerg Roedel" <joro@8bytes.org>,
"Jun Nakajima" <jun.nakajima@intel.com>,
"Laura Abbott" <labbott@redhat.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Masami Hiramatsu" <mhiramat@kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Tim Chen" <tim.c.chen@linux.intel.com>,
"Tom Lendacky" <thomas.lendacky@amd.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Fred Jacobs" <fjacobs@vmware.com>,
"David Woodhouse" <dwmw2@infradead.org>
Subject: Re: [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure
Date: Mon, 29 Jan 2018 14:49:51 -0800 [thread overview]
Message-ID: <CALMp9eQfuiXdnJkiAM3g933AUpLmhugsryhONOYo5MPATUS4rQ@mail.gmail.com> (raw)
In-Reply-To: <20180129224124.GU26209@tassilo.jf.intel.com>
And if we expect to introduce Cascade Lake into the pool in the
future, we use a Cascade Lake model number?
It sounds like you are suggesting that we set the model number to the
highest model number that will ever be introduced into the pool, at
any time in the future. That approach would also fail the
'is_skylake_era()' test. (Not to mention that we have no idea what
Intel's highest compatible model number will be.)
On Mon, Jan 29, 2018 at 2:41 PM, Andi Kleen <ak@linux.intel.com> wrote:
>> Even if we expose bit to indicate that FMS matches the underlying host, when does the guest know to query that? The VM can be moved at any point in time, including after the guest asks if FMS matches host.
>
> There's no way to enable these mitigations later, so if you always
> have to enable the super set of all the mitigations for all the hosts you
> might be migrating too.
>
> As of currently that means if you want to ever migrate to Skylake you should
> set the Skylake model number and you're good.
>
> -Andi
next prev parent reply other threads:[~2018-01-29 22:49 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-29 22:29 [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure David Dunn
2018-01-29 22:41 ` Andi Kleen
2018-01-29 22:49 ` Jim Mattson [this message]
2018-01-30 1:10 ` Eduardo Habkost
2018-01-30 1:20 ` David Dunn
2018-01-30 1:30 ` Eduardo Habkost
2018-01-29 23:51 ` Fred Jacobs
2018-01-30 1:08 ` Eduardo Habkost
-- strict thread matches above, loose matches on Subject: below --
2018-01-20 19:22 [RFC 00/10] Speculation Control feature support KarimAllah Ahmed
2018-01-20 19:22 ` [RFC 05/10] x86/speculation: Add basic IBRS support infrastructure KarimAllah Ahmed
2018-01-21 14:31 ` Thomas Gleixner
2018-01-21 14:56 ` Borislav Petkov
2018-01-22 9:51 ` Peter Zijlstra
2018-01-22 12:06 ` Borislav Petkov
2018-01-22 13:30 ` Greg Kroah-Hartman
2018-01-22 13:37 ` Woodhouse, David
2018-01-21 15:25 ` David Woodhouse
2018-01-23 20:58 ` David Woodhouse
2018-01-23 22:43 ` Johannes Erdfelt
2018-01-24 8:47 ` Peter Zijlstra
2018-01-24 9:02 ` David Woodhouse
2018-01-24 9:10 ` Greg Kroah-Hartman
2018-01-24 15:09 ` Arjan van de Ven
2018-01-24 15:18 ` David Woodhouse
2018-01-24 9:34 ` Peter Zijlstra
2018-01-24 10:49 ` Henrique de Moraes Holschuh
2018-01-24 12:30 ` David Woodhouse
2018-01-24 12:14 ` David Woodhouse
2018-01-24 12:29 ` Peter Zijlstra
2018-01-24 12:58 ` David Woodhouse
2018-01-29 20:14 ` [RFC,05/10] " Eduardo Habkost
2018-01-29 20:17 ` David Woodhouse
2018-01-29 20:42 ` Eduardo Habkost
2018-01-29 20:44 ` Arjan van de Ven
2018-01-29 21:02 ` David Woodhouse
2018-01-29 21:37 ` Jim Mattson
2018-01-29 21:50 ` Eduardo Habkost
2018-01-29 22:12 ` Jim Mattson
2018-01-30 1:22 ` Eduardo Habkost
2018-01-29 22:25 ` Andi Kleen
2018-01-30 1:37 ` Eduardo Habkost
2018-01-29 21:37 ` Andi Kleen
2018-01-29 21:44 ` Eduardo Habkost
2018-01-29 22:10 ` Konrad Rzeszutek Wilk
2018-01-30 1:12 ` Eduardo Habkost
2018-01-30 0:23 ` Linus Torvalds
2018-01-30 1:03 ` Jim Mattson
2018-01-30 3:13 ` Andi Kleen
2018-01-31 15:03 ` Paolo Bonzini
2018-01-31 15:07 ` Dr. David Alan Gilbert
2018-01-30 1:32 ` Arjan van de Ven
2018-01-30 3:32 ` Linus Torvalds
2018-01-30 12:04 ` Eduardo Habkost
2018-01-30 13:54 ` Arjan van de Ven
2018-01-30 8:22 ` David Woodhouse
2018-01-30 11:35 ` David Woodhouse
2018-01-30 11:56 ` Dr. David Alan Gilbert
2018-01-30 12:11 ` Christian Borntraeger
2018-01-30 14:46 ` Christophe de Dinechin
2018-01-30 14:52 ` Christian Borntraeger
2018-01-30 14:56 ` Christophe de Dinechin
2018-01-30 15:33 ` Christian Borntraeger
2018-01-30 20:46 ` Alan Cox
2018-01-31 10:05 ` Christophe de Dinechin
2018-01-31 10:15 ` Thomas Gleixner
2018-01-31 11:04 ` Dr. David Alan Gilbert
2018-01-31 11:52 ` Borislav Petkov
2018-01-31 12:30 ` Dr. David Alan Gilbert
2018-01-31 13:18 ` Borislav Petkov
2018-01-31 14:04 ` Dr. David Alan Gilbert
2018-01-31 14:44 ` Eduardo Habkost
2018-01-31 16:28 ` Borislav Petkov
2018-01-31 11:07 ` Christophe de Dinechin
2018-01-31 15:00 ` Eduardo Habkost
2018-01-31 15:11 ` Arjan van de Ven
2018-01-31 10:03 ` [RFC 05/10] " Christophe de Dinechin
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=CALMp9eQfuiXdnJkiAM3g933AUpLmhugsryhONOYo5MPATUS4rQ@mail.gmail.com \
--to=jmattson@google.com \
--cc=Janakarajan.Natarajan@amd.com \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=arjan@linux.intel.com \
--cc=ashok.raj@intel.com \
--cc=asit.k.mallick@intel.com \
--cc=bp@suse.de \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=ddunn@vmware.com \
--cc=dgilbert@redhat.com \
--cc=dwmw2@infradead.org \
--cc=ehabkost@redhat.com \
--cc=fjacobs@vmware.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=joro@8bytes.org \
--cc=jun.nakajima@intel.com \
--cc=karahmed@amazon.de \
--cc=kvm@vger.kernel.org \
--cc=labbott@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=msw@amazon.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=rkrcmar@redhat.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--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).