From: Ian Jackson <iwj@xenproject.org>
To: Jan Beulich <jbeulich@suse.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>,
"Anthony PERARD" <anthony.perard@citrix.com>,
"Jun Nakajima" <jun.nakajima@intel.com>,
"Kevin Tian" <kevin.tian@intel.com>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
xen-devel@lists.xenproject.org
Subject: Re: [PATCH RFC for-4.15] x86/msr: introduce an option for legacy MSR behavior selection
Date: Thu, 4 Mar 2021 11:24:41 +0000 [thread overview]
Message-ID: <24640.50041.969590.549237@mariner.uk.xensource.com> (raw)
In-Reply-To: <7e9ac991-f575-aa92-5fd8-33c8193cad67@suse.com>
Jan Beulich writes ("Re: [PATCH RFC for-4.15] x86/msr: introduce an option for legacy MSR behavior selection"):
> On 04.03.2021 11:05, Roger Pau Monné wrote:
...
> > This one seems like a fine candidate to implement in
> > svm_msr_read_intercept, because Xen needs to return a specific value
> > for this MSR.
> >
> > Regarding the global approach to fixing the fallout from the MSR
> > policy change, I don't see why we couldn't do a mix between pro-active
> > and reactive.
> >
> > I think we must have an option to fallback to something similar to the
> > old policy for HVM guests so that users have a way to get their guests
> > running after an update without requiring a code change.
> >
> > That doesn't mean we can't reactively add the missing MSRs as we go
> > discovering them. I would even print a warning when using such
> > fallback legacy MSR handling option that you need to report the issue
> > to xen-devel because the option might be removed in future releases.
> >
> > Does the above seem like a sensible plan?
>
> I think so, yes. I wonder what Andrew thinks, though.
FTR I am on board with this plan. I would like to see quick progress
on this issue as it seems like one of the major risks in the release.
Thanks,
Ian.
prev parent reply other threads:[~2021-03-04 11:25 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-01 16:23 [PATCH RFC for-4.15] x86/msr: introduce an option for legacy MSR behavior selection Roger Pau Monne
2021-03-01 17:16 ` Ian Jackson
2021-03-01 17:52 ` Roger Pau Monné
2021-03-01 17:57 ` Ian Jackson
2021-03-01 19:33 ` Boris Ostrovsky
2021-03-04 14:02 ` Andrew Cooper
2021-03-04 14:17 ` Andrew Cooper
2021-03-02 11:16 ` Jan Beulich
2021-03-02 15:00 ` Roger Pau Monné
2021-03-02 15:18 ` Jan Beulich
2021-03-03 15:38 ` Roger Pau Monné
2021-03-04 8:48 ` Jan Beulich
2021-03-04 10:05 ` Roger Pau Monné
2021-03-04 10:58 ` Jan Beulich
2021-03-04 11:24 ` Ian Jackson [this message]
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