From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel List <xen-devel@lists.xen.org>,
Jan Beulich <JBeulich@suse.com>,
Kevin Tian <kevin.tian@intel.com>,
Jun Nakajima <jun.nakajima@intel.com>,
"Lai, Paul C" <paul.c.lai@intel.com>
Subject: PC8 Residency on Broadwell hardware
Date: Mon, 12 Sep 2016 09:47:59 +0100 [thread overview]
Message-ID: <2515b770-ee65-8d8c-6ddb-cfca01e087ba@citrix.com> (raw)
Hello,
c/s 350bc1a9d4 "x86: support newer Intel CPU models" changed the set of
MSRs read by Xeon Broadwell hardware (specifically, model 79 / 0x47).
Rereading the manual, it does indeed indicate that this MSR is available.
However, experimentally it is not. All Broadwell hardware XenServer has
(both SDPs and production systems) reliably take a #GP fault when trying
to read this MSR. Haswell hardware appears fine (and indeed, was
reading that MSR before).
Intel: Please can you confirm whether the documentation is correct? If
it is, do you have any idea why the MSR might not be available? I can't
spot anything relevant in the platform errata documents.
Thanks,
~Andrew
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next reply other threads:[~2016-09-12 8:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-12 8:47 Andrew Cooper [this message]
2016-09-12 9:00 ` PC8 Residency on Broadwell hardware Jan Beulich
2016-09-12 17:28 ` Nakajima, Jun
2016-09-13 7:51 ` Jan Beulich
2016-09-13 9:05 ` Andrew Cooper
2016-09-13 16:10 ` Nakajima, Jun
2016-09-18 23:24 ` Nakajima, Jun
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