Bug 665972 - ISVM bit (ECX:31) for CPUID 0x00000001 is missing for HVM on AMD
Summary: ISVM bit (ECX:31) for CPUID 0x00000001 is missing for HVM on AMD
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel-xen
Version: 5.6
Hardware: Unspecified
OS: Unspecified
low
medium
Target Milestone: rc
: ---
Assignee: Paolo Bonzini
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-12-28 07:36 UTC by Jinxin Zheng
Modified: 2011-07-21 18:59 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-07-21 10:28:38 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)
fix for the bug (883 bytes, patch)
2011-01-05 08:21 UTC, Paolo Bonzini
no flags Details | Diff


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2011:1065 0 normal SHIPPED_LIVE Important: Red Hat Enterprise Linux 5.7 kernel security and bug fix update 2011-07-21 09:21:37 UTC

Description Jinxin Zheng 2010-12-28 07:36:19 UTC
Description of problem:
Bug 573771 adds IsVM test support for guest. However this is found not working for HVM on an AMD CPU.

Version-Release number of selected component (if applicable):
kernel-xen-2.6.18-238.el5

How reproducible:
Always on AMD.

Steps to Reproduce:
In the HVM guest, run the code attached in bug 573771. It outputs

HVM guest, hypervisor present bit *NOT* set

or

$ x86info -r | grep 0x00000001
eax in: 0x00000001, eax = 00100f23 ebx = 02010800 ecx = 00002001 edx = 0789fbff

see bit 31 of ecx is not set.

Comment 1 Paolo Bonzini 2011-01-05 08:21:19 UTC
Created attachment 471812 [details]
fix for the bug

Alternatively, one could backport c/s 16990 from upstream.

Comment 2 RHEL Program Management 2011-02-01 16:50:59 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 4 Jarod Wilson 2011-02-09 14:57:27 UTC
in kernel-2.6.18-243.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

Comment 6 Qixiang Wan 2011-02-24 06:39:27 UTC
Test with kernel 2.6.18-243.el5xen, ISVM bit is set on AMD cpu now, run the program attached in but 573771 comment 1 will get the output:

HVM guest, hypervisor present bit set

change to VERIFIED.

Comment 8 errata-xmlrpc 2011-07-21 10:28:38 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-1065.html


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