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Bug 625903

Summary: [Xen] backport hardware task switching for HVM guests
Product: Red Hat Enterprise Linux 5 Reporter: Paolo Bonzini <pbonzini>
Component: kernel-xenAssignee: Paolo Bonzini <pbonzini>
Status: CLOSED ERRATA QA Contact: Jan Tluka <jtluka>
Severity: high Docs Contact:
Priority: high    
Version: 5.5CC: cshao, drjones, minovotn, mrezanin, mshao, pbonzini, rwu, xen-maint, yuzhang
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 624598 Environment:
Last Closed: 2011-01-13 21:12:35 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 514489, 624598    
Attachments:
Description Flags
simple reproducer for 32-bit Linux guests
none
patch series to fix the bug none

Description Paolo Bonzini 2010-08-20 18:28:53 UTC
Windows sends NMI using a task gate.  This needs to be backported to Xen.

Comment 1 Paolo Bonzini 2010-08-27 08:28:17 UTC
Created attachment 441435 [details]
simple reproducer for 32-bit Linux guests

To reproduce under a RHEL5.5 Linux guest:

1) place the attached file into the guest's file system
2) install kernel-headers
3) Run the following commands:

sh double-fault.sh
cd double-fault
make
insmod double-fault.ko
rmmod double-fault

4) The guest should hang and not reset.  xm dmesg should _not_ mention a triple fault.

Comment 2 RHEL Program Management 2010-08-27 15:29:30 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 3 Paolo Bonzini 2010-08-30 16:53:07 UTC
Created attachment 441986 [details]
patch series to fix the bug

on top of the patches for 625902

Comment 10 Jarod Wilson 2010-09-17 14:03:07 UTC
in kernel-2.6.18-222.el5
You can download this test kernel from http://people.redhat.com/jwilson/el5

Detailed testing feedback is always welcomed.

Comment 14 errata-xmlrpc 2011-01-13 21:12:35 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-2011-0017.html