Bug 595780

Summary:	NIC hotplug and hotunplug is very buggy
Product:	Red Hat Enterprise Linux 5	Reporter:	Paolo Bonzini <pbonzini>
Component:	xenpv-win	Assignee:	Paolo Bonzini <pbonzini>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	low
Version:	5.4	CC:	fnadge, gyang, llim, xen-maint
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	1.3.0-1	Doc Type:	Bug Fix
Doc Text:	Previously, the network card hot-plug and hot-unplug triggered problems in the SCSI driver and could cause the guest to crash. With this update, the network card hot-plug and hot-unplug work as reliable.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-02-01 09:00:54 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:	526393
Bug Blocks:	518405, 598100

Description Paolo Bonzini 2010-05-25 15:28:53 UTC

There are several problems with NIC hotplug and unplug.  Hotplugging can cause bug 523693, and unplugging is subject to memory leaks that can cause blue screens after a certain number of hotplug/hotunplug operations.

On top of that, some code in the drivers is executed at high interrupt levels, causing the system to be unresponsive for approximately half a second while the hotplugging and hotunplugging is completed.

Comment 1 Paolo Bonzini 2010-06-01 15:32:09 UTC

Back to ASSIGNED as the previous solution does not work on Windows 2008. :-(

Comment 4 Florian Nadge 2010-10-18 16:27:54 UTC

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Previously, the network card hot-plug and hot-unplug triggered problems in the SCSI driver and could cause the guest to crash. With this update, the network card hot-plug and hot-unplug work as reliable.

Comment 5 YangGuang 2010-10-19 09:26:47 UTC

Version-Release number of selected component:
xen-3.0.3-117.el5
kernel-xen-2.6.18-228.el5
xenpv-win: 1.2.0
guest: Windows2008r2 HVM

Detailed steps:
1. Edit the vm's config file to install xenpv-win, change the disk specification like
    disk=['file:...', 'file:/usr/share/xenpv-win/xenpv-win.iso,hdc:cdrom,r',
	      'file:/usr/share/xenpv-win/xenpv-win-debug.iso,hdd:cdrom,r']
2. Start the vm with xm create command:
   [host]# xm create $vm-config
3. Open "My Computer", double click "xenpv-win-1.2.0(D:)(CDROM Drive)"
	Or Open CD Drive, then double click xenpv-win.exe
   Then the installer start the installation process, choose "next" all the way.
4. Execute hot-plug and hot-unplug 50 times.
   [host]# xm pci-attach $domU $dev
   [host]# xm pci-detach $domU $dev
5. using vncviewer to login the guest vm and check.

Detailed result:
1. The guest works well and blue-screen doesn't occur.

Comment 7 Paolo Bonzini 2010-10-19 13:22:41 UTC

1) Does the network work after the cycles?  That would be bug 598100.

2) Try 100-120 hotplug cycles. :)

Comment 9 Paolo Bonzini 2010-10-20 08:29:04 UTC

I think both bugs are verified then.

Comment 10 errata-xmlrpc 2011-02-01 09:00:54 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/RHBA-2011-0187.html