Bug 1180942

Summary:	qemu core dumped when unhotplug gpu card assigned to guest
Product:	Red Hat Enterprise Linux 7	Reporter:	Alex Williamson <alex.williamson>
Component:	qemu-kvm	Assignee:	Alex Williamson <alex.williamson>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	high	Docs Contact:
Priority:	high
Version:	7.1	CC:	hhuang, juzhang, linchen, lmiksik, michen, rbalakri, virt-bugs, virt-maint, xfu
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	qemu-kvm-1.5.3-86.el7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1170871	Environment:
Last Closed:	2015-03-05 08:14:18 UTC	Type:	Bug
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:	1170871
Bug Blocks:

Comment 2 Alex Williamson 2015-01-12 05:00:56 UTC

This is a potential QEMU segfault, so I've cloned to qemu-kvm for RHEL.

Fixed by qemu.git b3e27c3aee8f5a96debfe0346e9c0e3a641a8516

A fairly effective test for this is to install the debuginfo package and run gdb on qemu before removing the device.  Set a breakpoint on vfio_intx_interrupt.  After removing the device with device_del or libvirt tools, vfio_intx_interrupt should not be called.  In the failing case, it continues to be called with the opaque data for the deleted device.  Since the error is continued use of an fd with freed data, reliable test cases can be temporary.

Comment 5 Miroslav Rezanina 2015-01-25 17:27:47 UTC

Fix included in qemu-kvm-1.5.3-86.el7

Comment 7 FuXiangChun 2015-01-27 09:59:14 UTC

QE tested bug with the latest qemu-kvm-1.5.3-86.el7.x86_64. The following are test scenarios and result.

S1. Assigned one GPU device(k1 or k2) to guest. then unhotplug it.

For windows(win7 64big) guest. qemu and guest work well

For RHEL7.1 guest. qemu and guest work well(guest kernel 3.10.0-226.el7.x86_64)

S2. Assigned two GPU devices(k1 and k2) to guest. then unhotplug one of them and restart guest.  

result:guest kernel panic. I filed a new bug 1186194 to track it.

Comment 8 FuXiangChun 2015-01-27 10:02:31 UTC

(In reply to FuXiangChun from comment #7)
> QE tested bug with the latest qemu-kvm-1.5.3-86.el7.x86_64. The following
> are test scenarios and result.
> 
> S1. Assigned one GPU device(k1 or k2) to guest. then unhotplug it.
> 
> For windows(win7 64big) guest. qemu and guest work well
> 
> For RHEL7.1 guest. qemu and guest work well(guest kernel
> 3.10.0-226.el7.x86_64)
> 
> S2. Assigned two GPU devices(k1 and k2) to guest. then unhotplug one of them
> and restart guest.  
> 
> result:guest kernel panic. I filed a new bug 1186194 to track it.

Additional info, I tested win7 guest as well, window guest does not hit this issue.

Comment 11 errata-xmlrpc 2015-03-05 08:14:18 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-0349.html