Bug 596315

Summary:	device assignment truncates MSIX table size
Product:	Red Hat Enterprise Linux 6	Reporter:	Alex Williamson <alex.williamson>
Component:	qemu-kvm	Assignee:	Alex Williamson <alex.williamson>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	low
Version:	6.0	CC:	khong, mjenner, qzhang, virt-maint
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	qemu-kvm-0.12.1.2-2.72.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2010-07-02 03:27:04 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:

Description Alex Williamson 2010-05-26 15:19:11 UTC

Description of problem:
device assignment code truncates the top byte of the MSIX table size when setting up capabilities for the guest.

Version-Release number of selected component (if applicable):
qemu-kvm-0.12.1.2-2.52.el6.x86_64

How reproducible:
always

Steps to Reproduce:
1. obvious coding error
2.
3.
  
Actual results:
won't see more than 256 MSIX vectors

Expected results:
match actual hw

Additional info:

Comment 1 Alex Williamson 2010-05-26 15:20:47 UTC

Patch posted upstream:

http://www.spinics.net/lists/kvm/msg35443.html

Comment 3 RHEL Program Management 2010-05-26 17:06:47 UTC

This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux major release.  Product Management has requested further
review of this request by Red Hat Engineering, for potential inclusion in a Red
Hat Enterprise Linux Major release.  This request is not yet committed for
inclusion.

Comment 6 Qunfang Zhang 2010-06-12 08:40:07 UTC

Hi, Alax

Could you tell me how to verify this bug?

Thanks

Comment 7 Alex Williamson 2010-06-15 00:37:35 UTC

(In reply to comment #6)
> Hi, Alax
> 
> Could you tell me how to verify this bug?

This issue was found by code review, so it may be difficult to actually test the boundary condition.  You'd need a device that supported more than 256 vectors in it's MSIX table.  I think it should be sufficient to verify there's no regression by testing a device that supports MSIX interrupts as an assigned device.