Bug 681962

Summary: backport fair event-channel notification
Product: Red Hat Enterprise Linux 5 Reporter: Paolo Bonzini <pbonzini>
Component: kernel-xenAssignee: Paolo Bonzini <pbonzini>
Status: CLOSED DUPLICATE QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 5.6CC: drjones, kkolakow, qcai, xen-maint
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-04-18 08:41:14 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 514490, 648851    

Description Paolo Bonzini 2011-03-03 18:16:15 UTC
The following patches have been forward ported recently to pvops from 2.6.18-xen.hg: 

      * 324:7fe1c6d02a2b 
      * 325:b2768401db94 
      * 988:c88a02a22a05 
      * 990:427276ac595d 
      * 991:9ba6d9f3fbc0

For RHEL5 the issue could even be exploited by a malicious domU to cause a DoS towards any domain whose backends have higher event channel numbers.  I doubt it's severe enough to need a CVE, though.

There is also no hurry to backport them to RHEL6 pvops (where we have no dom0 support), but it could be done for 6.2/6.3.

Comment 1 Paolo Bonzini 2011-03-03 18:18:42 UTC
To test, start 5-10 guests 1 minute from each other, possibly with drives backed by a ram-disk (i.e. large files in tmpfs).  fsmark/iozone on the guests should give roughly the same performance.

Comment 3 Paolo Bonzini 2011-04-18 08:41:14 UTC
c/s 324 and 325 went in as part of bug 456171; the others are cleanups, or otherwise provide diminishing returns.  Not worth it.

*** This bug has been marked as a duplicate of bug 456171 ***