Bug 484148

Summary: VTd: changeset 10 of 16: avoid redundant context mapping
Product: Red Hat Enterprise Linux 5 Reporter: Don Dugger <ddugger>
Component: kernel-xenAssignee: Xen Maintainance List <xen-maint>
Status: CLOSED WONTFIX QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: low    
Version: 5.4CC: knoel, xen-maint
Target Milestone: rc   
Target Release: 5.4   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-02-05 15:23:43 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: 484147    
Bug Blocks: 331741, 484150    
Attachments:
Description Flags
avoid redundant context mapping none

Description Don Dugger 2009-02-04 23:51:39 UTC
Created attachment 330942 [details]
avoid redundant context mapping

Description of patch:

In case DEV_TYPE_PCI in domain_context_mapping(), redundant context
mapping may occur for some devices.
                                                                                For example, the NIC is 03:00.0, and its parent bridge is: 00:1e.0.
After domain_context_mapping_one() 03:00.0 and 00:1e.0, the
'secbus' is 3 and 'bus' is 0, so will domain_context_mapping_one()
03:00.0 again -- this redundant invocation returns -EINVAL because
we have created the mapping but haven't changed pdev->domain from
Dom0 to a new domain at this time and eventually the
XEN_DOMCTL_assign_device hypercall returns a failure.
 
This patch detects this case and avoids the redundant invocation.


Upstream Status: Accepted (CS 18964)

Comment 1 Don Dugger 2009-02-05 15:23:43 UTC
Process error, don't need a separate BZ per patch