Bug 463525
| Summary: | [LTC 6.0 FEAT] 200970:Include CalIOC2 IOMMU Support (follow on to Calgary) | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | IBM Bug Proxy <bugproxy> | ||||
| Component: | kernel | Assignee: | James Takahashi (IBM) <nobody+PNT0273897> | ||||
| Status: | CLOSED CURRENTRELEASE | QA Contact: | Red Hat Kernel QE team <kernel-qe> | ||||
| Severity: | high | Docs Contact: | |||||
| Priority: | high | ||||||
| Version: | 6.0 | CC: | ejratl, emcnabb, jjarvis, notting, peterm, snagar | ||||
| Target Milestone: | alpha | Keywords: | FutureFeature | ||||
| Target Release: | 6.0 | ||||||
| Hardware: | All | ||||||
| OS: | All | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Enhancement | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2010-11-11 15:54:23 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: | |||||||
| Bug Blocks: | 356741, 554559, 555224, 555228 | ||||||
| Attachments: |
|
||||||
|
Description
IBM Bug Proxy
2008-09-23 20:11:30 UTC
RHEL 6 will include a newer kernel than 2.6.23, so this shouldn't be an issue. The feature requested has already been accepted into the upstream code base planned for the next major release of Red Hat Enterprise Linux. When the next milestone release of Red Hat Enterprise Linux 6 is available, please verify that the feature requested is present and functioning as desired. in Red Hat CVS Tree Marking as Accepted There are additional critical changes to the calgary IOMMU code post 2.6.23. But, since these are already upstream, that shouldn't be a problem for RHEL6. There are 2 additional issues that need to be addressed, but have not be submitted upstream yet: 1) There is an assumption made regarding the number of supported PCI-X Host Bridge buses in a Calgary based system that doesn't hold true for CalIOC2 based systems. The CalIOC2 based servers have more PCI bridges (PCIe root ports) per node and are (more) sparsely allocated. There are currently 2 ways to work around this problem, but neither is very desirable, since it implies disabling the calgary iommu. a) To workaround this problem without any changes to the kernel, use the 'iommu=soft' boot option. b) To workaround this problem with a kernel change, modify the CALGARY_IOMMU_ENABLED_BY_DEFAULT config option from 'Y' to 'N'. This will allow the Calgary/CalioC2 code to still be enabled when the 'iommu=calgary' boot option is suppled, and will prevent the kernel from oopsing without any boot options on the large multi-node CalIOC2 based systems (x3950 M2). This is how RHEL5 configures the Calgary IOMMU today. 2) cagary_init() uses dev->bus->number to index into bus_info[] before the bus number is verified as valid (in calgary_init_one()). ------- Comment From coschult.com 2010-07-07 16:54 EDT------- The patch fixing the number of phbs has been accepted upstream. I'm attaching a backport here. It should apply against rhel 6 beta2. Created attachment 430174 [details]
patch corrects max number of phbs
------- Comment (attachment only) From coschult.com 2010-07-07 16:55 EDT-------
------- Comment From pbogdanovic.com 2010-07-27 14:41 EDT------- This feature is not used anyone and is only relevant to old hardware. ------- Comment From tpnoonan.com 2010-09-28 12:21 EDT------- (In reply to comment #12) > We propose to add a release note that this feature is disabled and advise not > to enable it on the kernel command line, since the patch is not in rhel6. this feature will not be verified on rhel6.0 because of the above Red Hat Enterprise Linux 6.0 is now available and should resolve the problem described in this bug report. This report is therefore being closed with a resolution of CURRENTRELEASE. You may reopen this bug report if the solution does not work for you. |