Bug 502826
Summary: | [RHEL-5 Xen]: F-11 Xen 64-bit domU cannot be started with > 2047MB of memory | ||||||||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | Chris Lalancette <clalance> | ||||||
Component: | kernel-xen | Assignee: | Chris Lalancette <clalance> | ||||||
Status: | CLOSED ERRATA | QA Contact: | Red Hat Kernel QE team <kernel-qe> | ||||||
Severity: | medium | Docs Contact: | |||||||
Priority: | low | ||||||||
Version: | 5.4 | CC: | ajia, drjones, dzickus, itamar, jeremy, kernel-maint, markmc, pasik, pbonzini, virt-maint, xen-maint | ||||||
Target Milestone: | rc | ||||||||
Target Release: | --- | ||||||||
Hardware: | All | ||||||||
OS: | Linux | ||||||||
Whiteboard: | |||||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||||
Doc Text: |
When booting paravirtualized guests that support gigabyte page tables (i.e. a Fedora 11 guest) on Red Hat Enterprise Linux 5.4 Xen, the domain may fail to start if more than 2047MB of memory is configured for the domain. To work around this issue, pass the "nogbpages" parameter on the guest kernel command-line.
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Story Points: | --- | ||||||
Clone Of: | 499592 | Environment: | |||||||
Last Closed: | 2010-03-30 07:40:45 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: | 499592 | ||||||||
Bug Blocks: | 513501, 526946 | ||||||||
Attachments: |
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Description
Chris Lalancette
2009-05-27 11:29:15 UTC
A direct link to the relevant c/s is: http://xenbits.xensource.com/xen-unstable.hg?rev/4b157affc08f Chris Lalancette Created attachment 345617 [details]
Patch to mask more of the PV bits
This is the patch that I'm currently testing to fix this issue. Essentially it masks more of the CPUID bits from PV guests when the hypervisor knows they can't work. Importantly, this will mask out the GBpages feature from newer kernels so they won't try to use it while running on Xen. This is a backport of c/s 17238, plus cpufeatures.h defines from 15803, 16101, 16102, and 16117.
Chris Lalancette
In order to effectively test this patch, we first need to make sure we are on a Barcelona (or newer) AMD box that has the GB pages feature. Then we need to run 3 tests: 1) Make sure that existing PV guests have no problems booting up. For our purposes, this mostly means that RHEL-4 and RHEL-5 PV guests, both x86_64 and i386, boot up and run basic tests fine. 2) Make sure that newer guests (such as F-11) can boot up with > 2047MB of memory. 3) Start a guest on a RHEL-5.3 box. Save the guest (xm save <guest> <file>). Now, reboot the dom0 into the new kernel with this patch in place. Now restore the guest, and make sure it operates properly. Chris Lalancette Created attachment 350912 [details]
Replacement patch to mask more CPUID bits for PV guests
This is a slightly updated patch to mask more CPUID bits. It has one bugfix (make sure to mask out SYSCALL for all 32-bit PV guests), plus it adds a few less #define's that proved not to be necessary.
Release note added. If any revisions are required, please set the "requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: When booting paravirtualized guests that support gigabyte page tables (such as a Fedora 11 guest) on RHEL-5.4 Xen, the domain may fail to start if more than 2047MB of memory is configured for the domain. To work around this issue, pass "nogbpages" on the guest kernel command-line. This limitation will be addressed in a future version of RHEL-5 Xen. Release note updated. If any revisions are required, please set the "requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -When booting paravirtualized guests that support gigabyte page tables (such as a Fedora 11 guest) on RHEL-5.4 Xen, the domain may fail to start if more than 2047MB of memory is configured for the domain. To work around this issue, pass "nogbpages" on the guest kernel command-line. This limitation will be addressed in a future version of RHEL-5 Xen.+When booting paravirtualized guests that support gigabyte page tables (i.e. a Fedora 11 guest) on Red Hat Enterprise Linux 5.4 Xen, the domain may fail to start if more than 2047MB of memory is configured for the domain. To work around this issue, pass the "nogbpages" parameter on the guest kernel command-line. I've uploaded a test kernel that should have a fix for this problem here: http://people.redhat.com/clalance/virttest/ Can the reporters who are having problems please download and try out this test kernel? Thanks, Chris Lalancette in kernel-2.6.18-170.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Please do NOT transition this bugzilla state to VERIFIED until our QE team has sent specific instructions indicating when to do so. However feel free to provide a comment indicating that this fix has been verified. *** Bug 524719 has been marked as a duplicate of this bug. *** An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2010-0178.html |