Bug 667354
| Summary: | PV cdrom should be disabled on HVM guests | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Paolo Bonzini <pbonzini> |
| Component: | kernel | Assignee: | Paolo Bonzini <pbonzini> |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | medium | Docs Contact: | |
| Priority: | low | ||
| Version: | 6.0 | CC: | arozansk, drjones, mjenner, xen-maint, yuzhang |
| Target Milestone: | rc | Keywords: | TestOnly |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | kernel-2.6.32-83.el6 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-05-23 20:32:57 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: | 632021 | ||
| Bug Blocks: | |||
This is a good patch for the reasons stated by Stefano when RHEL6 runs on non-RHEL hosts or on RHEL hosts pre-5.6. However, with RHEL 5.6 the host no longer allows PV cdroms for HVM guests either. So as a note to QE, make sure this patch is tested with a host < 5.6. Actually, since there was a change to how the PV cdrom was [not] exposed to a guest for 5.5 as well, it would be even better to test this patch with a host < 5.5. Actually, it was already added as part of http://patchwork.usersys.redhat.com/patch/28671/ We should still ensure that 6.1 handles media insert and eject of an HVM cdrom, so marking this as TestOnly and moving to MODIFIED This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. (In reply to comment #2) > This is a good patch for the reasons stated by Stefano when RHEL6 runs on > non-RHEL hosts or on RHEL hosts pre-5.6. However, with RHEL 5.6 the host no > longer allows PV cdroms for HVM guests either. So as a note to QE, make sure > this patch is tested with a host < 5.6. Actually, since there was a change to > how the PV cdrom was [not] exposed to a guest for 5.5 as well, it would be even > better to test this patch with a host < 5.5. Hi Andrew, Could you please provide some information on how to create pv cdrom for rhel6 HVM guest? I try to do this with the following config option on a RHEL5.6 host: disk = ['file:/xen-autotest/xen-autotest/client/tests/xen/images/RHEL-Server-6.1-64-hvm.raw,xvda,w', 'tap:aio:/root/boot.iso,xvdc:cdrom,r'] After guest boots, I could only see the emulated cdrom within the guest(seems that it is not unpluged). Could this be seen as a good point that the bug is fixed? Thanks. Yufang I would probably use 'file', instead of 'tap:aio', but it probably doesn't matter. Note, to get any chance of seeing a bug you need a host with a dom0 kernel that is < -176 and a rhel6 guest with a kernel that is < -83. If you can see some bug with that, then bump the rhel6 kernel up to the latest and make sure it goes away. I'm actually not sure you'll see a bug at all though... Actually, if you don't see any problems (only the qemu cdrom pops up) with any sort of cdrom config file/tap, hdc/xvdc, then I would consider this BZ verified. Tested with 2.6.32-128.el6: I have tried any sort of cdrom config with file/tap, hdc/xvdc, only emulated(qemu) cdrom could be seen within HVM guest. So I would consider this bug as VERIFIED. 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-2011-0542.html |
commit b98a409b80ac510c95b4f1bafdef28edaeabd3e7 Author: Stefano Stabellini <stefano.stabellini.com> Date: Thu Jul 29 14:53:16 2010 +0100 blkfront: do not create a PV cdrom device if xen_hvm_guest It is not possible to unplug emulated cdrom devices, and PV cdroms don't handle media insert, eject and stream, so we are better off disabling PV cdroms when running as a Xen HVM guest. Signed-off-by: Stefano Stabellini <stefano.stabellini.com>