Bug 732461

Summary:	QEMU rejects ide drives readonly unless CDROM. This stops SELinux readonly support from working.
Product:	[Fedora] Fedora	Reporter:	Richard Haines <rch_bugs>
Component:	libvirt	Assignee:	Libvirt Maintainers <libvirt-maint>
Status:	CLOSED WONTFIX	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	17	CC:	aquini, berrange, clalance, crobinso, dougsland, itamar, jforbes, laine, veillard, virt-maint
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-10-20 21:24:58 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:

Description Richard Haines 2011-08-22 14:34:36 UTC

Description of problem:
When an IDE drive parameter "readonly=on" is passed to QEMU, QEMU will return an error that read-only ide drives cannot be used (except when its a CDROM).

To overcome this and allow SELinux to manage the readonly service via policy, libvirt should check the ide device and if CDROM and <readonly/> is set in the XML config file, then pass over "readonly=on".

If the ide device is not CDROM but <readonly/> is set in the XML config file, then do not pass over "readonly=on", this will allow QEMU to work and also SELinux to set the appropriate contexts for read-only management via the policy.

Version-Release number of selected component (if applicable):
libvirt-0.8.8-7.fc15.x86_64
with:
qemu-system-x86-0.14.0-7.fc15.x86_64


How reproducible:
Always

Steps to Reproduce:
1. Using Virtual Machine Manager set VM details "IDE Disk 1" to "readonly"
2. Run VM and error will appear.

Comment 1 Fedora Admin XMLRPC Client 2011-09-22 17:53:13 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 2 Fedora Admin XMLRPC Client 2011-09-22 17:57:05 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 3 Fedora Admin XMLRPC Client 2011-11-30 20:03:50 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 4 Fedora Admin XMLRPC Client 2011-11-30 20:03:55 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 5 Fedora Admin XMLRPC Client 2011-11-30 20:08:18 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 6 Fedora Admin XMLRPC Client 2011-11-30 20:08:24 UTC

This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.

Comment 7 Cole Robinson 2012-06-07 00:33:37 UTC

That sounds like a valid idea. Does qemu still error on readonly=on? Maybe this isn't relevant anymore. Either way it's straightforward to test, so moving to F17 for further triage.

Comment 8 Richard Haines 2012-06-08 15:53:38 UTC

(In reply to comment #7)
> That sounds like a valid idea. Does qemu still error on readonly=on? Maybe
> this isn't relevant anymore. Either way it's straightforward to test, so
> moving to F17 for further triage.

I've just tested Fedora 17 and still has the same problem.

Comment 9 Cole Robinson 2012-10-20 21:24:58 UTC

Actually thinking some more about this, I don't think there's anything to change here.

Requesting <readonly/> in the XML is not only about disk image permissions but about actually setting having the HW bits set as readonly. qemu is correctly reporting it can't handle a readonly IDE disk and we should honor that.

You can have libvirt use the RO selinux label for a particular disk using an <seclabel> element in the <disk> block, check the 'source' section here:

http://libvirt.org/formatdomain.html#elementsDisks

Closing as WONTFIX