Bug 1624735
| Summary: | libvirt refuses to start a guest with vfio-ccw on s390 because of missing 'display' attribute | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Erik Skultety <eskultet> | |
| Component: | libvirt | Assignee: | Erik Skultety <eskultet> | |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | high | Docs Contact: | ||
| Priority: | high | |||
| Version: | 7.6 | CC: | dzheng, mtessun | |
| Target Milestone: | rc | Keywords: | Regression | |
| Target Release: | --- | |||
| Hardware: | s390 | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | libvirt-4.5.0-8.el7 | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 1624740 (view as bug list) | Environment: | ||
| Last Closed: | 2018-10-30 09:59:06 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
fixed upstream by:
commit d6f97d1338ba9470f7c745fab317d272cde84d38
Refs: v4.7.0-rc2-2-gd6f97d1338
Author: Farhan Ali <alifm.com>
AuthorDate: Thu Aug 30 13:07:34 2018 -0400
Commit: Erik Skultety <eskultet>
CommitDate: Fri Aug 31 14:18:16 2018 +0200
qemu: mdev: Use vfio-pci 'display' property only with vfio-pci mdevs
S390 is aware of both vfio-pci and vfio-ccw devices, so
on S390 the capability QEMU_CAPS_VFIO_PCI_DISPLAY will be
available. Add an extra check to make sure we only set the
display to off for vfio-pci mediated devices. Otherwise we
add display for vfio-ccw device and this breaks vfio-ccw
device qemu command line.
Fixes: d54e45b6e conf: Introduce new <hostdev> attribute 'display'
Signed-off-by: Farhan Ali <alifm.com>
Reviewed-by: Marc Hartmayer <mhartmay.com>
Reviewed-by: Erik Skultety <eskultet>
Package:
libvirt-4.5.0-8.virtcov.el7.s390x
qemu-kvm-ma-2.12.0-12.el7.s390x
kernel-4.14.0-106.el7a.s390x
Steps:
1. Add below in the guest xml and save
<hostdev mode='subsystem' type='mdev' model='vfio-ccw'>
<source>
<address uuid='cfbb5f90-0465-4ed2-8949-248c9eeba1ee'/>
</source>
</hostdev>
2. Dump guest xml
# virsh dumpxml guest |grep hostdev -A4
<hostdev mode='subsystem' type='mdev' managed='no' model='vfio-ccw'>
<source>
<address uuid='cfbb5f90-0465-4ed2-8949-248c9eeba1ee'/>
</source>
</hostdev>
3. Start the guest
# virsh start guest
error: Failed to start domain guest
error: device not found: mediated device 'cfbb5f90-0465-4ed2-8949-248c9eeba1ee' not found
As I do not have mdev device in the beaker machine, so above error messages are as expected.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2018:3113 |
Description of problem: libvirt fails to start a guest with an mdev device on s390. Version-Release number of selected component (if applicable): libvirt-4.5.0-4.el7 How reproducible: Steps to Reproduce: 1. define a guest foo with an vfio-ccw mdev ... <hostdev mode='subsystem' type='mdev' model='vfio-ccw'> <source> <address uuid='cfbb5f90-0465-4ed2-8949-248c9eeba1ee'/> </source> <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0003'/> </hostdev> ... 2. start the guest # virsh start foo 3. Actual results: error: unsupported configuration: <hostdev> attribute 'display' is only supported with model='vfio-pci' Expected results: libvirt starts a guest with an mdev on s390 successfully Additional info: upstream commit d54e45b6 introduced a new <hostdev> attribute 'display' which is only supported with vfio-pci backends - the error is kind of confusing on s390 because the definition doesn't even contain the attribute, because libvirt adds it by default, which is wrong with vfio-ccw