Bug 1003744

Summary: Booting VM with virtio disks/virtio network(multifunction=on) caused QEMU error(unable to map ioeventfd: -28)
Product: Red Hat Enterprise Linux 6 Reporter: zhonglinzhang <zhzhang>
Component: qemu-kvmAssignee: Michael S. Tsirkin <mst>
Status: CLOSED WONTFIX QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: low    
Version: 6.5CC: acathrow, bsarathy, juzhang, michen, mkenneth, qzhang, rhod, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-04-01 16:24:11 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:
Attachments:
Description Flags
with 100 virtio network
none
with 200 virtio disks none

Description zhonglinzhang 2013-09-03 06:14:39 UTC 
Description of problem:
+++ This bug was initially created as a clone of Bug #753692 +++

1. During boot win2012 guest with 100 virtio network, it causes qemu-kvm show  the following information:
(qemu) qemu-kvm: virtio_pci_set_host_notifier_internal: unable to map ioeventfd: -28 
vhost VQ 1 notifier binding failed: 28

2. Boot win2012 guest with more than 200 virtio disks, cause qemu-kvm show the following information:
(qemu) qemu-kvm: virtio_pci_set_host_notifier_internal: unable to map ioeventfd: -28
qemu-kvm: virtio_pci_start_ioeventfd: failed. Fallback to a userspace (slower).

Version-Release number of selected component (if applicable):
kernel: 2.6.32-414.el6.x86_64
qemu-kvm: qemu-kvm-0.12.1.2-2.398.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Boot win2012 guest with 100 virtio network, the following command line:
in attachment virtio-network

2. Boot win2012 guest with more than 200 virtio disks
in attachment virtio-disks

3.

Actual results:
1. win2012 guest with 100 virtio network: 
(qemu) qemu-kvm: virtio_pci_set_host_notifier_internal: unable to map ioeventfd: -28
vhost VQ 1 notifier binding failed: 28

2. win2012 guest with more than 200 virtio disks
(qemu) qemu-kvm: virtio_pci_set_host_notifier_internal: unable to map ioeventfd: -28
qemu-kvm: virtio_pci_start_ioeventfd: failed. Fallback to a userspace (slower).

Expected results:
guest boot successful

Additional info:
Comment 1 zhonglinzhang 2013-09-03 06:16:18 UTC 
Created attachment 793026 [details]
with 100 virtio network
Comment 2 zhonglinzhang 2013-09-03 06:17:30 UTC 
Created attachment 793027 [details]
with 200 virtio disks