Bug 1482856 – Unable to start vhost if iommu_platform=on but intel_iommu=on not specified in guest [rhel-7.4.z]

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Bug 1482856 - Unable to start vhost if iommu_platform=on but intel_iommu=on not specified in guest [rhel-7.4.z]

Summary:	Unable to start vhost if iommu_platform=on but intel_iommu=on not specified i...

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	qemu-kvm-rhev (Show other bugs)
Sub Component:
Version:	7.5
Hardware:	Unspecified Unspecified

Priority	high Severity high
Target Milestone:	rc
Target Release:	---
Assigned To:	Peter Xu
QA Contact:	xiywang
Docs Contact:

URL:
Whiteboard:
Keywords:	ZStream

Depends On:	1476121
Blocks:
	Show dependency tree / graph

Reported:	2017-08-18 04:38 EDT by Oneata Mircea Teodor
Modified:	2017-09-05 07:52 EDT (History)
CC List:	12 users (show)

See Also:
Fixed In Version:	qemu-kvm-rhev-2.9.0-16.el7_4.5
Doc Type:	If docs needed, set a value
Doc Text:
Story Points:	---
Clone Of:	1476121
Environment:
Last Closed:	2017-09-05 07:52:57 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2017:2628	normal	SHIPPED_LIVE	Moderate: qemu-kvm-rhev security and bug fix update	2017-09-05 11:52:24 EDT

Groups: None (edit)

Description Oneata Mircea Teodor 2017-08-18 04:38:47 EDT

This bug has been copied from bug #1476121 and has been proposed to be backported to 7.4 z-stream (EUS).

Comment 2 Miroslav Rezanina 2017-08-23 01:17:25 EDT

Fix included in qemu-kvm-rhev-2.9.0-16.el7_4.5

Comment 3 xiywang 2017-08-23 04:58:55 EDT

Before fix included: 
qemu-kvm-rhev-2.9.0-14.el7.x86_64
# /usr/libexec/qemu-kvm \
-name 'virt-tests-vm2' -sandbox off -machine q35,kernel-irqchip=split -vga std \
-drive id=drive_image1,if=none,snapshot=on,aio=threads,cache=none,format=qcow2,file=/home/kvm_autotest_root/images/rhel74-64-virtio.qcow2 -device virtio-blk-pci,id=image1,drive=drive_image1 \
-device intel-iommu,intremap=on,device-iotlb=on -device ioh3420,id=pcie.1,chassis=1 \
-device virtio-net-pci,mac=9a:86:87:88:89:8a,id=idRB0WNk,vectors=4,netdev=idb3O1YX,disable-legacy=on,disable-modern=off,iommu_platform=on,ats=on -netdev tap,id=idb3O1YX,vhost=on,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown,vhostforce \
-m 8192 -smp 8 -cpu 'Haswell-noTSX',+kvm_pv_unhalt,hv_spinlocks=0x1fff,hv_vapic,hv_time \
-vnc :1 -rtc base=localtime,clock=host,driftfix=slew -enable-kvm -monitor stdio
QEMU 2.9.0 monitor - type 'help' for more information
(qemu) qemu-kvm: unable to start vhost net: 14: falling back on userspace virtio



After fix included:
# rpm -qa | grep qemu-kvm-rhev
qemu-kvm-rhev-2.9.0-16.el7_4.5.x86_64
Use the same qemu command as above to boot the guest, 'qemu-kvm: unable to start vhost net: 14: falling back on userspace virtio' does not appear again.

Comment 5 xiywang 2017-08-23 21:37:52 EDT

According to comment 3, set this bug to Verified.

Comment 7 errata-xmlrpc 2017-09-05 07:52:57 EDT

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-2017:2628

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