Bug 1126666

Summary:	qemu-kvm does not quit when booting guest w/ 161 vcpus and "-no-kvm"
Product:	Red Hat Enterprise Linux 7	Reporter:	FuXiangChun <xfu>
Component:	qemu-kvm-rhev	Assignee:	Marcelo Tosatti <mtosatti>
Status:	CLOSED ERRATA	QA Contact:	FuXiangChun <xfu>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.1	CC:	drjones, hhuang, huding, juzhang, knoel, mrezanin, mtosatti, rbalakri, virt-bugs, virt-maint, xfu
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	qemu-kvm-rhev-2.6.0-11.el7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1076326	Environment:
Last Closed:	2016-11-07 20:15:15 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:

Comment 1 Andrew Jones 2014-08-05 08:01:26 UTC

The 160 vcpu limit is a KVM limit, so when booting without kvm, -no-kvm, then that limit no longer matters. Does the windows guest boot on qemu using TCG at all? If so, how many cpus can be configured and still boot? Does it work with 160?

Comment 2 FuXiangChun 2014-08-06 11:11:24 UTC

(In reply to Andrew Jones from comment #1)
> The 160 vcpu limit is a KVM limit, so when booting without kvm, -no-kvm,
> then that limit no longer matters. Does the windows guest boot on qemu using
> TCG at all? If so, how many cpus can be configured and still boot? Does it
> work with 160?

For windows guest.
QE tested two scenarios.
1. /usr/libexec/qemu-kvm -M pc -no-kvm  -smp 1
2. /usr/libexec/qemu-kvm -machine pc,accel=tcg -no-kvm -smp 1

got the same result:
1. guest boot fail and show error code as below
error code:000000C4

For linux guest.
QE tested two scenarios.
1./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 40 -m 4G
guest works

2./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 50 -m 4G
guest kernel panic

Additional:
If remove -no-kvm option from command line for linux guest. then works with 160.

Comment 7 Miroslav Rezanina 2016-07-01 08:23:38 UTC

Fix included in qemu-kvm-rhev-2.6.0-11.el7

Comment 9 FuXiangChun 2016-09-01 10:54:36 UTC

According to comment2. verified this bug with qemu-kvm-rhev-2.6.0-22.el7.

result:

for windows guest-PASS(guest works well)
1. /usr/libexec/qemu-kvm -M pc -no-kvm  -smp 1
2. /usr/libexec/qemu-kvm -machine pc,accel=tcg -no-kvm -smp 1


For linux guest-PASS(guest works well)
1./usr/libexec/qemu-kvm -M q35 -no-kvm -smp 50 -m 4G
guest kernel panic

So,Base on this testing result. this bug is fixed.

Comment 11 errata-xmlrpc 2016-11-07 20:15:15 UTC

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://rhn.redhat.com/errata/RHBA-2016-2673.html