Bug 755594

Summary: -m 1 crashes
Product: Red Hat Enterprise Linux 6 Reporter: Markus Armbruster <armbru>
Component: qemu-kvmAssignee: Markus Armbruster <armbru>
Status: CLOSED ERRATA QA Contact: Virtualization Bugs <virt-bugs>
Severity: low Docs Contact:
Priority: unspecified    
Version: 6.2CC: acathrow, areis, bsarathy, flang, juzhang, mkenneth, qzhang, shuang, shu, tburke, virt-maint
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: qemu-kvm-0.12.1.2-2.313.el6 Doc Type: Bug Fix
Doc Text:
No documentation needed.
Story Points: ---
Clone Of:
: 999836 (view as bug list) Environment:
Last Closed: 2013-02-21 07:31:33 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 999836    

Description Markus Armbruster 2011-11-21 14:49:43 UTC
Description of problem:


How reproducible:
Always

Steps to Reproduce:
1. Run qemu-kvm -nodefaults --enable-kvm -S  -m 1

Actual results:
Bad ram offset 100000
Aborted (core dumped)

Expected results:
Just works (few guests will be happy with just 1MiB of memory, though).  Failing with a decent error message would be okay, too.

Additional info:
-m 2 works.  -m 1.5 works.  -m 1.6 fails differently:
create_userspace_phys_mem: Invalid argument
kvm_cpu_register_physical_memory: failed
[Exit 1 ]

Upstream seems to be fine with all of these -m arguments.

Comment 2 Shaolong Hu 2011-11-22 09:08:47 UTC
reproduced on qemu-kvm-0.12.1.2-2.209.el6.x86_64:

[root@localhost nfs]# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1
Bad ram offset 100000
Aborted (core dumped)

[root@localhost nfs]# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 2
VNC server running on `::1:5900'

[root@localhost nfs]# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.5
VNC server running on `::1:5900'

[root@localhost nfs]# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.6
create_userspace_phys_mem: Invalid argument
kvm_cpu_register_physical_memory: failed

Comment 3 Dor Laor 2011-12-08 09:44:42 UTC
Markus, why should we fix it? We can close it as won't fix

Comment 4 Markus Armbruster 2011-12-08 10:44:57 UTC
It's a rather embarrassing crash.  I think we should fix it if the patch is simple, and finding it doesn't take longer than an hour or so.

Comment 6 Markus Armbruster 2012-07-31 07:47:39 UTC
I managed to crash upstream with -m 0.8.  I'm working on a patch.

RHEL-6 will need an additional small patch.

Comment 7 Markus Armbruster 2012-09-06 08:47:21 UTC
Upstream patches:
e89001f pc: Fix RTC CMOS info on RAM for ram_size < 1MiB
ff96101 vl: Round argument of -m up to multiple of 8KiB

Not fixed upstream: SeaBIOS requires 1MiB, but doesn't check for it. QEMU doesn't either.

Plan for RHEL-6: round up to multiple of 2MiB instead of 8KiB.

Comment 12 langfang 2012-11-23 06:59:23 UTC
reproduce this bug as follow version:
# uname -r
2.6.32-279.9.1.el6.x86_64
# rpm -q qemu-kvm
qemu-kvm-0.12.1.2-2.295.el6_3.2.x86_64

steps:
# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1
Bad ram offset 100000
Aborted (core dumped)
# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.5
VNC server running on `::1:5900'

# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.6
create_userspace_phys_mem: Invalid argument
kvm_cpu_register_physical_memory: failed

verify this bug as follow version:
# uname -r
2.6.32-338.el6.x86_64
# rpm -q  qemu-kvm
qemu-kvm-0.12.1.2-2.334.el6.x86_64

steps:
# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1
VNC server running on `::1:5900'

#/usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.6
VNC server running on `::1:5900'

# /usr/libexec/qemu-kvm -nodefaults --enable-kvm -S -m 1.5
VNC server running on `::1:5900'

addinfo :tried more than ten times ,not hit the problem,so this bug has been fixed

Comment 14 errata-xmlrpc 2013-02-21 07:31:33 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.

http://rhn.redhat.com/errata/RHBA-2013-0527.html