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Bug 907556 - windows 8 32bit can not be installed by using libvirt (sep flag is not passed through to the guest)
Summary: windows 8 32bit can not be installed by using libvirt (sep flag is not passed...
Keywords:
Status: CLOSED DUPLICATE of bug 821741
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: libvirt
Version: 6.4
Hardware: Unspecified
OS: Unspecified
urgent
urgent
Target Milestone: rc
: ---
Assignee: Peter Krempa
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On: 832301
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-02-04 17:30 UTC by Mike Cao
Modified: 2013-03-25 13:52 UTC (History)
26 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 832301
Environment:
Last Closed: 2013-03-08 09:37:48 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
This the qemu log as instructed (16.86 KB, application/octet-stream)
2013-02-26 19:57 UTC, Alves 		no flags Details
View All

Description Mike Cao 2013-02-04 17:30:52 UTC 
commentor reports when specify sep flag for the cpu cluster in libvirt XML file ,sep flag is not be added in qemu-kvm commadline which cause windows8-32 bit guest can not start .

Since We officially support win8-32/win8-64 ,Feel free to fix this bug 



+++ This bug was initially created as a clone of Bug #832301 +++




--- Additional comment from Alves on 2013-02-04 14:44:39 CST ---

Dear Gentlemen, please raise alert. I installed a server with Beta 6.4, and the bug is still there. I tried also forcing NX and SEP, but the same issue. So this is not fixed. I can give access to Redhat engineer to my system via VNC, so he may see the problem.
Should I open a new bug or we may continue here??

If we don't fix KVM, the enterprise is going ignore it.

--- Additional comment from Mike Cao on 2013-02-04 14:53:56 CST ---

(In reply to comment #56)
> Dear Gentlemen, please raise alert. I installed a server with Beta 6.4, and
> the bug is still there. I tried also forcing NX and SEP, but the same issue.
> So this is not fixed. I can give access to Redhat engineer to my system via
> VNC, so he may see the problem.
> Should I open a new bug or we may continue here??
> 
> If we don't fix KVM, the enterprise is going ignore it.

pls use ps -eaf|grep qemu-kvm to check the qemu-kvm commandline.
if no sep flag in cpu param ,pls add it manually.

eg : /usr/libexec/qemu-kvm  -cpu Nehalem,+sep ...

--- Additional comment from Mike Cao on 2013-02-04 15:01:12 CST ---

(In reply to comment #56)
> Dear Gentlemen, please raise alert. I installed a server with Beta 6.4, and
> the bug is still there. I tried also forcing NX and SEP, but the same issue.
> So this is not fixed. I can give access to Redhat engineer to my system via
> VNC, so he may see the problem.
> Should I open a new bug or we may continue here??
> 
> If we don't fix KVM, the enterprise is going ignore it.

Can you provide use qemu-kvm(-rhev) & kernel version as well ?

--- Additional comment from Gleb Natapov on 2013-02-04 16:44:25 CST ---

(In reply to comment #56)
> Dear Gentlemen, please raise alert. I installed a server with Beta 6.4, and
> the bug is still there. I tried also forcing NX and SEP, but the same issue.
> So this is not fixed. I can give access to Redhat engineer to my system via
> VNC, so he may see the problem.
> Should I open a new bug or we may continue here??
> 
> If we don't fix KVM, the enterprise is going ignore it.

We appreciate you concern about KVM enterprise adoption, but you have't provide any information about your environment. What is your qemu/kernel versions and your commadn line?

--- Additional comment from Alves on 2013-02-04 20:58:29 CST ---

I don't think I made myself clear, but here it goes again. I took a Dell R910 server and installed a new, fresh copy of RHEL 6.4, Beta. The bug remains identical.
This is from /boot/grub/menu.lst

kernel /vmlinuz-2.6.32-343.el6.x86_64 ro root=/dev/mapper/vg_system3-lv_root rd_NO_LUKS rd_LVM_LV=vg_system3/lv_root LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=vg_system3/lv_swap SYSFONT=latarcyrheb-sun16  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

I can give you direct access, if you wish, via VNC, and you will see the problem.

--- Additional comment from Gleb Natapov on 2013-02-04 21:07:44 CST ---

(In reply to comment #60)
> I don't think I made myself clear, but here it goes again. I took a Dell
> R910 server and installed a new, fresh copy of RHEL 6.4, Beta. The bug
> remains identical.
> This is from /boot/grub/menu.lst
> 
> kernel /vmlinuz-2.6.32-343.el6.x86_64 ro root=/dev/mapper/vg_system3-lv_root
> rd_NO_LUKS rd_LVM_LV=vg_system3/lv_root LANG=en_US.UTF-8 rd_NO_MD
> rd_LVM_LV=vg_system3/lv_swap SYSFONT=latarcyrheb-sun16  KEYBOARDTYPE=pc
> KEYTABLE=us rd_NO_DM rhgb quiet
This answers my question about the kernel version. Now what is your qemu-kvm version and qemu command line. How do you start qemu? How failure looks like?
What is the ouput of /proc/cpuinfo.

> 
> I can give you direct access, if you wish, via VNC, and you will see the
> problem.
I believe we can solve the problem by getting relevant information first.

--- Additional comment from Alves on 2013-02-04 22:08:11 CST ---

kindly look at this image
http://minixel.com/crash.png

It is this bug. It was never fixed

Everything is my box is default. I use Libvirt. The issue happened in a box with X7350 and Nahalem,X7560. The CPU was defined with "copy host configuration". 
Please look below. I tried with arch="i686" and the "x86_64". Nothing works. Tried forcing SEP and NX, etc. 

<domain type='kvm'>
  <name>Windows-8</name>
  <uuid>478a2330-4bf0-d4d5-08ac-82c328df06e9</uuid>
  <memory unit='KiB'>2097152</memory>
  <currentMemory unit='KiB'>2097152</currentMemory>
  <vcpu placement='static'>2</vcpu>
  <os>
    <type arch='x86_64' machine='rhel6.4.0'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <cpu mode='custom' match='exact'>
    <model fallback='allow'>Nehalem</model>
    <vendor>Intel</vendor>
    <feature policy='require' name='tm2'/>
    <feature policy='require' name='est'/>
    <feature policy='require' name='monitor'/>
    <feature policy='require' name='ds'/>
    <feature policy='require' name='ss'/>
    <feature policy='require' name='vme'/>
    <feature policy='require' name='dtes64'/>
    <feature policy='require' name='rdtscp'/>
    <feature policy='require' name='ht'/>
    <feature policy='require' name='dca'/>
    <feature policy='require' name='pbe'/>
    <feature policy='require' name='tm'/>
    <feature policy='require' name='pdcm'/>
    <feature policy='require' name='vmx'/>
    <feature policy='require' name='ds_cpl'/>
    <feature policy='require' name='xtpr'/>
    <feature policy='require' name='acpi'/>
    <feature policy='require' name='x2apic'/>
    <feature policy='force' name='sep'/>
    <feature policy='force' name='nx'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/libexec/qemu-kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source file='/var/lib/libvirt/images/WIN8.img'/>
      <target dev='hda' bus='ide'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:d1:e4:15'/>
      <source bridge='br5'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <input type='tablet' bus='usb'/>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes'/>
    <sound model='ich6'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </sound>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </memballoon>
  </devices>
</domain>

--- Additional comment from Mike Cao on 2013-02-04 22:45:30 CST ---

(In reply to comment #62)
> kindly look at this image
> http://minixel.com/crash.png
> 
> It is this bug. It was never fixed
> 
> Everything is my box is default. I use Libvirt. The issue happened in a box
> with X7350 and Nahalem,X7560. The CPU was defined with "copy host
> configuration". 
> Please look below. I tried with arch="i686" and the "x86_64". Nothing works.
> Tried forcing SEP and NX, etc. 
> 
> <domain type='kvm'>
>   <name>Windows-8</name>
>   <uuid>478a2330-4bf0-d4d5-08ac-82c328df06e9</uuid>
>   <memory unit='KiB'>2097152</memory>
>   <currentMemory unit='KiB'>2097152</currentMemory>
>   <vcpu placement='static'>2</vcpu>
>   <os>
>     <type arch='x86_64' machine='rhel6.4.0'>hvm</type>
>     <boot dev='hd'/>
>   </os>
>   <features>
>     <acpi/>
>     <apic/>
>     <pae/>
>   </features>
>   <cpu mode='custom' match='exact'>
>     <model fallback='allow'>Nehalem</model>
>     <vendor>Intel</vendor>
>     <feature policy='require' name='tm2'/>
>     <feature policy='require' name='est'/>
>     <feature policy='require' name='monitor'/>
>     <feature policy='require' name='ds'/>
>     <feature policy='require' name='ss'/>
>     <feature policy='require' name='vme'/>
>     <feature policy='require' name='dtes64'/>
>     <feature policy='require' name='rdtscp'/>
>     <feature policy='require' name='ht'/>
>     <feature policy='require' name='dca'/>
>     <feature policy='require' name='pbe'/>
>     <feature policy='require' name='tm'/>
>     <feature policy='require' name='pdcm'/>
>     <feature policy='require' name='vmx'/>
>     <feature policy='require' name='ds_cpl'/>
>     <feature policy='require' name='xtpr'/>
>     <feature policy='require' name='acpi'/>
>     <feature policy='require' name='x2apic'/>
>     <feature policy='force' name='sep'/>
>     <feature policy='force' name='nx'/>
>   </cpu>
>   <clock offset='localtime'>
>     <timer name='rtc' tickpolicy='catchup'/>
>   </clock>
>   <on_poweroff>destroy</on_poweroff>
>   <on_reboot>restart</on_reboot>
>   <on_crash>restart</on_crash>
>   <devices>
>     <emulator>/usr/libexec/qemu-kvm</emulator>
>     <disk type='file' device='disk'>
>       <driver name='qemu' type='raw' cache='none'/>
>       <source file='/var/lib/libvirt/images/WIN8.img'/>
>       <target dev='hda' bus='ide'/>
>       <address type='drive' controller='0' bus='0' target='0' unit='0'/>
>     </disk>
>     <controller type='usb' index='0'>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> function='0x2'/>
>     </controller>
>     <controller type='ide' index='0'>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x01'
> function='0x1'/>
>     </controller>
>     <interface type='bridge'>
>       <mac address='52:54:00:d1:e4:15'/>
>       <source bridge='br5'/>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x03'
> function='0x0'/>
>     </interface>
>     <serial type='pty'>
>       <target port='0'/>
>     </serial>
>     <console type='pty'>
>       <target type='serial' port='0'/>
>     </console>
>     <input type='tablet' bus='usb'/>
>     <input type='mouse' bus='ps2'/>
>     <graphics type='vnc' port='-1' autoport='yes'/>
>     <sound model='ich6'>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x04'
> function='0x0'/>
>     </sound>
>     <video>
>       <model type='cirrus' vram='9216' heads='1'/>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x02'
> function='0x0'/>
>     </video>
>     <memballoon model='virtio'>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x05'
> function='0x0'/>
>     </memballoon>
>   </devices>
> </domain>

Again:
1.Pls provide qemu-kvm version by using #rpm -q qemu-kvm
1.Pls provide qemu-kvm commandline instead of libvirt configuration file #ps aux|grep qemu

--- Additional comment from Alves on 2013-02-04 23:01:42 CST ---

qemu-kvm-0.12.1.2-2.335.el6.x86_64

qemu     66793 85.3  0.1 2520444 372968 ?      Sl   09:59   1:07 /usr/libexec/qemu-kvm -name Windows-8 -S -M rhel6.4.0 -cpu Nehalem,+rdtscp,+x2apic,+dca,+pdcm,+xtpr,+tm2,+est,+vmx,+ds_cpl,+monitor,+dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme -enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -uuid 478a2330-4bf0-d4d5-08ac-82c328df06e9 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/Windows-8.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=localtime,driftfix=slew -no-shutdown -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/var/lib/libvirt/images/WIN8.img,if=none,id=drive-ide0-0-0,format=raw,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -netdev tap,fd=26,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:d1:e4:15,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -device usb-tablet,id=input0 -vnc 127.0.0.1:0 -vga cirrus -device intel-hda,id=sound0,bus=pci.0,addr=0x4 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5

--- Additional comment from Mike Cao on 2013-02-04 23:09:37 CST ---

(In reply to comment #64)
> qemu-kvm-0.12.1.2-2.335.el6.x86_64
> 
> qemu     66793 85.3  0.1 2520444 372968 ?      Sl   09:59   1:07
> /usr/libexec/qemu-kvm -name Windows-8 -S -M rhel6.4.0 -cpu
> Nehalem,+rdtscp,+x2apic,+dca,+pdcm,+xtpr,+tm2,+est,+vmx,+ds_cpl,+monitor,
> +dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme -enable-kvm -m 2048 -smp

This is the point .no +sep flag in -cpu parmater
Pls start VM with -cpu Nehalem,+sep and try again

> 2,sockets=2,cores=1,threads=1 -uuid 478a2330-4bf0-d4d5-08ac-82c328df06e9
> -nodefconfig -nodefaults -chardev
> socket,id=charmonitor,path=/var/lib/libvirt/qemu/Windows-8.monitor,server,
> nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc
> base=localtime,driftfix=slew -no-shutdown -device
> piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive
> file=/var/lib/libvirt/images/WIN8.img,if=none,id=drive-ide0-0-0,format=raw,
> cache=none -device
> ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1
> -netdev tap,fd=26,id=hostnet0 -device
> rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:d1:e4:15,bus=pci.0,addr=0x3
> -chardev pty,id=charserial0 -device
> isa-serial,chardev=charserial0,id=serial0 -device usb-tablet,id=input0 -vnc
> 127.0.0.1:0 -vga cirrus -device intel-hda,id=sound0,bus=pci.0,addr=0x4
> -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device
> virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5

--- Additional comment from Alves on 2013-02-04 23:59:53 CST ---

If you look at the XML that I submitted, it shows clearly sep=force. I tried with "require", "model", etc. It does not get translated to the command line. Maybe that is the bug. I use only the interface provided by libvirt, not command lines. 99% of all customers will work the same way. If it cannot be set in the GUI, then it will be abandoned. Kindly indicate a workaround for this issue.

--- Additional comment from Mike Cao on 2013-02-05 01:21:14 CST ---
Comment 5 Alves 2013-02-04 20:48:23 UTC 
While we are at it, the NX parameter also gets ignored and does not transfer to the command line. Windows 8 requires sse2, nx and sep. I can be an early tester of a fix, once one is made available.
Comment 6 Peter Krempa 2013-02-26 16:33:24 UTC 
Libvirt doesn't add flags to the command line that are already part of the model definition in qemu, thus the sep, nx and others are missing from the command line. This is to make the command line shorter. Qemu should enable them by using the correct model.

The error originates from 2 possible sources:

1) qemu does not support that feature for some reason and complains about it. Libvirt is unfortunately not enforcing all the flags and allows the guest to start.
This leads to two possible resolutions:

  1a) The lack of support of the feature flag is intentional for some reason in qemu and libvirt should fail rather than silently ignore the missing flag. In that case this bug should be closed as a duplicate of https://bugzilla.redhat.com/show_bug.cgi?id=822148 that tracks the issue of enforcing flags globally.

  1b) It is a qemu/kernel/other bug that should be fixed as sep is expected to work on the setup used.

2) the sep flag needs to be enforced even if it is part of the cpu model definition in qemu.
  This would be very unfortunate and it would also be preferably fixed in qemu rather than in libvirt.
  
I'm reassigning this bug to qemu-kvm to investigate further.

Alves, 
could you please attach a relevant part of /var/log/libvirt/qemu/Windows-8 that contains messages printed by qemu on startup? This might help investigating the problem.
Comment 7 Alves 2013-02-26 19:57:04 UTC 
Created attachment 703097 [details]
This the qemu log as instructed

I started the domain WW8 until it blew up and this is the qemu log
Comment 8 Eduardo Habkost 2013-02-28 17:29:17 UTC 
(In reply to comment #6)
> Libvirt doesn't add flags to the command line that are already part of the
> model definition in qemu, thus the sep, nx and others are missing from the
> command line. This is to make the command line shorter. Qemu should enable
> them by using the correct model.

Actually, the SEP flag is _not_ part of the CPU model definition we have in rhel6.4.0 machine-types and older. This happened because of kernel bug 821463.
This problem is combined with other issues:

- I believe libvirt doesn't expect the CPU model definitions from QEMU to ever change between machine-types. So removing SEP from cpu_map.xml will probably cause problems when we finally fix bug 821741 (where rhel6.5.0 and newer machine-types will finally have SEP enabled).

- The kernel from RHEL 6.3.0 and older can't expose SEP to guests (bug 821463), but libvirt is completely unable to detect that. So even if cpu_map.xml didn't include "sep" on Nehalem, libvirt would try to use "-cpu Nehalem,+sep" and expect it to work. But:

- libvirt doesn't use the "enforce" flag, so "-cpu <model>,+sep" wouldn't work on RHEL 6.3.0 and older, but it wouldn't emit any errors or warnings.


So, I see two solutions to this:

 1) Changing libvirt to handle the fact that QEMU CPU models may be different depending on the machine-type, and take into account that "-M rhel6.4.0 -cpu Nehalem" doesn't have the SEP flag (but "-M rhel6.4.0 -cpu Nehalem,+sep" would work) and that "-M rhel6.5.0 -cpu Nehalem" will probably have it (when we fix bug 821741).

 2) Live with the fact that libvirt can't handle CPU models that change between machine-types, and wait until bug 821741 is fixed in QEMU.


I will move this bug back to libvirt just in case you want to follow the first approach. If you think the second approach is better, you can close this bug as duplicate of bug 821741.
Comment 9 Itamar Heim 2013-03-07 07:03:28 UTC 
do all models support sep at hardware level (conroe, penryn, nehalem, westemere, etc, and AMD G1-G5)?
Comment 10 Lev Veyde 2013-03-07 09:31:36 UTC 
(In reply to comment #5)
> While we are at it, the NX parameter also gets ignored and does not transfer
> to the command line. Windows 8 requires sse2, nx and sep. I can be an early
> tester of a fix, once one is made available.

Please try to modify the XML of the domain:

a) add xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0' to the domain tag so it will look like:
<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>

b) add the following tags inside the domain tag:
  <qemu:commandline>
    <qemu:arg value='-cpu'/>
    <qemu:arg value='<YOUR_CPU_MODEL>,+sep'/>
  </qemu:commandline>

so that the final XML will look like i.e.:

<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  <name>Windows-8</name>
  <uuid>478a2330-4bf0-d4d5-08ac-82c328df06e9</uuid>
  <memory unit='KiB'>2097152</memory>
  <currentMemory unit='KiB'>2097152</currentMemory>
  <vcpu placement='static'>2</vcpu>
  <os>
    <type arch='x86_64' machine='rhel6.4.0'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <cpu mode='custom' match='exact'>
    <model fallback='allow'>Nehalem</model>
    <vendor>Intel</vendor>
    <feature policy='require' name='tm2'/>
    <feature policy='require' name='est'/>
    <feature policy='require' name='monitor'/>
    <feature policy='require' name='ds'/>
    <feature policy='require' name='ss'/>
    <feature policy='require' name='vme'/>
    <feature policy='require' name='dtes64'/>
    <feature policy='require' name='rdtscp'/>
    <feature policy='require' name='ht'/>
    <feature policy='require' name='dca'/>
    <feature policy='require' name='pbe'/>
    <feature policy='require' name='tm'/>
    <feature policy='require' name='pdcm'/>
    <feature policy='require' name='vmx'/>
    <feature policy='require' name='ds_cpl'/>
    <feature policy='require' name='xtpr'/>
    <feature policy='require' name='acpi'/>
    <feature policy='require' name='x2apic'/>
    <feature policy='force' name='sep'/>
    <feature policy='force' name='nx'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/libexec/qemu-kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source file='/var/lib/libvirt/images/WIN8.img'/>
      <target dev='hda' bus='ide'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:d1:e4:15'/>
      <source bridge='br5'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <input type='tablet' bus='usb'/>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes'/>
    <sound model='ich6'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </sound>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </memballoon>
  </devices>
  <qemu:commandline>
    <qemu:arg value='-cpu'/>
    <qemu:arg value='Nehalem,+sep'/>
  </qemu:commandline>
</domain>
Comment 11 Peter Krempa 2013-03-08 09:37:48 UTC 
As discussed, I'm closing this one as a duplicate of the qemu-kvm bug for re-adding "sep" to the CPU definitions. Libvirt isn't aware of changes done to cpu features across machine types and also we don't expect removing features so we can't fix this satisfactorily for now.

*** This bug has been marked as a duplicate of bug 821741 ***
Comment 12 Eduardo Habkost 2013-03-25 13:52:01 UTC 
Side note: the feature was not exactly removed from the CPU models in qemu-kvm. The problem is that the feature was never present in any of the CPU models, because of kernel bug 821463.
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