[CentOS-virt] qemu-kvm SLIC acpitable workaround of Windows bug

[Gena Makhomed]

On 30.07.2015 10:49, Nux! wrote:

> Then you should definitely submit a bug with redhat about this, seems like a serious one.

Ok, done:

https://bugzilla.redhat.com/show_bug.cgi?id=1248758

P.S.

As I can see - bugzilla.redhat.com for oVirt Product
does not contain qemu-kvm-ev Component at all - looks
like this is yet another bug - in the bugzilla settings.

But I can't find how to report this bugzilla misconfiguration,
so I just report this oVirt bugreport as bugreport for package
qemu-kvm-rhev from Red Hat Enterprise Virtualization Manager Product.

I hope this help.

> ----- Original Message -----

>> On 29.07.2015 21:34, Nux! wrote:
>>
>>> Yes, you can.
>>> In fact you can use the binaries from the ovirt repo itself, no need to rebuild.
>>
>> Thank you!
>>
>> In fact - I can't use raw binaries from the ovirt repo itself,
>> because these qemu-kvm binaries contains one bug,
>> which is already fixed in Debian:
>>
>> If you want to migrate Windows from hardware node
>> to VM using CentOS 7.1 on hardware node and libvirt xml config:
>>
>> <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
>> .....
>>    <qemu:commandline>
>>      <qemu:arg value='-acpitable'/>
>>      <qemu:arg value='file=/sys/firmware/acpi/tables/SLIC'/>
>>    </qemu:commandline>
>> </domain>
>>
>> Winodws not working correctly in this case, because Windows requires,
>> what oem_id and oem_table_id from SLIC must be also placed
>> into oem_id and oem_table_id of RSDT.
>>
>> Debian version of qemu-kvm contains workaround for this windows bug,
>> and using Debian - Windows VM will works fine. But CentOS packages
>> does not contain such workaround, so qemu-kvm-ev now must be patched
>> manually with each new release.
>>
>> Patch already was created by Michael Tokarev in 2014:
>> this is file mjt-set-oem-in-rsdt-like-slic.diff
>> from https://packages.debian.org/jessie/qemu-kvm
>>
>> This patch cleanly applies also to qemu-kvm-ev-2.1.2-23.el7_1.3.1
>>
>> See mjt-set-oem-in-rsdt-like-slic.diff
>> and qemu-kvm.spec.patch in attach for details.
>>
>> After executing rpmbuild -ba qemu-kvm.spec
>> you can place new qemu-kvm binaries into
>> /srv/download/centos/7/privat/x86_64/Packages
>> create local repo and use it for upgrading rpm packages,
>> for example, see privat.repo and privat-createrepo-7-x86_64
>> in attach.
>>
>> ==============================================================
>>
>> Better if this workaround of Windows bug will be included
>> into RHEL/CentOS ovirt repo binaries, and this will allow
>> to anybody easy migrate Windows from hardware nodes
>> to VMs and easy run CentOS/RHEL at hardware nodes.
>>
>>
>> P.S.
>>       After patching qemu-kvm - option
>>       acpitable works without any bugs:
>>
>>    # man qemu-kvm
>>
>>      -acpitable [sig=str][...]
>>          If a SLIC table is supplied to qemu,
>>          then the oem_id from the SLIC table
>>          will be copied into the RSDT table
>>          (this is a Debian addition).
>>
>>> ----- Original Message -----
>>
>>>> Is it possible to use binary packages build from
>>>> http://resources.ovirt.org/pub/ovirt-3.5/rpm/el7/SRPMS/qemu-kvm-ev-2.1.2-23.el7_1.3.1.src.rpm
>>>> with plain CentOS 7.1 and use all other packages from CentOS
>>>> (libvirt, virt-manager, etc)
>>>>
>>>> Is it have reasons, if I not use live migrations and qcow2 snapshots?
>>>> (instead use zfs, zvols and zfs snapshots for VM disks online backups)
>>>>
>>>> Is using qemu-kvm-ev with CentOS 7.1 have any disadvantages?

-- 
Best regards,
  Gena