[arch-general] [arch-dev-public] [announcement] qemu/qemu-kvm announcement draft

[Simon Boulay]

On 01/12/2010 07:33 AM, Tobias Powalowski wrote:
> Am Dienstag 12 Januar 2010 schrieb Alexander Duscheleit:
>> On Sun, 10 Jan 2010 11:07:19 +0100
>>
>> Tobias Powalowski<t.powa at gmx.de>  wrote:
>>> Am Sonntag 10 Januar 2010 schrieb Simon Boulay:
>>>> On 01/10/2010 09:48 AM, Tobias Powalowski wrote:
>>>>> Am Samstag 09 Januar 2010 schrieb Simon Boulay:
>>>>>> On 01/09/2010 09:09 PM, Tobias Powalowski wrote:
>>>>>>> Am Samstag 09 Januar 2010 schrieb Dan McGee:
>>>>>>>> On Sat, Jan 9, 2010 at 11:52 AM, Tobias
>>>>>>>> Powalowski<t.powa at gmx.de>
>>>
>>> wrote:
>>>>>>>>>     >    Yes will change the install message.
>>>>>>>>>>
>>>>>>>>>> Yes there is no mention in the changelogs, really strange.
>>>>>>>>>> greetings
>>>>>>>>>> tpowa
>>>>>>>>>
>>>>>>>>> Ok like this?
>>>>>>>>>     echo ">>>    Since kernel 2.6.29:"
>>>>>>>>>     echo ">>>    Qemu package now provides standard qemu with
>>>>>>>>> kvm enabled." echo ""
>>>>>>>>>     echo ">>>    PLEASE READ FOR KVM USAGE!"
>>>>>>>>>     echo ">>>     Load the correct KVM module, you will need a
>>>>>>>>> KVM capable CPU!" echo ">>>     Add yourself to the group
>>>>>>>>> 'kvm'." echo ">>>     Use 'qemu --enable-kvm' to use KVM."
>>>>>>>>>     echo ""
>>>>>>>>>     echo "With the release of qemu and qemu-kvm 0.12.X, the
>>>>>>>>> kqemu kernel module" echo "is no longer supported and will be
>>>>>>>>> removed from the repositories. You" echo "can safely
>>>>>>>>> uninstall it from your system."
>>>>>>>>
>>>>>>>> Can we put some vercmp checks around messages like this? That
>>>>>>>> way people only have to see them once (when they upgrade the
>>>>>>>> first time to a 0.12.x version for the second message). The
>>>>>>>> first message should really be a post_install message.
>>>>>>>>
>>>>>>>> And with all that said, why are there two packages in extra if
>>>>>>>> "qemu package now provides standard qemu with kvm enabled"?
>>>>>>>>
>>>>>>>> -Dan
>>>>>>>
>>>>>>> Yes sure i can add those vercmp stuff.
>>>>>>> qemu and qemu-kvm is different.
>>>>>>> qemu-kvm is only for  kvm while qemu provides much more
>>>>>>> machines to emulate.
>>>>>>
>>>>>> I'm not sure about that. Both seems to share the same code for
>>>>>> machine emulation; only the kvm stuff is different. In fedora
>>>>>> 12, they build kvm and qemu-system-xxx from qemu-kvm 0.11. But I
>>>>>> don't know how this will evolve in the future.
>>>>>> If qemu and qemu-kvm are used for different purposes, one may
>>>>>> need to install both apps side by side but that's not possible
>>>>>> in archlinux.
>>>>>
>>>>> Why?
>>>>> qemu is for those who need more different emulation types.
>>>>> qemu-kvm is only for 86 emulation with kvm hardware support.
>>>>> Both differ in files you would need to hack bios file destination
>>>>> etc. I don't see any need to install both at the same time.
>>>>
>>>> Because one may want to use x86 emulation with kvm hardware support
>>>> and qemu-system-arm for example on the same machine.
>>>> It is possible to build all targets with qemu-kvm but that's not the
>>>> default and I don't know if that'll be the case for future release.
>>>> For 0.11 release, qemu and qemu-kvm seems to converge, but with 0.12
>>>> that's not so clear (at least to me). As I understand it, the
>>>> development of platform emulation is done in qemu and kvm
>>>> virtualization is done in qemu-kvm (even if qemu has some kvm
>>>> support) but the qemu repository is regularly merged in qemu-kvm. I
>>>> don't find any official statement about that, so...
>>>
>>> normal qemu supports kvm too, just use --enable-kvm start parameter.
>>> So no need to install qemu-kvm.
>>> greetings
>>> tpowa
>>
>> In this light, what actually is qemu-kvm good for? We don't split
>> packges for -src, -devel, but for startup-parameters?
>>
>> If there is no other difference then a few more binaries (which as far
>> as i know doesn't justify another package) why not kill qemu-kvm
>> alltogether and include something like /usr/bin/kvm:
>>
>> ---8<---
>> #!/bin/bash
>> qemu --enable-kvm $*
>> --->8---
>>
>> When I tested both packages here qemu with --enable-kvm *felt* a little
>> slower when running XP, but that's a) entirely subjective and b) I
>> dodn't test identical workloads.
>>
>> So, again, what is the reason for there being a qemu-kvm package, when
>> it is apparently a subset of the qemu package?
>>
>> Greetings,
>> 	jinks
>>
> The size of the package differs enormous. I'll keep both.
The size differs because qemu-kvm doesn't build all targets by default 
unlike qemu. If you build qemu-kvm with ./configure --target-list="" 
both packages will be the same size...
AFAIK the difference between the two is in the kvm implementation. 
qemu-kvm is far more advanced in this area (support more targets, ksm, 
and certainly many other things regarding the amount of code 
differences). The point is, as kqemu is gone, qemu-kvm can replace qemu 
and even provide more functionality. But it is not so clear that this 
will be always true.
archlinux choose to offer both packages for two different purposes and 
it's fine. But if they are two different applications, why not make it 
possible to install both at the same time?

You, archlinux developers make an amazing job. The beauty and the power 
of archlinux is that I can easily build qemu and/or qemu-kvm in my own 
particular weird way ;-)

Greetings,
Simon.