Re: [Qemu-devel] Re: SVM support in 0.12?

[Jun Koi]

On Sat, Dec 19, 2009 at 2:34 AM, Alexander Graf <address@hidden> wrote:
>
> Am 18.12.2009 um 17:52 schrieb Jun Koi <address@hidden>:
>
>> On Fri, Dec 18, 2009 at 8:35 PM, Alexander Graf <address@hidden> wrote:
>>>
>>> Am 18.12.2009 um 03:39 schrieb Jun Koi <address@hidden>
>>>
>>>> On Fri, Dec 18, 2009 at 11:37 AM, Jun Koi <address@hidden> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> I am running latest Qemu 0.12-rc. My guest VM runs Linux kernel 2.6.31.
>>>>>
>>>>> Because Qemu now supports SVM, I expect to see the SVM flag in
>>>>> /proc/cpuinfo, but that is not the case.
>>>>>
>>>>> So it seems SVM support is not enabled by default configuration??
>>>>>
>>>>
>>>> My host and guest are both 32 bit Linux, if that matters.
>>>>
>>>> (And this is pure Qemu, without using KVM or KQemu)
>>>
>>> Kqemu actually works with svm emulation.
>>>
>>> Have you tried -cpu qemu32,+svm? I think I only enabled svm on qemu64,
>>> because I'm not aware of 32-bit AMD CPUs that can do svm.
>>>
>>> If you use -cpu qemu32 that also means you'll get an emulated Intel CPU.
>>> KVM-AMD will refuse there.
>>>
>>> Also, back when I developed it, 32-bit kvm didn't really work properly.
>>> So
>>> please let me know what you find out!
>>
>> I tried the latest Qemu code, with the following command:
>>
>> qemu -m 500 -cpu qemu32,+svm -cdrom ubuntu.iso
>>
>> I verified that /proc/cpuinfo has no svm flag. So SVM doesnt work on 32bit
>> host.
>>
>> I will try that with 64bit host to see how it goes.
>
> The host doesn't matter. You can easily run qemu-system-x86_64 on a 32-bit
> host.
>

I can confirm that SVM works well on x86-64 target, but fails on i386 target.

Thanks,
J