Hypervisor detector for Windows

[Yasumasa Suenaga]

On 2020/07/27 15:59, Baesken, Matthias wrote:
> Hi  Yasumasa , I'll  put  your  patch  into our build/test  queue  and check the outcome.

Thanks Matthias, can you check this webrev rather than in my first email?

   http://cr.openjdk.java.net/~ysuenaga/JDK-8250598/webrev.00/


Yasumasa


> And thanks for filing the JBS issue too .
>   
> Regarding ...
> 
>> Does not support x86 (32bit) platform
> 
> Yes , I think 32bit is not very important any more in current OpenJDK .
> But if your patch addresses it too , then  it's not a bad thing for sure !
> 
> Best regards, Matthias
> 
> 
> 
> 
> -----Original Message-----
> From: Yasumasa Suenaga <suenaga at oss.nttdata.com>
> Sent: Samstag, 25. Juli 2020 17:02
> To: David Holmes <david.holmes at oracle.com>; hotspot-runtime-dev at openjdk.java.net; Baesken, Matthias <matthias.baesken at sap.com>
> Subject: Re: Hypervisor detector for Windows
> 
> Thanks David!
> 
> On 2020/07/25 21:13, David Holmes wrote:
>> Hi Yasumasa,
>>
>> My recollection from reviewing this was that it was all based on vendor strings. Best to ask Matthias (cc'd) if you need more details.
> 
> I think we can fix like following webrev. It works fine on Windows 10 (host), Windows 10 (guest) on Hyper-V, and Fedora 32 on Hyper-V.
> Matthias, what do you think? If this webrev seems good, I will file it to JBS and will send review request.
> 
>     http://cr.openjdk.java.net/~ysuenaga/hv-detection/
> 
> 
> Thanks,
> 
> Yasumasa
> 
> 
>> Cheers,
>> David
>>
>> On 25/07/2020 3:51 pm, Yasumasa Suenaga wrote:
>>> Hi all,
>>>
>>> When I got hs_err log on Windows, I saw "HyperV virtualization detected" in it in spite of running on host OS.
>>>
>>> I tried to file it to JBS and to fix it, but I have some questions for this.
>>> (This feature has been introduced in JDK-8219241)
>>>
>>>
>>>     - According to [1] (it is mentioned in the source code), we need to check bit 31 in ECX when CPUID is called with EAX = 1h. Why it would not do so?
>>>
>>>     - Why would VM_Version::check_virtualizations() call CPUID with 40000000h to 4000FF00h? 40000000h should be used if we want to get vendor ID.
>>>
>>>     - Why VM_Version::check_virt_cpuid() is separated for GNU C (GAS) and MacroAssembler? I guess we can use MacroAssembler for x86 / x86_64.
>>>
>>>     - In case of Hyper-V, host OS is treated as root partition [2], so we cannot use this CPUID solution for Hyper-V. I guess we need to check it with other solutions like [3].
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> [1] https://kb.vmware.com/s/article/1009458
>>> [2] https://docs.microsoft.com/virtualization/hyper-v-on-windows/reference/hyper-v-architecture
>>> [3] https://stackoverflow.com/questions/10544498/detect-the-virtualization-layer-from-a-guest-instancevm-vpc-or-hyper-v-in-c