RFR: 8250598: Hyper-V is detected in spite of running on host OS

[Yasumasa Suenaga]

Hi Matthias,

On 2020/08/05 0:02, Baesken, Matthias wrote:
> Hi  Suenaga,  sorry for answering very late .
>    I did not see any  jck / jtreg errors  in our  internal nightly  tests.

Thanks!

> I also checked the  hserr on another Hyper-V guest and still get the expected " HyperV virtualization detected"   (which is good �� ).
> 
> 
> However on a host, I would still prefer to get some output (probably different than the guest output now) .

What message do you expect? How about "Hyper-V role detected" ?

> Regarding the usage of
> 
> #pragma comment(lib, "wbemuuid.lib")
> 
> This seem to add an additional lib dependency ,  should some people from build/deploy  area comment on this maybe ?
> (not saying it is a very bad thing )

We add wbemuuid.lib to make/autoconf/libraries.m4 .
I will change it in next webrev, and I will CCing to build-dev on next turn.


Thanks,

Yasumasa


> Best regards, Matthias
> 
> 
> 
> -----Original Message-----
> From: Yasumasa Suenaga <suenaga at oss.nttdata.com>
> Sent: Samstag, 1. August 2020 01:04
> To: Baesken, Matthias <matthias.baesken at sap.com>; hotspot-runtime-dev at openjdk.java.net
> Cc: David Holmes <david.holmes at oracle.com>
> Subject: Re: RFR: 8250598: Hyper-V is detected in spite of running on host OS
> 
> Hi Matthias,
> 
> Have you got the result from your internal nightly build / test?
> Also all comments are welcome.
> 
> 
> Thanks,
> 
> Yasumasa
> 
> 
> On 2020/07/27 21:21, Yasumasa Suenaga wrote:
>> On 2020/07/27 19:36, Baesken, Matthias wrote:
>>> Hi Yasumasa, I put your patch into our internal  nightly  build/test  queue .
>>
>> Thanks!
>>
>>>>     - Hyper-V is detected on Windows in spite of running on host OS
>>>
>>> So it is in your case a host that  runs  Hyper-V guests.  And the host  reports too  "HyperV virtualization detected" .
>>> Do I get you  right ?
>>
>> Yes, that's right!
>>
>>> Maybe we should be more specific in this case (however I did not see much problem so far with the  current output ).
>>>
>>>>     - Call CPUID with other than EAX = 40000000h (it is not described in the spec [1])
>>>
>>> I think we had  some virtualizations that needed checking  CPUID with other than EAX = 40000000h  for detection,
>>>    But might be these were old or buggy versions , cannot find much details about it atm .
>>
>> As David shows, virt-what checks CPUID with other than EAX = 40000000h, but at least, current supported hypervisor (VMware, Hyper-V, KVM, Xen) do not seem to need to do it.
>>
>>>>     - Does not check CPUID hypervisor present bit [1]
>>>
>>> Yes, this could/should indeed be added  ( we even did this in our internal JVM a while ago).
>>>
>>>>     - Does not support x86 (32bit) platform
>>>
>>> This is true , it was not added because   I think 32bit support has not much importance any more in current jdk .
>>> However in case the new version does  support 32bit too, it is for sure a good thing!
>>
>> I found out "TODO support 32 bit" in current code, so I attempt to fix it :)
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>>> Best regards, Matthias
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Yasumasa Suenaga <suenaga at oss.nttdata.com>
>>> Sent: Montag, 27. Juli 2020 06:25
>>> To: hotspot-runtime-dev at openjdk.java.net; Baesken, Matthias <matthias.baesken at sap.com>
>>> Cc: David Holmes <david.holmes at oracle.com>
>>> Subject: RFR: 8250598: Hyper-V is detected in spite of running on host OS
>>>
>>> Hi all,
>>>
>>> Please review this change:
>>>
>>>      JBS: https://bugs.openjdk.java.net/browse/JDK-8250598
>>>      webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8250598/webrev.00/
>>>
>>> When I got hs_err log on Windows, I saw "HyperV virtualization detected" in it in spite of running on host OS.
>>>
>>> Hypervisor detector has been introduced in JDK-8219241, but it has some problems as below:
>>>
>>>      - Hyper-V is detected on Windows in spite of running on host OS
>>>      - Call CPUID with other than EAX = 40000000h (it is not described in the spec [1])
>>>      - Does not check CPUID hypervisor present bit [1]
>>>      - Does not support x86 (32bit) platform
>>>
>>> I've tested this change on submit repo, and have checked output from VM.info jcmd on following environment:
>>>
>>>      - Windows x64 (host)
>>>      - Windows x64 (Hyper-V guest)
>>>      - Fedora32 x64 (Hyper-V guest)
>>>      - 32 bit JDK on Fedora32 x64 (Hyper-V guest)
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> [1] https://kb.vmware.com/s/article/1009458
>>>