vmx=on with -accel hax

vmx=on with -accel hax

[Rui Prior]

Dear qemu developers,

I found a bug/limitation of qemu on windows (qemu-w64-setup-20200201.exe
from https://qemu.weilnetz.de/w64/ ) that makes qemu terminate
immediately with "VCPU shutdown request" (twice) if I try to use the
"vmx=on" CPU option while simultaneously using "-accel hax".  Without
"vmx=on", it works fine (but it prevents me from using nested
virtualization).

I am using HAXM v7.5.6.

Should you need any further information, please let me know.

Best regards,
-- 
Rui Prior
*********************************************
Departamento de Ciência de Computadores,
Faculdade de Ciências, Universidade do Porto
*********************************************
Instituto de Telecomunicações
*********************************************

Re: vmx=on with -accel hax

[Markus Armbruster]

Cc'ing people listed by "scripts/get_maintainer.pl -f target/i386/hax*".

Rui Prior <rprior@dcc.fc.up.pt> writes:

> Dear qemu developers,
>
> I found a bug/limitation of qemu on windows (qemu-w64-setup-20200201.exe
> from https://qemu.weilnetz.de/w64/ ) that makes qemu terminate
> immediately with "VCPU shutdown request" (twice) if I try to use the
> "vmx=on" CPU option while simultaneously using "-accel hax".  Without
> "vmx=on", it works fine (but it prevents me from using nested
> virtualization).
>
> I am using HAXM v7.5.6.
>
> Should you need any further information, please let me know.
>
> Best regards,

Re: vmx=on with -accel hax

[Eduardo Habkost]

On Thu, Mar 05, 2020 at 06:32:07AM +0100, Markus Armbruster wrote:
> Cc'ing people listed by "scripts/get_maintainer.pl -f target/i386/hax*".
> 

Thanks!  get_maintainer.pl output here is a bit misleading.  We
have no maintainers listed for the hax accel.  CCing the original
authors, hoping they can help.

> Rui Prior <rprior@dcc.fc.up.pt> writes:
> 
> > Dear qemu developers,
> >
> > I found a bug/limitation of qemu on windows (qemu-w64-setup-20200201.exe
> > from https://qemu.weilnetz.de/w64/ ) that makes qemu terminate
> > immediately with "VCPU shutdown request" (twice) if I try to use the
> > "vmx=on" CPU option while simultaneously using "-accel hax".  Without
> > "vmx=on", it works fine (but it prevents me from using nested
> > virtualization).
> >
> > I am using HAXM v7.5.6.
> >

I don't see any CPUID handling in the hax accel code, so "vmx=on"
isn't even supposed to have any effect.  I don't think HAXM
supports nested virtualization, does it?


> > Should you need any further information, please let me know.
> >
> > Best regards,

-- 
Eduardo

Re: vmx=on with -accel hax

[Paolo Bonzini]

On 05/03/20 06:32, Markus Armbruster wrote:
> Cc'ing people listed by "scripts/get_maintainer.pl -f target/i386/hax*".
> 
> Rui Prior <rprior@dcc.fc.up.pt> writes:
> 
>> Dear qemu developers,
>>
>> I found a bug/limitation of qemu on windows (qemu-w64-setup-20200201.exe
>> from https://qemu.weilnetz.de/w64/ ) that makes qemu terminate
>> immediately with "VCPU shutdown request" (twice) if I try to use the
>> "vmx=on" CPU option while simultaneously using "-accel hax".  Without
>> "vmx=on", it works fine (but it prevents me from using nested
>> virtualization).
>>
>> I am using HAXM v7.5.6.

Hello, as far as I know HAXM does not support nested virtualization.

Paolo