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Date: Tue, 29 Oct 2013 15:12:26 +0100
From: Laszlo Ersek <lersek@redhat.com>
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Subject: Re: [Qemu-devel] Prohibit Windows from running in QEMU
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To: Peter Lieven <pl@kamp.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

On 10/29/13 11:50, Peter Lieven wrote:
> On 29.10.2013 11:48, Paolo Bonzini wrote:
>> Il 29/10/2013 11:40, Peter Lieven ha scritto:
>>>> The KVM signature should be at CPUID leaf 0x40000100.
>>> If I enable hyperv for all vServers the signature is at
>>> KVM_CPUID_SIGNATURE_NEXT (0x40000100) otherwise
>>> at KVM_CPUID_SIGNATURE (0x0).
>> KVM_CPU_ID_SIGNATURE is 0x40000000.
>>
>>> Does this matter to Linux?
>> For recent versions it doesn't.  Older versions will not be able to use
>> kvmclock (and other PV enhancements for KVM such as steal time or PV
>> EOI).
> Ok, so this is not an option today - maybe later...
> 
> Any other idea to detect Windows is running or trying to start?

I don't know what I'm talking about. But:

- Maybe tracing MSR accesses could give you a "profile".

- Windows' ACPI parser is super cranky. You could pass in a custom (but
standardized) ACPI table on the command line (-acpitable) that only
triggers some warnings in Linux's port of ACPICA, but crashes Windows
(BSOD). Like, write & compile a simple table to AML, then mess it up
(eg. Package encoding or some such) with a hex editor. This would take
some experimentation as well, but searching existing bug reports could help.

Laszlo