Am 04.08.2017 um 12:43 schrieb Paolo Bonzini: > On 04/08/2017 12:27, Peter Lieven wrote: >> Am 04.08.2017 um 12:23 schrieb Paolo Bonzini: >>> On 04/08/2017 11:58, Peter Lieven wrote: >>>> Am 29.10.2013 um 10:59 schrieb Paolo Bonzini: >>>>> Il 29/10/2013 10:48, Peter Lieven ha scritto: >>>>>> Hi all, >>>>>> >>>>>> this question might seem a bit weird, but does anyone see a good way to >>>>>> avoid >>>>>> that Windows is able to boot inside qemu? >>>>>> >>>>>> We have defined several profiles for different operation systems and I >>>>>> want >>>>>> to avoid that someone chooses Linux and then installs Windows within >>>>>> a VM. Reason is licensing. >>>>> Patch QEMU to crash when Hyper-V extensions are enabled... >>>> Hi all, >>>> >>>> this is an old topic that has become important for me again recently. >>>> Now all Linux versions should be able to detect KVM even if Hyper-V is >>>> enabled. >>>> >>>> But how do I detect from Qemu userspace that Hyper-V is enabled? >>> Maybe a better one: make KVM crash the guest if CR8 is nonzero on a >>> vmexit. Linux doesn't use it, Windows should not survive long. >> You mean the kvm kernel module? Or can I access this register also >> from Qemu on any call that is handled in userspace? It would be easier >> to have a cmdline option to Qemu than an option to a kernel module. > Yes, the kernel module. Accessing it in QEMU requires > cpu_synchronize_state so it's slow. However, you could piggyback on > some other functionality that is never used by Linux to do the check, > for example the RTC I/O port. > > That is, in the RTC I/O port code you call cpu_synchronize_state and > check CR8.
Thanks, I will try that out and let you know. Peter