On 10/29/2014 11:37 AM, Andrew Cooper wrote: > While testing various nested combinations, XenServer has found that > modern Windows Server versions must have the hypervisor bit hidden from > them for them to be happy running HyperV, despite the fact that they > will make use of the Viridian virtual extensions also provided.
Right. > As a result, while it is certainly advisable for the hypervisor bit to > be set, CommonHV should be available to be found by paravirtualised > drivers inside an OS which can't cope with the hypervisor bit set. Microsoft should just stop putting arbitrary limitations on their software; or pay the price which, in this case, is not being able to use the features from the common specification. I guess what they'd do is reinvent the RNG as a Viridian extension (if they need it). You can certainly do CPUID(0x4F000000) even if HYPERVISOR=0. What you get back is undefined, but in all likelihood it won't be the "CommonHVIntf" string. Paolo _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
