system/i386/hyperv.rst

22 No Hyper-V enlightenments are enabled by default by either KVM or QEMU. In
23 QEMU, individual enlightenments can be enabled through CPU flags, e.g:
32 When any set of the Hyper-V enlightenments is enabled, QEMU changes hypervisor
80   page (enabled via MSR HV_X64_MSR_REFERENCE_TSC, 0x40000021). Both clocksources
87   When enabled, this enlightenment provides additional communication facilities
134   itself by writing to it. Even when this MSR is enabled, it is not a recommended
144   enabled, it provides HV_X64_MSR_REENLIGHTENMENT_CONTROL (0x40000106),
161   enabled, it provides Enlightened VMCS version 1 feature to the guest. The feature
166   hv-evmcs is enabled. It may make sense to measure your nested workload with and
176   enabled.
181   The enlightenment allows to use Hyper-V SynIC with hardware APICv/AVIC enabled.
219   When enabled, this enlightenment provides additional communication facilities
230   enabled, it allows L0 (KVM) and L1 (Hyper-V) hypervisors to collaborate to
233   Enlightened VMCS (``hv-evmcs``) feature to also be enabled.
250   enabled, it allows L0 (KVM) to directly handle TLB flush hypercalls from L2
253   Enlightened VMCS (``hv-evmcs``) feature to also be enabled.
274   ``hv-syndbg`` can be enabled additionally.
276   Note: ``hv-passthrough`` effectively prevents migration as the list of enabled
294 - ``hv-syndbg``, ``hv-passthrough``, ``hv-enforce-cpuid`` should not be enabled
297 - ``hv-evmcs`` can (and should) be enabled on Intel CPUs only. While the feature
300 - ``hv-no-nonarch-coresharing`` must only be enabled if vCPUs are properly pinned
306 - ``hv-crash`` must only be enabled if the crash information is consumed via
314 - ``hv-avic``/``hv-apicv`` should not be enabled if the hardware does not