system/i386/hyperv.rst

9 implements its own paravirtualized interfaces. This works well for Linux as
41   This feature tells guest OS to disable watchdog timeouts as it is running on a
42   hypervisor. It is known that some Windows versions will do this even when they
47   more efficiently. In particular, this enlightenment allows paravirtualized
57   processor index information. This enlightenment makes sense in conjunction with
64   virtual processor run time in 100ns units. This gives guest operating system an
72   contain additional crash information. This information is outputted in QEMU log
75   to shutdown. This effectively blocks crash dump generation by Windows.
82   readings. Using this enlightenment leads to significant speedup of all timestamp
87   When enabled, this enlightenment provides additional communication facilities
88   to the guest: SynIC messages and Events. This is a pre-requisite for
89   implementing VMBus devices (not yet in QEMU). Additionally, this enlightenment
101   (or even RTC when HPET is unavailable) extensively when this enlightenment is
102   not provided; this can lead to significant CPU consumption, even when virtual
125   This changes Hyper-V identification in CPUID 0x40000000.EBX-EDX from the default
127   to the specification, guests shouldn't use this information and it is unknown
134   itself by writing to it. Even when this MSR is enabled, it is not a recommended
148   the hypervisor) until it is ready to switch to the new one. This, in conjunction
184   Note: enabling this feature on old hardware (without APICv/AVIC support) may
188   This enlightenment tells guest OS that virtual processors will never share a
189   physical core unless they are reported as sibling SMT threads. This information
194   reports that non-architectural coresharing is impossible, this means that
195   hyper-threading is not supported or completely disabled on the host. This
198   of host setup. To keep guests secure, this can only be used in conjunction with
202   This changes Hyper-V version identification in CPUID 0x40000002.EAX-EDX from the
216   Enables Hyper-V synthetic debugger interface, this is a special interface used
219   When enabled, this enlightenment provides additional communication facilities
221   This new communication is used by Windows Kernel debugger rather than sending
224   This enlightenment requires a VMBus device (-device vmbus-bridge,irq=15).
283   feature alters this behavior and only allows the guest to use exposed Hyper-V
307   QAPI by higher levels of the virtualization stack. Enabling this feature