system/i386/kvm-pv.rst

1 Paravirtualized KVM features
5 -----------
11 -----
13 Paravirtualized ``KVM`` features are represented as CPU flags. The following
14 features are enabled by default for any CPU model when ``KVM`` acceleration is
17 - ``kvmclock``
18 - ``kvm-nopiodelay``
19 - ``kvm-asyncpf``
20 - ``kvm-steal-time``
21 - ``kvm-pv-eoi``
22 - ``kvmclock-stable-bit``
24 ``kvm-msi-ext-dest-id`` feature is enabled by default in x2apic mode with split
25 irqchip (e.g. "-machine ...,kernel-irqchip=split -cpu ...,x2apic").
28 paravirtualized ``KVM`` features to the guest.
30 Existing features
31 -----------------
37 ``kvm-nopiodelay``
41 ``kvm-mmu``
44 ``kvm-asyncpf``
47   Use ``kvm-asyncpf-int`` instead.
49 ``kvm-steal-time``
53 ``kvm-pv-eoi``
54   Enable paravirtualized end-of-interrupt signaling. Supported since Linux
57 ``kvm-pv-unhalt``
60 ``kvm-pv-tlb-flush``
63 ``kvm-pv-ipi``
66 ``kvm-poll-control``
67   Enable host-side polling on HLT control from the guest. Supported since Linux
70 ``kvm-pv-sched-yield``
73 ``kvm-asyncpf-int``
77 ``kvm-msi-ext-dest-id``
79   to use up to 32768 CPUs without IRQ remapping (but other limits may apply making
83 ``kvmclock-stable-bit``
87 Supplementary features
88 ----------------------
90 ``kvm-pv-enforce-cpuid``
91   Limit the supported paravirtualized feature set to the exposed features only.
92   Note, by default, ``KVM`` allows the guest to use all currently supported
93   paravirtualized features even when they were not announced in guest visible
98 ------------