system/arm/cpu-features.rst

27 when using the KVM accelerator and when running on a host CPU type that
28 supports the feature.  While ``aarch64`` currently only works with KVM,
29 it could work with TCG.  CPU features that are specific to KVM are
30 prefixed with "kvm-" and are described in "KVM VCPU Features".
58 all SVE vector lengths can be supported, when KVM is in use it's more
81        "'aarch64' feature cannot be disabled unless KVM is enabled and 32-bit EL1 is supported"
122 A note about CPU models and KVM
125 Named CPU models generally do not work with KVM.  There are a few cases
126 that do work, e.g. using the named CPU model ``cortex-a57`` with KVM on a
127 seattle host, but mostly if KVM is enabled the ``host`` CPU type must be
135 Enabling KVM also affects the ``query-cpu-model-expansion`` QMP command.  The
138 When KVM is enabled, only the ``max``, ``host``, and current CPU type may be
140 CPU types that may work with KVM, but it does impose a small risk of users
142 above, the ``cortex-a57`` CPU type is also valid when KVM is enabled.
146 users have been preferring the ``host`` CPU type for use with KVM for quite
147 some time.  Additionally, if the KVM-enabled QEMU instance running on a
170 KVM VCPU Features
173 KVM VCPU features are CPU features that are specific to KVM, such as
175 The features' CPU properties are only available when KVM is enabled and
176 are named with the prefix "kvm-".  KVM VCPU features may be probed,
178 the list of KVM VCPU features and their descriptions.
198   Since v5.2, kvm-steal-time is enabled by default when KVM is
248   2) If a vector length ``N`` is enabled, then, when KVM is enabled, all
250      KVM is not enabled, then only all the smaller, power-of-two vector
251      lengths must be enabled.  E.g. with KVM if the host supports all
254      384-bit vector length must also be enabled. Without KVM, the 384-bit
257   3) If KVM is enabled then only vector lengths that the host CPU type
275      KVM is not in use means including the non-power-of-two lengths, and,
276      when KVM is in use, it means all vector lengths supported by the host
288   5) When KVM is enabled, if the host does not support SVE, then an error
292   6) When KVM is enabled, if the host does support SVE, then an error is
300      When KVM is not enabled, disabling a power-of-two vector length also
302      When KVM is enabled, then disabling any supported vector length also
329   3) When KVM is enabled, implicitly enable all host CPU supported vector
423 SME is not supported by KVM at this time.