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path: root/docs/arm-cpu-features.rst
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2019-12-19docs: fix rst syntax errors in unbuilt docsStefan Hajnoczi
The .rst files outside docs/{devel,interop,specs} aren't built yet and therefore a few syntax errors have slipped through. Fix them. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20191111094411.427174-1-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-11-01target/arm/kvm: host cpu: Add support for sve<N> propertiesAndrew Jones
Allow cpu 'host' to enable SVE when it's available, unless the user chooses to disable it with the added 'sve=off' cpu property. Also give the user the ability to select vector lengths with the sve<N> properties. We don't adopt 'max' cpu's other sve property, sve-max-vq, because that property is difficult to use with KVM. That property assumes all vector lengths in the range from 1 up to and including the specified maximum length are supported, but there may be optional lengths not supported by the host in that range. With KVM one must be more specific when enabling vector lengths. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Message-id: 20191031142734.8590-10-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/cpu64: max cpu: Support sve properties with KVMAndrew Jones
Extend the SVE vq map initialization and validation with KVM's supported vector lengths when KVM is enabled. In order to determine and select supported lengths we add two new KVM functions for getting and setting the KVM_REG_ARM64_SVE_VLS pseudo-register. This patch has been co-authored with Richard Henderson, who reworked the target/arm/cpu64.c changes in order to push all the validation and auto-enabling/disabling steps into the finalizer, resulting in a nice LOC reduction. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Message-id: 20191031142734.8590-9-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/cpu64: max cpu: Introduce sve<N> propertiesAndrew Jones
Introduce cpu properties to give fine control over SVE vector lengths. We introduce a property for each valid length up to the current maximum supported, which is 2048-bits. The properties are named, e.g. sve128, sve256, sve384, sve512, ..., where the number is the number of bits. See the updates to docs/arm-cpu-features.rst for a description of the semantics and for example uses. Note, as sve-max-vq is still present and we'd like to be able to support qmp_query_cpu_model_expansion with guests launched with e.g. -cpu max,sve-max-vq=8 on their command lines, then we do allow sve-max-vq and sve<N> properties to be provided at the same time, but this is not recommended, and is why sve-max-vq is not mentioned in the document. If sve-max-vq is provided then it enables all lengths smaller than and including the max and disables all lengths larger. It also has the side-effect that no larger lengths may be enabled and that the max itself cannot be disabled. Smaller non-power-of-two lengths may, however, be disabled, e.g. -cpu max,sve-max-vq=4,sve384=off provides a guest the vector lengths 128, 256, and 512 bits. This patch has been co-authored with Richard Henderson, who reworked the target/arm/cpu64.c changes in order to push all the validation and auto-enabling/disabling steps into the finalizer, resulting in a nice LOC reduction. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-5-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/monitor: Introduce qmp_query_cpu_model_expansionAndrew Jones
Add support for the query-cpu-model-expansion QMP command to Arm. We do this selectively, only exposing CPU properties which represent optional CPU features which the user may want to enable/disable. Additionally we restrict the list of queryable cpu models to 'max', 'host', or the current type when KVM is in use. And, finally, we only implement expansion type 'full', as Arm does not yet have a "base" CPU type. More details and example queries are described in a new document (docs/arm-cpu-features.rst). Note, certainly more features may be added to the list of advertised features, e.g. 'vfp' and 'neon'. The only requirement is that we can detect invalid configurations and emit failures at QMP query time. For 'vfp' and 'neon' this will require some refactoring to share a validation function between the QMP query and the CPU realize functions. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-2-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>