On 10/1/19 5:58 AM, Andrew Jones wrote: > 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 <drjo...@redhat.com> > ---
Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
