From 0df9142d27d519f8686c8e92b8cfc4e04f2ddbe3 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Thu, 31 Oct 2019 15:27:29 +0100 Subject: target/arm/cpu64: max cpu: Introduce sve properties 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 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 Reviewed-by: Richard Henderson Reviewed-by: Eric Auger Tested-by: Masayoshi Mizuma Reviewed-by: Beata Michalska Message-id: 20191031142734.8590-5-drjones@redhat.com Signed-off-by: Peter Maydell --- target/arm/cpu.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'target/arm/cpu.h') diff --git a/target/arm/cpu.h b/target/arm/cpu.h index d844ea21d8..a044d6028b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -184,8 +184,13 @@ typedef struct { #ifdef TARGET_AARCH64 # define ARM_MAX_VQ 16 +void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp); +uint32_t arm_cpu_vq_map_next_smaller(ARMCPU *cpu, uint32_t vq); #else # define ARM_MAX_VQ 1 +static inline void arm_cpu_sve_finalize(ARMCPU *cpu, Error **errp) { } +static inline uint32_t arm_cpu_vq_map_next_smaller(ARMCPU *cpu, uint32_t vq) +{ return 0; } #endif typedef struct ARMVectorReg { @@ -918,6 +923,18 @@ struct ARMCPU { /* Used to set the maximum vector length the cpu will support. */ uint32_t sve_max_vq; + + /* + * In sve_vq_map each set bit is a supported vector length of + * (bit-number + 1) * 16 bytes, i.e. each bit number + 1 is the vector + * length in quadwords. + * + * While processing properties during initialization, corresponding + * sve_vq_init bits are set for bits in sve_vq_map that have been + * set by properties. + */ + DECLARE_BITMAP(sve_vq_map, ARM_MAX_VQ); + DECLARE_BITMAP(sve_vq_init, ARM_MAX_VQ); }; void arm_cpu_post_init(Object *obj); @@ -1837,6 +1854,8 @@ static inline int arm_feature(CPUARMState *env, int feature) return (env->features & (1ULL << feature)) != 0; } +void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp); + #if !defined(CONFIG_USER_ONLY) /* Return true if exception levels below EL3 are in secure state, * or would be following an exception return to that level. -- cgit v1.2.3-55-g7522