From 8b599e5c0274cd5e4a33be6a10d6cd04631a74d1 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 8 Jun 2022 19:38:55 +0100 Subject: [PATCH] linux-user/aarch64: Introduce sve_vq Add an interface function to extract the digested vector length rather than the raw zcr_el[1] value. This fixes an incorrect return from do_prctl_set_vl where we didn't take into account the set of vector lengths supported by the cpu. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20220607203306.657998-3-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- linux-user/aarch64/signal.c | 4 ++-- linux-user/aarch64/target_prctl.h | 20 +++++++++++++------- target/arm/cpu.h | 11 +++++++++++ 3 files changed, 26 insertions(+), 9 deletions(-) diff --git a/linux-user/aarch64/signal.c b/linux-user/aarch64/signal.c index 7de4c96eb9..7da0e36c6d 100644 --- a/linux-user/aarch64/signal.c +++ b/linux-user/aarch64/signal.c @@ -315,7 +315,7 @@ static int target_restore_sigframe(CPUARMState *env, case TARGET_SVE_MAGIC: if (cpu_isar_feature(aa64_sve, env_archcpu(env))) { - vq = (env->vfp.zcr_el[1] & 0xf) + 1; + vq = sve_vq(env); sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); if (!sve && size == sve_size) { sve = (struct target_sve_context *)ctx; @@ -434,7 +434,7 @@ static void target_setup_frame(int usig, struct target_sigaction *ka, /* SVE state needs saving only if it exists. */ if (cpu_isar_feature(aa64_sve, env_archcpu(env))) { - vq = (env->vfp.zcr_el[1] & 0xf) + 1; + vq = sve_vq(env); sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16); sve_ofs = alloc_sigframe_space(sve_size, &layout); } diff --git a/linux-user/aarch64/target_prctl.h b/linux-user/aarch64/target_prctl.h index 3f5a5d3933..1d440ffbea 100644 --- a/linux-user/aarch64/target_prctl.h +++ b/linux-user/aarch64/target_prctl.h @@ -10,7 +10,7 @@ static abi_long do_prctl_get_vl(CPUArchState *env) { ARMCPU *cpu = env_archcpu(env); if (cpu_isar_feature(aa64_sve, cpu)) { - return ((cpu->env.vfp.zcr_el[1] & 0xf) + 1) * 16; + return sve_vq(env) * 16; } return -TARGET_EINVAL; } @@ -25,18 +25,24 @@ static abi_long do_prctl_set_vl(CPUArchState *env, abi_long arg2) */ if (cpu_isar_feature(aa64_sve, env_archcpu(env)) && arg2 >= 0 && arg2 <= 512 * 16 && !(arg2 & 15)) { - ARMCPU *cpu = env_archcpu(env); uint32_t vq, old_vq; - old_vq = (env->vfp.zcr_el[1] & 0xf) + 1; - vq = MAX(arg2 / 16, 1); - vq = MIN(vq, cpu->sve_max_vq); + old_vq = sve_vq(env); + /* + * Bound the value of arg2, so that we know that it fits into + * the 4-bit field in ZCR_EL1. Rely on the hflags rebuild to + * sort out the length supported by the cpu. + */ + vq = MAX(arg2 / 16, 1); + vq = MIN(vq, ARM_MAX_VQ); + env->vfp.zcr_el[1] = vq - 1; + arm_rebuild_hflags(env); + + vq = sve_vq(env); if (vq < old_vq) { aarch64_sve_narrow_vq(env, vq); } - env->vfp.zcr_el[1] = vq - 1; - arm_rebuild_hflags(env); return vq * 16; } return -TARGET_EINVAL; diff --git a/target/arm/cpu.h b/target/arm/cpu.h index e791ffdd6b..f5af88b686 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3286,6 +3286,17 @@ static inline int cpu_mmu_index(CPUARMState *env, bool ifetch) return EX_TBFLAG_ANY(env->hflags, MMUIDX); } +/** + * sve_vq + * @env: the cpu context + * + * Return the VL cached within env->hflags, in units of quadwords. + */ +static inline int sve_vq(CPUARMState *env) +{ + return EX_TBFLAG_A64(env->hflags, VL) + 1; +} + static inline bool bswap_code(bool sctlr_b) { #ifdef CONFIG_USER_ONLY