On 6/21/19 6:34 PM, Andrew Jones wrote:
> Since 97a28b0eeac14 ("target/arm: Allow VFP and Neon to be disabled via
> a CPU property") we can disable the 'max' cpu model's VFP and neon
> features, but there's no way to disable SVE. Add the 'sve=on|off'
> property to give it that flexibility. We also rename
> cpu_max_get/set_sve_vq to cpu_max_get/set_sve_max_vq in order for them
> to follow the typical *_get/set_<property-name> pattern.
I think perhaps the new property should not be overloaded on cpu->sve_max_vq.
At present you are generating an error for
-cpu max,sve=off,sve_max_vq=2
but not for
-cpu max,sve_max_vq=2,sve=off
and then there's the issue of
-cpu max,sve_max_vq=2,sve=off,sve=on
discarding the earlier sve_max_vq setting.
> @@ -1129,6 +1129,14 @@ static void arm_cpu_realizefn(DeviceState *dev, Error
> **errp)
> cpu->isar.mvfr0 = u;
> }
>
> + if (!cpu->sve_max_vq) {
> + uint64_t t;
> +
> + t = cpu->isar.id_aa64pfr0;
> + t = FIELD_DP64(t, ID_AA64PFR0, SVE, 0);
> + cpu->isar.id_aa64pfr0 = t;
> + }
I suppse the isar bits are initialized too late for you to be able to re-use
the ID_AA64PFR0.SVE field *as* the property?
> static void zcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
> uint64_t value)
> {
> + ARMCPU *cpu = env_archcpu(env);
> int cur_el = arm_current_el(env);
> - int old_len = sve_zcr_len_for_el(env, cur_el);
> - int new_len;
> + int old_len, new_len;
> +
> + assert(cpu->sve_max_vq);
Certainly there's no reason for this assert, given the above.
r~
