Add a cpu property to set GPCCR_EL3.L0GPTSZ, for testing
various possible configurations.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu64.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 0e021960fb..b9343004fb 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -672,6 +672,40 @@ void arm_cpu_lpa2_finalize(ARMCPU *cpu, Error **errp)
     cpu->isar.id_aa64mmfr0 = t;
 }
 
+static void cpu_max_set_l0gptsz(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    uint32_t value;
+
+    if (!visit_type_uint32(v, name, &value, errp)) {
+        return;
+    }
+
+    /* Encode the value for the GPCCR_EL3 field. */
+    switch (value) {
+    case 30:
+    case 34:
+    case 36:
+    case 39:
+        cpu->reset_l0gptsz = value - 30;
+        break;
+    default:
+        error_setg(errp, "invalid value for l0gptsz");
+        error_append_hint(errp, "valid values are 30, 34, 36, 39\n");
+        break;
+    }
+}
+
+static void cpu_max_get_l0gptsz(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    uint32_t value = cpu->reset_l0gptsz + 30;
+
+    visit_type_uint32(v, name, &value, errp);
+}
+
 static void aarch64_a57_initfn(Object *obj)
 {
     ARMCPU *cpu = ARM_CPU(obj);
@@ -1200,6 +1234,7 @@ static void aarch64_max_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64PFR0, SVE, 1);
     t = FIELD_DP64(t, ID_AA64PFR0, SEL2, 1);      /* FEAT_SEL2 */
     t = FIELD_DP64(t, ID_AA64PFR0, DIT, 1);       /* FEAT_DIT */
+    t = FIELD_DP64(t, ID_AA64PFR0, RME, 1);       /* FEAT_RME */
     t = FIELD_DP64(t, ID_AA64PFR0, CSV2, 2);      /* FEAT_CSV2_2 */
     t = FIELD_DP64(t, ID_AA64PFR0, CSV3, 1);      /* FEAT_CSV3 */
     cpu->isar.id_aa64pfr0 = t;
@@ -1300,6 +1335,8 @@ static void aarch64_max_initfn(Object *obj)
     object_property_add(obj, "sve-max-vq", "uint32", cpu_max_get_sve_max_vq,
                         cpu_max_set_sve_max_vq, NULL, NULL);
     qdev_property_add_static(DEVICE(obj), &arm_cpu_lpa2_property);
+    object_property_add(obj, "l0gptsz", "uint32", cpu_max_get_l0gptsz,
+                        cpu_max_set_l0gptsz, NULL, NULL);
 }
 
 static const ARMCPUInfo aarch64_cpus[] = {
-- 
2.34.1

On Tue, 24 Jan 2023 at 00:01, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Add a cpu property to set GPCCR_EL3.L0GPTSZ, for testing
> various possible configurations.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Looks OK, but I think we probably shouldn't enable RME by default
until we're happy with what we're planning to do at the
system/board level (eg should it be like MTE where it's only
turned on if the board has support and turns it on?)

thanks
-- PMM

On 2/10/23 04:20, Peter Maydell wrote:
> On Tue, 24 Jan 2023 at 00:01, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Add a cpu property to set GPCCR_EL3.L0GPTSZ, for testing
>> various possible configurations.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> 
> Looks OK, but I think we probably shouldn't enable RME by default
> until we're happy with what we're planning to do at the
> system/board level (eg should it be like MTE where it's only
> turned on if the board has support and turns it on?)

You're probably right about not enabling by default, and certainly right about figuring 
out what firmware actually expects and needs.


r~