target/arm: Enable GCSPR_EL0 for read in user-mode

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20251008215613.300150-68-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index cbb00c3db336a42e688f6e9c3c311ee4dfd8203c..11e7c10cef577c81fce9f72872dc71ef42eaf3b5 100644 (file)
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -311,6 +311,10 @@ static void arm_cpu_reset_hold(Object *obj, ResetType type)
         env->cp15.mdscr_el1 |= 1 << 12;
         /* Enable FEAT_MOPS */
         env->cp15.sctlr_el[1] |= SCTLR_MSCEN;
+        /* For Linux, GCSPR_EL0 is always readable. */
+        if (cpu_isar_feature(aa64_gcs, cpu)) {
+            env->cp15.gcscr_el[0] = GCSCRE0_NTR;
+        }
 #else
         /* Reset into the highest available EL */
         if (arm_feature(env, ARM_FEATURE_EL3)) {