diff --git a/target/arm/helper.c b/target/arm/helper.c
index 562ea5c418..d9837b5bd2 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -8519,13 +8519,14 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
                                    int crm, int opc1, int opc2,
                                    const char *name)
 {
+    CPUARMState *env = &cpu->env;
     uint32_t key;
     ARMCPRegInfo *r2;
     bool is64 = r->type & ARM_CP_64BIT;
     bool ns = secstate & ARM_CP_SECSTATE_NS;
     int cp = r->cp;
-    bool isbanked;
     size_t name_len;
+    bool make_const;
 
     switch (state) {
     case ARM_CP_STATE_AA32:
@@ -8560,6 +8561,24 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
         }
     }
 
+    /*
+     * Eliminate registers that are not present because the EL is missing.
+     * Doing this here makes it easier to put all registers for a given
+     * feature into the same ARMCPRegInfo array and define them all at once.
+     */
+    if (arm_feature(env, ARM_FEATURE_EL3)) {
+        /* An EL2 register without EL2 but with EL3 is (usually) RES0. */
+        int min_el = ctz32(r->access) / 2;
+        make_const = min_el == 2 && !arm_feature(env, ARM_FEATURE_EL2);
+    } else {
+        CPAccessRights max_el = (arm_feature(env, ARM_FEATURE_EL2)
+                                 ? PL2_RW : PL1_RW);
+        if ((r->access & max_el) == 0) {
+            return;
+        }
+        make_const = false;
+    }
+
     /* Combine cpreg and name into one allocation. */
     name_len = strlen(name) + 1;
     r2 = g_malloc(sizeof(*r2) + name_len);
@@ -8580,44 +8599,74 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
         r2->opaque = opaque;
     }
 
-    isbanked = r->bank_fieldoffsets[0] && r->bank_fieldoffsets[1];
-    if (isbanked) {
+    if (make_const) {
+        /* This should not have been a very special register to begin. */
+        int old_special = r2->type & ARM_CP_SPECIAL_MASK;
+        assert(old_special == 0 || old_special == ARM_CP_CONST);
         /*
-         * Register is banked (using both entries in array).
-         * Overwriting fieldoffset as the array is only used to define
-         * banked registers but later only fieldoffset is used.
+         * Set the special function to CONST, retaining the flags.
+         * This is important for e.g. ARM_CP_SVE so that we still
+         * take the SVE trap if CPTR_EL3.EZ == 0.
          */
-        r2->fieldoffset = r->bank_fieldoffsets[ns];
-    }
-    if (state == ARM_CP_STATE_AA32) {
+        r2->type |= ARM_CP_CONST;
+        /*
+         * Usually, these registers become RES0, but there are a few
+         * special cases like VPIDR_EL2 which have a constant non-zero
+         * value with writes ignored.  So leave resetvalue as is.
+         *
+         * ARM_CP_SPECIAL_MASK has precedence, so removing the callbacks
+         * and offsets are not strictly necessary, but is potentially
+         * less confusing to debug later.
+         */
+        r2->readfn = NULL;
+        r2->writefn = NULL;
+        r2->raw_readfn = NULL;
+        r2->raw_writefn = NULL;
+        r2->resetfn = NULL;
+        r2->fieldoffset = 0;
+        r2->bank_fieldoffsets[0] = 0;
+        r2->bank_fieldoffsets[1] = 0;
+    } else {
+        bool isbanked = r->bank_fieldoffsets[0] && r->bank_fieldoffsets[1];
+
         if (isbanked) {
             /*
-             * If the register is banked then we don't need to migrate or
-             * reset the 32-bit instance in certain cases:
-             *
-             * 1) If the register has both 32-bit and 64-bit instances then we
-             *    can count on the 64-bit instance taking care of the
-             *    non-secure bank.
-             * 2) If ARMv8 is enabled then we can count on a 64-bit version
-             *    taking care of the secure bank.  This requires that separate
-             *    32 and 64-bit definitions are provided.
+             * Register is banked (using both entries in array).
+             * Overwriting fieldoffset as the array is only used to define
+             * banked registers but later only fieldoffset is used.
              */
-            if ((r->state == ARM_CP_STATE_BOTH && ns) ||
-                (arm_feature(&cpu->env, ARM_FEATURE_V8) && !ns)) {
+            r2->fieldoffset = r->bank_fieldoffsets[ns];
+        }
+        if (state == ARM_CP_STATE_AA32) {
+            if (isbanked) {
+                /*
+                 * If the register is banked then we don't need to migrate or
+                 * reset the 32-bit instance in certain cases:
+                 *
+                 * 1) If the register has both 32-bit and 64-bit instances
+                 *    then we can count on the 64-bit instance taking care
+                 *    of the non-secure bank.
+                 * 2) If ARMv8 is enabled then we can count on a 64-bit
+                 *    version taking care of the secure bank.  This requires
+                 *    that separate 32 and 64-bit definitions are provided.
+                 */
+                if ((r->state == ARM_CP_STATE_BOTH && ns) ||
+                    (arm_feature(env, ARM_FEATURE_V8) && !ns)) {
+                    r2->type |= ARM_CP_ALIAS;
+                }
+            } else if ((secstate != r->secure) && !ns) {
+                /*
+                 * The register is not banked so we only want to allow
+                 * migration of the non-secure instance.
+                 */
                 r2->type |= ARM_CP_ALIAS;
             }
-        } else if ((secstate != r->secure) && !ns) {
-            /*
-             * The register is not banked so we only want to allow migration
-             * of the non-secure instance.
-             */
-            r2->type |= ARM_CP_ALIAS;
-        }
 
-        if (r->state == ARM_CP_STATE_BOTH && r->fieldoffset) {
+            if (r->state == ARM_CP_STATE_BOTH && r->fieldoffset) {
 #ifdef HOST_WORDS_BIGENDIAN
-            r2->fieldoffset += sizeof(uint32_t);
+                r2->fieldoffset += sizeof(uint32_t);
 #endif
+            }
         }
     }
 
@@ -8628,7 +8677,7 @@ static void add_cpreg_to_hashtable(ARMCPU *cpu, const ARMCPRegInfo *r,
      * multiple times. Special registers (ie NOP/WFI) are
      * never migratable and not even raw-accessible.
      */
-    if (r->type & ARM_CP_SPECIAL_MASK) {
+    if (r2->type & ARM_CP_SPECIAL_MASK) {
         r2->type |= ARM_CP_NO_RAW;
     }
     if ((r->crm == CP_ANY && crm != 0) ||
