diff --git a/target/riscv/crypto_helper.c b/target/riscv/crypto_helper.c
index 71694b787c..affa8292d1 100644
--- a/target/riscv/crypto_helper.c
+++ b/target/riscv/crypto_helper.c
@@ -104,96 +104,6 @@ target_ulong HELPER(aes32dsi)(target_ulong rs1, target_ulong rs2,
     return aes32_operation(shamt, rs1, rs2, false, false);
 }
 
-#define BY(X, I) ((X >> (8 * I)) & 0xFF)
-
-#define AES_SHIFROWS_LO(RS1, RS2) ( \
-    (((RS1 >> 24) & 0xFF) << 56) | (((RS2 >> 48) & 0xFF) << 48) | \
-    (((RS2 >> 8) & 0xFF) << 40) | (((RS1 >> 32) & 0xFF) << 32) | \
-    (((RS2 >> 56) & 0xFF) << 24) | (((RS2 >> 16) & 0xFF) << 16) | \
-    (((RS1 >> 40) & 0xFF) << 8) | (((RS1 >> 0) & 0xFF) << 0))
-
-#define AES_INVSHIFROWS_LO(RS1, RS2) ( \
-    (((RS2 >> 24) & 0xFF) << 56) | (((RS2 >> 48) & 0xFF) << 48) | \
-    (((RS1 >> 8) & 0xFF) << 40) | (((RS1 >> 32) & 0xFF) << 32) | \
-    (((RS1 >> 56) & 0xFF) << 24) | (((RS2 >> 16) & 0xFF) << 16) | \
-    (((RS2 >> 40) & 0xFF) << 8) | (((RS1 >> 0) & 0xFF) << 0))
-
-#define AES_MIXBYTE(COL, B0, B1, B2, B3) ( \
-    BY(COL, B3) ^ BY(COL, B2) ^ AES_GFMUL(BY(COL, B1), 3) ^ \
-    AES_GFMUL(BY(COL, B0), 2))
-
-#define AES_MIXCOLUMN(COL) ( \
-    AES_MIXBYTE(COL, 3, 0, 1, 2) << 24 | \
-    AES_MIXBYTE(COL, 2, 3, 0, 1) << 16 | \
-    AES_MIXBYTE(COL, 1, 2, 3, 0) << 8 | AES_MIXBYTE(COL, 0, 1, 2, 3) << 0)
-
-#define AES_INVMIXBYTE(COL, B0, B1, B2, B3) ( \
-    AES_GFMUL(BY(COL, B3), 0x9) ^ AES_GFMUL(BY(COL, B2), 0xd) ^ \
-    AES_GFMUL(BY(COL, B1), 0xb) ^ AES_GFMUL(BY(COL, B0), 0xe))
-
-#define AES_INVMIXCOLUMN(COL) ( \
-    AES_INVMIXBYTE(COL, 3, 0, 1, 2) << 24 | \
-    AES_INVMIXBYTE(COL, 2, 3, 0, 1) << 16 | \
-    AES_INVMIXBYTE(COL, 1, 2, 3, 0) << 8 | \
-    AES_INVMIXBYTE(COL, 0, 1, 2, 3) << 0)
-
-static inline target_ulong aes64_operation(target_ulong rs1, target_ulong rs2,
-                                           bool enc, bool mix)
-{
-    uint64_t RS1 = rs1;
-    uint64_t RS2 = rs2;
-    uint64_t result;
-    uint64_t temp;
-    uint32_t col_0;
-    uint32_t col_1;
-
-    if (enc) {
-        temp = AES_SHIFROWS_LO(RS1, RS2);
-        temp = (((uint64_t)AES_sbox[(temp >> 0) & 0xFF] << 0) |
-                ((uint64_t)AES_sbox[(temp >> 8) & 0xFF] << 8) |
-                ((uint64_t)AES_sbox[(temp >> 16) & 0xFF] << 16) |
-                ((uint64_t)AES_sbox[(temp >> 24) & 0xFF] << 24) |
-                ((uint64_t)AES_sbox[(temp >> 32) & 0xFF] << 32) |
-                ((uint64_t)AES_sbox[(temp >> 40) & 0xFF] << 40) |
-                ((uint64_t)AES_sbox[(temp >> 48) & 0xFF] << 48) |
-                ((uint64_t)AES_sbox[(temp >> 56) & 0xFF] << 56));
-        if (mix) {
-            col_0 = temp & 0xFFFFFFFF;
-            col_1 = temp >> 32;
-
-            col_0 = AES_MIXCOLUMN(col_0);
-            col_1 = AES_MIXCOLUMN(col_1);
-
-            result = ((uint64_t)col_1 << 32) | col_0;
-        } else {
-            result = temp;
-        }
-    } else {
-        temp = AES_INVSHIFROWS_LO(RS1, RS2);
-        temp = (((uint64_t)AES_isbox[(temp >> 0) & 0xFF] << 0) |
-                ((uint64_t)AES_isbox[(temp >> 8) & 0xFF] << 8) |
-                ((uint64_t)AES_isbox[(temp >> 16) & 0xFF] << 16) |
-                ((uint64_t)AES_isbox[(temp >> 24) & 0xFF] << 24) |
-                ((uint64_t)AES_isbox[(temp >> 32) & 0xFF] << 32) |
-                ((uint64_t)AES_isbox[(temp >> 40) & 0xFF] << 40) |
-                ((uint64_t)AES_isbox[(temp >> 48) & 0xFF] << 48) |
-                ((uint64_t)AES_isbox[(temp >> 56) & 0xFF] << 56));
-        if (mix) {
-            col_0 = temp & 0xFFFFFFFF;
-            col_1 = temp >> 32;
-
-            col_0 = AES_INVMIXCOLUMN(col_0);
-            col_1 = AES_INVMIXCOLUMN(col_1);
-
-            result = ((uint64_t)col_1 << 32) | col_0;
-        } else {
-            result = temp;
-        }
-    }
-
-    return result;
-}
-
 target_ulong HELPER(aes64esm)(target_ulong rs1, target_ulong rs2)
 {
     AESState t, z = { };
@@ -230,7 +140,16 @@ target_ulong HELPER(aes64ds)(target_ulong rs1, target_ulong rs2)
 
 target_ulong HELPER(aes64dsm)(target_ulong rs1, target_ulong rs2)
 {
-    return aes64_operation(rs1, rs2, false, true);
+    AESState t, z = { };
+
+    /*
+     * This instruction does not include a round key,
+     * so supply a zero to our primitive.
+     */
+    t.d[HOST_BIG_ENDIAN] = rs1;
+    t.d[!HOST_BIG_ENDIAN] = rs2;
+    aesdec_ISB_ISR_IMC_AK(&t, &t, &z, false);
+    return t.d[HOST_BIG_ENDIAN];
 }
 
 target_ulong HELPER(aes64ks2)(target_ulong rs1, target_ulong rs2)
