[PATCH v6 07/17] target/s390x: Minimal AES XTS support for cpacf pcc instruction

[Harald Freudenberger <freude@linux.ibm.com>]

Support CPACF pcc subfunctions PCC-Compute-XTS-Parameter-AES-128
and PCC-Compute-XTS-Parameter-AES-128 but only for the special
case block sequential number is 0. However, this covers the s390
AES XTS implementation in the Linux kernel and Libica and thus
also Opencryptoki clear key via Libica.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Holger Dengler <dengler@linux.ibm.com>
---
 target/s390x/gen-features.c      |  2 +
 target/s390x/tcg/cpacf.h         |  2 +
 target/s390x/tcg/cpacf_aes.c     | 71 ++++++++++++++++++++++++++++++++
 target/s390x/tcg/crypto_helper.c | 20 +++++++++
 4 files changed, 95 insertions(+)

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index 59c2a47539..1b6a874b90 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -930,6 +930,8 @@ static uint16_t qemu_MAX[] = {
     S390_FEAT_KMCTR_AES_128,
     S390_FEAT_KMCTR_AES_192,
     S390_FEAT_KMCTR_AES_256,
+    S390_FEAT_PCC_XTS_AES_128,
+    S390_FEAT_PCC_XTS_AES_256,
 };
 
 /****** END FEATURE DEFS ******/
diff --git a/target/s390x/tcg/cpacf.h b/target/s390x/tcg/cpacf.h
index d73cb98c38..381a6c3ff1 100644
--- a/target/s390x/tcg/cpacf.h
+++ b/target/s390x/tcg/cpacf.h
@@ -32,5 +32,7 @@ int cpacf_aes_ctr(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                   uint64_t *src_ptr_reg, uint64_t *src_len_reg,
                   uint64_t *ctr_ptr_reg, uint32_t type,
                   uint8_t fc, uint8_t mod);
+int cpacf_aes_pcc(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                  uint64_t param_addr, uint8_t fc);
 
 #endif
diff --git a/target/s390x/tcg/cpacf_aes.c b/target/s390x/tcg/cpacf_aes.c
index e200a9a87a..43c556f31b 100644
--- a/target/s390x/tcg/cpacf_aes.c
+++ b/target/s390x/tcg/cpacf_aes.c
@@ -16,6 +16,13 @@
 #include "crypto/aes.h"
 #include "cpacf.h"
 
+/* #define DEBUG_HELPER */
+#ifdef DEBUG_HELPER
+#define HELPER_LOG(x...) qemu_log(x)
+#else
+#define HELPER_LOG(x...)
+#endif
+
 static void aes_read_block(CPUS390XState *env, const int mmu_idx,
                            uint64_t addr, uint8_t *a, uintptr_t ra)
 {
@@ -289,3 +296,67 @@ int cpacf_aes_ctr(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
 
     return !len ? 0 : 3;
 }
+
+int cpacf_aes_pcc(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                  uint64_t param_addr, uint8_t fc)
+{
+    uint8_t key[32], tweak[AES_BLOCK_SIZE], buf[AES_BLOCK_SIZE];
+    const MemOpIdx oi = make_memop_idx(MO_8, mmu_idx);
+    int keysize, i;
+    uint64_t addr;
+    AES_KEY exkey;
+
+    switch (fc) {
+    case 0x32: /* CPACF_PCC compute XTS param AES-128 */
+        keysize = 16;
+        break;
+    case 0x34: /* CPACF PCC compute XTS param AES-256 */
+        keysize = 32;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    /* fetch block sequence nr from param block into buf */
+    for (i = 0; i < AES_BLOCK_SIZE; i++) {
+        addr = wrap_address(env, param_addr + keysize + AES_BLOCK_SIZE + i);
+        buf[i] = cpu_ldb_mmu(env, addr, oi, ra);
+    }
+
+    /* is the block sequence nr 0 ? */
+    for (i = 0; i < AES_BLOCK_SIZE && !buf[i]; i++) {
+            ;
+    }
+    if (i < AES_BLOCK_SIZE) {
+        /* no, sorry handling of non zero block sequence is not implemented */
+        cpu_abort(env_cpu(env),
+                  "PCC-compute-XTS-param with non zero block sequence is not implemented\n");
+        return 1;
+    }
+
+    /* fetch key from param block */
+    for (i = 0; i < keysize; i++) {
+        addr = wrap_address(env, param_addr + i);
+        key[i] = cpu_ldb_mmu(env, addr, oi, ra);
+    }
+
+    /* fetch tweak from param block into tweak */
+    for (i = 0; i < AES_BLOCK_SIZE; i++) {
+        addr = wrap_address(env, param_addr + keysize + i);
+        tweak[i] = cpu_ldb_mmu(env, addr, oi, ra);
+    }
+
+    /* expand key */
+    AES_set_encrypt_key(key, keysize * 8, &exkey);
+
+    /* encrypt tweak */
+    AES_encrypt(tweak, buf, &exkey);
+
+    /* store encrypted tweak into xts parameter field of the param block */
+    for (i = 0; i < AES_BLOCK_SIZE; i++) {
+        addr = wrap_address(env, param_addr + keysize + 3 * AES_BLOCK_SIZE + i);
+        cpu_stb_mmu(env, addr, buf[i], oi, ra);
+    }
+
+    return 0;
+}
diff --git a/target/s390x/tcg/crypto_helper.c b/target/s390x/tcg/crypto_helper.c
index 98dfa37185..1a0a503844 100644
--- a/target/s390x/tcg/crypto_helper.c
+++ b/target/s390x/tcg/crypto_helper.c
@@ -169,6 +169,23 @@ static int cpacf_ppno(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
     return rc;
 }
 
+static int cpacf_pcc(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                     uint8_t fc)
+{
+    int rc = 0;
+
+    switch (fc) {
+    case 0x32: /* CPACF_PCC compute XTS param AES-128 */
+    case 0x34: /* CPACF PCC compute XTS param AES-256 */
+            rc = cpacf_aes_pcc(env, mmu_idx, ra, env->regs[1], fc);
+            break;
+    default:
+        g_assert_not_reached();
+    }
+
+    return rc;
+}
+
 uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3,
                      uint32_t type)
 {
@@ -228,6 +245,9 @@ uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3,
     case S390_FEAT_TYPE_KMCTR:
         rc = cpacf_kmctr(env, mmu_idx, ra, r1, r2, r3, fc, mod);
         break;
+    case S390_FEAT_TYPE_PCC:
+        rc = cpacf_pcc(env, mmu_idx, ra, fc);
+        break;
     default:
         g_assert_not_reached();
     }
-- 
2.43.0