[PULL 14/33] target/s390x: Support protected key AES ECB for cpacf km instruction

[Eric Farman <farman@linux.ibm.com>]

From: Harald Freudenberger <freude@linux.ibm.com>

Support the subfunctions CPACF_KM_PAES_128, CPACF_KM_PAES_192
and CPACF_KM_PAES_256 for the cpacf km instruction.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Finn Callies <fcallies@linux.ibm.com>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20260824083204.40877-15-freude@linux.ibm.com
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 target/s390x/gen-features.c      |   3 +
 target/s390x/tcg/cpacf.h         |   4 ++
 target/s390x/tcg/cpacf_aes.c     | 103 +++++++++++++++++++++++++++++++
 target/s390x/tcg/crypto_helper.c |   7 +++
 4 files changed, 117 insertions(+)

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index e00255af67..4e3d851873 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -932,6 +932,9 @@ static uint16_t qemu_MAX[] = {
     S390_FEAT_KM_AES_128,
     S390_FEAT_KM_AES_192,
     S390_FEAT_KM_AES_256,
+    S390_FEAT_KM_EAES_128,
+    S390_FEAT_KM_EAES_192,
+    S390_FEAT_KM_EAES_256,
     S390_FEAT_KM_XTS_AES_128,
     S390_FEAT_KM_XTS_AES_256,
     S390_FEAT_KMC_AES_128,
diff --git a/target/s390x/tcg/cpacf.h b/target/s390x/tcg/cpacf.h
index 1964de5b6d..9c654c3353 100644
--- a/target/s390x/tcg/cpacf.h
+++ b/target/s390x/tcg/cpacf.h
@@ -40,5 +40,9 @@ int cpacf_aes_xts(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                   uint32_t type, uint8_t fc, uint8_t mod);
 int cpacf_aes_pckmo(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                     uint64_t param_addr, uint8_t fc);
+int cpacf_paes_ecb(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                   uint64_t param_addr, uint64_t *dst_ptr_reg,
+                   uint64_t *src_ptr_reg, uint64_t *src_len_reg,
+                   uint32_t type, uint8_t fc, uint8_t mod);
 
 #endif /* S390X_CPACF_H */
diff --git a/target/s390x/tcg/cpacf_aes.c b/target/s390x/tcg/cpacf_aes.c
index 5a835016df..cbe7547c0b 100644
--- a/target/s390x/tcg/cpacf_aes.c
+++ b/target/s390x/tcg/cpacf_aes.c
@@ -483,6 +483,17 @@ static void encrypt_clrkey(uint8_t *key, int keysize)
     }
 }
 
+/*
+ * 'decrypt' the protected key by reverting the xor
+ * of the protkey_xor_pattern onto the clear key value.
+ */
+static void decrypt_protkey(uint8_t *key, int keysize)
+{
+    for (int i = 0; i < keysize; i++) {
+        key[i] ^= protkey_xor_pattern[i];
+    }
+}
+
 int cpacf_aes_pckmo(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                     uint64_t param_addr, uint8_t fc)
 {
@@ -518,3 +529,95 @@ int cpacf_aes_pckmo(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
 
     return 0;
 }
+
+int cpacf_paes_ecb(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                   uint64_t param_addr, uint64_t *dst_ptr_reg,
+                   uint64_t *src_ptr_reg, uint64_t *src_len_reg,
+                   uint32_t type, uint8_t fc, uint8_t mod)
+{
+    enum { MAX_BLOCKS_PER_RUN = 8192 / AES_BLOCK_SIZE };
+    uint8_t in[AES_BLOCK_SIZE], out[AES_BLOCK_SIZE];
+    uint64_t len = *src_len_reg, done = 0;
+    int i, keysize, addr_reg_size;
+    uint8_t key[32], wkvp[32];
+    AES_KEY exkey;
+
+    g_assert(type == S390_FEAT_TYPE_KM);
+
+    switch (fc) {
+    case CPACF_KM_PAES_128:
+        keysize = 16;
+        break;
+    case CPACF_KM_PAES_192:
+        keysize = 24;
+        break;
+    case CPACF_KM_PAES_256:
+        keysize = 32;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    /* check addressing mode, raise exception if not supported here */
+    addr_reg_size = get_address_bitsize(env);
+    switch (addr_reg_size) {
+    case 64:
+        break;
+    case 32:
+        len = (uint32_t)len;
+        break;
+    default:
+        tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+    }
+
+    /* early bail out if length is zero */
+    if (!len) {
+        return 0;
+    }
+
+    /* length has to be properly aligned. */
+    if (!QEMU_IS_ALIGNED(len, AES_BLOCK_SIZE)) {
+        tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+    }
+
+    /* fetch and check wkvp from param block */
+    read_guest_wrap_u8(env, mmu_idx, ra,
+                       param_addr + keysize, wkvp, sizeof(wkvp));
+    if (memcmp(wkvp, protkey_wkvp, sizeof(wkvp))) {
+        /* wkvp mismatch -> return with cc 1 */
+        return 1;
+    }
+
+    /* fetch protected key from param block */
+    read_guest_wrap_u8(env, mmu_idx, ra, param_addr, key, keysize);
+    /* decrypt the protected key */
+    decrypt_protkey(key, keysize);
+
+    /* expand key */
+    if (mod) {
+        AES_set_decrypt_key(key, keysize * 8, &exkey);
+    } else {
+        AES_set_encrypt_key(key, keysize * 8, &exkey);
+    }
+
+    /* process up to MAX_BLOCKS_PER_RUN aes blocks */
+    for (i = 0; i < MAX_BLOCKS_PER_RUN && len >= AES_BLOCK_SIZE; i++) {
+        aes_read_block(env, mmu_idx, ra, *src_ptr_reg + done, in);
+        if (mod) {
+            AES_decrypt(in, out, &exkey);
+        } else {
+            AES_encrypt(in, out, &exkey);
+        }
+        aes_write_block(env, mmu_idx, ra, *dst_ptr_reg + done, out);
+        len -= AES_BLOCK_SIZE;
+        done += AES_BLOCK_SIZE;
+    }
+
+    *src_ptr_reg = deposit64(*src_ptr_reg, 0, addr_reg_size,
+                             *src_ptr_reg + done);
+    *dst_ptr_reg = deposit64(*dst_ptr_reg, 0, addr_reg_size,
+                             *dst_ptr_reg + done);
+    *src_len_reg -= done;
+
+    return !len ? 0 : 3;
+}
diff --git a/target/s390x/tcg/crypto_helper.c b/target/s390x/tcg/crypto_helper.c
index 191b30e0f8..82d03fb8a1 100644
--- a/target/s390x/tcg/crypto_helper.c
+++ b/target/s390x/tcg/crypto_helper.c
@@ -112,6 +112,13 @@ static int cpacf_km(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                            &env->regs[r1], &env->regs[r2], &env->regs[r2 + 1],
                            S390_FEAT_TYPE_KM, fc, mod);
         break;
+    case CPACF_KM_PAES_128:
+    case CPACF_KM_PAES_192:
+    case CPACF_KM_PAES_256:
+        rc = cpacf_paes_ecb(env, mmu_idx, ra, env->regs[1],
+                            &env->regs[r1], &env->regs[r2], &env->regs[r2 + 1],
+                            S390_FEAT_TYPE_KM, fc, mod);
+        break;
     case CPACF_KM_XTS_128:
     case CPACF_KM_XTS_256:
         rc = cpacf_aes_xts(env, mmu_idx, ra, env->regs[1],
-- 
2.55.0