[PULL 08/33] target/s390x: Support AES ECB for cpacf km instruction

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

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

Support the subfunctions CPACF_KM_AES_128, CPACF_KM_AES_192
and CPACF_KM_AES_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/20260824083204.40877-9-freude@linux.ibm.com
[farman@linux.ibm.com: Resolve merge conflict in gen-features.c]
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 target/s390x/gen-features.c      |   3 +
 target/s390x/tcg/cpacf.h         |   6 ++
 target/s390x/tcg/cpacf_aes.c     | 137 +++++++++++++++++++++++++++++++
 target/s390x/tcg/crypto_helper.c |  24 ++++++
 target/s390x/tcg/meson.build     |   1 +
 5 files changed, 171 insertions(+)
 create mode 100644 target/s390x/tcg/cpacf_aes.c

diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index e1d924d04c..d6d4c45434 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -929,6 +929,9 @@ static uint16_t qemu_MAX[] = {
     S390_FEAT_CERT_STORE,
     S390_FEAT_SIPL,
     S390_FEAT_SCLAF,
+    S390_FEAT_KM_AES_128,
+    S390_FEAT_KM_AES_192,
+    S390_FEAT_KM_AES_256,
 };
 
 /****** END FEATURE DEFS ******/
diff --git a/target/s390x/tcg/cpacf.h b/target/s390x/tcg/cpacf.h
index 67b8368e4d..49630bab5e 100644
--- a/target/s390x/tcg/cpacf.h
+++ b/target/s390x/tcg/cpacf.h
@@ -18,4 +18,10 @@ int cpacf_sha512(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                  uint64_t param_addr, uint64_t *message_reg, uint64_t *len_reg,
                  uint32_t type);
 
+/* from cpacf_aes.c */
+int cpacf_aes_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
new file mode 100644
index 0000000000..d87da18c19
--- /dev/null
+++ b/target/s390x/tcg/cpacf_aes.c
@@ -0,0 +1,137 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * s390 cpacf aes
+ *
+ * Authors:
+ *   Harald Freudenberger <freude@linux.ibm.com>
+ */
+
+#include "qemu/osdep.h"
+#include "s390x-internal.h"
+#include "tcg_s390x.h"
+#include "accel/tcg/cpu-ldst-common.h"
+#include "accel/tcg/cpu-mmu-index.h"
+#include "crypto/aes.h"
+#include "crypto/aes-helpers.h"
+#include "target/s390x/tcg/cpacf-arch.h"
+#include "target/s390x/tcg/cpacf.h"
+#include "target/s390x/tcg/crypto_helper.h"
+
+/*
+ * read exactly one AES block from guest memory into a local buffer
+ */
+static inline void aes_read_block(CPUS390XState *env, const int mmu_idx,
+                                  const uintptr_t ra, uint64_t guest_addr,
+                                  uint8_t *buf)
+{
+    read_guest_wrap_u8(env, mmu_idx, ra, guest_addr, buf, AES_BLOCK_SIZE);
+}
+
+/*
+ * write exactly one AES block from local buffer to guest memory
+ */
+static void aes_write_block(CPUS390XState *env, const int mmu_idx,
+                            const uintptr_t ra, uint64_t guest_addr,
+                            uint8_t *buf)
+{
+    write_guest_wrap_u8(env, mmu_idx, ra, guest_addr, buf, AES_BLOCK_SIZE);
+}
+
+/*
+ * Helper function returning the bitsize of the address mode.
+ * Within this file only 64 bit and 32 bit are supported and
+ * thus this function returns either 64 or 32 or 0.
+ */
+static int get_address_bitsize(CPUS390XState *env)
+{
+    if (env->psw.mask & PSW_MASK_64) {
+        return 64;
+    } else if (env->psw.mask & PSW_MASK_32) {
+        return 32;
+    } else {
+        /* unknown or unsupported here */
+        return 0;
+    }
+}
+
+int cpacf_aes_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];
+    AES_KEY exkey;
+
+    g_assert(type == S390_FEAT_TYPE_KM);
+    switch (fc) {
+    case CPACF_KM_AES_128:
+        keysize = 16;
+        break;
+    case CPACF_KM_AES_192:
+        keysize = 24;
+        break;
+    case CPACF_KM_AES_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 key from param block */
+    read_guest_wrap_u8(env, mmu_idx, ra, param_addr, 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 27decdda63..534498173c 100644
--- a/target/s390x/tcg/crypto_helper.c
+++ b/target/s390x/tcg/crypto_helper.c
@@ -98,6 +98,27 @@ static int cpacf_klmd(CPUS390XState *env, const int mmu_idx, const uintptr_t ra,
     return rc;
 }
 
+static int cpacf_km(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
+                    uint32_t r1, uint32_t r2, uint32_t r3,
+                    uint8_t fc, uint8_t mod)
+{
+    int rc = 0;
+
+    switch (fc) {
+    case CPACF_KM_AES_128:
+    case CPACF_KM_AES_192:
+    case CPACF_KM_AES_256:
+        rc = cpacf_aes_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;
+    default:
+        tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
+    }
+
+    return rc;
+}
+
 static int cpacf_ppno(CPUS390XState *env, const int mmu_idx, uintptr_t ra,
                       uint32_t r1, uint32_t r2, uint32_t r3, uint8_t fc)
 {
@@ -166,6 +187,9 @@ uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3,
     case S390_FEAT_TYPE_KLMD:
         rc = cpacf_klmd(env, mmu_idx, ra, r1, r2, r3, fc);
         break;
+    case S390_FEAT_TYPE_KM:
+        rc = cpacf_km(env, mmu_idx, ra, r1, r2, r3, fc, mod);
+        break;
     case S390_FEAT_TYPE_PPNO:
         rc = cpacf_ppno(env, mmu_idx, ra, r1, r2, r3, fc);
         break;
diff --git a/target/s390x/tcg/meson.build b/target/s390x/tcg/meson.build
index 8ae8da9708..6f2e75764b 100644
--- a/target/s390x/tcg/meson.build
+++ b/target/s390x/tcg/meson.build
@@ -5,6 +5,7 @@ s390x_ss.add(when: 'CONFIG_TCG', if_true: files(
 ))
 s390x_common_ss.add(when: 'CONFIG_TCG', if_true: files(
   'cc_helper.c',
+  'cpacf_aes.c',
   'cpacf_sha256.c',
   'cpacf_sha512.c',
   'crypto_helper.c',
-- 
2.55.0