target/s390x/tcg/crypto_helper.c - qemu - Git at Google

 /*
  *  s390x crypto helpers
  *
  *  Copyright (C) 2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  *  Copyright (c) 2017 Red Hat Inc
  *
  *  Authors:
  *   David Hildenbrand <david@redhat.com>
  *   Jason A. Donenfeld <Jason@zx2c4.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */

 #include "qemu/osdep.h"
 #include "qemu/main-loop.h"
 #include "qemu/guest-random.h"
 #include "s390x-internal.h"
 #include "tcg_s390x.h"
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"

 static uint64_t R(uint64_t x, int c)
 {
     return (x >> c) | (x << (64 - c));
 }
 static uint64_t Ch(uint64_t x, uint64_t y, uint64_t z)
 {
     return (x & y) ^ (~x & z);
 }
 static uint64_t Maj(uint64_t x, uint64_t y, uint64_t z)
 {
     return (x & y) ^ (x & z) ^ (y & z);
 }
 static uint64_t Sigma0(uint64_t x)
 {
     return R(x, 28) ^ R(x, 34) ^ R(x, 39);
 }
 static uint64_t Sigma1(uint64_t x)
 {
     return R(x, 14) ^ R(x, 18) ^ R(x, 41);
 }
 static uint64_t sigma0(uint64_t x)
 {
     return R(x, 1) ^ R(x, 8) ^ (x >> 7);
 }
 static uint64_t sigma1(uint64_t x)
 {
     return R(x, 19) ^ R(x, 61) ^ (x >> 6);
 }

 static const uint64_t K[80] = {
     0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
     0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
     0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
     0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
     0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
     0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
     0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
     0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
     0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
     0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
     0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
     0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
     0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
     0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
     0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
     0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
     0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
     0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
     0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
     0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
     0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
     0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
     0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
     0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
     0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
     0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
     0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
 };

 /* a is icv/ocv, w is a single message block. w will get reused internally. */
 static void sha512_bda(uint64_t a[8], uint64_t w[16])
 {
     uint64_t t, z[8], b[8];
     int i, j;

     memcpy(z, a, sizeof(z));
     for (i = 0; i < 80; i++) {
         memcpy(b, a, sizeof(b));

         t = a[7] + Sigma1(a[4]) + Ch(a[4], a[5], a[6]) + K[i] + w[i % 16];
         b[7] = t + Sigma0(a[0]) + Maj(a[0], a[1], a[2]);
         b[3] += t;
         for (j = 0; j < 8; ++j) {
             a[(j + 1) % 8] = b[j];
         }
         if (i % 16 == 15) {
             for (j = 0; j < 16; ++j) {
                 w[j] += w[(j + 9) % 16] + sigma0(w[(j + 1) % 16]) +
                         sigma1(w[(j + 14) % 16]);
             }
         }
     }

     for (i = 0; i < 8; i++) {
         a[i] += z[i];
     }
 }

 /* a is icv/ocv, w is a single message block that needs be64 conversion. */
 static void sha512_bda_be64(uint64_t a[8], uint64_t w[16])
 {
     uint64_t t[16];
     int i;

     for (i = 0; i < 16; i++) {
         t[i] = be64_to_cpu(w[i]);
     }
     sha512_bda(a, t);
 }

 static void sha512_read_icv(CPUS390XState *env, uint64_t addr,
                             uint64_t a[8], uintptr_t ra)
 {
     int i;

     for (i = 0; i < 8; i++, addr += 8) {
         addr = wrap_address(env, addr);
         a[i] = cpu_ldq_be_data_ra(env, addr, ra);
     }
 }

 static void sha512_write_ocv(CPUS390XState *env, uint64_t addr,
                              uint64_t a[8], uintptr_t ra)
 {
     int i;

     for (i = 0; i < 8; i++, addr += 8) {
         addr = wrap_address(env, addr);
         cpu_stq_be_data_ra(env, addr, a[i], ra);
     }
 }

 static void sha512_read_block(CPUS390XState *env, uint64_t addr,
                               uint64_t a[16], uintptr_t ra)
 {
     int i;

     for (i = 0; i < 16; i++, addr += 8) {
         addr = wrap_address(env, addr);
         a[i] = cpu_ldq_be_data_ra(env, addr, ra);
     }
 }

 static void sha512_read_mbl_be64(CPUS390XState *env, uint64_t addr,
                                  uint8_t a[16], uintptr_t ra)
 {
     int i;

     for (i = 0; i < 16; i++, addr += 1) {
         addr = wrap_address(env, addr);
         a[i] = cpu_ldub_data_ra(env, addr, ra);
     }
 }

 static int cpacf_sha512(CPUS390XState *env, uintptr_t ra, uint64_t param_addr,
                       uint64_t *message_reg, uint64_t *len_reg, uint32_t type)
 {
     enum { MAX_BLOCKS_PER_RUN = 64 }; /* Arbitrary: keep interactivity. */
     uint64_t len = *len_reg, a[8], processed = 0;
     int i, message_reg_len = 64;

     g_assert(type == S390_FEAT_TYPE_KIMD || type == S390_FEAT_TYPE_KLMD);

     if (!(env->psw.mask & PSW_MASK_64)) {
         len = (uint32_t)len;
         message_reg_len = (env->psw.mask & PSW_MASK_32) ? 32 : 24;
     }

     /* KIMD: length has to be properly aligned. */
     if (type == S390_FEAT_TYPE_KIMD && !QEMU_IS_ALIGNED(len, 128)) {
         tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
     }

     sha512_read_icv(env, param_addr, a, ra);

     /* Process full blocks first. */
     for (; len >= 128; len -= 128, processed += 128) {
         uint64_t w[16];

         if (processed >= MAX_BLOCKS_PER_RUN * 128) {
             break;
         }

         sha512_read_block(env, *message_reg + processed, w, ra);
         sha512_bda(a, w);
     }

     /* KLMD: Process partial/empty block last. */
     if (type == S390_FEAT_TYPE_KLMD && len < 128) {
         uint8_t x[128];

         /* Read the remainder of the message byte-per-byte. */
         for (i = 0; i < len; i++) {
             uint64_t addr = wrap_address(env, *message_reg + processed + i);

             x[i] = cpu_ldub_data_ra(env, addr, ra);
         }
         /* Pad the remainder with zero and set the top bit. */
         memset(x + len, 0, 128 - len);
         x[len] = 128;

         /*
          * Place the MBL either into this block (if there is space left),
          * or use an additional one.
          */
         if (len < 112) {
             sha512_read_mbl_be64(env, param_addr + 64, x + 112, ra);
         }
         sha512_bda_be64(a, (uint64_t *)x);

         if (len >= 112) {
             memset(x, 0, 112);
             sha512_read_mbl_be64(env, param_addr + 64, x + 112, ra);
             sha512_bda_be64(a, (uint64_t *)x);
         }

         processed += len;
         len = 0;
     }

     /*
      * Modify memory after we read all inputs and modify registers only after
      * writing memory succeeded.
      *
      * TODO: if writing fails halfway through (e.g., when crossing page
      * boundaries), we're in trouble. We'd need something like access_prepare().
      */
     sha512_write_ocv(env, param_addr, a, ra);
     *message_reg = deposit64(*message_reg, 0, message_reg_len,
                              *message_reg + processed);
     *len_reg -= processed;
     return !len ? 0 : 3;
 }

 static void fill_buf_random(CPUS390XState *env, uintptr_t ra,
                             uint64_t *buf_reg, uint64_t *len_reg)
 {
     uint8_t tmp[256];
     uint64_t len = *len_reg;
     int buf_reg_len = 64;

     if (!(env->psw.mask & PSW_MASK_64)) {
         len = (uint32_t)len;
         buf_reg_len = (env->psw.mask & PSW_MASK_32) ? 32 : 24;
     }

     while (len) {
         size_t block = MIN(len, sizeof(tmp));

         qemu_guest_getrandom_nofail(tmp, block);
         for (size_t i = 0; i < block; ++i) {
             cpu_stb_data_ra(env, wrap_address(env, *buf_reg), tmp[i], ra);
             *buf_reg = deposit64(*buf_reg, 0, buf_reg_len, *buf_reg + 1);
             --*len_reg;
         }
         len -= block;
     }
 }

 uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3,
                      uint32_t type)
 {
     const uintptr_t ra = GETPC();
     const uint8_t mod = env->regs[0] & 0x80ULL;
     const uint8_t fc = env->regs[0] & 0x7fULL;
     uint8_t subfunc[16] = { 0 };
     uint64_t param_addr;
     int i;

     switch (type) {
     case S390_FEAT_TYPE_KMAC:
     case S390_FEAT_TYPE_KIMD:
     case S390_FEAT_TYPE_KLMD:
     case S390_FEAT_TYPE_PCKMO:
     case S390_FEAT_TYPE_PCC:
         if (mod) {
             tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
         }
         break;
     }

     s390_get_feat_block(type, subfunc);
     if (!test_be_bit(fc, subfunc)) {
         tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
     }

     switch (fc) {
     case 0: /* query subfunction */
         for (i = 0; i < 16; i++) {
             param_addr = wrap_address(env, env->regs[1] + i);
             cpu_stb_data_ra(env, param_addr, subfunc[i], ra);
         }
         break;
     case 3: /* CPACF_*_SHA_512 */
         return cpacf_sha512(env, ra, env->regs[1], &env->regs[r2],
                             &env->regs[r2 + 1], type);
     case 114: /* CPACF_PRNO_TRNG */
         fill_buf_random(env, ra, &env->regs[r1], &env->regs[r1 + 1]);
         fill_buf_random(env, ra, &env->regs[r2], &env->regs[r2 + 1]);
         break;
     default:
         /* we don't implement any other subfunction yet */
         g_assert_not_reached();
     }

     return 0;
 }
	/*
	* s390x crypto helpers
	*
	* Copyright (C) 2022 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
	* Copyright (c) 2017 Red Hat Inc
	*
	* Authors:
	* David Hildenbrand <david@redhat.com>
	* Jason A. Donenfeld <Jason@zx2c4.com>
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	* See the COPYING file in the top-level directory.
	*/

	#include "qemu/osdep.h"
	#include "qemu/main-loop.h"
	#include "qemu/guest-random.h"
	#include "s390x-internal.h"
	#include "tcg_s390x.h"
	#include "exec/helper-proto.h"
	#include "exec/exec-all.h"
	#include "exec/cpu_ldst.h"

	static uint64_t R(uint64_t x, int c)
	{
	return (x >> c) \| (x << (64 - c));
	}
	static uint64_t Ch(uint64_t x, uint64_t y, uint64_t z)
	{
	return (x & y) ^ (~x & z);
	}
	static uint64_t Maj(uint64_t x, uint64_t y, uint64_t z)
	{
	return (x & y) ^ (x & z) ^ (y & z);
	}
	static uint64_t Sigma0(uint64_t x)
	{
	return R(x, 28) ^ R(x, 34) ^ R(x, 39);
	}
	static uint64_t Sigma1(uint64_t x)
	{
	return R(x, 14) ^ R(x, 18) ^ R(x, 41);
	}
	static uint64_t sigma0(uint64_t x)
	{
	return R(x, 1) ^ R(x, 8) ^ (x >> 7);
	}
	static uint64_t sigma1(uint64_t x)
	{
	return R(x, 19) ^ R(x, 61) ^ (x >> 6);
	}

	static const uint64_t K[80] = {
	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
	0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
	0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
	0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
	0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
	0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
	0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
	0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
	0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
	0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
	0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
	0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
	0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
	0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
	};

	/* a is icv/ocv, w is a single message block. w will get reused internally. */
	static void sha512_bda(uint64_t a[8], uint64_t w[16])
	{
	uint64_t t, z[8], b[8];
	int i, j;

	memcpy(z, a, sizeof(z));
	for (i = 0; i < 80; i++) {
	memcpy(b, a, sizeof(b));

	t = a[7] + Sigma1(a[4]) + Ch(a[4], a[5], a[6]) + K[i] + w[i % 16];
	b[7] = t + Sigma0(a[0]) + Maj(a[0], a[1], a[2]);
	b[3] += t;
	for (j = 0; j < 8; ++j) {
	a[(j + 1) % 8] = b[j];
	}
	if (i % 16 == 15) {
	for (j = 0; j < 16; ++j) {
	w[j] += w[(j + 9) % 16] + sigma0(w[(j + 1) % 16]) +
	sigma1(w[(j + 14) % 16]);
	}
	}
	}

	for (i = 0; i < 8; i++) {
	a[i] += z[i];
	}
	}

	/* a is icv/ocv, w is a single message block that needs be64 conversion. */
	static void sha512_bda_be64(uint64_t a[8], uint64_t w[16])
	{
	uint64_t t[16];
	int i;

	for (i = 0; i < 16; i++) {
	t[i] = be64_to_cpu(w[i]);
	}
	sha512_bda(a, t);
	}

	static void sha512_read_icv(CPUS390XState *env, uint64_t addr,
	uint64_t a[8], uintptr_t ra)
	{
	int i;

	for (i = 0; i < 8; i++, addr += 8) {
	addr = wrap_address(env, addr);
	a[i] = cpu_ldq_be_data_ra(env, addr, ra);
	}
	}

	static void sha512_write_ocv(CPUS390XState *env, uint64_t addr,
	uint64_t a[8], uintptr_t ra)
	{
	int i;

	for (i = 0; i < 8; i++, addr += 8) {
	addr = wrap_address(env, addr);
	cpu_stq_be_data_ra(env, addr, a[i], ra);
	}
	}

	static void sha512_read_block(CPUS390XState *env, uint64_t addr,
	uint64_t a[16], uintptr_t ra)
	{
	int i;

	for (i = 0; i < 16; i++, addr += 8) {
	addr = wrap_address(env, addr);
	a[i] = cpu_ldq_be_data_ra(env, addr, ra);
	}
	}

	static void sha512_read_mbl_be64(CPUS390XState *env, uint64_t addr,
	uint8_t a[16], uintptr_t ra)
	{
	int i;

	for (i = 0; i < 16; i++, addr += 1) {
	addr = wrap_address(env, addr);
	a[i] = cpu_ldub_data_ra(env, addr, ra);
	}
	}

	static int cpacf_sha512(CPUS390XState *env, uintptr_t ra, uint64_t param_addr,
	uint64_t message_reg, uint64_t len_reg, uint32_t type)
	{
	enum { MAX_BLOCKS_PER_RUN = 64 }; /* Arbitrary: keep interactivity. */
	uint64_t len = *len_reg, a[8], processed = 0;
	int i, message_reg_len = 64;

	g_assert(type == S390_FEAT_TYPE_KIMD \|\| type == S390_FEAT_TYPE_KLMD);

	if (!(env->psw.mask & PSW_MASK_64)) {
	len = (uint32_t)len;
	message_reg_len = (env->psw.mask & PSW_MASK_32) ? 32 : 24;
	}

	/* KIMD: length has to be properly aligned. */
	if (type == S390_FEAT_TYPE_KIMD && !QEMU_IS_ALIGNED(len, 128)) {
	tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
	}

	sha512_read_icv(env, param_addr, a, ra);

	/* Process full blocks first. */
	for (; len >= 128; len -= 128, processed += 128) {
	uint64_t w[16];

	if (processed >= MAX_BLOCKS_PER_RUN * 128) {
	break;
	}

	sha512_read_block(env, *message_reg + processed, w, ra);
	sha512_bda(a, w);
	}

	/* KLMD: Process partial/empty block last. */
	if (type == S390_FEAT_TYPE_KLMD && len < 128) {
	uint8_t x[128];

	/* Read the remainder of the message byte-per-byte. */
	for (i = 0; i < len; i++) {
	uint64_t addr = wrap_address(env, *message_reg + processed + i);

	x[i] = cpu_ldub_data_ra(env, addr, ra);
	}
	/* Pad the remainder with zero and set the top bit. */
	memset(x + len, 0, 128 - len);
	x[len] = 128;

	/*
	* Place the MBL either into this block (if there is space left),
	* or use an additional one.
	*/
	if (len < 112) {
	sha512_read_mbl_be64(env, param_addr + 64, x + 112, ra);
	}
	sha512_bda_be64(a, (uint64_t *)x);

	if (len >= 112) {
	memset(x, 0, 112);
	sha512_read_mbl_be64(env, param_addr + 64, x + 112, ra);
	sha512_bda_be64(a, (uint64_t *)x);
	}

	processed += len;
	len = 0;
	}

	/*
	* Modify memory after we read all inputs and modify registers only after
	* writing memory succeeded.
	*
	* TODO: if writing fails halfway through (e.g., when crossing page
	* boundaries), we're in trouble. We'd need something like access_prepare().
	*/
	sha512_write_ocv(env, param_addr, a, ra);
	message_reg = deposit64(message_reg, 0, message_reg_len,
	*message_reg + processed);
	*len_reg -= processed;
	return !len ? 0 : 3;
	}

	static void fill_buf_random(CPUS390XState *env, uintptr_t ra,
	uint64_t buf_reg, uint64_t len_reg)
	{
	uint8_t tmp[256];
	uint64_t len = *len_reg;
	int buf_reg_len = 64;

	if (!(env->psw.mask & PSW_MASK_64)) {
	len = (uint32_t)len;
	buf_reg_len = (env->psw.mask & PSW_MASK_32) ? 32 : 24;
	}

	while (len) {
	size_t block = MIN(len, sizeof(tmp));

	qemu_guest_getrandom_nofail(tmp, block);
	for (size_t i = 0; i < block; ++i) {
	cpu_stb_data_ra(env, wrap_address(env, *buf_reg), tmp[i], ra);
	buf_reg = deposit64(buf_reg, 0, buf_reg_len, *buf_reg + 1);
	--*len_reg;
	}
	len -= block;
	}
	}

	uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3,
	uint32_t type)
	{
	const uintptr_t ra = GETPC();
	const uint8_t mod = env->regs[0] & 0x80ULL;
	const uint8_t fc = env->regs[0] & 0x7fULL;
	uint8_t subfunc[16] = { 0 };
	uint64_t param_addr;
	int i;

	switch (type) {
	case S390_FEAT_TYPE_KMAC:
	case S390_FEAT_TYPE_KIMD:
	case S390_FEAT_TYPE_KLMD:
	case S390_FEAT_TYPE_PCKMO:
	case S390_FEAT_TYPE_PCC:
	if (mod) {
	tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
	}
	break;
	}

	s390_get_feat_block(type, subfunc);
	if (!test_be_bit(fc, subfunc)) {
	tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
	}

	switch (fc) {
	case 0: /* query subfunction */
	for (i = 0; i < 16; i++) {
	param_addr = wrap_address(env, env->regs[1] + i);
	cpu_stb_data_ra(env, param_addr, subfunc[i], ra);
	}
	break;
	case 3: /* CPACF__SHA_512 /
	return cpacf_sha512(env, ra, env->regs[1], &env->regs[r2],
	&env->regs[r2 + 1], type);
	case 114: /* CPACF_PRNO_TRNG */
	fill_buf_random(env, ra, &env->regs[r1], &env->regs[r1 + 1]);
	fill_buf_random(env, ra, &env->regs[r2], &env->regs[r2 + 1]);
	break;
	default:
	/* we don't implement any other subfunction yet */
	g_assert_not_reached();
	}

	return 0;
	}