diff options
| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-09-21 12:07:29 +0200 |
|---|---|---|
| committer | Thomas Huth <thuth@redhat.com> | 2022-09-26 17:23:11 +0200 |
| commit | 3dbc5fdacb5af08dffa408ac7315eae53c4d5497 (patch) | |
| tree | 38b3f4c565db6558d1406b1b38d7b219031af263 /target | |
| parent | 9f17bfdab422887807cbd5260ed6b0b6e54ddb33 (diff) | |
target/s390x: support PRNO_TRNG instruction
In order for hosts running inside of TCG to initialize the kernel's
random number generator, we should support the PRNO_TRNG instruction,
backed in the usual way with the qemu_guest_getrandom helper. This is
confirmed working on Linux 5.19.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220921100729.2942008-2-Jason@zx2c4.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[thuth: turn prno-trng off in avocado test to avoid breaking it]
Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'target')
| -rw-r--r-- | target/s390x/gen-features.c | 1 | ||||
| -rw-r--r-- | target/s390x/tcg/crypto_helper.c | 30 |
2 files changed, 31 insertions, 0 deletions
diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c index baadbf4517..1e3b7c0dc9 100644 --- a/target/s390x/gen-features.c +++ b/target/s390x/gen-features.c @@ -757,6 +757,7 @@ static uint16_t qemu_MAX[] = { S390_FEAT_MSA_EXT_5, S390_FEAT_KIMD_SHA_512, S390_FEAT_KLMD_SHA_512, + S390_FEAT_PRNO_TRNG, }; /****** END FEATURE DEFS ******/ diff --git a/target/s390x/tcg/crypto_helper.c b/target/s390x/tcg/crypto_helper.c index 106c89fd2d..762b277884 100644 --- a/target/s390x/tcg/crypto_helper.c +++ b/target/s390x/tcg/crypto_helper.c @@ -14,6 +14,7 @@ #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" @@ -244,6 +245,31 @@ static int cpacf_sha512(CPUS390XState *env, uintptr_t ra, uint64_t param_addr, 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) { @@ -281,6 +307,10 @@ uint32_t HELPER(msa)(CPUS390XState *env, uint32_t r1, uint32_t r2, uint32_t r3, 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(); |