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authorJason A. Donenfeld <Jason@zx2c4.com>2022-09-21 12:07:29 +0200
committerThomas Huth <thuth@redhat.com>2022-09-26 17:23:11 +0200
commit3dbc5fdacb5af08dffa408ac7315eae53c4d5497 (patch)
tree38b3f4c565db6558d1406b1b38d7b219031af263
parent9f17bfdab422887807cbd5260ed6b0b6e54ddb33 (diff)
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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>
-rw-r--r--target/s390x/gen-features.c1
-rw-r--r--target/s390x/tcg/crypto_helper.c30
-rw-r--r--tests/avocado/machine_s390_ccw_virtio.py1
3 files changed, 32 insertions, 0 deletions
diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index baadbf4..1e3b7c0 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 106c89f..762b277 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();
diff --git a/tests/avocado/machine_s390_ccw_virtio.py b/tests/avocado/machine_s390_ccw_virtio.py
index 438a6f4..78152f2 100644
--- a/tests/avocado/machine_s390_ccw_virtio.py
+++ b/tests/avocado/machine_s390_ccw_virtio.py
@@ -66,6 +66,7 @@ class S390CCWVirtioMachine(QemuSystemTest):
'-kernel', kernel_path,
'-initrd', initrd_path,
'-append', kernel_command_line,
+ '-cpu', 'max,prno-trng=off',
'-device', 'virtio-net-ccw,devno=fe.1.1111',
'-device',
'virtio-rng-ccw,devno=fe.2.0000,max_revision=0,id=rn1',