[PATCH] eal: add support for TRNG with Arm RNG feature
Stephen Hemminger
stephen at networkplumber.org
Wed Jul 24 16:35:01 CEST 2024
On Wed, 24 Jul 2024 08:40:39 +0200
Mattias Rönnblom <hofors at lysator.liu.se> wrote:
> On 2024-07-23 23:27, Shunzhi Wen wrote:> True Random Number Generator
> (TRNG) is capable of
> > generating random numbers from a physical entropy source.
> > TRNG is enabled when compiled on Arm arch that supports
> > FEAT_RNG introduced in Armv8.5-A flagged by __ARM_FEATURE_RNG.
> >
>
> I'm missing a rationale here. Why is this useful?
>
> > Signed-off-by: Shunzhi Wen <shunzhi.wen at arm.com>
> > Reviewed-by: Wathsala Vithanage <wathsala.vithanage at arm.com>
> > Reviewed-by: Jack Bond-Preston <jack.bond-preston at arm.com>
> > Reviewed-by: Dhruv Tripathi <dhruv.tripathi at arm.com>
> > ---
> > .mailmap | 2 ++
> > app/test/test_rand_perf.c | 25 +++++++++++++++++--
> > config/arm/meson.build | 2 +-
> > lib/eal/arm/include/rte_cpuflags_64.h | 3 +++
> > lib/eal/arm/meson.build | 1 +
> > lib/eal/arm/rte_cpuflags.c | 1 +
> > lib/eal/arm/rte_random.c | 20 +++++++++++++++
> > .../{rte_random.c => eal_common_random.c} | 0
> > lib/eal/common/meson.build | 2 +-
> > lib/eal/include/rte_random.h | 17 +++++++++++++
> > lib/eal/loongarch/meson.build | 1 +
> > lib/eal/loongarch/rte_random.c | 14 +++++++++++
> > lib/eal/ppc/meson.build | 1 +
> > lib/eal/ppc/rte_random.c | 14 +++++++++++
> > lib/eal/riscv/meson.build | 1 +
> > lib/eal/riscv/rte_random.c | 14 +++++++++++
> > lib/eal/version.map | 1 +
> > lib/eal/x86/meson.build | 1 +
> > lib/eal/x86/rte_random.c | 14 +++++++++++
> > 19 files changed, 130 insertions(+), 4 deletions(-)
> > create mode 100644 lib/eal/arm/rte_random.c
> > rename lib/eal/common/{rte_random.c => eal_common_random.c} (100%)
> > create mode 100644 lib/eal/loongarch/rte_random.c
> > create mode 100644 lib/eal/ppc/rte_random.c
> > create mode 100644 lib/eal/riscv/rte_random.c
> > create mode 100644 lib/eal/x86/rte_random.c
> >
> > diff --git a/.mailmap b/.mailmap
> > index ac06962e82..23209edfd2 100644
> > --- a/.mailmap
> > +++ b/.mailmap
> > @@ -338,6 +338,7 @@ Dexia Li <dexia.li at jaguarmicro.com>
> > Dexuan Cui <decui at microsoft.com>
> > Dharmik Thakkar <dharmikjayesh.thakkar at arm.com>
> <dharmik.thakkar at arm.com>
> > Dheemanth Mallikarjun <dheemanthm at vmware.com>
> > +Dhruv Tripathi <dhruv.tripathi at arm.com>
> > Diana Wang <na.wang at corigine.com>
> > Didier Pallard <didier.pallard at 6wind.com>
> > Dilshod Urazov <dilshod.urazov at oktetlabs.ru>
> > @@ -1353,6 +1354,7 @@ Shuki Katzenelson <shuki at lightbitslabs.com>
> > Shun Hao <shunh at nvidia.com>
> > Shu Shen <shu.shen at radisys.com>
> > Shujing Dong <shujing.dong at corigine.com>
> > +Shunzhi Wen <shunzhi.wen at arm.com>
> > Shweta Choudaha <shweta.choudaha at att.com>
> > Shyam Kumar Shrivastav <shrivastav.shyam at gmail.com>
> > Shy Shyman <shys at nvidia.com> <shys at mellanox.com>
> > diff --git a/app/test/test_rand_perf.c b/app/test/test_rand_perf.c
> > index 30204e12c0..b61cc75014 100644
> > --- a/app/test/test_rand_perf.c
> > +++ b/app/test/test_rand_perf.c
> > @@ -20,6 +20,7 @@ static volatile uint64_t vsum;
> >
> > enum rand_type {
> > rand_type_64,
> > + rand_type_true_rand_64,
> > rand_type_float,
> > rand_type_bounded_best_case,
> > rand_type_bounded_worst_case
> > @@ -31,6 +32,8 @@ rand_type_desc(enum rand_type rand_type)
> > switch (rand_type) {
> > case rand_type_64:
> > return "Full 64-bit [rte_rand()]";
> > + case rand_type_true_rand_64:
> > + return "Full 64-bit True Random [rte_trand()]";
> > case rand_type_float:
> > return "Floating point [rte_drand()]";
> > case rand_type_bounded_best_case:
> > @@ -50,6 +53,9 @@ test_rand_perf_type(enum rand_type rand_type)
> > uint64_t end;
> > uint64_t sum = 0;
> > uint64_t op_latency;
> > + int ret;
> > + uint64_t val;
> > + uint32_t fail_count = 0;
> >
> > start = rte_rdtsc();
> >
> > @@ -58,6 +64,13 @@ test_rand_perf_type(enum rand_type rand_type)
> > case rand_type_64:
> > sum += rte_rand();
> > break;
> > + case rand_type_true_rand_64:
> > + ret = rte_trand(&val);
> > + if (ret == 0)
> > + sum += val;
> > + else
> > + fail_count++;
> > + break;
> > case rand_type_float:
> > sum += 1000. * rte_drand();
> > break;
> > @@ -77,8 +90,15 @@ test_rand_perf_type(enum rand_type rand_type)
> >
> > op_latency = (end - start) / ITERATIONS;
> >
> > - printf("%s: %"PRId64" TSC cycles/op\n", rand_type_desc(rand_type),
> > - op_latency);
> > + if (!fail_count)
> > + printf("%s: %"PRId64" TSC cycles/op\n",
> > + rand_type_desc(rand_type),
> > + op_latency);
> > + else
> > + printf("%s: %"PRId64" TSC cycles/op (failed %d time(s))\n",
> > + rand_type_desc(rand_type),
> > + op_latency,
> > + fail_count);
> > }
> >
> > static int
> > @@ -89,6 +109,7 @@ test_rand_perf(void)
> > printf("Pseudo-random number generation latencies:\n");
> >
> > test_rand_perf_type(rand_type_64);
> > + test_rand_perf_type(rand_type_true_rand_64);
> > test_rand_perf_type(rand_type_float);
> > test_rand_perf_type(rand_type_bounded_best_case);
> > test_rand_perf_type(rand_type_bounded_worst_case);
> > diff --git a/config/arm/meson.build b/config/arm/meson.build
> > index 012935d5d7..13be94254e 100644
> > --- a/config/arm/meson.build
> > +++ b/config/arm/meson.build
> > @@ -95,7 +95,7 @@ part_number_config_arm = {
> > },
> > '0xd49': {
> > 'march': 'armv9-a',
> > - 'march_features': ['sve2'],
> > + 'march_features': ['sve2', 'rng'],
> > 'fallback_march': 'armv8.5-a',
> > 'mcpu': 'neoverse-n2',
> > 'flags': [
> > diff --git a/lib/eal/arm/include/rte_cpuflags_64.h
> b/lib/eal/arm/include/rte_cpuflags_64.h
> > index afe70209c3..6aa067339f 100644
> > --- a/lib/eal/arm/include/rte_cpuflags_64.h
> > +++ b/lib/eal/arm/include/rte_cpuflags_64.h
> > @@ -36,6 +36,9 @@ enum rte_cpu_flag_t {
> > RTE_CPUFLAG_SVEF64MM,
> > RTE_CPUFLAG_SVEBF16,
> > RTE_CPUFLAG_AARCH64,
> > +
> > + /* RNDR, RNDRRS instructions */
> > + RTE_CPUFLAG_RNG,
> > };
> >
> > #include "generic/rte_cpuflags.h"
> > diff --git a/lib/eal/arm/meson.build b/lib/eal/arm/meson.build
> > index 6fba3d6ba7..e9e468cbf0 100644
> > --- a/lib/eal/arm/meson.build
> > +++ b/lib/eal/arm/meson.build
> > @@ -9,4 +9,5 @@ sources += files(
> > 'rte_hypervisor.c',
> > 'rte_mmu.c',
> > 'rte_power_intrinsics.c',
> > + 'rte_random.c',
> > )
> > diff --git a/lib/eal/arm/rte_cpuflags.c b/lib/eal/arm/rte_cpuflags.c
> > index 7ba4f8ba97..56074f0c6a 100644
> > --- a/lib/eal/arm/rte_cpuflags.c
> > +++ b/lib/eal/arm/rte_cpuflags.c
> > @@ -116,6 +116,7 @@ const struct feature_entry
> rte_cpu_feature_table[] = {
> > FEAT_DEF(SVEF64MM, REG_HWCAP2, 11)
> > FEAT_DEF(SVEBF16, REG_HWCAP2, 12)
> > FEAT_DEF(AARCH64, REG_PLATFORM, 0)
> > + FEAT_DEF(RNG, REG_HWCAP2, 16)
> > };
> > #endif /* RTE_ARCH */
> >
> > diff --git a/lib/eal/arm/rte_random.c b/lib/eal/arm/rte_random.c
> > new file mode 100644
> > index 0000000000..74c8fa733b
> > --- /dev/null
> > +++ b/lib/eal/arm/rte_random.c
> > @@ -0,0 +1,20 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(c) 2024 Arm Limited
> > + */
> > +
> > +#include "arm_acle.h"
> > +#include "rte_common.h"
> > +#include "rte_random.h"
> > +#include <errno.h>
> > +
> > +int
> > +rte_trand(uint64_t *val)
> > +{
> > +#if defined __ARM_FEATURE_RNG
> > + int ret = __rndr(val);
> > + return (ret == 0) ? 0 : -ENODATA;
> > +#else
> > + RTE_SET_USED(val);
> > + return -ENOTSUP;
> > +#endif
> > +}
> > diff --git a/lib/eal/common/rte_random.c
> b/lib/eal/common/eal_common_random.c
> > similarity index 100%
> > rename from lib/eal/common/rte_random.c
> > rename to lib/eal/common/eal_common_random.c
> > diff --git a/lib/eal/common/meson.build b/lib/eal/common/meson.build
> > index 22a626ba6f..c4405aa48b 100644
> > --- a/lib/eal/common/meson.build
> > +++ b/lib/eal/common/meson.build
> > @@ -32,7 +32,6 @@ sources += files(
> > 'malloc_elem.c',
> > 'malloc_heap.c',
> > 'rte_malloc.c',
> > - 'rte_random.c',
> > 'rte_reciprocal.c',
> > 'rte_service.c',
> > 'rte_version.c',
> > @@ -48,6 +47,7 @@ if not is_windows
> > 'eal_common_trace.c',
> > 'eal_common_trace_ctf.c',
> > 'eal_common_trace_utils.c',
> > + 'eal_common_random.c',
> > 'hotplug_mp.c',
> > 'malloc_mp.c',
> > 'rte_keepalive.c',
> > diff --git a/lib/eal/include/rte_random.h b/lib/eal/include/rte_random.h
> > index 5031c6fe5f..e6b5ac46ed 100644
> > --- a/lib/eal/include/rte_random.h
> > +++ b/lib/eal/include/rte_random.h
> > @@ -15,6 +15,7 @@
> > extern "C" {
> > #endif
> >
> > +#include <rte_compat.h>
> > #include <stdint.h>
> >
> > /**
> > @@ -84,6 +85,22 @@ rte_rand_max(uint64_t upper_bound);
> > */
> > double rte_drand(void);
> >
> > +/**
> > + * Get a true random value.
> > + *
> > + * The generator is cryptographically secure.
>
> If you want to extend <rte_random.h> with a cryptographically secure
> random number generator, that's fine.
>
> To have an API that's only available on certain ARM CPUs is not.
>
> NAK
>
> A new function should be called something with "secure", rather than
> "true" (which is a bit silly, since we might well live in a completely
> deterministic universe). "secure" would more clearly communicate the
> intent, and also doesn't imply any particular implementation.
Agree, with Mattias. What constitutes a secure random number generator
is a matter of much debate. Most of the HW random generators are taking
diode (Schottky noise) and doing transforms on it to get something uniform.
If a key generation type API was added, why not just use existing and more
researched kernel get_random()?
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