[dpdk-dev] [PATCH v2] build: disable armv8 crypto extension

[Yongseok Koh <yskoh@mellanox.com>]

Per armv8 crypto extension support, make build always enable it by default
as long as compiler supports the feature while meson build only enables it
for 'default' machine of generic armv8 architecture.

It is known that not all the armv8 platforms have the crypto extension. For
example, Mellanox BlueField has a variant which doesn't have it. If crypto
enabled binary runs on such a platform, rte_eal_init() fails.

'+crypto' flag currently implies only '+aes' and '+sha2' and enabling it
will generate the crypto instructions only when crypto intrinsics are used.
For the devices supporting 8.2 crypto or newer, compiler could generate
such instructions beyond intrinsics or asm code. For example, compiler can
generate 3-way exclusive OR instructions if sha3 is supported. However, it
has to be enabled by adding '+sha3' as of today.

In DPDK, armv8 cryptodev is the only one which requires the crypto support.
As it even uses external library of Marvell which is compiled out of DPDK
with crypto support and there's run-time check for required cpuflags,
crypto support can be disabled in DPDK.

Cc: stable@dpdk.org

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---

v2:
* disable crypto support instead of having a build config

 config/arm/meson.build        | 2 +-
 mk/machine/armv8a/rte.vars.mk | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/config/arm/meson.build b/config/arm/meson.build
index 7fa6ed3105..abc8cf346c 100644
--- a/config/arm/meson.build
+++ b/config/arm/meson.build
@@ -74,7 +74,7 @@ flags_octeontx2_extra = [
 	['RTE_USE_C11_MEM_MODEL', true]]
 
 machine_args_generic = [
-	['default', ['-march=armv8-a+crc+crypto']],
+	['default', ['-march=armv8-a+crc']],
 	['native', ['-march=native']],
 	['0xd03', ['-mcpu=cortex-a53']],
 	['0xd04', ['-mcpu=cortex-a35']],
diff --git a/mk/machine/armv8a/rte.vars.mk b/mk/machine/armv8a/rte.vars.mk
index 8252efbb7b..5e3ffc3adf 100644
--- a/mk/machine/armv8a/rte.vars.mk
+++ b/mk/machine/armv8a/rte.vars.mk
@@ -28,4 +28,4 @@
 # CPU_LDFLAGS =
 # CPU_ASFLAGS =
 
-MACHINE_CFLAGS += -march=armv8-a+crc+crypto
+MACHINE_CFLAGS += -march=armv8-a+crc
-- 
2.11.0