Re: [PATCH v6 7/7] tests/tcg/x86_64: add test for plugin memory access

[Alex Bennée]

Pierrick Bouvier <pierrick.bouvier@linaro.org> writes:

> Add an explicit test to check expected memory values are read/written.
> For sizes 8, 16, 32, 64 and 128, we generate a load/store operation.
> For size 8 -> 64, we generate an atomic __sync_val_compare_and_swap too.
> For 128bits memory access, we rely on SSE2 instructions.
>
> By default, atomic accesses are non atomic if a single cpu is running,
> so we force creation of a second one by creating a new thread first.
>
> load/store helpers code path can't be triggered easily in user mode (no
> softmmu), so we can't test it here.
>
> Can be run with:
> make -C build/tests/tcg/x86_64-linux-user 
> run-plugin-test-plugin-mem-access-with-libmem.so
>
> Tested-by: Xingtao Yao <yaoxt.fnst@fujitsu.com>
> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
> ---
>  tests/tcg/x86_64/test-plugin-mem-access.c   | 89 +++++++++++++++++++++
>  tests/tcg/x86_64/Makefile.target            |  7 ++
>  tests/tcg/x86_64/check-plugin-mem-access.sh | 48 +++++++++++
>  3 files changed, 144 insertions(+)
>  create mode 100644 tests/tcg/x86_64/test-plugin-mem-access.c
>  create mode 100755 tests/tcg/x86_64/check-plugin-mem-access.sh
>
> diff --git a/tests/tcg/x86_64/test-plugin-mem-access.c 
> b/tests/tcg/x86_64/test-plugin-mem-access.c
> new file mode 100644
> index 00000000000..7fdd6a55829
> --- /dev/null
> +++ b/tests/tcg/x86_64/test-plugin-mem-access.c
> @@ -0,0 +1,89 @@
> +#include <emmintrin.h>
> +#include <pthread.h>
> +#include <stdint.h>
> +#include <stdlib.h>
> +
> +static void *data;
> +
> +#define DEFINE_STORE(name, type, value) \
> +static void store_##name(void)          \
> +{                                       \
> +    *((type *)data) = value;            \
> +}
> +
> +#define DEFINE_ATOMIC_OP(name, type, value)                 \
> +static void atomic_op_##name(void)                          \
> +{                                                           \
> +    *((type *)data) = 0x42;                                 \
> +    __sync_val_compare_and_swap((type *)data, 0x42, value); \

Should we exercise the other compare and swap ops? Do they all come
through the same rwm path?

> +}
> +
> +#define DEFINE_LOAD(name, type)                         \
> +static void load_##name(void)                           \
> +{                                                       \
> +    register type var asm("eax") = *((type *) data);    \
> +    (void)var;                                          \

This is a bit weird. It's the only inline asm needed that makes this a
non-multiarch test. Why?

> +}
> +
> +DEFINE_STORE(u8, uint8_t, 0xf1)
> +DEFINE_ATOMIC_OP(u8, uint8_t, 0xf1)
> +DEFINE_LOAD(u8, uint8_t)
> +DEFINE_STORE(u16, uint16_t, 0xf123)
> +DEFINE_ATOMIC_OP(u16, uint16_t, 0xf123)
> +DEFINE_LOAD(u16, uint16_t)
> +DEFINE_STORE(u32, uint32_t, 0xff112233)
> +DEFINE_ATOMIC_OP(u32, uint32_t, 0xff112233)
> +DEFINE_LOAD(u32, uint32_t)
> +DEFINE_STORE(u64, uint64_t, 0xf123456789abcdef)
> +DEFINE_ATOMIC_OP(u64, uint64_t, 0xf123456789abcdef)
> +DEFINE_LOAD(u64, uint64_t)
> +
> +static void store_u128(void)
> +{
> +    _mm_store_si128(data, _mm_set_epi32(0xf1223344, 0x55667788,
> +                                        0xf1234567, 0x89abcdef));
> +}
> +
> +static void load_u128(void)
> +{
> +    __m128i var = _mm_load_si128(data);
> +    (void)var;
> +}
> +
> +static void *f(void *p)
> +{
> +    return NULL;
> +}
> +
> +int main(void)
> +{
> +    /*
> +     * We force creation of a second thread to enable cpu flag CF_PARALLEL.
> +     * This will generate atomic operations when needed.
> +     */
> +    pthread_t thread;
> +    pthread_create(&thread, NULL, &f, NULL);
> +    pthread_join(thread, NULL);
> +
> +    data = malloc(sizeof(__m128i));
> +    atomic_op_u8();
> +    store_u8();
> +    load_u8();
> +
> +    atomic_op_u16();
> +    store_u16();
> +    load_u16();
> +
> +    atomic_op_u32();
> +    store_u32();
> +    load_u32();
> +
> +    atomic_op_u64();
> +    store_u64();
> +    load_u64();
> +
> +    store_u128();
> +    load_u128();
> +
> +    free(data);
> +}
> diff --git a/tests/tcg/x86_64/Makefile.target 
> b/tests/tcg/x86_64/Makefile.target
> index eda9bd7396c..3edc29b924d 100644
> --- a/tests/tcg/x86_64/Makefile.target
> +++ b/tests/tcg/x86_64/Makefile.target
> @@ -16,6 +16,7 @@ X86_64_TESTS += noexec
>  X86_64_TESTS += cmpxchg
>  X86_64_TESTS += adox
>  X86_64_TESTS += test-1648
> +PLUGINS_TESTS += test-plugin-mem-access
>  TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64
>  else
>  TESTS=$(MULTIARCH_TESTS)
> @@ -26,6 +27,12 @@ adox: CFLAGS=-O2
>  run-test-i386-ssse3: QEMU_OPTS += -cpu max
>  run-plugin-test-i386-ssse3-%: QEMU_OPTS += -cpu max
>  
> +run-plugin-test-plugin-mem-access-with-libmem.so: \
> +     PLUGIN_ARGS=$(COMMA)print-accesses=true
> +run-plugin-test-plugin-mem-access-with-libmem.so: \
> +     CHECK_PLUGIN_OUTPUT_COMMAND= \
> +     $(SRC_PATH)/tests/tcg/x86_64/check-plugin-mem-access.sh
> +
>  test-x86_64: LDFLAGS+=-lm -lc
>  test-x86_64: test-i386.c test-i386.h test-i386-shift.h test-i386-muldiv.h
>       $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
> diff --git a/tests/tcg/x86_64/check-plugin-mem-access.sh 
> b/tests/tcg/x86_64/check-plugin-mem-access.sh
> new file mode 100755
> index 00000000000..163f1cfad34
> --- /dev/null
> +++ b/tests/tcg/x86_64/check-plugin-mem-access.sh
> @@ -0,0 +1,48 @@
> +#!/usr/bin/env bash
> +
> +set -euo pipefail
> +
> +die()
> +{
> +    echo "$@" 1>&2
> +    exit 1
> +}
> +
> +check()
> +{
> +    file=$1
> +    pattern=$2
> +    grep "$pattern" "$file" > /dev/null || die "\"$pattern\" not found in 
> $file"
> +}
> +
> +[ $# -eq 1 ] || die "usage: plugin_out_file"
> +
> +plugin_out=$1
> +
> +expected()
> +{
> +    cat << EOF
> +,store_u8,.*,8,store,0xf1
> +,atomic_op_u8,.*,8,load,0x42
> +,atomic_op_u8,.*,8,store,0xf1
> +,load_u8,.*,8,load,0xf1
> +,store_u16,.*,16,store,0xf123
> +,atomic_op_u16,.*,16,load,0x0042
> +,atomic_op_u16,.*,16,store,0xf123
> +,load_u16,.*,16,load,0xf123
> +,store_u32,.*,32,store,0xff112233
> +,atomic_op_u32,.*,32,load,0x00000042
> +,atomic_op_u32,.*,32,store,0xff112233
> +,load_u32,.*,32,load,0xff112233
> +,store_u64,.*,64,store,0xf123456789abcdef
> +,atomic_op_u64,.*,64,load,0x0000000000000042
> +,atomic_op_u64,.*,64,store,0xf123456789abcdef
> +,load_u64,.*,64,load,0xf123456789abcdef
> +,store_u128,.*,128,store,0xf122334455667788f123456789abcdef
> +,load_u128,.*,128,load,0xf122334455667788f123456789abcdef
> +EOF
> +}
> +
> +expected | while read line; do
> +    check "$plugin_out" "$line"
> +done

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro