diff options
| -rw-r--r-- | meson.build | 17 | ||||
| -rw-r--r-- | meson_options.txt | 2 | ||||
| -rw-r--r-- | migration/ram.c | 34 | ||||
| -rw-r--r-- | migration/xbzrle.c | 124 | ||||
| -rw-r--r-- | migration/xbzrle.h | 4 | ||||
| -rw-r--r-- | scripts/meson-buildoptions.sh | 3 |
6 files changed, 181 insertions, 3 deletions
diff --git a/meson.build b/meson.build index 4ba3bf3..c626ccf 100644 --- a/meson.build +++ b/meson.build @@ -2351,6 +2351,22 @@ config_host_data.set('CONFIG_AVX512F_OPT', get_option('avx512f') \ int main(int argc, char *argv[]) { return bar(argv[argc - 1]); } '''), error_message: 'AVX512F not available').allowed()) +config_host_data.set('CONFIG_AVX512BW_OPT', get_option('avx512bw') \ + .require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX512BW') \ + .require(cc.links(''' + #pragma GCC push_options + #pragma GCC target("avx512bw") + #include <cpuid.h> + #include <immintrin.h> + static int bar(void *a) { + + __m512i *x = a; + __m512i res= _mm512_abs_epi8(*x); + return res[1]; + } + int main(int argc, char *argv[]) { return bar(argv[0]); } + '''), error_message: 'AVX512BW not available').allowed()) + have_pvrdma = get_option('pvrdma') \ .require(rdma.found(), error_message: 'PVRDMA requires OpenFabrics libraries') \ .require(cc.compiles(gnu_source_prefix + ''' @@ -3783,6 +3799,7 @@ summary_info += {'debug stack usage': get_option('debug_stack_usage')} summary_info += {'mutex debugging': get_option('debug_mutex')} summary_info += {'memory allocator': get_option('malloc')} summary_info += {'avx2 optimization': config_host_data.get('CONFIG_AVX2_OPT')} +summary_info += {'avx512bw optimization': config_host_data.get('CONFIG_AVX512BW_OPT')} summary_info += {'avx512f optimization': config_host_data.get('CONFIG_AVX512F_OPT')} summary_info += {'gprof enabled': get_option('gprof')} summary_info += {'gcov': get_option('b_coverage')} diff --git a/meson_options.txt b/meson_options.txt index 559a571..e5f1991 100644 --- a/meson_options.txt +++ b/meson_options.txt @@ -104,6 +104,8 @@ option('avx2', type: 'feature', value: 'auto', description: 'AVX2 optimizations') option('avx512f', type: 'feature', value: 'disabled', description: 'AVX512F optimizations') +option('avx512bw', type: 'feature', value: 'auto', + description: 'AVX512BW optimizations') option('keyring', type: 'feature', value: 'auto', description: 'Linux keyring support') diff --git a/migration/ram.c b/migration/ram.c index 0890816..18ac68b 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -83,6 +83,34 @@ /* 0x80 is reserved in migration.h start with 0x100 next */ #define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100 +int (*xbzrle_encode_buffer_func)(uint8_t *, uint8_t *, int, + uint8_t *, int) = xbzrle_encode_buffer; +#if defined(CONFIG_AVX512BW_OPT) +#include "qemu/cpuid.h" +static void __attribute__((constructor)) init_cpu_flag(void) +{ + unsigned max = __get_cpuid_max(0, NULL); + int a, b, c, d; + if (max >= 1) { + __cpuid(1, a, b, c, d); + /* We must check that AVX is not just available, but usable. */ + if ((c & bit_OSXSAVE) && (c & bit_AVX) && max >= 7) { + int bv; + __asm("xgetbv" : "=a"(bv), "=d"(d) : "c"(0)); + __cpuid_count(7, 0, a, b, c, d); + /* 0xe6: + * XCR0[7:5] = 111b (OPMASK state, upper 256-bit of ZMM0-ZMM15 + * and ZMM16-ZMM31 state are enabled by OS) + * XCR0[2:1] = 11b (XMM state and YMM state are enabled by OS) + */ + if ((bv & 0xe6) == 0xe6 && (b & bit_AVX512BW)) { + xbzrle_encode_buffer_func = xbzrle_encode_buffer_avx512; + } + } + } +} +#endif + XBZRLECacheStats xbzrle_counters; /* used by the search for pages to send */ @@ -806,9 +834,9 @@ static int save_xbzrle_page(RAMState *rs, PageSearchStatus *pss, memcpy(XBZRLE.current_buf, *current_data, TARGET_PAGE_SIZE); /* XBZRLE encoding (if there is no overflow) */ - encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf, - TARGET_PAGE_SIZE, XBZRLE.encoded_buf, - TARGET_PAGE_SIZE); + encoded_len = xbzrle_encode_buffer_func(prev_cached_page, XBZRLE.current_buf, + TARGET_PAGE_SIZE, XBZRLE.encoded_buf, + TARGET_PAGE_SIZE); /* * Update the cache contents, so that it corresponds to the data diff --git a/migration/xbzrle.c b/migration/xbzrle.c index 1ba482d..05366e8 100644 --- a/migration/xbzrle.c +++ b/migration/xbzrle.c @@ -174,3 +174,127 @@ int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen) return d; } + +#if defined(CONFIG_AVX512BW_OPT) +#pragma GCC push_options +#pragma GCC target("avx512bw") +#include <immintrin.h> +int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen, + uint8_t *dst, int dlen) +{ + uint32_t zrun_len = 0, nzrun_len = 0; + int d = 0, i = 0, num = 0; + uint8_t *nzrun_start = NULL; + /* add 1 to include residual part in main loop */ + uint32_t count512s = (slen >> 6) + 1; + /* countResidual is tail of data, i.e., countResidual = slen % 64 */ + uint32_t count_residual = slen & 0b111111; + bool never_same = true; + uint64_t mask_residual = 1; + mask_residual <<= count_residual; + mask_residual -= 1; + __m512i r = _mm512_set1_epi32(0); + + while (count512s) { + if (d + 2 > dlen) { + return -1; + } + + int bytes_to_check = 64; + uint64_t mask = 0xffffffffffffffff; + if (count512s == 1) { + bytes_to_check = count_residual; + mask = mask_residual; + } + __m512i old_data = _mm512_mask_loadu_epi8(r, + mask, old_buf + i); + __m512i new_data = _mm512_mask_loadu_epi8(r, + mask, new_buf + i); + uint64_t comp = _mm512_cmpeq_epi8_mask(old_data, new_data); + count512s--; + + bool is_same = (comp & 0x1); + while (bytes_to_check) { + if (is_same) { + if (nzrun_len) { + d += uleb128_encode_small(dst + d, nzrun_len); + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + } + /* 64 data at a time for speed */ + if (count512s && (comp == 0xffffffffffffffff)) { + i += 64; + zrun_len += 64; + break; + } + never_same = false; + num = __builtin_ctzll(~comp); + num = (num < bytes_to_check) ? num : bytes_to_check; + zrun_len += num; + bytes_to_check -= num; + comp >>= num; + i += num; + if (bytes_to_check) { + /* still has different data after same data */ + d += uleb128_encode_small(dst + d, zrun_len); + zrun_len = 0; + } else { + break; + } + } + if (never_same || zrun_len) { + /* + * never_same only acts if + * data begins with diff in first count512s + */ + d += uleb128_encode_small(dst + d, zrun_len); + zrun_len = 0; + never_same = false; + } + /* has diff, 64 data at a time for speed */ + if ((bytes_to_check == 64) && (comp == 0x0)) { + i += 64; + nzrun_len += 64; + break; + } + num = __builtin_ctzll(comp); + num = (num < bytes_to_check) ? num : bytes_to_check; + nzrun_len += num; + bytes_to_check -= num; + comp >>= num; + i += num; + if (bytes_to_check) { + /* mask like 111000 */ + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + nzrun_len = 0; + is_same = true; + } + } + } + + if (nzrun_len != 0) { + d += uleb128_encode_small(dst + d, nzrun_len); + /* overflow */ + if (d + nzrun_len > dlen) { + return -1; + } + nzrun_start = new_buf + i - nzrun_len; + memcpy(dst + d, nzrun_start, nzrun_len); + d += nzrun_len; + } + return d; +} +#pragma GCC pop_options +#endif diff --git a/migration/xbzrle.h b/migration/xbzrle.h index a0db507..6feb491 100644 --- a/migration/xbzrle.h +++ b/migration/xbzrle.h @@ -18,4 +18,8 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t *new_buf, int slen, uint8_t *dst, int dlen); int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen); +#if defined(CONFIG_AVX512BW_OPT) +int xbzrle_encode_buffer_avx512(uint8_t *old_buf, uint8_t *new_buf, int slen, + uint8_t *dst, int dlen); +#endif #endif diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh index 0f71e92..c2982ea 100644 --- a/scripts/meson-buildoptions.sh +++ b/scripts/meson-buildoptions.sh @@ -70,6 +70,7 @@ meson_options_help() { printf "%s\n" ' attr attr/xattr support' printf "%s\n" ' auth-pam PAM access control' printf "%s\n" ' avx2 AVX2 optimizations' + printf "%s\n" ' avx512bw AVX512BW optimizations' printf "%s\n" ' avx512f AVX512F optimizations' printf "%s\n" ' blkio libblkio block device driver' printf "%s\n" ' bochs bochs image format support' @@ -198,6 +199,8 @@ _meson_option_parse() { --disable-auth-pam) printf "%s" -Dauth_pam=disabled ;; --enable-avx2) printf "%s" -Davx2=enabled ;; --disable-avx2) printf "%s" -Davx2=disabled ;; + --enable-avx512bw) printf "%s" -Davx512bw=enabled ;; + --disable-avx512bw) printf "%s" -Davx512bw=disabled ;; --enable-avx512f) printf "%s" -Davx512f=enabled ;; --disable-avx512f) printf "%s" -Davx512f=disabled ;; --enable-gcov) printf "%s" -Db_coverage=true ;; |