Commit Graph

9 Commits

Author SHA1 Message Date
Richard Henderson 1b48d0abdf migration/xbzrle: Shuffle function order
Place the CONFIG_AVX512BW_OPT block at the top,
which will aid function selection in the next patch.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-05-23 16:51:18 -07:00
Richard Henderson dc165fcd4e migration/xbzrle: Use __attribute__((target)) for avx512
Use the attribute, which is supported by clang, instead of
the #pragma, which is not supported and, for some reason,
also not detected by the meson probe, so we fail by -Werror.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230501210555.289806-1-richard.henderson@linaro.org>
2023-05-02 13:05:45 -07:00
Matheus Tavares Bernardino 1776b70f55 migration/xbzrle: fix out-of-bounds write with axv512
xbzrle_encode_buffer_avx512() checks for overflows too scarcely in its
outer loop, causing out-of-bounds writes:

$ ../configure --target-list=aarch64-softmmu --enable-sanitizers --enable-avx512bw
$ make tests/unit/test-xbzrle && ./tests/unit/test-xbzrle

==5518==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62100000b100 at pc 0x561109a7714d bp 0x7ffed712a440 sp 0x7ffed712a430
WRITE of size 1 at 0x62100000b100 thread T0
    #0 0x561109a7714c in uleb128_encode_small ../util/cutils.c:831
    #1 0x561109b67f6a in xbzrle_encode_buffer_avx512 ../migration/xbzrle.c:275
    #2 0x5611099a7428 in test_encode_decode_overflow ../tests/unit/test-xbzrle.c:153
    #3 0x7fb2fb65a58d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a58d)
    #4 0x7fb2fb65a333  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a333)
    #5 0x7fb2fb65aa79 in g_test_run_suite (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa79)
    #6 0x7fb2fb65aa94 in g_test_run (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa94)
    #7 0x5611099a3a23 in main ../tests/unit/test-xbzrle.c:218
    #8 0x7fb2fa78c082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)
    #9 0x5611099a608d in _start (/qemu/build/tests/unit/test-xbzrle+0x28408d)

0x62100000b100 is located 0 bytes to the right of 4096-byte region [0x62100000a100,0x62100000b100)
allocated by thread T0 here:
    #0 0x7fb2fb823a06 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:153
    #1 0x7fb2fb637ef0 in g_malloc0 (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57ef0)

Fix that by performing the overflow check in the inner loop, instead.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Matheus Tavares Bernardino d84a78d15d migration/xbzrle: use ctz64 to avoid undefined result
__builtin_ctzll() produces undefined results when the argument is 0.
This can be seen through test-xbzrle, which produces the following
warning:

../migration/xbzrle.c:265: runtime error: passing zero to ctz(), which is not a valid argument

Replace __builtin_ctzll() with our ctz64() wrapper which properly
handles 0.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
ling xu 04ffce137b AVX512 support for xbzrle_encode_buffer
This commit is the same with [PATCH v6 1/2], and provides avx512 support for xbzrle_encode_buffer
function to accelerate xbzrle encoding speed. Runtime check of avx512
support and benchmark for this feature are added. Compared with C
version of xbzrle_encode_buffer function, avx512 version can achieve
50%-70% performance improvement on benchmarking. In addition, if dirty
data is randomly located in 4K page, the avx512 version can achieve
almost 140% performance gain.

Signed-off-by: ling xu <ling1.xu@intel.com>
Co-authored-by: Zhou Zhao <zhou.zhao@intel.com>
Co-authored-by: Jun Jin <jun.i.jin@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela 709e3fe825 migration: Create migration/xbzrle.h
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
2017-05-18 18:04:54 +02:00
Veronia Bahaa f348b6d1a5 util: move declarations out of qemu-common.h
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)

Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:17 +01:00
Peter Maydell 1393a48526 migration: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-2-git-send-email-peter.maydell@linaro.org
2016-01-29 15:07:22 +00:00
Dr. David Alan Gilbert 60fe637bf0 Start migrating migration code into a migration directory
The migration code now occupies a fair chunk of the top level .c
files, it seems time to give it it's own directory.

I've not touched:
   arch_init.c - that's mostly RAM migration but has a few random other
                 bits
   savevm.c    - because it's built target specific

This is purely a code move; no code has changed.
   - it fails checkpatch because of old violations, it feels safer
     to keep this as purely a move and fix those at some mythical future
     date.

The xbzrle and vmstate tests are now only run for softmmu builds
since they require files in the migrate/ directory which is only built
for softmmu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2014-12-16 17:47:36 +05:30