Question about the x86_64 SIMD instruction support by qemu-softmmu

[Fengwei Yin]

Hi List,
When I run the Chromium v8 unit test within qmeu-softmmu, following
failure is triggered:

=== cctest/test-gc/RunWasmLiftoff_RefTrivialCasts ===

                       [60/149]
#

                               # Fatal error in
../../v8/test/cctest/wasm/test-gc.cc, line 109
# Test wasm GC: Wasm SIMD unsupported @+23
#
#

                               #
#FailureMessage Object: 0x7fffffffd540
==== C stack trace ===============================
    
/mnt/src/chromium/src/out/Default/libv8_libbase.so(v8::base::debug::StackTrace::StackTrace()+0x13)
[0x7ffff7fc3403]
    /mnt/src/chromium/src/out/Default/libv8_libplatform.so(+0x173ad)
[0x7ffff7f713ad]
    /mnt/src/chromium/src/out/Default/libv8_libbase.so(V8_Fatal(char
const*, int, char const*, ...)+0x153) [0x7ffff7fa5343]
    /mnt/src/chromium/src/out/Default/cctest(+0x153f427)
[0x555556a93427]

/mnt/src/chromium/src/out/Default/cctest(+0x1547c3e) [0x555556a9bc3e]
    /mnt/src/chromium/src/out/Default/cctest(+0xd662f3) [0x5555562ba2f3]
    /mnt/src/chromium/src/out/Default/cctest(+0xd67a9c) [0x5555562bba9c]
    /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xea) [0x7ffff4476d0a]
    /mnt/src/chromium/src/out/Default/cctest(_start+0x2a) [0x5555562ba0ba]
Aborted
Command: /mnt/src/chromium/src/out/Default/cctest
test-gc/RunWasmLiftoff_RefTrivialCasts --random-seed=2033349456
--nohard-abort --enable-slow-asserts --verify-heap --testin
g-d8-test-runner

If run it with qemu from Debian bullseye  (with --enable-kvm and --cpu
host) on 10th-generation Cascade Lake, there is no such failure.

The qemu-softmmu was built from following commit:

commit 553032db17440f8de011390e5a1cfddd13751b0b (tag: v5.2.0)
Author: Peter Maydell <peter.maydell@linaro.org>
Date:   Tue Dec 8 15:55:19 2020 +0000

    Update version for v5.2.0 release

    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Question: is some SIMD instruction not supported by qemu-softmmu
build? If more information is needed, just let me know. Thanks.


Regards
Yin, Fengwei