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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2024-09-20 17:44:22 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-10-20 12:10:27 -0400 |
| commit | 9a400068a1586bc4f10ee8b0443527de27d8834c (patch) | |
| tree | c5bda3c08283a5786f48b7fc7092aef58e6e98ab | |
| parent | f559b2e9c5c5308850544ab59396b7d53cfc67bd (diff) | |
| download | linux-9a400068a1586bc4f10ee8b0443527de27d8834c.tar.gz linux-9a400068a1586bc4f10ee8b0443527de27d8834c.tar.bz2 linux-9a400068a1586bc4f10ee8b0443527de27d8834c.zip | |
KVM: selftests: x86: Avoid using SSE/AVX instructions
Some distros switched gcc to '-march=x86-64-v3' by default and while it's
hard to find a CPU which doesn't support it today, many KVM selftests fail
with
==== Test Assertion Failure ====
lib/x86_64/processor.c:570: Unhandled exception in guest
pid=72747 tid=72747 errno=4 - Interrupted system call
Unhandled exception '0x6' at guest RIP '0x4104f7'
The failure is easy to reproduce elsewhere with
$ make clean && CFLAGS='-march=x86-64-v3' make -j && ./x86_64/kvm_pv_test
The root cause of the problem seems to be that with '-march=x86-64-v3' GCC
uses AVX* instructions (VMOVQ in the example above) and without prior
XSETBV() in the guest this results in #UD. It is certainly possible to add
it there, e.g. the following saves the day as well:
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-ID: <20240920154422.2890096-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | tools/testing/selftests/kvm/Makefile | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 960cf6a77198..e6b7e01d5708 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -244,6 +244,7 @@ CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \ -I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \ -I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \ + -march=x86-64-v2 \ $(KHDR_INCLUDES) ifeq ($(ARCH),s390) CFLAGS += -march=z10 |