Messages in this thread Patch in this message | | | From | Paolo Bonzini <> | Subject | [PATCH v4 29/30] KVM: selftests: Define cpu_relax() helpers for s390 and x86 | Date | Thu, 3 Mar 2022 14:38:41 -0500 |
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From: Sean Christopherson <seanjc@google.com>
Add cpu_relax() for s390 and x86 for use in arch-agnostic tests. arm64 already defines its own version.
Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220226001546.360188-28-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- tools/testing/selftests/kvm/include/s390x/processor.h | 8 ++++++++ tools/testing/selftests/kvm/include/x86_64/processor.h | 5 +++++ 2 files changed, 13 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/s390x/processor.h b/tools/testing/selftests/kvm/include/s390x/processor.h index e0e96a5f608c..255c9b990f4c 100644 --- a/tools/testing/selftests/kvm/include/s390x/processor.h +++ b/tools/testing/selftests/kvm/include/s390x/processor.h @@ -5,6 +5,8 @@ #ifndef SELFTEST_KVM_PROCESSOR_H #define SELFTEST_KVM_PROCESSOR_H +#include <linux/compiler.h> + /* Bits in the region/segment table entry */ #define REGION_ENTRY_ORIGIN ~0xfffUL /* region/segment table origin */ #define REGION_ENTRY_PROTECT 0x200 /* region protection bit */ @@ -19,4 +21,10 @@ #define PAGE_PROTECT 0x200 /* HW read-only bit */ #define PAGE_NOEXEC 0x100 /* HW no-execute bit */ +/* Is there a portable way to do this? */ +static inline void cpu_relax(void) +{ + barrier(); +} + #endif diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 8a470da7b71a..37db341d4cc5 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -363,6 +363,11 @@ static inline unsigned long get_xmm(int n) return 0; } +static inline void cpu_relax(void) +{ + asm volatile("rep; nop" ::: "memory"); +} + bool is_intel_cpu(void); bool is_amd_cpu(void); -- 2.31.1
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