Add safe_halt() and cli() helpers to processor.h to make them broadly available in KVM selftests.
Suggested-by: Sean Christopherson seanjc@google.com Signed-off-by: Manali Shukla manali.shukla@amd.com --- .../selftests/kvm/include/x86_64/processor.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 20c9e3b33b07..6de37f6b8ddc 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -1217,6 +1217,23 @@ static inline void kvm_hypercall_map_gpa_range(uint64_t gpa, uint64_t size, GUEST_ASSERT(!ret); }
+/* + * Execute HLT in an STI interrupt shadow to ensure that a pending IRQ that's + * intended to be a wake event arrives *after* HLT is executed. Modern CPUs, + * except for a few oddballs that KVM is unlikely to run on, block IRQs for one + * instruction after STI, *if* RFLAGS.IF=0 before STI. Note, Intel CPUs may + * block other events beyond regular IRQs, e.g. may block NMIs and SMIs too. + */ +static inline void safe_halt(void) +{ + asm volatile("sti; hlt"); +} + +static inline void cli(void) +{ + asm volatile ("cli"); +} + void __vm_xsave_require_permission(uint64_t xfeature, const char *name);
#define vm_xsave_require_permission(xfeature) \