Create udelay() utility for x86_64 tests to match udelay() available to ARM and RISC-V tests. Calibrate guest frequency using the KVM_GET_TSC_KHZ ioctl() and share it between host and guest with the new tsc_khz global variable. Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> --- Changes v8: - Use appropriate signed type to discover TSC freq from KVM. - Switch type used to store TSC frequency from unsigned long to unsigned int to match the type used by the kernel. Changes v7: - New patch --- .../selftests/kvm/include/x86_64/processor.h | 15 +++++++++++++++ .../testing/selftests/kvm/lib/x86_64/processor.c | 12 ++++++++++++ 2 files changed, 27 insertions(+) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 8eb57de0b587..b473f210ba6c 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -23,6 +23,7 @@ extern bool host_cpu_is_intel; extern bool host_cpu_is_amd; +extern unsigned int tsc_khz; /* Forced emulation prefix, used to invoke the emulator unconditionally. */ #define KVM_FEP "ud2; .byte 'k', 'v', 'm';" @@ -815,6 +816,20 @@ static inline void cpu_relax(void) asm volatile("rep; nop" ::: "memory"); } +static inline void udelay(unsigned long usec) +{ + unsigned long cycles = tsc_khz / 1000 * usec; + uint64_t start, now; + + start = rdtsc(); + for (;;) { + now = rdtsc(); + if (now - start >= cycles) + break; + cpu_relax(); + } +} + #define ud2() \ __asm__ __volatile__( \ "ud2\n" \ diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index c664e446136b..ff579674032f 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -25,6 +25,7 @@ vm_vaddr_t exception_handlers; bool host_cpu_is_amd; bool host_cpu_is_intel; bool is_forced_emulation_enabled; +unsigned int tsc_khz; static void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent) { @@ -616,6 +617,8 @@ void assert_on_unhandled_exception(struct kvm_vcpu *vcpu) void kvm_arch_vm_post_create(struct kvm_vm *vm) { + int r; + vm_create_irqchip(vm); vm_init_descriptor_tables(vm); @@ -628,6 +631,15 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm) vm_sev_ioctl(vm, KVM_SEV_INIT2, &init); } + + if (kvm_has_cap(KVM_CAP_GET_TSC_KHZ)) { + r = __vm_ioctl(vm, KVM_GET_TSC_KHZ, NULL); + if (r < 0) + tsc_khz = 0; + else + tsc_khz = r; + sync_global_to_guest(vm, tsc_khz); + } } void vcpu_arch_set_entry_point(struct kvm_vcpu *vcpu, void *guest_code) -- 2.34.1