[PATCH v8 08/17] KVM: x86: Wrap all of __get_kvmclock_master_clock() with CONFIG_X86_64=y
Sean Christopherson <[email protected]> Tue, 4 Aug 2026 16:39:12 -0700
| Newsgroups | org.kernel.vger.kvm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: David Woodhouse <[email protected]> Wrap the entire use_master_clock block in #ifdef CONFIG_X86_64, since use_master_clock is never true on 32-bit (host_tsc_clocksource is only set under CONFIG_X86_64), and declare hv_clock inside the block so it is not left as an unused variable on 32-bit. Signed-off-by: David Woodhouse <[email protected]> [sean: keep only the CONFIG_X86_64 ifdef, update changelog accordingly] Signed-off-by: Sean Christopherson <[email protected]> --- arch/x86/kvm/x86.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8666bd0337b8..cd2a140e8e63 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1654,8 +1654,10 @@ static unsigned long get_cpu_tsc_khz(void) static bool __get_kvmclock_master_clock(struct kvm *kvm, struct kvm_clock_data *data) { +#ifdef CONFIG_X86_64 struct kvm_arch *ka = &kvm->arch; struct pvclock_vcpu_time_info hv_clock; + struct timespec64 ts; u64 tsc_hz; if (!ka->use_master_clock) @@ -1672,25 +1674,24 @@ static bool __get_kvmclock_master_clock(struct kvm *kvm, if (!tsc_hz) return false; - { -#ifdef CONFIG_X86_64 - struct timespec64 ts; - - if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) { - data->realtime = ts.tv_nsec + NSEC_PER_SEC * ts.tv_sec; - data->flags |= KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC; - } else -#endif + if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) { + data->realtime = ts.tv_nsec + NSEC_PER_SEC * ts.tv_sec; + data->flags |= KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC; + } else { data->host_tsc = rdtsc(); - - data->flags |= KVM_CLOCK_TSC_STABLE; - hv_clock.tsc_timestamp = ka->master_cycle_now; - hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset; - kvm_get_time_scale(NSEC_PER_SEC, tsc_hz, - &hv_clock.tsc_shift, - &hv_clock.tsc_to_system_mul); - data->clock = __pvclock_read_cycles(&hv_clock, data->host_tsc); } + + data->flags |= KVM_CLOCK_TSC_STABLE; + hv_clock.tsc_timestamp = ka->master_cycle_now; + hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset; + kvm_get_time_scale(NSEC_PER_SEC, tsc_hz, + &hv_clock.tsc_shift, + &hv_clock.tsc_to_system_mul); + data->clock = __pvclock_read_cycles(&hv_clock, data->host_tsc); + return true; +#else + return false; +#endif } static void get_kvmclock(struct kvm *kvm, struct kvm_clock_data *data) -- 2.55.0.571.g244d577d93-goog