KVM: X86: Let kvm-clock report the right tsc frequency
This patch changes the kvm_guest_time_update function to use
TSC frequency the guest actually has for updating its clock.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0d6524f..78d7291 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -969,6 +969,14 @@
return ret;
}
+static u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.virtual_tsc_khz)
+ return vcpu->arch.virtual_tsc_khz;
+ else
+ return __this_cpu_read(cpu_tsc_khz);
+}
+
static inline u64 nsec_to_cycles(u64 nsec)
{
u64 ret;
@@ -982,20 +990,19 @@
return ret;
}
-static void kvm_arch_set_tsc_khz(struct kvm *kvm, u32 this_tsc_khz)
+static void kvm_init_tsc_catchup(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
{
/* Compute a scale to convert nanoseconds in TSC cycles */
kvm_get_time_scale(this_tsc_khz, NSEC_PER_SEC / 1000,
- &kvm->arch.virtual_tsc_shift,
- &kvm->arch.virtual_tsc_mult);
- kvm->arch.virtual_tsc_khz = this_tsc_khz;
+ &vcpu->arch.tsc_catchup_shift,
+ &vcpu->arch.tsc_catchup_mult);
}
static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
{
u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.last_tsc_nsec,
- vcpu->kvm->arch.virtual_tsc_mult,
- vcpu->kvm->arch.virtual_tsc_shift);
+ vcpu->arch.tsc_catchup_mult,
+ vcpu->arch.tsc_catchup_shift);
tsc += vcpu->arch.last_tsc_write;
return tsc;
}
@@ -1062,8 +1069,7 @@
local_irq_save(flags);
kvm_get_msr(v, MSR_IA32_TSC, &tsc_timestamp);
kernel_ns = get_kernel_ns();
- this_tsc_khz = __this_cpu_read(cpu_tsc_khz);
-
+ this_tsc_khz = vcpu_tsc_khz(v);
if (unlikely(this_tsc_khz == 0)) {
local_irq_restore(flags);
kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
@@ -6060,8 +6066,7 @@
}
vcpu->arch.pio_data = page_address(page);
- if (!kvm->arch.virtual_tsc_khz)
- kvm_arch_set_tsc_khz(kvm, max_tsc_khz);
+ kvm_init_tsc_catchup(vcpu, max_tsc_khz);
r = kvm_mmu_create(vcpu);
if (r < 0)