When the host supported TSC scaling, L2 would use a TSC multipler of 0
-- i.e., TSC wouldn't tick in L2. Now L2's TSC runs at the same
frequency as L1's TSC.
Signed-off-by: Peter Feiner <pfeiner@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a45d858..9d1d0dc 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2198,6 +2198,12 @@ static void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu)
new.control) != old.control);
}
+static void decache_tsc_multiplier(struct vcpu_vmx *vmx)
+{
+ vmx->current_tsc_ratio = vmx->vcpu.arch.tsc_scaling_ratio;
+ vmcs_write64(TSC_MULTIPLIER, vmx->current_tsc_ratio);
+}
+
/*
* Switches to specified vcpu, until a matching vcpu_put(), but assumes
* vcpu mutex is already taken.
@@ -2256,10 +2262,8 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
/* Setup TSC multiplier */
if (kvm_has_tsc_control &&
- vmx->current_tsc_ratio != vcpu->arch.tsc_scaling_ratio) {
- vmx->current_tsc_ratio = vcpu->arch.tsc_scaling_ratio;
- vmcs_write64(TSC_MULTIPLIER, vmx->current_tsc_ratio);
- }
+ vmx->current_tsc_ratio != vcpu->arch.tsc_scaling_ratio)
+ decache_tsc_multiplier(vmx);
vmx_vcpu_pi_load(vcpu, cpu);
vmx->host_pkru = read_pkru();
@@ -10011,6 +10015,8 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
vmx->nested.vmcs01_tsc_offset + vmcs12->tsc_offset);
else
vmcs_write64(TSC_OFFSET, vmx->nested.vmcs01_tsc_offset);
+ if (kvm_has_tsc_control)
+ decache_tsc_multiplier(vmx);
if (enable_vpid) {
/*
@@ -10767,6 +10773,8 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
else
vmcs_set_bits(PIN_BASED_VM_EXEC_CONTROL,
PIN_BASED_VMX_PREEMPTION_TIMER);
+ if (kvm_has_tsc_control)
+ decache_tsc_multiplier(vmx);
/* This is needed for same reason as it was needed in prepare_vmcs02 */
vmx->host_rsp = 0;
--
2.8.0.rc3.226.g39d4020
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