On 17/08/2016 18:36, Peter Feiner wrote:
> When the host supported TSC scaling, L2 would use a TSC multiplier of
> 0, which causes a VM entry failure. Now L2's TSC uses the same
> multiplier as L1.
>
> Signed-off-by: Peter Feiner <pfeiner@xxxxxxxxxx>
> ---
>
> v1->v2: Updated commit message per VMX spec and fixed spelling.
> ---
> 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;
>
Queued for 4.8-rc, thanks.
Paolo
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