On Wed, 2021-05-19 at 00:07 +0000, Sean Christopherson wrote:
> On Wed, May 12, 2021, Ilias Stamatis wrote:
> > Now that nested TSC scaling is supported we need to calculate the
> > correct 02 values for both the offset and the multiplier using the
> > corresponding functions. On L2's exit the L1 values are restored.
> >
> > Signed-off-by: Ilias Stamatis <ilstam@xxxxxxxxxx>
> > ---
> > arch/x86/kvm/vmx/nested.c | 13 +++++++++----
> > 1 file changed, 9 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> > index 6058a65a6ede..f1dff1ebaccb 100644
> > --- a/arch/x86/kvm/vmx/nested.c
> > +++ b/arch/x86/kvm/vmx/nested.c
> > @@ -3354,8 +3354,9 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
> > }
> >
> > enter_guest_mode(vcpu);
> > - if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETTING)
> > - vcpu->arch.tsc_offset += vmcs12->tsc_offset;
> > +
> > + kvm_set_02_tsc_offset(vcpu);
> > + kvm_set_02_tsc_multiplier(vcpu);
>
> Please move this code into prepare_vmcs02() to co-locate it with the relevant
> vmcs02 logic. If there's something in prepare_vmcs02() that consumes
> vcpu->arch.tsc_offset() other than the obvious VMWRITE, I vote to move things
> around to fix that rather than create this weird split.
>
Agreed. It makes more sense.
> > if (prepare_vmcs02(vcpu, vmcs12, &entry_failure_code)) {
> > exit_reason.basic = EXIT_REASON_INVALID_STATE;
> > @@ -4463,8 +4464,12 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
> > if (nested_cpu_has_preemption_timer(vmcs12))
> > hrtimer_cancel(&to_vmx(vcpu)->nested.preemption_timer);
> >
> > - if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETTING)
> > - vcpu->arch.tsc_offset -= vmcs12->tsc_offset;
> > + if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETTING) {
> > + vcpu->arch.tsc_offset = vcpu->arch.l1_tsc_offset;
> > +
> > + if (vmcs12->secondary_vm_exec_control & SECONDARY_EXEC_TSC_SCALING)
> > + vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio;
> > + }
I guess these need to stay where they are though.
And thinking about it the two if conditions are unnecessary really.
Thanks for the reviews!
Ilias
> >
> > if (likely(!vmx->fail)) {
> > sync_vmcs02_to_vmcs12(vcpu, vmcs12);
> > --
> > 2.17.1
> >
