On Tue, Apr 21, 2020 at 06:57:59PM -0700, Sean Christopherson wrote:
> On Fri, Apr 17, 2020 at 11:34:52AM -0700, Makarand Sonare wrote:
> > Don't clobber the VMX-preemption timer value in the VMCS12 during
> > migration on the source while handling an L1 VMLAUNCH/VMRESUME but
> > before L2 ran. In that case the VMCS12 preemption timer value
> > should not be touched as it will be restarted on the target
> > from its original value. This emulates migration occurring while L1
> > awaits completion of its VMLAUNCH/VMRESUME instruction.
> >
> > Signed-off-by: Makarand Sonare <makarandsonare@xxxxxxxxxx>
> > Signed-off-by: Peter Shier <pshier@xxxxxxxxxx>
>
> The SOB tags are reversed, i.e. Peter's should be first to show that he
> wrote the patch and then transfered it to you for upstreaming.
>
> > Change-Id: I376d151585d4f1449319f7512151f11bbf08c5bf
> > ---
> > arch/x86/kvm/vmx/nested.c | 12 +++++++-----
> > 1 file changed, 7 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> > index 5365d7e5921ea..66155e9114114 100644
> > --- a/arch/x86/kvm/vmx/nested.c
> > +++ b/arch/x86/kvm/vmx/nested.c
> > @@ -3897,11 +3897,13 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
> > vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE;
> >
> > if (nested_cpu_has_preemption_timer(vmcs12)) {
> > - vmx->nested.preemption_timer_remaining =
> > - vmx_get_preemption_timer_value(vcpu);
> > - if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
> > - vmcs12->vmx_preemption_timer_value =
> > - vmx->nested.preemption_timer_remaining;
> > + if (!vmx->nested.nested_run_pending) {
> > + vmx->nested.preemption_timer_remaining =
> > + vmx_get_preemption_timer_value(vcpu);
> > + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
> > + vmcs12->vmx_preemption_timer_value =
> > + vmx->nested.preemption_timer_remaining;
> > + }
>
> This indentation is messed up, the closing brace is for !nested_run_pending,
> but it's aligned with (vm_exit_controls & ..._PREEMPTION_TIMER).
>
> Even better than fixing the indentation would be to include !nested_run_pending
> in the top-level if statement, which reduces the nesting level and produces
> a much cleaner diff, e.g.
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 409a39af121f..7dd6440425ab 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -3951,7 +3951,8 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
> else
> vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE;
>
> - if (nested_cpu_has_preemption_timer(vmcs12)) {
> + if (nested_cpu_has_preemption_timer(vmcs12) &&
> + !vmx->nested.nested_run_pending) {
> vmx->nested.preemption_timer_remaining =
> vmx_get_preemption_timer_value(vcpu);
> if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
Actually, why is this a separate patch? The code it's fixing was introduced
in patch one of this series.
