Re: [PATCH 7/7] KVM: VMX: Handle NMI VM-Exits in noinstr region

Peter Zijlstra
2023-01-19T09:50:08Z

On Tue, Dec 13, 2022 at 06:09:12AM +0000, Sean Christopherson wrote:

> @@ -7119,6 +7118,18 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
>
> vmx_enable_fb_clear(vmx);
>
> + if (unlikely(vmx->fail))
> + vmx->exit_reason.full = 0xdead;
> + else
> + vmx->exit_reason.full = vmcs_read32(VM_EXIT_REASON);
> +
> + if ((u16)vmx->exit_reason.basic == EXIT_REASON_EXCEPTION_NMI &&
> + is_nmi(vmx_get_intr_info(vcpu))) {
> + kvm_before_interrupt(vcpu, KVM_HANDLING_NMI);
> + vmx_do_nmi_irqoff();
> + kvm_after_interrupt(vcpu);
> + }
> +
> guest_state_exit_irqoff();
> }

I think we're going to have to sprinkle __always_inline on the
kvm_{before,after}_interrupt() things (or I missed the earlier patches
doing this already), sometimes compilers are just weird.