Wanpeng Li <kernellwp@xxxxxxxxx> writes:
> From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
>
> Introduce generic fastpath handler to handle MSR fastpath, VMX-preemption
> timer fastpath etc, move it after vmx_complete_interrupts() in order that
> later patch can catch the case vmexit occurred while another event was
> being delivered to guest. There is no obversed performance difference for
> IPI fastpath testing after this move.
>
> Tested-by: Haiwei Li <lihaiwei@xxxxxxxxxxx>
> Cc: Haiwei Li <lihaiwei@xxxxxxxxxxx>
> Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/vmx.c | 21 ++++++++++++++++-----
> 1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 3ab6ca6..9b5adb4 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -6583,6 +6583,20 @@ void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp)
> }
> }
>
> +static enum exit_fastpath_completion vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
> +{
> + if (!is_guest_mode(vcpu)) {
Nitpick: do we actually expect to have any fastpath handlers anytime
soon? If not, we could've written this as
if (is_guest_mode(vcpu))
return EXIT_FASTPATH_NONE;
and save on identation)
> + switch (to_vmx(vcpu)->exit_reason) {
> + case EXIT_REASON_MSR_WRITE:
> + return handle_fastpath_set_msr_irqoff(vcpu);
> + default:
> + return EXIT_FASTPATH_NONE;
> + }
> + }
> +
> + return EXIT_FASTPATH_NONE;
> +}
> +
> bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);
>
> static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu)
> @@ -6757,17 +6771,14 @@ static enum exit_fastpath_completion vmx_vcpu_run(struct kvm_vcpu *vcpu)
> if (unlikely(vmx->exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY))
> return EXIT_FASTPATH_NONE;
>
> - if (!is_guest_mode(vcpu) && vmx->exit_reason == EXIT_REASON_MSR_WRITE)
> - exit_fastpath = handle_fastpath_set_msr_irqoff(vcpu);
> - else
> - exit_fastpath = EXIT_FASTPATH_NONE;
> -
> vmx->loaded_vmcs->launched = 1;
> vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
>
> vmx_recover_nmi_blocking(vmx);
> vmx_complete_interrupts(vmx);
>
> + exit_fastpath = vmx_exit_handlers_fastpath(vcpu);
> +
> return exit_fastpath;
> }
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
--
Vitaly
