Re: [PATCH v10 34/38] KVM: VMX: Call fred_entry_from_kvm() for IRQ/NMI handling

[Paolo Bonzini]

On 9/14/23 06:48, Xin Li wrote:
> When FRED is enabled, call fred_entry_from_kvm() to handle IRQ/NMI in
> IRQ/NMI induced VM exits.
>
> Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
> Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>

Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

> ---
>   arch/x86/kvm/vmx/vmx.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 72e3943f3693..db55b8418fa3 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -38,6 +38,7 @@
>   #include <asm/desc.h>
>   #include <asm/fpu/api.h>
>   #include <asm/fpu/xstate.h>
> +#include <asm/fred.h>
>   #include <asm/idtentry.h>
>   #include <asm/io.h>
>   #include <asm/irq_remapping.h>
> @@ -6962,14 +6963,16 @@ static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
>   {
>   	u32 intr_info = vmx_get_intr_info(vcpu);
>   	unsigned int vector = intr_info & INTR_INFO_VECTOR_MASK;
> -	gate_desc *desc = (gate_desc *)host_idt_base + vector;
>   
>   	if (KVM_BUG(!is_external_intr(intr_info), vcpu->kvm,
>   	    "unexpected VM-Exit interrupt info: 0x%x", intr_info))
>   		return;
>   
>   	kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
> -	vmx_do_interrupt_irqoff(gate_offset(desc));
> +	if (cpu_feature_enabled(X86_FEATURE_FRED))
> +		fred_entry_from_kvm(EVENT_TYPE_EXTINT, vector);
> +	else
> +		vmx_do_interrupt_irqoff(gate_offset((gate_desc *)host_idt_base + vector));
>   	kvm_after_interrupt(vcpu);
>   
>   	vcpu->arch.at_instruction_boundary = true;
> @@ -7262,7 +7265,10 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
>   	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();
> +		if (cpu_feature_enabled(X86_FEATURE_FRED))
> +			fred_entry_from_kvm(EVENT_TYPE_NMI, NMI_VECTOR);
> +		else
> +			vmx_do_nmi_irqoff();
>   		kvm_after_interrupt(vcpu);
>   	}
>