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Message-ID: <26b92bbb-0519-8b94-07fc-75d900fde600@redhat.com>
Date:   Wed, 20 Sep 2023 19:54:59 +0200
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Subject: Re: [PATCH v10 34/38] KVM: VMX: Call fred_entry_from_kvm() for
 IRQ/NMI handling
Content-Language: en-US
To:     Xin Li <xin3.li@intel.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org,
        linux-hyperv@vger.kernel.org, kvm@vger.kernel.org,
        xen-devel@lists.xenproject.org
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        luto@kernel.org, seanjc@google.com, peterz@infradead.org,
        jgross@suse.com, ravi.v.shankar@intel.com, mhiramat@kernel.org,
        andrew.cooper3@citrix.com, jiangshanlai@gmail.com
References: <20230914044805.301390-1-xin3.li@intel.com>
 <20230914044805.301390-35-xin3.li@intel.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <20230914044805.301390-35-xin3.li@intel.com>
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Precedence: bulk

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@intel.com>
> Signed-off-by: Xin Li <xin3.li@intel.com>

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

> ---
>   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);
>   	}
>