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Message-ID: <ad1ede19-3b48-818a-5c6e-bab37e5c5539@intel.com>
Date:   Tue, 3 May 2022 10:44:50 +0800
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Subject: Re: [PATCH v9 9/9] KVM: VMX: enable IPI virtualization
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To:     Paolo Bonzini <pbonzini@redhat.com>,
        "Christopherson,, Sean" <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "Luck, Tony" <tony.luck@intel.com>,
        Kan Liang <kan.liang@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Kim Phillips <kim.phillips@amd.com>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Jethro Beekman <jethro@fortanix.com>,
        "Huang, Kai" <kai.huang@intel.com>
Cc:     "x86@kernel.org" <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Hu, Robert" <robert.hu@intel.com>,
        "Gao, Chao" <chao.gao@intel.com>
References: <20220419154510.11938-1-guang.zeng@intel.com>
 <bcb2a90f-a2ed-94fa-985e-d7b9efe52ae4@redhat.com>
From:   Zeng Guang <guang.zeng@intel.com>
In-Reply-To: <bcb2a90f-a2ed-94fa-985e-d7b9efe52ae4@redhat.com>
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On 5/3/2022 12:16 AM, Paolo Bonzini wrote:
> On 4/19/22 17:45, Zeng Guang wrote:
>> +static bool vmx_can_use_pi_wakeup(struct kvm_vcpu *vcpu)
>> +{
>> +	/*
>> +	 * If a blocked vCPU can be the target of posted interrupts,
>> +	 * switching notification vector is needed so that kernel can
>> +	 * be informed when an interrupt is posted and get the chance
>> +	 * to wake up the blocked vCPU. For now, using posted interrupt
>> +	 * for vCPU wakeup when IPI virtualization or VT-d PI can be
>> +	 * enabled.
>> +	 */
>> +	return vmx_can_use_ipiv(vcpu) || vmx_can_use_vtd_pi(vcpu->kvm);
>> +}
> Slightly more accurate name and comment:
>
> static bool vmx_needs_pi_wakeup(struct kvm_vcpu *vcpu)
> {
>           /*
>            * The default posted interrupt vector does nothing when
>            * invoked outside guest mode.   Return whether a blocked vCPU
>            * can be the target of posted interrupts, as is the case when
>            * using either IPI virtualization or VT-d PI, so that the
>            * notification vector is switched to the one that calls
>            * back to the pi_wakeup_handler() function.
>            */
>           return vmx_can_use_ipiv(vcpu) || vmx_can_use_vtd_pi(vcpu->kvm);
> }
>
>
> Paolo
Thanks. It's much accurate and better to describe the functionality of 
this API.
I will change it.