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From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <kernellwp@gmail.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH] KVM: LAPIC: Narrow down the timer fastpath to tscdeadline timer
Date: Tue, 10 May 2022 16:18:26 +0200	[thread overview]
Message-ID: <80ddc8a2-41c6-4e12-62f9-7acd51cabdb7@redhat.com> (raw)
In-Reply-To: <YnpzetR/B3nXVJxu@google.com>

On 5/10/22 16:15, Sean Christopherson wrote:
>>   
>> -static fastpath_t handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu)
>> +static bool __handle_preemption_timer(struct kvm_vcpu *vcpu)
>>   {
>>   	struct vcpu_vmx *vmx = to_vmx(vcpu);
>>   
>>   	if (!vmx->req_immediate_exit &&
>>   	    !unlikely(vmx->loaded_vmcs->hv_timer_soft_disabled)) {
>>   		kvm_lapic_expired_hv_timer(vcpu);
>> -		return EXIT_FASTPATH_REENTER_GUEST;
>> +		return true;
>>   	}
>>   
>> +	return false;
> It's a bit odd for the non-fastpath case, but I'd prefer to return fastpath_t
> instead of a bool from the inner helper, e.g.
> 

Yeah, enum > bool almost always (or negative errno).  But I also agree 
that using the fast path for periodic or oneshot timers is not 
inherently a bad idea.

Paolo


      reply	other threads:[~2022-05-10 14:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-06  9:47 [PATCH] KVM: LAPIC: Narrow down the timer fastpath to tscdeadline timer Wanpeng Li
2022-05-10 14:15 ` Sean Christopherson
2022-05-10 14:18   ` Paolo Bonzini [this message]

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