Re: [PATCH 06/10] KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page

From: Paolo Bonzini
Date: Thu Apr 12 2018 - 16:23:18 EST


On 12/04/2018 19:57, Sean Christopherson wrote:
> On Thu, Apr 12, 2018 at 04:38:39PM +0200, Paolo Bonzini wrote:
>> On 21/02/2018 18:47, KarimAllah Ahmed wrote:
>>> +
>>> + if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->virtual_apic_page_addr), map))
>>> + vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, gfn_to_gpa(map->pfn));
>>
>> This should in principle be pfn_to_hpa. However, pfn_to_hpa is unused;
>> let's just remove it and do "<< PAGE_SHIFT". Unlike gfn_to_gpa, where
>> in principle the shift could be different, pfn_to_hpa is *by definition*
>> a shift left by PAGE_SHIFT.
>
> Any reason not to use PFN_PHYS instead of the handcoded shift?

That works too of course. It's just not used much (or at all?) in KVM.

Paolo