Re: [PATCH] KVM: VMX: use vmcs_set/clear_bits for CPU-based execution controls

From: Bandan Das
Date: Fri Feb 17 2017 - 12:22:30 EST


Paolo Bonzini <pbonzini@xxxxxxxxxx> writes:

> ----- Original Message -----
>> From: "Bandan Das" <bsd@xxxxxxxxxx>
>> To: "Paolo Bonzini" <pbonzini@xxxxxxxxxx>
>> Cc: linux-kernel@xxxxxxxxxxxxxxx, kvm@xxxxxxxxxxxxxxx
>> Sent: Friday, February 17, 2017 1:04:14 AM
>> Subject: Re: [PATCH] KVM: VMX: use vmcs_set/clear_bits for CPU-based execution controls
>>
>> Paolo Bonzini <pbonzini@xxxxxxxxxx> writes:
>>
>> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>> > ---
>>
>> I took a quick look and found these two potential
>> consumers of these set/clear wrappers.
>>
>> vmcs_set_secondary_exec_control()
>> vmx_set_virtual_x2apic_mode()
>>
>> Since this has been reviewed already,
>> we can just have them later in a follow up
>> (unless you left them out intentionally).
>
> Both of these can both set and clear bits, so they could be the
> consumer of a new function
>
> void vmcs_write_bits(u16 field, u32 value, u32 mask)
>
> but I don't see much benefit in introducing it; the cognitive
> load is higher than vmcs_{set,clear}_bits.

Yes, agreed. Thanks!

> Paolo