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

From: Paolo Bonzini
Date: Fri Feb 17 2017 - 03:42:10 EST




----- 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.

Paolo