Re: [PATCH] KVM: x86/mmu: Remove unused "const u8 *new" for kvm_mmu_track_write()

From: Sean Christopherson
Date: Tue Aug 08 2023 - 11:55:12 EST


On Tue, Aug 08, 2023, Like Xu wrote:
> From: Like Xu <likexu@xxxxxxxxxxx>
>
> The incoming parameter @new has not been required since commit 0e0fee5c539b
> ("kvm: mmu: Fix race in emulated page table writes"). And the callback
> kvmgt_page_track_write() registered by KVMGT still formally consumes it.
>
> No functional change intended.
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>

No need to give me credit, you spotted the unnecessary param, all I did was confirm
that it wasn't needed.

> -void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
> - int bytes)
> +void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes)
> {
> gfn_t gfn = gpa >> PAGE_SHIFT;
> struct kvm_mmu_page *sp;
> diff --git a/arch/x86/kvm/mmu/page_track.h b/arch/x86/kvm/mmu/page_track.h
> index 62f98c6c5af3..ea5dfd53b5c4 100644
> --- a/arch/x86/kvm/mmu/page_track.h
> +++ b/arch/x86/kvm/mmu/page_track.h
> @@ -52,7 +52,7 @@ static inline void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa,

Please remove it from the entire kvm_page_track_write() chain. Yes, it will be
a larger patch and need an ack from the KVMGT folks, but there is no reason to
only do a partial cleanup