On Fri, Nov 19, 2021, David Matlack wrote:
> Consolidate is_large_pte and is_present_pte into a single helper. This
> will be used in a follow-up commit to check for present large-pages
> during Eager Page Splitting.
>
> No functional change intended.
>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu/spte.h | 5 +++++
> arch/x86/kvm/mmu/tdp_mmu.c | 3 +--
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
> index cc432f9a966b..e73c41d31816 100644
> --- a/arch/x86/kvm/mmu/spte.h
> +++ b/arch/x86/kvm/mmu/spte.h
> @@ -257,6 +257,11 @@ static inline bool is_large_pte(u64 pte)
> return pte & PT_PAGE_SIZE_MASK;
> }
>
> +static inline bool is_large_present_pte(u64 pte)
> +{
> + return is_shadow_present_pte(pte) && is_large_pte(pte);
> +}
> +
> static inline bool is_last_spte(u64 pte, int level)
> {
> return (level == PG_LEVEL_4K) || is_large_pte(pte);
> diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
> index ff4d83ad7580..f8c4337f1fcf 100644
> --- a/arch/x86/kvm/mmu/tdp_mmu.c
> +++ b/arch/x86/kvm/mmu/tdp_mmu.c
> @@ -1011,8 +1011,7 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
> * than the target, that SPTE must be cleared and replaced
> * with a non-leaf SPTE.
> */
> - if (is_shadow_present_pte(iter.old_spte) &&
> - is_large_pte(iter.old_spte)) {
> + if (is_large_present_pte(iter.old_spte)) {
I strongly object to this helper. PRESENT in hardware and shadow-present are two
very different things, the name is_large_present_pte() doesn't capture that detail.
Yeah, we could name it is_large_shadow_present_pte(), but for me at least that
requires more effort to read, and it's not like this is replacing 10s of instances.
> if (!tdp_mmu_zap_spte_atomic(vcpu->kvm, &iter))
> break;
> }
> --
> 2.34.0.rc2.393.gf8c9666880-goog
>
