On Fri, Apr 22, 2022, David Matlack wrote:
> Consolidate kvm_mmu_alloc_page() and kvm_mmu_alloc_shadow_page() under
> the latter so that all shadow page allocation and initialization happens
> in one place.
>
> No functional change intended.
>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu/mmu.c | 39 +++++++++++++++++----------------------
> 1 file changed, 17 insertions(+), 22 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 5582badf4947..7d03320f6e08 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -1703,27 +1703,6 @@ static void drop_parent_pte(struct kvm_mmu_page *sp,
> mmu_spte_clear_no_track(parent_pte);
> }
>
> -static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, bool direct)
> -{
> - struct kvm_mmu_page *sp;
> -
> - sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
> - sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
> - if (!direct)
> - sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache);
> - set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
> -
> - /*
> - * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages()
> - * depends on valid pages being added to the head of the list. See
> - * comments in kvm_zap_obsolete_pages().
> - */
> - sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;
> - list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
> - kvm_mod_used_mmu_pages(vcpu->kvm, +1);
> - return sp;
> -}
> -
> static void mark_unsync(u64 *spte);
> static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp)
> {
> @@ -2100,7 +2079,23 @@ static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm_vcpu *vcpu,
> struct hlist_head *sp_list,
> union kvm_mmu_page_role role)
> {
> - struct kvm_mmu_page *sp = kvm_mmu_alloc_page(vcpu, role.direct);
> + struct kvm_mmu_page *sp;
> +
> + sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache);
> + sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache);
> + if (!role.direct)
> + sp->gfns = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_gfn_array_cache);
> +
> + set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
> +
> + /*
> + * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages()
> + * depends on valid pages being added to the head of the list. See
> + * comments in kvm_zap_obsolete_pages().
> + */
> + sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;
> + list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
> + kvm_mod_used_mmu_pages(vcpu->kvm, +1);
To reduce churn later on, what about opportunistically grabbing vcpu->kvm in a
local variable in this patch?
Actually, at that point, it's a super trivial change, so you can probably just drop
KVM: x86/mmu: Replace vcpu with kvm in kvm_mmu_alloc_shadow_page()
and do the vcpu/kvm swap as part of
KVM: x86/mmu: Pass memory caches to allocate SPs separately
> sp->gfn = gfn;
> sp->role = role;
> --
> 2.36.0.rc2.479.g8af0fa9b8e-goog
>
