[v13,10/85] KVM: x86/mmu: Use gfn_to_page_many_atomic() when prefetching indirect PTEs

Commit Message

Sean Christopherson Oct. 10, 2024, 6:23 p.m. UTC

Use gfn_to_page_many_atomic() instead of gfn_to_pfn_memslot_atomic() when
prefetching indirect PTEs (direct_pte_prefetch_many() already uses the
"to page" APIS).  Functionally, the two are subtly equivalent, as the "to
pfn" API short-circuits hva_to_pfn() if hva_to_pfn_fast() fails, i.e. is
just a wrapper for get_user_page_fast_only()/get_user_pages_fast_only().

Switching to the "to page" API will allow dropping the @atomic parameter
from the entire hva_to_pfn() callchain.

Tested-by: Alex Bennée <[e-mail]>
Signed-off-by: Sean Christopherson <[e-mail]>
---
 arch/x86/kvm/mmu/paging_tmpl.h | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Patch

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index fbaae040218b..36b2607280f0 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -535,8 +535,8 @@  FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 {
 	struct kvm_memory_slot *slot;
 	unsigned pte_access;
+	struct page *page;
 	gfn_t gfn;
-	kvm_pfn_t pfn;
 
 	if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
 		return false;
@@ -549,12 +549,11 @@  FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 	if (!slot)
 		return false;
 
-	pfn = gfn_to_pfn_memslot_atomic(slot, gfn);
-	if (is_error_pfn(pfn))
+	if (gfn_to_page_many_atomic(slot, gfn, &page, 1) != 1)
 		return false;
 
-	mmu_set_spte(vcpu, slot, spte, pte_access, gfn, pfn, NULL);
-	kvm_release_pfn_clean(pfn);
+	mmu_set_spte(vcpu, slot, spte, pte_access, gfn, page_to_pfn(page), NULL);
+	kvm_release_page_clean(page);
 	return true;
 }