[PATCH v12 38/84] KVM: x86/mmu: Put direct prefetched pages via kvm_release_page_clean()

Sean Christopherson
2024-07-27T00:08:54Z

Use kvm_release_page_clean() to put prefeteched pages instead of calling
put_page() directly. This will allow de-duplicating the prefetch code
between indirect and direct MMUs.

Note, there's a small functional change as kvm_release_page_clean() marks
the page/folio as accessed. While it's not strictly guaranteed that the
guest will access the page, KVM won't intercept guest accesses, i.e. won't
mark the page accessed if it _is_ accessed by the guest (unless A/D bits
are disabled, but running without A/D bits is effectively limited to
pre-HSW Intel CPUs).

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/mmu/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 4d30920f653d..0def1444c01c 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2919,7 +2919,7 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
for (i = 0; i < ret; i++, gfn++, start++) {
mmu_set_spte(vcpu, slot, start, access, gfn,
page_to_pfn(pages[i]), NULL);
- put_page(pages[i]);
+ kvm_release_page_clean(pages[i]);
}

return 0;