[PATCH v13 38/85] KVM: x86/mmu: Put direct prefetched pages via kvm_release_page_clean()
From: Sean Christopherson <seanjc@google.com>
Date: 2024-10-10 18:26:12
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, lkml, loongarch
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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). Tested-by: Alex Bennée <redacted> 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 e451e1b9a55a..62924f95a398 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c@@ -2965,7 +2965,7 @@ 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;
--
2.47.0.rc1.288.g06298d1525-goog