Re: [PATCH v7 5/8] KVM: x86/mmu: Don't pass FOLL_GET to __kvm_follow_pfn
From: Isaku Yamahata <hidden>
Date: 2023-07-06 02:10:23
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
On Tue, Jul 04, 2023 at 04:50:50PM +0900, David Stevens [off-list ref] wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index cf2c6426a6fc..46c681dc45e6 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c@@ -138,7 +138,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, const struct kvm_memory_slot *slot, unsigned int pte_access, gfn_t gfn, kvm_pfn_t pfn, u64 old_spte, bool prefetch, bool can_unsync, - bool host_writable, u64 *new_spte) + bool host_writable, bool is_refcounted, u64 *new_spte) { int level = sp->role.level; u64 spte = SPTE_MMU_PRESENT_MASK;@@ -188,6 +188,8 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, if (level > PG_LEVEL_4K) spte |= PT_PAGE_SIZE_MASK; + else if (is_refcounted) + spte |= SPTE_MMU_PAGE_REFCOUNTED;
Is REFCOUNTED for 4K page only? What guarantees that large page doesn't have FOLL_GET? or can we set the bit for large page?
if (shadow_memtype_mask) spte |= static_call(kvm_x86_get_mt_mask)(vcpu, gfn,
-- Isaku Yamahata [off-list ref]