[PATCH V2 8/13] KVM: Add spte's point in the struct kvm_mmu_page

[Tianyu Lan]

It's necessary to check whether mmu page is last or large page when add
mmu page into flush list. "spte" is needed for such check and so add
spte point in the struct kvm_mmu_page.

Signed-off-by: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 1 +
 arch/x86/kvm/mmu.c              | 5 +++++
 arch/x86/kvm/paging_tmpl.h      | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c96bc4cbe4b7..d42d96e637b5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -296,6 +296,7 @@ struct kvm_mmu_page {
 	int root_count;          /* Currently serving as active root */
 	unsigned int unsync_children;
 	struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */
+	u64 *sptep;
 
 	/* The page is obsolete if mmu_valid_gen != kvm->arch.mmu_valid_gen.  */
 	unsigned long mmu_valid_gen;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 85a81a62e0a7..8f27cb8c3989 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3162,6 +3162,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
 			pseudo_gfn = base_addr >> PAGE_SHIFT;
 			sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
 					      iterator.level - 1, 1, ACC_ALL);
+			sp->sptep = iterator.sptep;
 
 			link_shadow_page(vcpu, iterator.sptep, sp);
 		}
@@ -3599,6 +3600,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
 		sp = kvm_mmu_get_page(vcpu, 0, 0,
 				vcpu->arch.mmu.shadow_root_level, 1, ACC_ALL);
 		++sp->root_count;
+		sp->sptep = NULL;
 		spin_unlock(&vcpu->kvm->mmu_lock);
 		vcpu->arch.mmu.root_hpa = __pa(sp->spt);
 	} else if (vcpu->arch.mmu.shadow_root_level == PT32E_ROOT_LEVEL) {
@@ -3615,6 +3617,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
 					i << 30, PT32_ROOT_LEVEL, 1, ACC_ALL);
 			root = __pa(sp->spt);
 			++sp->root_count;
+			sp->sptep = NULL;
 			spin_unlock(&vcpu->kvm->mmu_lock);
 			vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
 		}
@@ -3655,6 +3658,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 				vcpu->arch.mmu.shadow_root_level, 0, ACC_ALL);
 		root = __pa(sp->spt);
 		++sp->root_count;
+		sp->sptep = NULL;
 		spin_unlock(&vcpu->kvm->mmu_lock);
 		vcpu->arch.mmu.root_hpa = root;
 		return 0;
@@ -3692,6 +3696,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 				      0, ACC_ALL);
 		root = __pa(sp->spt);
 		++sp->root_count;
+		sp->sptep = NULL;
 		spin_unlock(&vcpu->kvm->mmu_lock);
 
 		vcpu->arch.mmu.pae_root[i] = root | pm_mask;
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 708a5e44861a..5cbaf7c4a729 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -632,6 +632,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			table_gfn = gw->table_gfn[it.level - 2];
 			sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,
 					      false, access);
+			sp->sptep = it.sptep;
 		}
 
 		/*
@@ -662,6 +663,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 
 		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
 				      true, direct_access);
+		sp->sptep = it.sptep;
 		link_shadow_page(vcpu, it.sptep, sp);
 	}
 
-- 
2.14.4