[PATCH 8/9] KVM: x86/mmu: Plumb "struct kvm" all the way to pte_list_remove()

[Sean Christopherson <seanjc@google.com>]

From: Mingwei Zhang <mizhang@google.com>

Plumb "struct kvm" all the way to pte_list_remove() to allow the usage of
KVM_BUG() and/or KVM_BUG_ON().  This will allow killing only the offending
VM instead of doing BUG() if the kernel is built with
CONFIG_BUG_ON_DATA_CORRUPTION=n, i.e. does NOT want to BUG() if KVM's data
structures (rmaps) appear to be corrupted.

Signed-off-by: Mingwei Zhang <mizhang@google.com>
[sean: tweak changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/mmu/mmu.c | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d209d466d58f..8a8adeaa7dd7 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -962,7 +962,8 @@ static int pte_list_add(struct kvm_mmu_memory_cache *cache, u64 *spte,
 	return count;
 }
 
-static void pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head,
+static void pte_list_desc_remove_entry(struct kvm *kvm,
+				       struct kvm_rmap_head *rmap_head,
 				       struct pte_list_desc *desc, int i)
 {
 	struct pte_list_desc *head_desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);
@@ -998,7 +999,8 @@ static void pte_list_desc_remove_entry(struct kvm_rmap_head *rmap_head,
 	mmu_free_pte_list_desc(head_desc);
 }
 
-static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head)
+static void pte_list_remove(struct kvm *kvm, u64 *spte,
+			    struct kvm_rmap_head *rmap_head)
 {
 	struct pte_list_desc *desc;
 	int i;
@@ -1017,7 +1019,8 @@ static void pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head)
 		while (desc) {
 			for (i = 0; i < desc->spte_count; ++i) {
 				if (desc->sptes[i] == spte) {
-					pte_list_desc_remove_entry(rmap_head, desc, i);
+					pte_list_desc_remove_entry(kvm, rmap_head,
+								   desc, i);
 					return;
 				}
 			}
@@ -1032,7 +1035,7 @@ static void kvm_zap_one_rmap_spte(struct kvm *kvm,
 				  struct kvm_rmap_head *rmap_head, u64 *sptep)
 {
 	mmu_spte_clear_track_bits(kvm, sptep);
-	pte_list_remove(sptep, rmap_head);
+	pte_list_remove(kvm, sptep, rmap_head);
 }
 
 /* Return true if at least one SPTE was zapped, false otherwise */
@@ -1107,7 +1110,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
 	slot = __gfn_to_memslot(slots, gfn);
 	rmap_head = gfn_to_rmap(gfn, sp->role.level, slot);
 
-	pte_list_remove(spte, rmap_head);
+	pte_list_remove(kvm, spte, rmap_head);
 }
 
 /*
@@ -1751,16 +1754,16 @@ static void mmu_page_add_parent_pte(struct kvm_mmu_memory_cache *cache,
 	pte_list_add(cache, parent_pte, &sp->parent_ptes);
 }
 
-static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
+static void mmu_page_remove_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
 				       u64 *parent_pte)
 {
-	pte_list_remove(parent_pte, &sp->parent_ptes);
+	pte_list_remove(kvm, parent_pte, &sp->parent_ptes);
 }
 
-static void drop_parent_pte(struct kvm_mmu_page *sp,
+static void drop_parent_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
 			    u64 *parent_pte)
 {
-	mmu_page_remove_parent_pte(sp, parent_pte);
+	mmu_page_remove_parent_pte(kvm, sp, parent_pte);
 	mmu_spte_clear_no_track(parent_pte);
 }
 
@@ -2475,7 +2478,7 @@ static void validate_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 		if (child->role.access == direct_access)
 			return;
 
-		drop_parent_pte(child, sptep);
+		drop_parent_pte(vcpu->kvm, child, sptep);
 		kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep);
 	}
 }
@@ -2493,7 +2496,7 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
 			drop_spte(kvm, spte);
 		} else {
 			child = spte_to_child_sp(pte);
-			drop_parent_pte(child, spte);
+			drop_parent_pte(kvm, child, spte);
 
 			/*
 			 * Recursively zap nested TDP SPs, parentless SPs are
@@ -2524,13 +2527,13 @@ static int kvm_mmu_page_unlink_children(struct kvm *kvm,
 	return zapped;
 }
 
-static void kvm_mmu_unlink_parents(struct kvm_mmu_page *sp)
+static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	u64 *sptep;
 	struct rmap_iterator iter;
 
 	while ((sptep = rmap_get_first(&sp->parent_ptes, &iter)))
-		drop_parent_pte(sp, sptep);
+		drop_parent_pte(kvm, sp, sptep);
 }
 
 static int mmu_zap_unsync_children(struct kvm *kvm,
@@ -2569,7 +2572,7 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
 	++kvm->stat.mmu_shadow_zapped;
 	*nr_zapped = mmu_zap_unsync_children(kvm, sp, invalid_list);
 	*nr_zapped += kvm_mmu_page_unlink_children(kvm, sp, invalid_list);
-	kvm_mmu_unlink_parents(sp);
+	kvm_mmu_unlink_parents(kvm, sp);
 
 	/* Zapping children means active_mmu_pages has become unstable. */
 	list_unstable = *nr_zapped;
@@ -2927,7 +2930,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, struct kvm_memory_slot *slot,
 			u64 pte = *sptep;
 
 			child = spte_to_child_sp(pte);
-			drop_parent_pte(child, sptep);
+			drop_parent_pte(vcpu->kvm, child, sptep);
 			flush = true;
 		} else if (pfn != spte_to_pfn(*sptep)) {
 			drop_spte(vcpu->kvm, sptep);
-- 
2.40.1.606.ga4b1b128d6-goog