[PATCH 01/13] KVM: MMU: properly assert spte on rmap_next path

[Xiao Guangrong]

Only test present bit is not enough since mmio spte is also set this bit,
use is_rmap_spte() instead of it

Also move the BUG_ONs to the common function to cleanup the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
---
 arch/x86/kvm/mmu.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dc5f245..c759e4f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -989,7 +989,12 @@ static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)

 static u64 *rmap_next(unsigned long *rmapp, u64 *spte)
 {
-	return pte_list_next(rmapp, spte);
+	u64 *sptep;
+
+	sptep = pte_list_next(rmapp, spte);
+
+	WARN_ON(sptep && !is_rmap_spte(*sptep));
+	return sptep;
 }

 static void rmap_remove(struct kvm *kvm, u64 *spte)
@@ -1016,7 +1021,6 @@ static int __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, int level
 	int write_protected = 0;

 	while ((spte = rmap_next(rmapp, spte))) {
-		BUG_ON(!(*spte & PT_PRESENT_MASK));
 		rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);

 		if (!is_writable_pte(*spte))
@@ -1087,7 +1091,6 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 	int need_tlb_flush = 0;

 	while ((spte = rmap_next(rmapp, NULL))) {
-		BUG_ON(!(*spte & PT_PRESENT_MASK));
 		rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
 		drop_spte(kvm, spte);
 		need_tlb_flush = 1;
@@ -1107,7 +1110,6 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 	new_pfn = pte_pfn(*ptep);
 	spte = rmap_next(rmapp, NULL);
 	while (spte) {
-		BUG_ON(!is_shadow_present_pte(*spte));
 		rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
 		need_flush = 1;
 		if (pte_write(*ptep)) {
@@ -1200,7 +1202,6 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 	while (spte) {
 		int _young;
 		u64 _spte = *spte;
-		BUG_ON(!(_spte & PT_PRESENT_MASK));
 		_young = _spte & PT_ACCESSED_MASK;
 		if (_young) {
 			young = 1;
@@ -1228,7 +1229,6 @@ static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 	spte = rmap_next(rmapp, NULL);
 	while (spte) {
 		u64 _spte = *spte;
-		BUG_ON(!(_spte & PT_PRESENT_MASK));
 		young = _spte & PT_ACCESSED_MASK;
 		if (young) {
 			young = 1;
-- 
1.7.7.6

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