[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 <xiaoguangr...@linux.vnet.ibm.com>
---
 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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