2 files changed, 23 insertions, 28 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6f8392d4034..6651dfadae5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -101,8 +101,6 @@ static int dbg = 1;
 #define PT_FIRST_AVAIL_BITS_SHIFT 9
 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
 
-#define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
-
 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
 
 #define PT64_LEVEL_BITS 9
@@ -200,7 +198,6 @@ static int is_present_pte(unsigned long pte)
 
 static int is_shadow_present_pte(u64 pte)
 {
-        pte &= ~PT_SHADOW_IO_MARK;
         return pte != shadow_trap_nonpresent_pte
                 && pte != shadow_notrap_nonpresent_pte;
 }
@@ -215,11 +212,6 @@ static int is_dirty_pte(unsigned long pte)
         return pte & PT_DIRTY_MASK;
 }
 
-static int is_io_pte(unsigned long pte)
-{
-        return pte & PT_SHADOW_IO_MARK;
-}
-
 static int is_rmap_pte(u64 pte)
 {
         return is_shadow_present_pte(pte);
@@ -538,7 +530,7 @@ static int is_empty_shadow_page(u64 *spt)
         u64 *end;
 
         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
-                if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
+                if (*pos != shadow_trap_nonpresent_pte) {
                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
                                pos, *pos);
                         return 0;
@@ -926,13 +918,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
         if (pte_access & ACC_USER_MASK)
                 spte |= PT_USER_MASK;
 
-        if (is_error_page(page)) {
-                set_shadow_pte(shadow_pte,
-                               shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
-                kvm_release_page_clean(page);
-                return;
-        }
-
         spte |= page_to_phys(page);
 
         if ((pte_access & ACC_WRITE_MASK)
@@ -1002,7 +987,7 @@ static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write,
                 if (level == 1) {
                         mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
                                      0, write, 1, &pt_write, gfn, page);
-                        return pt_write || is_io_pte(table[index]);
+                        return pt_write;
                 }
 
                 if (table[index] == shadow_trap_nonpresent_pte) {
@@ -1039,6 +1024,13 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
         page = gfn_to_page(vcpu->kvm, gfn);
         up_read(&current->mm->mmap_sem);
 
+        /* mmio */
+        if (is_error_page(page)) {
+                kvm_release_page_clean(page);
+                up_read(&vcpu->kvm->slots_lock);
+                return 1;
+        }
+
         spin_lock(&vcpu->kvm->mmu_lock);
         kvm_mmu_free_some_pages(vcpu);
         r = __nonpaging_map(vcpu, v, write, gfn, page);
@@ -1406,10 +1398,14 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                 return;
         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 
-        down_read(&current->mm->mmap_sem);
+        down_read(&vcpu->kvm->slots_lock);
         page = gfn_to_page(vcpu->kvm, gfn);
-        up_read(&current->mm->mmap_sem);
+        up_read(&vcpu->kvm->slots_lock);
 
+        if (is_error_page(page)) {
+                kvm_release_page_clean(page);
+                return;
+        }
         vcpu->arch.update_pte.gfn = gfn;
         vcpu->arch.update_pte.page = page;
 }
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index c2fd2b96144..4b55f462e2b 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -399,6 +399,14 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         page = gfn_to_page(vcpu->kvm, walker.gfn);
         up_read(&current->mm->mmap_sem);
 
+        /* mmio */
+        if (is_error_page(page)) {
+                pgprintk("gfn %x is mmio\n", walker.gfn);
+                kvm_release_page_clean(page);
+                up_read(&vcpu->kvm->slots_lock);
+                return 1;
+        }
+
         spin_lock(&vcpu->kvm->mmu_lock);
         kvm_mmu_free_some_pages(vcpu);
         shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
@@ -409,15 +417,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         if (!write_pt)
                 vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
 
-        /*
-         * mmio: emulate if accessible, otherwise its a guest fault.
-         */
-        if (shadow_pte && is_io_pte(*shadow_pte)) {
-                spin_unlock(&vcpu->kvm->mmu_lock);
-                up_read(&vcpu->kvm->slots_lock);
-                return 1;
-        }
-
         ++vcpu->stat.pf_fixed;
         kvm_mmu_audit(vcpu, "post page fault (fixed)");
         spin_unlock(&vcpu->kvm->mmu_lock);