5 files changed, 117 insertions, 71 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8f12ec52ad86..3b91227969a5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -974,7 +974,7 @@ static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
 {
 }
 
-static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
+static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 {
         int level = PT32E_ROOT_LEVEL;
         hpa_t table_addr = vcpu->arch.mmu.root_hpa;
@@ -1015,6 +1015,17 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
         }
 }
 
+static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
+{
+        int r;
+
+        mutex_lock(&vcpu->kvm->lock);
+        r = __nonpaging_map(vcpu, v, write, gfn);
+        mutex_unlock(&vcpu->kvm->lock);
+        return r;
+}
+
+
 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
                                     struct kvm_mmu_page *sp)
 {
@@ -1031,6 +1042,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
 
         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
                 return;
+        mutex_lock(&vcpu->kvm->lock);
 #ifdef CONFIG_X86_64
         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
                 hpa_t root = vcpu->arch.mmu.root_hpa;
@@ -1038,6 +1050,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
                 sp = page_header(root);
                 --sp->root_count;
                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
+                mutex_unlock(&vcpu->kvm->lock);
                 return;
         }
 #endif
@@ -1051,6 +1064,7 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
                 }
                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
         }
+        mutex_unlock(&vcpu->kvm->lock);
         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
 }
 
@@ -1250,15 +1264,15 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 {
         int r;
 
-        mutex_lock(&vcpu->kvm->lock);
         r = mmu_topup_memory_caches(vcpu);
         if (r)
                 goto out;
+        mutex_lock(&vcpu->kvm->lock);
         mmu_alloc_roots(vcpu);
+        mutex_unlock(&vcpu->kvm->lock);
         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
         kvm_mmu_flush_tlb(vcpu);
 out:
-        mutex_unlock(&vcpu->kvm->lock);
         return r;
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_load);
@@ -1353,6 +1367,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
         int npte;
 
         pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
+        mutex_lock(&vcpu->kvm->lock);
         ++vcpu->kvm->stat.mmu_pte_write;
         kvm_mmu_audit(vcpu, "pre pte write");
         if (gfn == vcpu->arch.last_pt_write_gfn
@@ -1421,17 +1436,27 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                 }
         }
         kvm_mmu_audit(vcpu, "post pte write");
+        mutex_unlock(&vcpu->kvm->lock);
 }
 
 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
 {
-        gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
+        gpa_t gpa;
+        int r;
 
-        return kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
+        down_read(&current->mm->mmap_sem);
+        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
+        up_read(&current->mm->mmap_sem);
+
+        mutex_lock(&vcpu->kvm->lock);
+        r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
+        mutex_unlock(&vcpu->kvm->lock);
+        return r;
 }
 
 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
 {
+        mutex_lock(&vcpu->kvm->lock);
         while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
                 struct kvm_mmu_page *sp;
 
@@ -1440,6 +1465,7 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
                 kvm_mmu_zap_page(vcpu->kvm, sp);
                 ++vcpu->kvm->stat.mmu_recycled;
         }
+        mutex_unlock(&vcpu->kvm->lock);
 }
 
 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
@@ -1447,7 +1473,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
         int r;
         enum emulation_result er;
 
-        mutex_lock(&vcpu->kvm->lock);
         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
         if (r < 0)
                 goto out;
@@ -1462,7 +1487,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
                 goto out;
 
         er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
-        mutex_unlock(&vcpu->kvm->lock);
 
         switch (er) {
         case EMULATE_DONE:
@@ -1477,7 +1501,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
                 BUG();
         }
 out:
-        mutex_unlock(&vcpu->kvm->lock);
         return r;
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
@@ -1574,8 +1597,10 @@ void kvm_mmu_zap_all(struct kvm *kvm)
 {
         struct kvm_mmu_page *sp, *node;
 
+        mutex_lock(&kvm->lock);
         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
                 kvm_mmu_zap_page(kvm, sp);
+        mutex_unlock(&kvm->lock);
 
         kvm_flush_remote_tlbs(kvm);
 }
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 56b88f7e83ef..7f83f5557d5e 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -368,11 +368,13 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         if (r)
                 return r;
 
+        down_read(&current->mm->mmap_sem);
         /*
          * Look up the shadow pte for the faulting address.
          */
         r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault,
                              fetch_fault);
+        up_read(&current->mm->mmap_sem);
 
         /*
          * The page is not mapped by the guest.  Let the guest handle it.
@@ -384,6 +386,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                 return 0;
         }
 
+        mutex_lock(&vcpu->kvm->lock);
         shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
                                   &write_pt);
         pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __FUNCTION__,
@@ -395,11 +398,14 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         /*
          * mmio: emulate if accessible, otherwise its a guest fault.
          */
-        if (shadow_pte && is_io_pte(*shadow_pte))
+        if (shadow_pte && is_io_pte(*shadow_pte)) {
+                mutex_unlock(&vcpu->kvm->lock);
                 return 1;
+        }
 
         ++vcpu->stat.pf_fixed;
         kvm_mmu_audit(vcpu, "post page fault (fixed)");
+        mutex_unlock(&vcpu->kvm->lock);
 
         return write_pt;
 }
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d1167fc303d6..c39493feba46 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1432,27 +1432,34 @@ static int init_rmode_tss(struct kvm *kvm)
 {
         gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT;
         u16 data = 0;
+        int ret = 0;
         int r;
 
+        down_read(&current->mm->mmap_sem);
         r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
         if (r < 0)
-                return 0;
+                goto out;
         data = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE;
         r = kvm_write_guest_page(kvm, fn++, &data, 0x66, sizeof(u16));
         if (r < 0)
-                return 0;
+                goto out;
         r = kvm_clear_guest_page(kvm, fn++, 0, PAGE_SIZE);
         if (r < 0)
-                return 0;
+                goto out;
         r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE);
         if (r < 0)
-                return 0;
+                goto out;
         data = ~0;
-        r = kvm_write_guest_page(kvm, fn, &data, RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1,
-                        sizeof(u8));
+        r = kvm_write_guest_page(kvm, fn, &data,
+                                 RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1,
+                                 sizeof(u8));
         if (r < 0)
-                return 0;
-        return 1;
+                goto out;
+
+        ret = 1;
+out:
+        up_read(&current->mm->mmap_sem);
+        return ret;
 }
 
 static void seg_setup(int seg)
@@ -1471,6 +1478,7 @@ static int alloc_apic_access_page(struct kvm *kvm)
         int r = 0;
 
         mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
         if (kvm->arch.apic_access_page)
                 goto out;
         kvm_userspace_mem.slot = APIC_ACCESS_PAGE_PRIVATE_MEMSLOT;
@@ -1482,6 +1490,7 @@ static int alloc_apic_access_page(struct kvm *kvm)
                 goto out;
         kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00);
 out:
+        up_write(&current->mm->mmap_sem);
         mutex_unlock(&kvm->lock);
         return r;
 }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1f48ec871035..e3b3141db13c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -181,7 +181,7 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
         int ret;
         u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
                                   offset * sizeof(u64), sizeof(pdpte));
         if (ret < 0) {
@@ -198,7 +198,7 @@ int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
 
         memcpy(vcpu->arch.pdptrs, pdpte, sizeof(vcpu->arch.pdptrs));
 out:
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 
         return ret;
 }
@@ -212,13 +212,13 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
         if (is_long_mode(vcpu) || !is_pae(vcpu))
                 return false;
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         r = kvm_read_guest(vcpu->kvm, vcpu->arch.cr3 & ~31u, pdpte, sizeof(pdpte));
         if (r < 0)
                 goto out;
         changed = memcmp(pdpte, vcpu->arch.pdptrs, sizeof(pdpte)) != 0;
 out:
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 
         return changed;
 }
@@ -278,9 +278,7 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         kvm_x86_ops->set_cr0(vcpu, cr0);
         vcpu->arch.cr0 = cr0;
 
-        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        mutex_unlock(&vcpu->kvm->lock);
         return;
 }
 EXPORT_SYMBOL_GPL(set_cr0);
@@ -320,9 +318,7 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
         }
         kvm_x86_ops->set_cr4(vcpu, cr4);
         vcpu->arch.cr4 = cr4;
-        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        mutex_unlock(&vcpu->kvm->lock);
 }
 EXPORT_SYMBOL_GPL(set_cr4);
 
@@ -360,7 +356,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                  */
         }
 
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         /*
          * Does the new cr3 value map to physical memory? (Note, we
          * catch an invalid cr3 even in real-mode, because it would
@@ -376,7 +372,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                 vcpu->arch.cr3 = cr3;
                 vcpu->arch.mmu.new_cr3(vcpu);
         }
-        mutex_unlock(&vcpu->kvm->lock);
+        up_read(&current->mm->mmap_sem);
 }
 EXPORT_SYMBOL_GPL(set_cr3);
 
@@ -1211,12 +1207,12 @@ static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
         if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
                 return -EINVAL;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
         kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
 
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
         return 0;
 }
 
@@ -1265,7 +1261,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
             < alias->target_phys_addr)
                 goto out;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         p = &kvm->arch.aliases[alias->slot];
         p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -1279,7 +1275,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 
         kvm_mmu_zap_all(kvm);
 
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
 
         return 0;
 
@@ -1355,7 +1351,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         struct kvm_memory_slot *memslot;
         int is_dirty = 0;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
 
         r = kvm_get_dirty_log(kvm, log, &is_dirty);
         if (r)
@@ -1371,7 +1367,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         }
         r = 0;
 out:
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
         return r;
 }
 
@@ -1565,25 +1561,32 @@ int emulator_read_std(unsigned long addr,
                              struct kvm_vcpu *vcpu)
 {
         void *data = val;
+        int r = X86EMUL_CONTINUE;
 
+        down_read(&current->mm->mmap_sem);
         while (bytes) {
                 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
                 unsigned offset = addr & (PAGE_SIZE-1);
                 unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
                 int ret;
 
-                if (gpa == UNMAPPED_GVA)
-                        return X86EMUL_PROPAGATE_FAULT;
+                if (gpa == UNMAPPED_GVA) {
+                        r = X86EMUL_PROPAGATE_FAULT;
+                        goto out;
+                }
                 ret = kvm_read_guest(vcpu->kvm, gpa, data, tocopy);
-                if (ret < 0)
-                        return X86EMUL_UNHANDLEABLE;
+                if (ret < 0) {
+                        r = X86EMUL_UNHANDLEABLE;
+                        goto out;
+                }
 
                 bytes -= tocopy;
                 data += tocopy;
                 addr += tocopy;
         }
-
-        return X86EMUL_CONTINUE;
+out:
+        up_read(&current->mm->mmap_sem);
+        return r;
 }
 EXPORT_SYMBOL_GPL(emulator_read_std);
 
@@ -1601,7 +1604,9 @@ static int emulator_read_emulated(unsigned long addr,
                 return X86EMUL_CONTINUE;
         }
 
+        down_read(&current->mm->mmap_sem);
         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        up_read(&current->mm->mmap_sem);
 
         /* For APIC access vmexit */
         if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
@@ -1617,11 +1622,14 @@ mmio:
         /*
          * Is this MMIO handled locally?
          */
+        mutex_lock(&vcpu->kvm->lock);
         mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
         if (mmio_dev) {
                 kvm_iodevice_read(mmio_dev, gpa, bytes, val);
+                mutex_unlock(&vcpu->kvm->lock);
                 return X86EMUL_CONTINUE;
         }
+        mutex_unlock(&vcpu->kvm->lock);
 
         vcpu->mmio_needed = 1;
         vcpu->mmio_phys_addr = gpa;
@@ -1636,10 +1644,14 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
 {
         int ret;
 
+        down_read(&current->mm->mmap_sem);
         ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
-        if (ret < 0)
+        if (ret < 0) {
+                up_read(&current->mm->mmap_sem);
                 return 0;
+        }
         kvm_mmu_pte_write(vcpu, gpa, val, bytes);
+        up_read(&current->mm->mmap_sem);
         return 1;
 }
 
@@ -1649,7 +1661,11 @@ static int emulator_write_emulated_onepage(unsigned long addr,
                                            struct kvm_vcpu *vcpu)
 {
         struct kvm_io_device *mmio_dev;
-        gpa_t                 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        gpa_t                 gpa;
+
+        down_read(&current->mm->mmap_sem);
+        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+        up_read(&current->mm->mmap_sem);
 
         if (gpa == UNMAPPED_GVA) {
                 kvm_inject_page_fault(vcpu, addr, 2);
@@ -1667,11 +1683,14 @@ mmio:
         /*
          * Is this MMIO handled locally?
          */
+        mutex_lock(&vcpu->kvm->lock);
         mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
         if (mmio_dev) {
                 kvm_iodevice_write(mmio_dev, gpa, bytes, val);
+                mutex_unlock(&vcpu->kvm->lock);
                 return X86EMUL_CONTINUE;
         }
+        mutex_unlock(&vcpu->kvm->lock);
 
         vcpu->mmio_needed = 1;
         vcpu->mmio_phys_addr = gpa;
@@ -1718,11 +1737,14 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
 #ifndef CONFIG_X86_64
         /* guests cmpxchg8b have to be emulated atomically */
         if (bytes == 8) {
-                gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+                gpa_t gpa;
                 struct page *page;
                 char *addr;
                 u64 val;
 
+                down_read(&current->mm->mmap_sem);
+                gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
+
                 if (gpa == UNMAPPED_GVA ||
                    (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
                         goto emul_write;
@@ -1736,8 +1758,9 @@ static int emulator_cmpxchg_emulated(unsigned long addr,
                 set_64bit((u64 *)(addr + offset_in_page(gpa)), val);
                 kunmap_atomic(addr, KM_USER0);
                 kvm_release_page_dirty(page);
+        emul_write:
+                up_read(&current->mm->mmap_sem);
         }
-emul_write:
 #endif
 
         return emulator_write_emulated(addr, new, bytes, vcpu);
@@ -2118,10 +2141,10 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                 kvm_x86_ops->skip_emulated_instruction(vcpu);
 
         for (i = 0; i < nr_pages; ++i) {
-                mutex_lock(&vcpu->kvm->lock);
+                down_read(&current->mm->mmap_sem);
                 page = gva_to_page(vcpu, address + i * PAGE_SIZE);
                 vcpu->arch.pio.guest_pages[i] = page;
-                mutex_unlock(&vcpu->kvm->lock);
+                up_read(&current->mm->mmap_sem);
                 if (!page) {
                         kvm_inject_gp(vcpu, 0);
                         free_pio_guest_pages(vcpu);
@@ -2247,7 +2270,6 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
         char instruction[3];
         int ret = 0;
 
-        mutex_lock(&vcpu->kvm->lock);
 
         /*
          * Blow out the MMU to ensure that no other VCPU has an active mapping
@@ -2262,8 +2284,6 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu)
             != X86EMUL_CONTINUE)
                 ret = -EFAULT;
 
-        mutex_unlock(&vcpu->kvm->lock);
-
         return ret;
 }
 
@@ -2447,8 +2467,10 @@ static void vapic_enter(struct kvm_vcpu *vcpu)
         if (!apic || !apic->vapic_addr)
                 return;
 
+        down_read(&current->mm->mmap_sem);
         page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
         vcpu->arch.apic->vapic_page = page;
+        up_read(&current->mm->mmap_sem);
 }
 
 static void vapic_exit(struct kvm_vcpu *vcpu)
@@ -2910,13 +2932,13 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
         gpa_t gpa;
 
         vcpu_load(vcpu);
-        mutex_lock(&vcpu->kvm->lock);
+        down_read(&current->mm->mmap_sem);
         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, vaddr);
+        up_read(&current->mm->mmap_sem);
         tr->physical_address = gpa;
         tr->valid = gpa != UNMAPPED_GVA;
         tr->writeable = 1;
         tr->usermode = 0;
-        mutex_unlock(&vcpu->kvm->lock);
         vcpu_put(vcpu);
 
         return 0;
@@ -3185,13 +3207,11 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
          */
         if (!user_alloc) {
                 if (npages && !old.rmap) {
-                        down_write(&current->mm->mmap_sem);
                         memslot->userspace_addr = do_mmap(NULL, 0,
                                                      npages * PAGE_SIZE,
                                                      PROT_READ | PROT_WRITE,
                                                      MAP_SHARED | MAP_ANONYMOUS,
                                                      0);
-                        up_write(&current->mm->mmap_sem);
 
                         if (IS_ERR((void *)memslot->userspace_addr))
                                 return PTR_ERR((void *)memslot->userspace_addr);
@@ -3199,10 +3219,8 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
                         if (!old.user_alloc && old.rmap) {
                                 int ret;
 
-                                down_write(&current->mm->mmap_sem);
                                 ret = do_munmap(current->mm, old.userspace_addr,
                                                 old.npages * PAGE_SIZE);
-                                up_write(&current->mm->mmap_sem);
                                 if (ret < 0)
                                         printk(KERN_WARNING
                                        "kvm_vm_ioctl_set_memory_region: "
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4026d7d64296..678e80561b74 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -227,7 +227,7 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
  *
  * Discontiguous memory is allowed, mostly for framebuffers.
  *
- * Must be called holding kvm->lock.
+ * Must be called holding mmap_sem for write.
  */
 int __kvm_set_memory_region(struct kvm *kvm,
                             struct kvm_userspace_memory_region *mem,
@@ -338,9 +338,9 @@ int kvm_set_memory_region(struct kvm *kvm,
 {
         int r;
 
-        mutex_lock(&kvm->lock);
+        down_write(&current->mm->mmap_sem);
         r = __kvm_set_memory_region(kvm, mem, user_alloc);
-        mutex_unlock(&kvm->lock);
+        up_write(&current->mm->mmap_sem);
         return r;
 }
 EXPORT_SYMBOL_GPL(kvm_set_memory_region);
@@ -456,7 +456,7 @@ static unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
 /*
  * Requires current->mm->mmap_sem to be held
  */
-static struct page *__gfn_to_page(struct kvm *kvm, gfn_t gfn)
+struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
 {
         struct page *page[1];
         unsigned long addr;
@@ -481,17 +481,6 @@ static struct page *__gfn_to_page(struct kvm *kvm, gfn_t gfn)
         return page[0];
 }
 
-struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
-{
-        struct page *page;
-
-        down_read(&current->mm->mmap_sem);
-        page = __gfn_to_page(kvm, gfn);
-        up_read(&current->mm->mmap_sem);
-
-        return page;
-}
-
 EXPORT_SYMBOL_GPL(gfn_to_page);
 
 void kvm_release_page_clean(struct page *page)
@@ -977,8 +966,7 @@ static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
         if (!kvm_is_visible_gfn(kvm, vmf->pgoff))
                 return VM_FAULT_SIGBUS;
-        /* current->mm->mmap_sem is already held so call lockless version */
-        page = __gfn_to_page(kvm, vmf->pgoff);
+        page = gfn_to_page(kvm, vmf->pgoff);
         if (is_error_page(page)) {
                 kvm_release_page_clean(page);
                 return VM_FAULT_SIGBUS;