KVM: Convert vm lock to a mutex

This allows the kvm mmu to perform sleepy operations, such as memory
allocation.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

5 files changed, 46 insertions, 50 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 0667183ecbed..1072c8322d4f 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -393,7 +393,7 @@ struct kvm_memory_slot {
 };
 
 struct kvm {
-        spinlock_t lock; /* protects everything except vcpus */
+        struct mutex lock; /* protects everything except vcpus */
         int naliases;
         struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];
         int nmemslots;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 6035e6d35417..7aeaaba79c54 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -363,7 +363,7 @@ static struct kvm *kvm_create_vm(void)
                 return ERR_PTR(-ENOMEM);
 
         kvm_io_bus_init(&kvm->pio_bus);
-        spin_lock_init(&kvm->lock);
+        mutex_init(&kvm->lock);
         INIT_LIST_HEAD(&kvm->active_mmu_pages);
         kvm_io_bus_init(&kvm->mmio_bus);
         spin_lock(&kvm_lock);
@@ -489,7 +489,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
         struct page *page;
         u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)];
 
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         page = gfn_to_page(vcpu->kvm, pdpt_gfn);
         if (!page) {
                 ret = 0;
@@ -510,7 +510,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
 
         memcpy(vcpu->pdptrs, pdpte, sizeof(vcpu->pdptrs));
 out:
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
 
         return ret;
 }
@@ -570,9 +570,9 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
         kvm_arch_ops->set_cr0(vcpu, cr0);
         vcpu->cr0 = cr0;
 
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
         return;
 }
 EXPORT_SYMBOL_GPL(set_cr0);
@@ -611,9 +611,9 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
                 return;
         }
         kvm_arch_ops->set_cr4(vcpu, cr4);
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         kvm_mmu_reset_context(vcpu);
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
 }
 EXPORT_SYMBOL_GPL(set_cr4);
 
@@ -650,7 +650,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
         }
 
         vcpu->cr3 = cr3;
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         /*
          * Does the new cr3 value map to physical memory? (Note, we
          * catch an invalid cr3 even in real-mode, because it would
@@ -664,7 +664,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                 inject_gp(vcpu);
         else
                 vcpu->mmu.new_cr3(vcpu);
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
 }
 EXPORT_SYMBOL_GPL(set_cr3);
 
@@ -741,7 +741,7 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
                 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
 
 raced:
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
 
         memory_config_version = kvm->memory_config_version;
         new = old = *memslot;
@@ -770,7 +770,7 @@ raced:
          * Do memory allocations outside lock.  memory_config_version will
          * detect any races.
          */
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
         /* Deallocate if slot is being removed */
         if (!npages)
@@ -809,10 +809,10 @@ raced:
                 memset(new.dirty_bitmap, 0, dirty_bytes);
         }
 
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
 
         if (memory_config_version != kvm->memory_config_version) {
-                spin_unlock(&kvm->lock);
+                mutex_unlock(&kvm->lock);
                 kvm_free_physmem_slot(&new, &old);
                 goto raced;
         }
@@ -830,13 +830,13 @@ raced:
         kvm_mmu_slot_remove_write_access(kvm, mem->slot);
         kvm_flush_remote_tlbs(kvm);
 
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
         kvm_free_physmem_slot(&old, &new);
         return 0;
 
 out_unlock:
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 out_free:
         kvm_free_physmem_slot(&new, &old);
 out:
@@ -854,14 +854,14 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         int n;
         unsigned long any = 0;
 
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
 
         /*
          * Prevent changes to guest memory configuration even while the lock
          * is not taken.
          */
         ++kvm->busy;
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
         r = -EINVAL;
         if (log->slot >= KVM_MEMORY_SLOTS)
                 goto out;
@@ -880,18 +880,18 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
                 goto out;
 
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
         kvm_mmu_slot_remove_write_access(kvm, log->slot);
         kvm_flush_remote_tlbs(kvm);
         memset(memslot->dirty_bitmap, 0, n);
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
         r = 0;
 
 out:
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
         --kvm->busy;
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
         return r;
 }
 
@@ -921,7 +921,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
             < alias->target_phys_addr)
                 goto out;
 
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
 
         p = &kvm->aliases[alias->slot];
         p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -935,7 +935,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 
         kvm_mmu_zap_all(kvm);
 
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
         return 0;
 
@@ -1900,12 +1900,12 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
         vcpu->pio.cur_count = now;
 
         for (i = 0; i < nr_pages; ++i) {
-                spin_lock(&vcpu->kvm->lock);
+                mutex_lock(&vcpu->kvm->lock);
                 page = gva_to_page(vcpu, address + i * PAGE_SIZE);
                 if (page)
                         get_page(page);
                 vcpu->pio.guest_pages[i] = page;
-                spin_unlock(&vcpu->kvm->lock);
+                mutex_unlock(&vcpu->kvm->lock);
                 if (!page) {
                         inject_gp(vcpu);
                         free_pio_guest_pages(vcpu);
@@ -2298,13 +2298,13 @@ static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
         gpa_t gpa;
 
         vcpu_load(vcpu);
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
         tr->physical_address = gpa;
         tr->valid = gpa != UNMAPPED_GVA;
         tr->writeable = 1;
         tr->usermode = 0;
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
         vcpu_put(vcpu);
 
         return 0;
@@ -2426,14 +2426,14 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
         if (r < 0)
                 goto free_vcpu;
 
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
         if (kvm->vcpus[n]) {
                 r = -EEXIST;
-                spin_unlock(&kvm->lock);
+                mutex_unlock(&kvm->lock);
                 goto mmu_unload;
         }
         kvm->vcpus[n] = vcpu;
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
         /* Now it's all set up, let userspace reach it */
         r = create_vcpu_fd(vcpu);
@@ -2442,9 +2442,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
         return r;
 
 unlink:
-        spin_lock(&kvm->lock);
+        mutex_lock(&kvm->lock);
         kvm->vcpus[n] = NULL;
-        spin_unlock(&kvm->lock);
+        mutex_unlock(&kvm->lock);
 
 mmu_unload:
         vcpu_load(vcpu);
@@ -2945,8 +2945,7 @@ static void decache_vcpus_on_cpu(int cpu)
         int i;
 
         spin_lock(&kvm_lock);
-        list_for_each_entry(vm, &vm_list, vm_list) {
-                spin_lock(&vm->lock);
+        list_for_each_entry(vm, &vm_list, vm_list)
                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                         vcpu = vm->vcpus[i];
                         if (!vcpu)
@@ -2967,8 +2966,6 @@ static void decache_vcpus_on_cpu(int cpu)
                                 mutex_unlock(&vcpu->mutex);
                         }
                 }
-                spin_unlock(&vm->lock);
-        }
         spin_unlock(&kvm_lock);
 }
 
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 396c736e546b..e303b4137bfa 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -275,10 +275,9 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
         r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
         kvm_mmu_free_some_pages(vcpu);
         if (r < 0) {
-                spin_unlock(&vcpu->kvm->lock);
+                mutex_unlock(&vcpu->kvm->lock);
                 r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
-                spin_lock(&vcpu->kvm->lock);
-                kvm_mmu_free_some_pages(vcpu);
+                mutex_lock(&vcpu->kvm->lock);
         }
         return r;
 }
@@ -1069,7 +1068,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 {
         int r;
 
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
         r = mmu_topup_memory_caches(vcpu);
         if (r)
                 goto out;
@@ -1077,7 +1076,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
         kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
         kvm_mmu_flush_tlb(vcpu);
 out:
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
         return r;
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_load);
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 3997bbd78fb7..9a840e08b207 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -941,21 +941,21 @@ static int pf_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         if (is_external_interrupt(exit_int_info))
                 push_irq(vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);
 
-        spin_lock(&vcpu->kvm->lock);
+        mutex_lock(&vcpu->kvm->lock);
 
         fault_address  = svm->vmcb->control.exit_info_2;
         error_code = svm->vmcb->control.exit_info_1;
         r = kvm_mmu_page_fault(vcpu, fault_address, error_code);
         if (r < 0) {
-                spin_unlock(&vcpu->kvm->lock);
+                mutex_unlock(&vcpu->kvm->lock);
                 return r;
         }
         if (!r) {
-                spin_unlock(&vcpu->kvm->lock);
+                mutex_unlock(&vcpu->kvm->lock);
                 return 1;
         }
         er = emulate_instruction(vcpu, kvm_run, fault_address, error_code);
-        spin_unlock(&vcpu->kvm->lock);
+        mutex_unlock(&vcpu->kvm->lock);
 
         switch (er) {
         case EMULATE_DONE:
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 8c87d20f8e39..5b77d9b7b1ac 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1711,19 +1711,19 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         if (is_page_fault(intr_info)) {
                 cr2 = vmcs_readl(EXIT_QUALIFICATION);
 
-                spin_lock(&vcpu->kvm->lock);
+                mutex_lock(&vcpu->kvm->lock);
                 r = kvm_mmu_page_fault(vcpu, cr2, error_code);
                 if (r < 0) {
-                        spin_unlock(&vcpu->kvm->lock);
+                        mutex_unlock(&vcpu->kvm->lock);
                         return r;
                 }
                 if (!r) {
-                        spin_unlock(&vcpu->kvm->lock);
+                        mutex_unlock(&vcpu->kvm->lock);
                         return 1;
                 }
 
                 er = emulate_instruction(vcpu, kvm_run, cr2, error_code);
-                spin_unlock(&vcpu->kvm->lock);
+                mutex_unlock(&vcpu->kvm->lock);
 
                 switch (er) {
                 case EMULATE_DONE: