KVM: document locking for kvm_io_device_ops
[safe/jmp/linux-2.6] / virt / kvm / kvm_main.c
index 013a5b3..bbb4029 100644 (file)
 #include "irq.h"
 #endif
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/kvm.h>
+
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
+/*
+ * Ordering of locks:
+ *
+ *             kvm->lock --> kvm->irq_lock
+ */
+
 DEFINE_SPINLOCK(kvm_lock);
 LIST_HEAD(vm_list);
 
@@ -79,6 +88,8 @@ static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
 
 static bool kvm_rebooting;
 
+static bool largepages_enabled = true;
+
 #ifdef KVM_CAP_DEVICE_ASSIGNMENT
 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
                                                      int assigned_dev_id)
@@ -120,17 +131,13 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
 {
        struct kvm_assigned_dev_kernel *assigned_dev;
        struct kvm *kvm;
-       int irq, i;
+       int i;
 
        assigned_dev = container_of(work, struct kvm_assigned_dev_kernel,
                                    interrupt_work);
        kvm = assigned_dev->kvm;
 
-       /* This is taken to safely inject irq inside the guest. When
-        * the interrupt injection (or the ioapic code) uses a
-        * finer-grained lock, update this
-        */
-       mutex_lock(&kvm->lock);
+       mutex_lock(&kvm->irq_lock);
        spin_lock_irq(&assigned_dev->assigned_dev_lock);
        if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
                struct kvm_guest_msix_entry *guest_entries =
@@ -143,23 +150,13 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
                        kvm_set_irq(assigned_dev->kvm,
                                    assigned_dev->irq_source_id,
                                    guest_entries[i].vector, 1);
-                       irq = assigned_dev->host_msix_entries[i].vector;
-                       if (irq != 0)
-                               enable_irq(irq);
-                       assigned_dev->host_irq_disabled = false;
                }
-       } else {
+       } else
                kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
                            assigned_dev->guest_irq, 1);
-               if (assigned_dev->irq_requested_type &
-                               KVM_DEV_IRQ_GUEST_MSI) {
-                       enable_irq(assigned_dev->host_irq);
-                       assigned_dev->host_irq_disabled = false;
-               }
-       }
 
        spin_unlock_irq(&assigned_dev->assigned_dev_lock);
-       mutex_unlock(&assigned_dev->kvm->lock);
+       mutex_unlock(&assigned_dev->kvm->irq_lock);
 }
 
 static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
@@ -179,8 +176,10 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
 
        schedule_work(&assigned_dev->interrupt_work);
 
-       disable_irq_nosync(irq);
-       assigned_dev->host_irq_disabled = true;
+       if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
+               disable_irq_nosync(irq);
+               assigned_dev->host_irq_disabled = true;
+       }
 
 out:
        spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags);
@@ -215,7 +214,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
 static void deassign_guest_irq(struct kvm *kvm,
                               struct kvm_assigned_dev_kernel *assigned_dev)
 {
-       kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier);
+       kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
        assigned_dev->ack_notifier.gsi = -1;
 
        if (assigned_dev->irq_source_id != -1)
@@ -417,6 +416,7 @@ static int assigned_device_enable_guest_msi(struct kvm *kvm,
 {
        dev->guest_irq = irq->guest_irq;
        dev->ack_notifier.gsi = -1;
+       dev->host_irq_disabled = false;
        return 0;
 }
 #endif
@@ -427,6 +427,7 @@ static int assigned_device_enable_guest_msix(struct kvm *kvm,
 {
        dev->guest_irq = irq->guest_irq;
        dev->ack_notifier.gsi = -1;
+       dev->host_irq_disabled = false;
        return 0;
 }
 #endif
@@ -693,11 +694,6 @@ out:
 }
 #endif
 
-static inline int valid_vcpu(int n)
-{
-       return likely(n >= 0 && n < KVM_MAX_VCPUS);
-}
-
 inline int kvm_is_mmio_pfn(pfn_t pfn)
 {
        if (pfn_valid(pfn)) {
@@ -746,10 +742,8 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
                cpumask_clear(cpus);
 
        me = get_cpu();
-       for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-               vcpu = kvm->vcpus[i];
-               if (!vcpu)
-                       continue;
+       spin_lock(&kvm->requests_lock);
+       kvm_for_each_vcpu(i, vcpu, kvm) {
                if (test_and_set_bit(req, &vcpu->requests))
                        continue;
                cpu = vcpu->cpu;
@@ -762,6 +756,7 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
                smp_call_function_many(cpus, ack_flush, NULL, 1);
        else
                called = false;
+       spin_unlock(&kvm->requests_lock);
        put_cpu();
        free_cpumask_var(cpus);
        return called;
@@ -982,8 +977,11 @@ static struct kvm *kvm_create_vm(void)
        kvm->mm = current->mm;
        atomic_inc(&kvm->mm->mm_count);
        spin_lock_init(&kvm->mmu_lock);
+       spin_lock_init(&kvm->requests_lock);
        kvm_io_bus_init(&kvm->pio_bus);
+       kvm_irqfd_init(kvm);
        mutex_init(&kvm->lock);
+       mutex_init(&kvm->irq_lock);
        kvm_io_bus_init(&kvm->mmio_bus);
        init_rwsem(&kvm->slots_lock);
        atomic_set(&kvm->users_count, 1);
@@ -1003,19 +1001,25 @@ out:
 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                                  struct kvm_memory_slot *dont)
 {
+       int i;
+
        if (!dont || free->rmap != dont->rmap)
                vfree(free->rmap);
 
        if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
                vfree(free->dirty_bitmap);
 
-       if (!dont || free->lpage_info != dont->lpage_info)
-               vfree(free->lpage_info);
+
+       for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+               if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
+                       vfree(free->lpage_info[i]);
+                       free->lpage_info[i] = NULL;
+               }
+       }
 
        free->npages = 0;
        free->dirty_bitmap = NULL;
        free->rmap = NULL;
-       free->lpage_info = NULL;
 }
 
 void kvm_free_physmem(struct kvm *kvm)
@@ -1068,6 +1072,8 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
 {
        struct kvm *kvm = filp->private_data;
 
+       kvm_irqfd_release(kvm);
+
        kvm_put_kvm(kvm);
        return 0;
 }
@@ -1087,7 +1093,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
        int r;
        gfn_t base_gfn;
        unsigned long npages, ugfn;
-       unsigned long largepages, i;
+       int lpages;
+       unsigned long i, j;
        struct kvm_memory_slot *memslot;
        struct kvm_memory_slot old, new;
 
@@ -1161,31 +1168,48 @@ int __kvm_set_memory_region(struct kvm *kvm,
                else
                        new.userspace_addr = 0;
        }
-       if (npages && !new.lpage_info) {
-               largepages = 1 + (base_gfn + npages - 1) / KVM_PAGES_PER_HPAGE;
-               largepages -= base_gfn / KVM_PAGES_PER_HPAGE;
+       if (!npages)
+               goto skip_lpage;
+
+       for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+               int level = i + 2;
 
-               new.lpage_info = vmalloc(largepages * sizeof(*new.lpage_info));
+               /* Avoid unused variable warning if no large pages */
+               (void)level;
 
-               if (!new.lpage_info)
+               if (new.lpage_info[i])
+                       continue;
+
+               lpages = 1 + (base_gfn + npages - 1) /
+                            KVM_PAGES_PER_HPAGE(level);
+               lpages -= base_gfn / KVM_PAGES_PER_HPAGE(level);
+
+               new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
+
+               if (!new.lpage_info[i])
                        goto out_free;
 
-               memset(new.lpage_info, 0, largepages * sizeof(*new.lpage_info));
+               memset(new.lpage_info[i], 0,
+                      lpages * sizeof(*new.lpage_info[i]));
 
-               if (base_gfn % KVM_PAGES_PER_HPAGE)
-                       new.lpage_info[0].write_count = 1;
-               if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE)
-                       new.lpage_info[largepages-1].write_count = 1;
+               if (base_gfn % KVM_PAGES_PER_HPAGE(level))
+                       new.lpage_info[i][0].write_count = 1;
+               if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE(level))
+                       new.lpage_info[i][lpages - 1].write_count = 1;
                ugfn = new.userspace_addr >> PAGE_SHIFT;
                /*
                 * If the gfn and userspace address are not aligned wrt each
-                * other, disable large page support for this slot
+                * other, or if explicitly asked to, disable large page
+                * support for this slot
                 */
-               if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE - 1))
-                       for (i = 0; i < largepages; ++i)
-                               new.lpage_info[i].write_count = 1;
+               if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
+                   !largepages_enabled)
+                       for (j = 0; j < lpages; ++j)
+                               new.lpage_info[i][j].write_count = 1;
        }
 
+skip_lpage:
+
        /* Allocate page dirty bitmap if needed */
        if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
                unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
@@ -1197,6 +1221,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
                if (old.npages)
                        kvm_arch_flush_shadow(kvm);
        }
+#else  /* not defined CONFIG_S390 */
+       new.user_alloc = user_alloc;
+       if (user_alloc)
+               new.userspace_addr = mem->userspace_addr;
 #endif /* not defined CONFIG_S390 */
 
        if (!npages)
@@ -1296,6 +1324,12 @@ out:
        return r;
 }
 
+void kvm_disable_largepages(void)
+{
+       largepages_enabled = false;
+}
+EXPORT_SYMBOL_GPL(kvm_disable_largepages);
+
 int is_error_page(struct page *page)
 {
        return page == bad_page;
@@ -1711,24 +1745,18 @@ static struct file_operations kvm_vcpu_fops = {
  */
 static int create_vcpu_fd(struct kvm_vcpu *vcpu)
 {
-       int fd = anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
-       if (fd < 0)
-               kvm_put_kvm(vcpu->kvm);
-       return fd;
+       return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, 0);
 }
 
 /*
  * Creates some virtual cpus.  Good luck creating more than one.
  */
-static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
+static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 {
        int r;
-       struct kvm_vcpu *vcpu;
-
-       if (!valid_vcpu(n))
-               return -EINVAL;
+       struct kvm_vcpu *vcpu, *v;
 
-       vcpu = kvm_arch_vcpu_create(kvm, n);
+       vcpu = kvm_arch_vcpu_create(kvm, id);
        if (IS_ERR(vcpu))
                return PTR_ERR(vcpu);
 
@@ -1739,23 +1767,38 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
                return r;
 
        mutex_lock(&kvm->lock);
-       if (kvm->vcpus[n]) {
-               r = -EEXIST;
+       if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
+               r = -EINVAL;
                goto vcpu_destroy;
        }
-       kvm->vcpus[n] = vcpu;
-       mutex_unlock(&kvm->lock);
+
+       kvm_for_each_vcpu(r, v, kvm)
+               if (v->vcpu_id == id) {
+                       r = -EEXIST;
+                       goto vcpu_destroy;
+               }
+
+       BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
 
        /* Now it's all set up, let userspace reach it */
        kvm_get_kvm(kvm);
        r = create_vcpu_fd(vcpu);
-       if (r < 0)
-               goto unlink;
+       if (r < 0) {
+               kvm_put_kvm(kvm);
+               goto vcpu_destroy;
+       }
+
+       kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
+       smp_wmb();
+       atomic_inc(&kvm->online_vcpus);
+
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       if (kvm->bsp_vcpu_id == id)
+               kvm->bsp_vcpu = vcpu;
+#endif
+       mutex_unlock(&kvm->lock);
        return r;
 
-unlink:
-       mutex_lock(&kvm->lock);
-       kvm->vcpus[n] = NULL;
 vcpu_destroy:
        mutex_unlock(&kvm->lock);
        kvm_arch_vcpu_destroy(vcpu);
@@ -2219,6 +2262,26 @@ static long kvm_vm_ioctl(struct file *filp,
        }
 #endif
 #endif /* KVM_CAP_IRQ_ROUTING */
+       case KVM_IRQFD: {
+               struct kvm_irqfd data;
+
+               r = -EFAULT;
+               if (copy_from_user(&data, argp, sizeof data))
+                       goto out;
+               r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
+               break;
+       }
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       case KVM_SET_BOOT_CPU_ID:
+               r = 0;
+               mutex_lock(&kvm->lock);
+               if (atomic_read(&kvm->online_vcpus) != 0)
+                       r = -EBUSY;
+               else
+                       kvm->bsp_vcpu_id = arg;
+               mutex_unlock(&kvm->lock);
+               break;
+#endif
        default:
                r = kvm_arch_vm_ioctl(filp, ioctl, arg);
        }
@@ -2285,6 +2348,9 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
        case KVM_CAP_USER_MEMORY:
        case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
        case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
+#ifdef CONFIG_KVM_APIC_ARCHITECTURE
+       case KVM_CAP_SET_BOOT_CPU_ID:
+#endif
                return 1;
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
        case KVM_CAP_IRQ_ROUTING:
@@ -2332,7 +2398,7 @@ static long kvm_dev_ioctl(struct file *filp,
        case KVM_TRACE_ENABLE:
        case KVM_TRACE_PAUSE:
        case KVM_TRACE_DISABLE:
-               r = kvm_trace_ioctl(ioctl, arg);
+               r = -EOPNOTSUPP;
                break;
        default:
                return kvm_arch_dev_ioctl(filp, ioctl, arg);
@@ -2454,7 +2520,7 @@ struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
        for (i = 0; i < bus->dev_count; i++) {
                struct kvm_io_device *pos = bus->devs[i];
 
-               if (pos->in_range(pos, addr, len, is_write))
+               if (kvm_iodevice_in_range(pos, addr, len, is_write))
                        return pos;
        }
 
@@ -2498,11 +2564,9 @@ static int vcpu_stat_get(void *_offset, u64 *val)
        *val = 0;
        spin_lock(&kvm_lock);
        list_for_each_entry(kvm, &vm_list, vm_list)
-               for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-                       vcpu = kvm->vcpus[i];
-                       if (vcpu)
-                               *val += *(u32 *)((void *)vcpu + offset);
-               }
+               kvm_for_each_vcpu(i, vcpu, kvm)
+                       *val += *(u32 *)((void *)vcpu + offset);
+
        spin_unlock(&kvm_lock);
        return 0;
 }
@@ -2684,7 +2748,7 @@ EXPORT_SYMBOL_GPL(kvm_init);
 
 void kvm_exit(void)
 {
-       kvm_trace_cleanup();
+       tracepoint_synchronize_unregister();
        misc_deregister(&kvm_dev);
        kmem_cache_destroy(kvm_vcpu_cache);
        sysdev_unregister(&kvm_sysdev);