Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[cascardo/linux.git] / virt / kvm / kvm_main.c

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2e79136..cc081cc 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1444,6 +1444,52 @@ static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
        return true;
 }
 
+static int hva_to_pfn_remapped(struct vm_area_struct *vma,
+                              unsigned long addr, bool *async,
+                              bool write_fault, kvm_pfn_t *p_pfn)
+{
+       unsigned long pfn;
+       int r;
+
+       r = follow_pfn(vma, addr, &pfn);
+       if (r) {
+               /*
+                * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
+                * not call the fault handler, so do it here.
+                */
+               bool unlocked = false;
+               r = fixup_user_fault(current, current->mm, addr,
+                                    (write_fault ? FAULT_FLAG_WRITE : 0),
+                                    &unlocked);
+               if (unlocked)
+                       return -EAGAIN;
+               if (r)
+                       return r;
+
+               r = follow_pfn(vma, addr, &pfn);
+               if (r)
+                       return r;
+
+       }
+
+
+       /*
+        * Get a reference here because callers of *hva_to_pfn* and
+        * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
+        * returned pfn.  This is only needed if the VMA has VM_MIXEDMAP
+        * set, but the kvm_get_pfn/kvm_release_pfn_clean pair will
+        * simply do nothing for reserved pfns.
+        *
+        * Whoever called remap_pfn_range is also going to call e.g.
+        * unmap_mapping_range before the underlying pages are freed,
+        * causing a call to our MMU notifier.
+        */ 
+       kvm_get_pfn(pfn);
+
+       *p_pfn = pfn;
+       return 0;
+}
+
 /*
  * Pin guest page in memory and return its pfn.
  * @addr: host virtual address which maps memory to the guest
@@ -1463,7 +1509,7 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
 {
        struct vm_area_struct *vma;
        kvm_pfn_t pfn = 0;
-       int npages;
+       int npages, r;
 
        /* we can do it either atomically or asynchronously, not both */
        BUG_ON(atomic && async);
@@ -1485,14 +1531,17 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
                goto exit;
        }
 
+retry:
        vma = find_vma_intersection(current->mm, addr, addr + 1);
 
        if (vma == NULL)
                pfn = KVM_PFN_ERR_FAULT;
-       else if ((vma->vm_flags & VM_PFNMAP)) {
-               pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
-                       vma->vm_pgoff;
-               BUG_ON(!kvm_is_reserved_pfn(pfn));
+       else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
+               r = hva_to_pfn_remapped(vma, addr, async, write_fault, &pfn);
+               if (r == -EAGAIN)
+                       goto retry;
+               if (r < 0)
+                       pfn = KVM_PFN_ERR_FAULT;
        } else {
                if (async && vma_is_valid(vma, write_fault))
                        *async = true;
@@ -2348,9 +2397,20 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
        if (id >= KVM_MAX_VCPU_ID)
                return -EINVAL;
 
+       mutex_lock(&kvm->lock);
+       if (kvm->created_vcpus == KVM_MAX_VCPUS) {
+               mutex_unlock(&kvm->lock);
+               return -EINVAL;
+       }
+
+       kvm->created_vcpus++;
+       mutex_unlock(&kvm->lock);
+
        vcpu = kvm_arch_vcpu_create(kvm, id);
-       if (IS_ERR(vcpu))
-               return PTR_ERR(vcpu);
+       if (IS_ERR(vcpu)) {
+               r = PTR_ERR(vcpu);
+               goto vcpu_decrement;
+       }
 
        preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
 
@@ -2359,14 +2419,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
                goto vcpu_destroy;
 
        mutex_lock(&kvm->lock);
-       if (!kvm_vcpu_compatible(vcpu)) {
-               r = -EINVAL;
-               goto unlock_vcpu_destroy;
-       }
-       if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
-               r = -EINVAL;
-               goto unlock_vcpu_destroy;
-       }
        if (kvm_get_vcpu_by_id(kvm, id)) {
                r = -EEXIST;
                goto unlock_vcpu_destroy;
@@ -2399,6 +2451,10 @@ unlock_vcpu_destroy:
        mutex_unlock(&kvm->lock);
 vcpu_destroy:
        kvm_arch_vcpu_destroy(vcpu);
+vcpu_decrement:
+       mutex_lock(&kvm->lock);
+       kvm->created_vcpus--;
+       mutex_unlock(&kvm->lock);
        return r;
 }
 
@@ -3487,6 +3543,30 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
        return r;
 }
 
+struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
+                                        gpa_t addr)
+{
+       struct kvm_io_bus *bus;
+       int dev_idx, srcu_idx;
+       struct kvm_io_device *iodev = NULL;
+
+       srcu_idx = srcu_read_lock(&kvm->srcu);
+
+       bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
+
+       dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1);
+       if (dev_idx < 0)
+               goto out_unlock;
+
+       iodev = bus->range[dev_idx].dev;
+
+out_unlock:
+       srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+       return iodev;
+}
+EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);
+
 static int kvm_debugfs_open(struct inode *inode, struct file *file,
                           int (*get)(void *, u64 *), int (*set)(void *, u64),
                           const char *fmt)