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Diffstat (limited to 'virt/kvm/kvm_main.c')
-rw-r--r--virt/kvm/kvm_main.c110
1 files changed, 95 insertions, 15 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2e791367c576..cc081ccfcaa3 100644
--- 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)