Merge tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Include Intel XXV710 in INTx workaround (Alex Williamson)

 - Make use of ERR_CAST() for error return (Dan Carpenter)

 - Fix vfio_group release deadlock from iommu notifier (Alex Williamson)

 - Unset KVM-VFIO attributes only on group match (Alex Williamson)

 - Fix release path group/file matching with KVM-VFIO (Alex Williamson)

 - Remove unnecessary lock uses triggering lockdep splat (Alex Williamson)

* tag 'vfio-v4.13-rc1' of git://github.com/awilliam/linux-vfio:
  vfio: Remove unnecessary uses of vfio_container.group_lock
  vfio: New external user group/file match
  kvm-vfio: Decouple only when we match a group
  vfio: Fix group release deadlock
  vfio: Use ERR_CAST() instead of open coding it
  vfio/pci: Add Intel XXV710 to hidden INTx devices

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 324c52e3a1a47736a819826eea2d1974e47c7a87..063c1ce6fa422e24d1bceb0ef10aeeccce864b96 100644 (file)
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -195,11 +195,11 @@ static bool vfio_pci_nointx(struct pci_dev *pdev)
        switch (pdev->vendor) {
        case PCI_VENDOR_ID_INTEL:
                switch (pdev->device) {
-               /* All i40e (XL710/X710) 10/20/40GbE NICs */
+               /* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
                case 0x1572:
                case 0x1574:
                case 0x1580 ... 0x1581:
-               case 0x1583 ... 0x1589:
+               case 0x1583 ... 0x158b:
                case 0x37d0 ... 0x37d2:
                        return true;
                default:

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 561084ab387f3fd7c8ae3fa3e91c27d8329f7fe4..330d50582f400e7cd93d3242d91270e0d1fdbf66 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -382,7 +382,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
        if (IS_ERR(dev)) {
                vfio_free_group_minor(minor);
                vfio_group_unlock_and_free(group);
-               return (struct vfio_group *)dev; /* ERR_PTR */
+               return ERR_CAST(dev);
        }
 
        group->minor = minor;
@@ -423,6 +423,34 @@ static void vfio_group_put(struct vfio_group *group)
        kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);
 }
 
+struct vfio_group_put_work {
+       struct work_struct work;
+       struct vfio_group *group;
+};
+
+static void vfio_group_put_bg(struct work_struct *work)
+{
+       struct vfio_group_put_work *do_work;
+
+       do_work = container_of(work, struct vfio_group_put_work, work);
+
+       vfio_group_put(do_work->group);
+       kfree(do_work);
+}
+
+static void vfio_group_schedule_put(struct vfio_group *group)
+{
+       struct vfio_group_put_work *do_work;
+
+       do_work = kmalloc(sizeof(*do_work), GFP_KERNEL);
+       if (WARN_ON(!do_work))
+               return;
+
+       INIT_WORK(&do_work->work, vfio_group_put_bg);
+       do_work->group = group;
+       schedule_work(&do_work->work);
+}
+
 /* Assume group_lock or group reference is held */
 static void vfio_group_get(struct vfio_group *group)
 {
@@ -762,7 +790,14 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb,
                break;
        }
 
-       vfio_group_put(group);
+       /*
+        * If we're the last reference to the group, the group will be
+        * released, which includes unregistering the iommu group notifier.
+        * We hold a read-lock on that notifier list, unregistering needs
+        * a write-lock... deadlock.  Release our reference asynchronously
+        * to avoid that situation.
+        */
+       vfio_group_schedule_put(group);
        return NOTIFY_OK;
 }
 
@@ -1140,15 +1175,11 @@ static long vfio_fops_unl_ioctl(struct file *filep,
                ret = vfio_ioctl_set_iommu(container, arg);
                break;
        default:
-               down_read(&container->group_lock);
-
                driver = container->iommu_driver;
                data = container->iommu_data;
 
                if (driver) /* passthrough all unrecognized ioctls */
                        ret = driver->ops->ioctl(data, cmd, arg);
-
-               up_read(&container->group_lock);
        }
 
        return ret;
@@ -1202,15 +1233,11 @@ static ssize_t vfio_fops_read(struct file *filep, char __user *buf,
        struct vfio_iommu_driver *driver;
        ssize_t ret = -EINVAL;
 
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->read))
                ret = driver->ops->read(container->iommu_data,
                                        buf, count, ppos);
 
-       up_read(&container->group_lock);
-
        return ret;
 }
 
@@ -1221,15 +1248,11 @@ static ssize_t vfio_fops_write(struct file *filep, const char __user *buf,
        struct vfio_iommu_driver *driver;
        ssize_t ret = -EINVAL;
 
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->write))
                ret = driver->ops->write(container->iommu_data,
                                         buf, count, ppos);
 
-       up_read(&container->group_lock);
-
        return ret;
 }
 
@@ -1239,14 +1262,10 @@ static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma)
        struct vfio_iommu_driver *driver;
        int ret = -EINVAL;
 
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->mmap))
                ret = driver->ops->mmap(container->iommu_data, vma);
 
-       up_read(&container->group_lock);
-
        return ret;
 }
 
@@ -1741,6 +1760,15 @@ void vfio_group_put_external_user(struct vfio_group *group)
 }
 EXPORT_SYMBOL_GPL(vfio_group_put_external_user);
 
+bool vfio_external_group_match_file(struct vfio_group *test_group,
+                                   struct file *filep)
+{
+       struct vfio_group *group = filep->private_data;
+
+       return (filep->f_op == &vfio_group_fops) && (group == test_group);
+}
+EXPORT_SYMBOL_GPL(vfio_external_group_match_file);
+
 int vfio_external_user_iommu_id(struct vfio_group *group)
 {
        return iommu_group_id(group->iommu_group);
@@ -1949,8 +1977,6 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
                goto err_pin_pages;
 
        container = group->container;
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->pin_pages))
                ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
@@ -1958,7 +1984,6 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
        else
                ret = -ENOTTY;
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
 err_pin_pages:
@@ -1998,8 +2023,6 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
                goto err_unpin_pages;
 
        container = group->container;
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->unpin_pages))
                ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
@@ -2007,7 +2030,6 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
        else
                ret = -ENOTTY;
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
 err_unpin_pages:
@@ -2029,8 +2051,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group,
                return -EINVAL;
 
        container = group->container;
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->register_notifier))
                ret = driver->ops->register_notifier(container->iommu_data,
@@ -2038,7 +2058,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group,
        else
                ret = -ENOTTY;
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
        return ret;
@@ -2056,8 +2075,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group,
                return -EINVAL;
 
        container = group->container;
-       down_read(&container->group_lock);
-
        driver = container->iommu_driver;
        if (likely(driver && driver->ops->unregister_notifier))
                ret = driver->ops->unregister_notifier(container->iommu_data,
@@ -2065,7 +2082,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group,
        else
                ret = -ENOTTY;
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
        return ret;
@@ -2083,7 +2099,6 @@ static int vfio_register_group_notifier(struct vfio_group *group,
                                        unsigned long *events,
                                        struct notifier_block *nb)
 {
-       struct vfio_container *container;
        int ret;
        bool set_kvm = false;
 
@@ -2101,9 +2116,6 @@ static int vfio_register_group_notifier(struct vfio_group *group,
        if (ret)
                return -EINVAL;
 
-       container = group->container;
-       down_read(&container->group_lock);
-
        ret = blocking_notifier_chain_register(&group->notifier, nb);
 
        /*
@@ -2114,7 +2126,6 @@ static int vfio_register_group_notifier(struct vfio_group *group,
                blocking_notifier_call_chain(&group->notifier,
                                        VFIO_GROUP_NOTIFY_SET_KVM, group->kvm);
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
        return ret;
@@ -2123,19 +2134,14 @@ static int vfio_register_group_notifier(struct vfio_group *group,
 static int vfio_unregister_group_notifier(struct vfio_group *group,
                                         struct notifier_block *nb)
 {
-       struct vfio_container *container;
        int ret;
 
        ret = vfio_group_add_container_user(group);
        if (ret)
                return -EINVAL;
 
-       container = group->container;
-       down_read(&container->group_lock);
-
        ret = blocking_notifier_chain_unregister(&group->notifier, nb);
 
-       up_read(&container->group_lock);
        vfio_group_try_dissolve_container(group);
 
        return ret;

diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index f57076b958b73d313b9f92639377f94d866197dd..586809abb273498705be4d75a0e2571caa81ec7a 100644 (file)
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -97,6 +97,8 @@ extern void vfio_unregister_iommu_driver(
  */
 extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
 extern void vfio_group_put_external_user(struct vfio_group *group);
+extern bool vfio_external_group_match_file(struct vfio_group *group,
+                                          struct file *filep);
 extern int vfio_external_user_iommu_id(struct vfio_group *group);
 extern long vfio_external_check_extension(struct vfio_group *group,
                                          unsigned long arg);

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 37d9118fd84be07bc119d40efe58b8edc1f2a889..d99850c462a1879e0a530c387ad4f756d0e64227 100644 (file)
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -51,6 +51,22 @@ static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep)
        return vfio_group;
 }
 
+static bool kvm_vfio_external_group_match_file(struct vfio_group *group,
+                                              struct file *filep)
+{
+       bool ret, (*fn)(struct vfio_group *, struct file *);
+
+       fn = symbol_get(vfio_external_group_match_file);
+       if (!fn)
+               return false;
+
+       ret = fn(group, filep);
+
+       symbol_put(vfio_external_group_match_file);
+
+       return ret;
+}
+
 static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)
 {
        void (*fn)(struct vfio_group *);
@@ -231,37 +247,31 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
                if (!f.file)
                        return -EBADF;
 
-               vfio_group = kvm_vfio_group_get_external_user(f.file);
-               fdput(f);
-
-               if (IS_ERR(vfio_group))
-                       return PTR_ERR(vfio_group);
-
                ret = -ENOENT;
 
                mutex_lock(&kv->lock);
 
                list_for_each_entry(kvg, &kv->group_list, node) {
-                       if (kvg->vfio_group != vfio_group)
+                       if (!kvm_vfio_external_group_match_file(kvg->vfio_group,
+                                                               f.file))
                                continue;
 
                        list_del(&kvg->node);
+                       kvm_arch_end_assignment(dev->kvm);
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+                       kvm_spapr_tce_release_vfio_group(dev->kvm,
+                                                        kvg->vfio_group);
+#endif
+                       kvm_vfio_group_set_kvm(kvg->vfio_group, NULL);
                        kvm_vfio_group_put_external_user(kvg->vfio_group);
                        kfree(kvg);
                        ret = 0;
                        break;
                }
 
-               kvm_arch_end_assignment(dev->kvm);
-
                mutex_unlock(&kv->lock);
 
-#ifdef CONFIG_SPAPR_TCE_IOMMU
-               kvm_spapr_tce_release_vfio_group(dev->kvm, vfio_group);
-#endif
-               kvm_vfio_group_set_kvm(vfio_group, NULL);
-
-               kvm_vfio_group_put_external_user(vfio_group);
+               fdput(f);
 
                kvm_vfio_update_coherency(dev);