vfio: simplify iommu group allocation for mediated devices
Reuse the logic in vfio_noiommu_group_alloc to allocate a fake single-device iommu group for mediated devices by factoring out a common function, and replacing the noiommu boolean field in struct vfio_group with an enum to distinguish the three different kinds of groups. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-8-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Christoph Hellwig
Alex Williamson
Родитель
c04ac34078
Коммит
c68ea0d00a
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@ -351,7 +351,7 @@ static int vfio_ap_mdev_probe(struct mdev_device *mdev)
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list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
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mutex_unlock(&matrix_dev->lock);
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ret = vfio_register_group_dev(&matrix_mdev->vdev);
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ret = vfio_register_emulated_iommu_dev(&matrix_mdev->vdev);
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if (ret)
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goto err_list;
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dev_set_drvdata(&mdev->dev, matrix_mdev);
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@ -13,60 +13,23 @@
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#include "mdev_private.h"
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static int mdev_attach_iommu(struct mdev_device *mdev)
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{
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int ret;
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struct iommu_group *group;
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group = iommu_group_alloc();
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if (IS_ERR(group))
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return PTR_ERR(group);
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ret = iommu_group_add_device(group, &mdev->dev);
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if (!ret)
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dev_info(&mdev->dev, "MDEV: group_id = %d\n",
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iommu_group_id(group));
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iommu_group_put(group);
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return ret;
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}
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static void mdev_detach_iommu(struct mdev_device *mdev)
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{
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iommu_group_remove_device(&mdev->dev);
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dev_info(&mdev->dev, "MDEV: detaching iommu\n");
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}
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static int mdev_probe(struct device *dev)
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{
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struct mdev_driver *drv =
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container_of(dev->driver, struct mdev_driver, driver);
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struct mdev_device *mdev = to_mdev_device(dev);
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int ret;
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ret = mdev_attach_iommu(mdev);
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if (ret)
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return ret;
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if (drv->probe) {
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ret = drv->probe(mdev);
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if (ret)
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mdev_detach_iommu(mdev);
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}
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return ret;
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if (!drv->probe)
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return 0;
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return drv->probe(to_mdev_device(dev));
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}
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static void mdev_remove(struct device *dev)
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{
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struct mdev_driver *drv =
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container_of(dev->driver, struct mdev_driver, driver);
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struct mdev_device *mdev = to_mdev_device(dev);
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if (drv->remove)
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drv->remove(mdev);
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mdev_detach_iommu(mdev);
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drv->remove(to_mdev_device(dev));
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}
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static int mdev_match(struct device *dev, struct device_driver *drv)
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@ -119,7 +119,7 @@ static int vfio_mdev_probe(struct mdev_device *mdev)
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return -ENOMEM;
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vfio_init_group_dev(vdev, &mdev->dev, &vfio_mdev_dev_ops);
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ret = vfio_register_group_dev(vdev);
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ret = vfio_register_emulated_iommu_dev(vdev);
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if (ret)
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goto out_uninit;
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@ -67,6 +67,30 @@ struct vfio_unbound_dev {
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struct list_head unbound_next;
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};
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enum vfio_group_type {
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/*
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* Physical device with IOMMU backing.
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*/
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VFIO_IOMMU,
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/*
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* Virtual device without IOMMU backing. The VFIO core fakes up an
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* iommu_group as the iommu_group sysfs interface is part of the
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* userspace ABI. The user of these devices must not be able to
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* directly trigger unmediated DMA.
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*/
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VFIO_EMULATED_IOMMU,
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/*
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* Physical device without IOMMU backing. The VFIO core fakes up an
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* iommu_group as the iommu_group sysfs interface is part of the
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* userspace ABI. Users can trigger unmediated DMA by the device,
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* usage is highly dangerous, requires an explicit opt-in and will
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* taint the kernel.
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*/
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VFIO_NO_IOMMU,
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};
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struct vfio_group {
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struct kref kref;
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int minor;
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@ -83,7 +107,7 @@ struct vfio_group {
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struct mutex unbound_lock;
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atomic_t opened;
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wait_queue_head_t container_q;
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bool noiommu;
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enum vfio_group_type type;
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unsigned int dev_counter;
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struct kvm *kvm;
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struct blocking_notifier_head notifier;
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@ -336,7 +360,7 @@ static void vfio_group_unlock_and_free(struct vfio_group *group)
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* Group objects - create, release, get, put, search
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*/
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static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
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bool noiommu)
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enum vfio_group_type type)
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{
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struct vfio_group *group, *tmp;
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struct device *dev;
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@ -355,7 +379,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
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atomic_set(&group->opened, 0);
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init_waitqueue_head(&group->container_q);
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group->iommu_group = iommu_group;
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group->noiommu = noiommu;
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group->type = type;
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BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
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group->nb.notifier_call = vfio_iommu_group_notifier;
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@ -391,8 +415,8 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
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}
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dev = device_create(vfio.class, NULL,
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MKDEV(MAJOR(vfio.group_devt), minor),
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group, "%s%d", group->noiommu ? "noiommu-" : "",
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MKDEV(MAJOR(vfio.group_devt), minor), group, "%s%d",
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group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
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iommu_group_id(iommu_group));
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if (IS_ERR(dev)) {
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vfio_free_group_minor(minor);
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@ -778,8 +802,8 @@ void vfio_uninit_group_dev(struct vfio_device *device)
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}
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EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
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#ifdef CONFIG_VFIO_NOIOMMU
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static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
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static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
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enum vfio_group_type type)
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{
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struct iommu_group *iommu_group;
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struct vfio_group *group;
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@ -794,7 +818,7 @@ static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
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if (ret)
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goto out_put_group;
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group = vfio_create_group(iommu_group, true);
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group = vfio_create_group(iommu_group, type);
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if (IS_ERR(group)) {
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ret = PTR_ERR(group);
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goto out_remove_device;
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@ -808,7 +832,6 @@ out_put_group:
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iommu_group_put(iommu_group);
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return ERR_PTR(ret);
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}
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#endif
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static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
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{
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@ -824,7 +847,7 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
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* bus. Taint the kernel because we're about to give a DMA
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* capable device to a user without IOMMU protection.
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*/
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group = vfio_noiommu_group_alloc(dev);
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group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
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if (!IS_ERR(group)) {
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add_taint(TAINT_USER, LOCKDEP_STILL_OK);
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dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
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@ -841,7 +864,7 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
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goto out_put;
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/* a newly created vfio_group keeps the reference. */
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group = vfio_create_group(iommu_group, false);
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group = vfio_create_group(iommu_group, VFIO_IOMMU);
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if (IS_ERR(group))
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goto out_put;
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return group;
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@ -851,10 +874,13 @@ out_put:
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return group;
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}
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int vfio_register_group_dev(struct vfio_device *device)
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static int __vfio_register_dev(struct vfio_device *device,
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struct vfio_group *group)
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{
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struct vfio_device *existing_device;
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struct vfio_group *group;
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if (IS_ERR(group))
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return PTR_ERR(group);
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/*
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* If the driver doesn't specify a set then the device is added to a
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@ -863,16 +889,13 @@ int vfio_register_group_dev(struct vfio_device *device)
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if (!device->dev_set)
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vfio_assign_device_set(device, device);
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group = vfio_group_find_or_alloc(device->dev);
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if (IS_ERR(group))
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return PTR_ERR(group);
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existing_device = vfio_group_get_device(group, device->dev);
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if (existing_device) {
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dev_WARN(device->dev, "Device already exists on group %d\n",
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iommu_group_id(group->iommu_group));
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vfio_device_put(existing_device);
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if (group->noiommu)
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if (group->type == VFIO_NO_IOMMU ||
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group->type == VFIO_EMULATED_IOMMU)
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iommu_group_remove_device(device->dev);
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vfio_group_put(group);
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return -EBUSY;
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@ -891,8 +914,25 @@ int vfio_register_group_dev(struct vfio_device *device)
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return 0;
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}
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int vfio_register_group_dev(struct vfio_device *device)
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{
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return __vfio_register_dev(device,
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vfio_group_find_or_alloc(device->dev));
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}
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EXPORT_SYMBOL_GPL(vfio_register_group_dev);
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/*
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* Register a virtual device without IOMMU backing. The user of this
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* device must not be able to directly trigger unmediated DMA.
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*/
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int vfio_register_emulated_iommu_dev(struct vfio_device *device)
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{
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return __vfio_register_dev(device,
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vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU));
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}
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EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
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/**
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* Get a reference to the vfio_device for a device. Even if the
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* caller thinks they own the device, they could be racing with a
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@ -1019,7 +1059,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
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if (list_empty(&group->device_list))
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wait_event(group->container_q, !group->container);
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if (group->noiommu)
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if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
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iommu_group_remove_device(device->dev);
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/* Matches the get in vfio_register_group_dev() */
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@ -1368,7 +1408,7 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd)
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if (atomic_read(&group->container_users))
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return -EINVAL;
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if (group->noiommu && !capable(CAP_SYS_RAWIO))
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if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO))
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return -EPERM;
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f = fdget(container_fd);
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@ -1388,7 +1428,7 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd)
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/* Real groups and fake groups cannot mix */
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if (!list_empty(&container->group_list) &&
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container->noiommu != group->noiommu) {
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container->noiommu != (group->type == VFIO_NO_IOMMU)) {
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ret = -EPERM;
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goto unlock_out;
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}
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@ -1402,7 +1442,7 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd)
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}
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group->container = container;
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container->noiommu = group->noiommu;
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container->noiommu = (group->type == VFIO_NO_IOMMU);
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list_add(&group->container_next, &container->group_list);
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/* Get a reference on the container and mark a user within the group */
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@ -1426,7 +1466,7 @@ static int vfio_group_add_container_user(struct vfio_group *group)
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if (!atomic_inc_not_zero(&group->container_users))
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return -EINVAL;
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if (group->noiommu) {
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if (group->type == VFIO_NO_IOMMU) {
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atomic_dec(&group->container_users);
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return -EPERM;
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}
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@ -1451,7 +1491,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
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!group->container->iommu_driver || !vfio_group_viable(group))
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return -EINVAL;
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if (group->noiommu && !capable(CAP_SYS_RAWIO))
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if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO))
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return -EPERM;
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device = vfio_device_get_from_name(group, buf);
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@ -1498,7 +1538,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
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fd_install(fdno, filep);
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if (group->noiommu)
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if (group->type == VFIO_NO_IOMMU)
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dev_warn(device->dev, "vfio-noiommu device opened by user "
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"(%s:%d)\n", current->comm, task_pid_nr(current));
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return fdno;
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@ -1594,7 +1634,7 @@ static int vfio_group_fops_open(struct inode *inode, struct file *filep)
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if (!group)
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return -ENODEV;
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if (group->noiommu && !capable(CAP_SYS_RAWIO)) {
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if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
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vfio_group_put(group);
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return -EPERM;
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}
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@ -75,6 +75,7 @@ void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
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const struct vfio_device_ops *ops);
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void vfio_uninit_group_dev(struct vfio_device *device);
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int vfio_register_group_dev(struct vfio_device *device);
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int vfio_register_emulated_iommu_dev(struct vfio_device *device);
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void vfio_unregister_group_dev(struct vfio_device *device);
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extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
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extern void vfio_device_put(struct vfio_device *device);
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@ -553,7 +553,7 @@ static int mbochs_probe(struct mdev_device *mdev)
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mbochs_create_config_space(mdev_state);
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mbochs_reset(mdev_state);
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ret = vfio_register_group_dev(&mdev_state->vdev);
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ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
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if (ret)
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goto err_mem;
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dev_set_drvdata(&mdev->dev, mdev_state);
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|
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@ -258,7 +258,7 @@ static int mdpy_probe(struct mdev_device *mdev)
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mdpy_count++;
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ret = vfio_register_group_dev(&mdev_state->vdev);
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ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
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if (ret)
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goto err_mem;
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dev_set_drvdata(&mdev->dev, mdev_state);
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@ -741,7 +741,7 @@ static int mtty_probe(struct mdev_device *mdev)
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mtty_create_config_space(mdev_state);
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ret = vfio_register_group_dev(&mdev_state->vdev);
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ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
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if (ret)
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goto err_vconfig;
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dev_set_drvdata(&mdev->dev, mdev_state);
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