From ce4b4657ff18925c315855aa290e93c5fa652d96 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 19 Jul 2022 21:02:48 -0300 Subject: vfio: Replace the DMA unmapping notifier with a callback Instead of having drivers register the notifier with explicit code just have them provide a dma_unmap callback op in their driver ops and rely on the core code to wire it up. Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Kevin Tian Reviewed-by: Tony Krowiak Reviewed-by: Eric Farman Reviewed-by: Zhenyu Wang Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com Signed-off-by: Alex Williamson --- drivers/vfio/vfio.c | 129 ++++++++++++++++++---------------------------------- drivers/vfio/vfio.h | 3 ++ 2 files changed, 47 insertions(+), 85 deletions(-) (limited to 'drivers/vfio') diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index bd84ca7c5e35..83c375fa2421 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -231,6 +231,9 @@ int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops) { struct vfio_iommu_driver *driver, *tmp; + if (WARN_ON(!ops->register_notifier != !ops->unregister_notifier)) + return -EINVAL; + driver = kzalloc(sizeof(*driver), GFP_KERNEL); if (!driver) return -ENOMEM; @@ -1079,8 +1082,20 @@ static void vfio_device_unassign_container(struct vfio_device *device) up_write(&device->group->group_rwsem); } +static int vfio_iommu_notifier(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct vfio_device *vfio_device = + container_of(nb, struct vfio_device, iommu_nb); + struct vfio_iommu_type1_dma_unmap *unmap = data; + + vfio_device->ops->dma_unmap(vfio_device, unmap->iova, unmap->size); + return NOTIFY_OK; +} + static struct file *vfio_device_open(struct vfio_device *device) { + struct vfio_iommu_driver *iommu_driver; struct file *filep; int ret; @@ -1111,6 +1126,18 @@ static struct file *vfio_device_open(struct vfio_device *device) if (ret) goto err_undo_count; } + + iommu_driver = device->group->container->iommu_driver; + if (device->ops->dma_unmap && iommu_driver && + iommu_driver->ops->register_notifier) { + unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; + + device->iommu_nb.notifier_call = vfio_iommu_notifier; + iommu_driver->ops->register_notifier( + device->group->container->iommu_data, &events, + &device->iommu_nb); + } + up_read(&device->group->group_rwsem); } mutex_unlock(&device->dev_set->lock); @@ -1145,8 +1172,16 @@ static struct file *vfio_device_open(struct vfio_device *device) err_close_device: mutex_lock(&device->dev_set->lock); down_read(&device->group->group_rwsem); - if (device->open_count == 1 && device->ops->close_device) + if (device->open_count == 1 && device->ops->close_device) { device->ops->close_device(device); + + iommu_driver = device->group->container->iommu_driver; + if (device->ops->dma_unmap && iommu_driver && + iommu_driver->ops->unregister_notifier) + iommu_driver->ops->unregister_notifier( + device->group->container->iommu_data, + &device->iommu_nb); + } err_undo_count: up_read(&device->group->group_rwsem); device->open_count--; @@ -1341,12 +1376,20 @@ static const struct file_operations vfio_group_fops = { static int vfio_device_fops_release(struct inode *inode, struct file *filep) { struct vfio_device *device = filep->private_data; + struct vfio_iommu_driver *iommu_driver; mutex_lock(&device->dev_set->lock); vfio_assert_device_open(device); down_read(&device->group->group_rwsem); if (device->open_count == 1 && device->ops->close_device) device->ops->close_device(device); + + iommu_driver = device->group->container->iommu_driver; + if (device->ops->dma_unmap && iommu_driver && + iommu_driver->ops->unregister_notifier) + iommu_driver->ops->unregister_notifier( + device->group->container->iommu_data, + &device->iommu_nb); up_read(&device->group->group_rwsem); device->open_count--; if (device->open_count == 0) @@ -2029,90 +2072,6 @@ int vfio_dma_rw(struct vfio_device *device, dma_addr_t user_iova, void *data, } EXPORT_SYMBOL(vfio_dma_rw); -static int vfio_register_iommu_notifier(struct vfio_group *group, - unsigned long *events, - struct notifier_block *nb) -{ - struct vfio_container *container; - struct vfio_iommu_driver *driver; - int ret; - - lockdep_assert_held_read(&group->group_rwsem); - - container = group->container; - driver = container->iommu_driver; - if (likely(driver && driver->ops->register_notifier)) - ret = driver->ops->register_notifier(container->iommu_data, - events, nb); - else - ret = -ENOTTY; - - return ret; -} - -static int vfio_unregister_iommu_notifier(struct vfio_group *group, - struct notifier_block *nb) -{ - struct vfio_container *container; - struct vfio_iommu_driver *driver; - int ret; - - lockdep_assert_held_read(&group->group_rwsem); - - container = group->container; - driver = container->iommu_driver; - if (likely(driver && driver->ops->unregister_notifier)) - ret = driver->ops->unregister_notifier(container->iommu_data, - nb); - else - ret = -ENOTTY; - - return ret; -} - -int vfio_register_notifier(struct vfio_device *device, - enum vfio_notify_type type, unsigned long *events, - struct notifier_block *nb) -{ - struct vfio_group *group = device->group; - int ret; - - if (!nb || !events || (*events == 0) || - !vfio_assert_device_open(device)) - return -EINVAL; - - switch (type) { - case VFIO_IOMMU_NOTIFY: - ret = vfio_register_iommu_notifier(group, events, nb); - break; - default: - ret = -EINVAL; - } - return ret; -} -EXPORT_SYMBOL(vfio_register_notifier); - -int vfio_unregister_notifier(struct vfio_device *device, - enum vfio_notify_type type, - struct notifier_block *nb) -{ - struct vfio_group *group = device->group; - int ret; - - if (!nb || !vfio_assert_device_open(device)) - return -EINVAL; - - switch (type) { - case VFIO_IOMMU_NOTIFY: - ret = vfio_unregister_iommu_notifier(group, nb); - break; - default: - ret = -EINVAL; - } - return ret; -} -EXPORT_SYMBOL(vfio_unregister_notifier); - /* * Module/class support */ diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index a67130221151..25da02ca1568 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -33,6 +33,9 @@ enum vfio_iommu_notify_type { VFIO_IOMMU_CONTAINER_CLOSE = 0, }; +/* events for register_notifier() */ +#define VFIO_IOMMU_NOTIFY_DMA_UNMAP BIT(0) + /** * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks */ -- cgit v1.2.3