From: Kirti Wankhede Date: Thu, 17 Nov 2016 04:58:26 +0000 (+0530) Subject: vfio iommu: Add blocking notifier to notify DMA_UNMAP X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c086de818dd81c3c2f7cecff23de6585b74340c0;p=linux-beck.git vfio iommu: Add blocking notifier to notify DMA_UNMAP Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers about DMA_UNMAP. Exported two APIs vfio_register_notifier() and vfio_unregister_notifier(). Notifier should be registered, if external user wants to use vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages. Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate mappings. Signed-off-by: Kirti Wankhede Signed-off-by: Neo Jia Signed-off-by: Alex Williamson --- diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index bd36c16b0ef2..301eed07a0ab 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1901,6 +1901,79 @@ err_unpin_pages: } EXPORT_SYMBOL(vfio_unpin_pages); +int vfio_register_notifier(struct device *dev, struct notifier_block *nb) +{ + struct vfio_container *container; + struct vfio_group *group; + struct vfio_iommu_driver *driver; + int ret; + + if (!dev || !nb) + return -EINVAL; + + group = vfio_group_get_from_dev(dev); + if (IS_ERR(group)) + return PTR_ERR(group); + + ret = vfio_group_add_container_user(group); + if (ret) + goto err_register_nb; + + 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, nb); + else + ret = -ENOTTY; + + up_read(&container->group_lock); + vfio_group_try_dissolve_container(group); + +err_register_nb: + vfio_group_put(group); + return ret; +} +EXPORT_SYMBOL(vfio_register_notifier); + +int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb) +{ + struct vfio_container *container; + struct vfio_group *group; + struct vfio_iommu_driver *driver; + int ret; + + if (!dev || !nb) + return -EINVAL; + + group = vfio_group_get_from_dev(dev); + if (IS_ERR(group)) + return PTR_ERR(group); + + ret = vfio_group_add_container_user(group); + if (ret) + goto err_unregister_nb; + + 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, + nb); + else + ret = -ENOTTY; + + up_read(&container->group_lock); + vfio_group_try_dissolve_container(group); + +err_unregister_nb: + vfio_group_put(group); + return ret; +} +EXPORT_SYMBOL(vfio_unregister_notifier); + /** * Module/class support */ diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index db0901f8a149..51810a95416e 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -38,6 +38,7 @@ #include #include #include +#include #define DRIVER_VERSION "0.2" #define DRIVER_AUTHOR "Alex Williamson " @@ -60,6 +61,7 @@ struct vfio_iommu { struct vfio_domain *external_domain; /* domain for external user */ struct mutex lock; struct rb_root dma_list; + struct blocking_notifier_head notifier; bool v2; bool nesting; }; @@ -561,7 +563,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, mutex_lock(&iommu->lock); - if (!iommu->external_domain) { + /* Fail if notifier list is empty */ + if ((!iommu->external_domain) || (!iommu->notifier.head)) { ret = -EINVAL; goto pin_done; } @@ -776,9 +779,9 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_unmap *unmap) { uint64_t mask; - struct vfio_dma *dma; + struct vfio_dma *dma, *dma_last = NULL; size_t unmapped = 0; - int ret = 0; + int ret = 0, retries = 0; mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; @@ -788,7 +791,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, return -EINVAL; WARN_ON(mask & PAGE_MASK); - +again: mutex_lock(&iommu->lock); /* @@ -844,6 +847,32 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, */ if (dma->task->mm != current->mm) break; + + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { + struct vfio_iommu_type1_dma_unmap nb_unmap; + + if (dma_last == dma) { + BUG_ON(++retries > 10); + } else { + dma_last = dma; + retries = 0; + } + + nb_unmap.iova = dma->iova; + nb_unmap.size = dma->size; + + /* + * Notify anyone (mdev vendor drivers) to invalidate and + * unmap iovas within the range we're about to unmap. + * Vendor drivers MUST unpin pages in response to an + * invalidation. + */ + mutex_unlock(&iommu->lock); + blocking_notifier_call_chain(&iommu->notifier, + VFIO_IOMMU_NOTIFY_DMA_UNMAP, + &nb_unmap); + goto again; + } unmapped += dma->size; vfio_remove_dma(iommu, dma); } @@ -1419,6 +1448,7 @@ static void *vfio_iommu_type1_open(unsigned long arg) INIT_LIST_HEAD(&iommu->domain_list); iommu->dma_list = RB_ROOT; mutex_init(&iommu->lock); + BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier); return iommu; } @@ -1553,16 +1583,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, return -ENOTTY; } +static int vfio_iommu_type1_register_notifier(void *iommu_data, + struct notifier_block *nb) +{ + struct vfio_iommu *iommu = iommu_data; + + return blocking_notifier_chain_register(&iommu->notifier, nb); +} + +static int vfio_iommu_type1_unregister_notifier(void *iommu_data, + struct notifier_block *nb) +{ + struct vfio_iommu *iommu = iommu_data; + + return blocking_notifier_chain_unregister(&iommu->notifier, nb); +} + static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { - .name = "vfio-iommu-type1", - .owner = THIS_MODULE, - .open = vfio_iommu_type1_open, - .release = vfio_iommu_type1_release, - .ioctl = vfio_iommu_type1_ioctl, - .attach_group = vfio_iommu_type1_attach_group, - .detach_group = vfio_iommu_type1_detach_group, - .pin_pages = vfio_iommu_type1_pin_pages, - .unpin_pages = vfio_iommu_type1_unpin_pages, + .name = "vfio-iommu-type1", + .owner = THIS_MODULE, + .open = vfio_iommu_type1_open, + .release = vfio_iommu_type1_release, + .ioctl = vfio_iommu_type1_ioctl, + .attach_group = vfio_iommu_type1_attach_group, + .detach_group = vfio_iommu_type1_detach_group, + .pin_pages = vfio_iommu_type1_pin_pages, + .unpin_pages = vfio_iommu_type1_unpin_pages, + .register_notifier = vfio_iommu_type1_register_notifier, + .unregister_notifier = vfio_iommu_type1_unregister_notifier, }; static int __init vfio_iommu_type1_init(void) diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 3c862a030029..6ab13f7e2920 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -80,6 +80,10 @@ struct vfio_iommu_driver_ops { unsigned long *phys_pfn); int (*unpin_pages)(void *iommu_data, unsigned long *user_pfn, int npage); + int (*register_notifier)(void *iommu_data, + struct notifier_block *nb); + int (*unregister_notifier)(void *iommu_data, + struct notifier_block *nb); }; extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); @@ -103,6 +107,14 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage); +#define VFIO_IOMMU_NOTIFY_DMA_UNMAP (1) + +extern int vfio_register_notifier(struct device *dev, + struct notifier_block *nb); + +extern int vfio_unregister_notifier(struct device *dev, + struct notifier_block *nb); + /* * Sub-module helpers */