From c086de818dd81c3c2f7cecff23de6585b74340c0 Mon Sep 17 00:00:00 2001 From: Kirti Wankhede Date: Thu, 17 Nov 2016 10:28:26 +0530 Subject: 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 --- drivers/vfio/vfio_iommu_type1.c | 74 +++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 13 deletions(-) (limited to 'drivers/vfio/vfio_iommu_type1.c') 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) -- cgit