From 40ae9b807b89e60f86a40f33b931e6cde7eed2b7 Mon Sep 17 00:00:00 2001 From: Steve Sistare Date: Fri, 29 Jan 2021 08:54:08 -0800 Subject: [PATCH] vfio/type1: massage unmap iteration Modify the iteration in vfio_dma_do_unmap so it does not depend on deletion of each dma entry. Add a variant of vfio_find_dma that returns the entry with the lowest iova in the search range to initialize the iteration. No externally visible change, but this behavior is needed in the subsequent update-vaddr patch. Signed-off-by: Steve Sistare Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 35 ++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 5b388e5d2972..ce97eda756fc 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -173,6 +173,31 @@ static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu, return NULL; } +static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu, + dma_addr_t start, size_t size) +{ + struct rb_node *res = NULL; + struct rb_node *node = iommu->dma_list.rb_node; + struct vfio_dma *dma_res = NULL; + + while (node) { + struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node); + + if (start < dma->iova + dma->size) { + res = node; + dma_res = dma; + if (start >= dma->iova) + break; + node = node->rb_left; + } else { + node = node->rb_right; + } + } + if (res && size && dma_res->iova >= start + size) + res = NULL; + return res; +} + static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new) { struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL; @@ -1079,6 +1104,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, dma_addr_t iova = unmap->iova; unsigned long size = unmap->size; bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL; + struct rb_node *n; mutex_lock(&iommu->lock); @@ -1149,7 +1175,13 @@ again: } ret = 0; - while ((dma = vfio_find_dma(iommu, iova, size))) { + n = vfio_find_dma_first_node(iommu, iova, size); + + while (n) { + dma = rb_entry(n, struct vfio_dma, node); + if (dma->iova >= iova + size) + break; + if (!iommu->v2 && iova > dma->iova) break; /* @@ -1194,6 +1226,7 @@ again: } unmapped += dma->size; + n = rb_next(n); vfio_remove_dma(iommu, dma); }