From c10c21efa4bccab486c2e6a047c13dfa6cf7426c Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Wed, 19 Dec 2018 19:52:15 +1100 Subject: powerpc/vfio/iommu/kvm: Do not pin device memory This new memory does not have page structs as it is not plugged to the host so gup() will fail anyway. This adds 2 helpers: - mm_iommu_newdev() to preregister the "memory device" memory so the rest of API can still be used; - mm_iommu_is_devmem() to know if the physical address is one of thise new regions which we must avoid unpinning of. This adds @mm to tce_page_is_contained() and iommu_tce_xchg() to test if the memory is device memory to avoid pfn_to_page(). This adds a check for device memory in mm_iommu_ua_mark_dirty_rm() which does delayed pages dirtying. Signed-off-by: Alexey Kardashevskiy Reviewed-by: Paul Mackerras Signed-off-by: Michael Ellerman --- drivers/vfio/vfio_iommu_spapr_tce.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) (limited to 'drivers/vfio/vfio_iommu_spapr_tce.c') diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 1d8b88928329..c424913324e3 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -222,8 +222,16 @@ put_exit: return ret; } -static bool tce_page_is_contained(struct page *page, unsigned page_shift) +static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa, + unsigned int page_shift) { + struct page *page; + unsigned long size = 0; + + if (mm_iommu_is_devmem(mm, hpa, page_shift, &size)) + return size == (1UL << page_shift); + + page = pfn_to_page(hpa >> PAGE_SHIFT); /* * Check that the TCE table granularity is not bigger than the size of * a page we just found. Otherwise the hardware can get access to @@ -499,7 +507,8 @@ static int tce_iommu_clear(struct tce_container *container, direction = DMA_NONE; oldhpa = 0; - ret = iommu_tce_xchg(tbl, entry, &oldhpa, &direction); + ret = iommu_tce_xchg(container->mm, tbl, entry, &oldhpa, + &direction); if (ret) continue; @@ -537,7 +546,6 @@ static long tce_iommu_build(struct tce_container *container, enum dma_data_direction direction) { long i, ret = 0; - struct page *page; unsigned long hpa; enum dma_data_direction dirtmp; @@ -548,15 +556,16 @@ static long tce_iommu_build(struct tce_container *container, if (ret) break; - page = pfn_to_page(hpa >> PAGE_SHIFT); - if (!tce_page_is_contained(page, tbl->it_page_shift)) { + if (!tce_page_is_contained(container->mm, hpa, + tbl->it_page_shift)) { ret = -EPERM; break; } hpa |= offset; dirtmp = direction; - ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); + ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa, + &dirtmp); if (ret) { tce_iommu_unuse_page(container, hpa); pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n", @@ -583,7 +592,6 @@ static long tce_iommu_build_v2(struct tce_container *container, enum dma_data_direction direction) { long i, ret = 0; - struct page *page; unsigned long hpa; enum dma_data_direction dirtmp; @@ -596,8 +604,8 @@ static long tce_iommu_build_v2(struct tce_container *container, if (ret) break; - page = pfn_to_page(hpa >> PAGE_SHIFT); - if (!tce_page_is_contained(page, tbl->it_page_shift)) { + if (!tce_page_is_contained(container->mm, hpa, + tbl->it_page_shift)) { ret = -EPERM; break; } @@ -610,7 +618,8 @@ static long tce_iommu_build_v2(struct tce_container *container, if (mm_iommu_mapped_inc(mem)) break; - ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp); + ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa, + &dirtmp); if (ret) { /* dirtmp cannot be DMA_NONE here */ tce_iommu_unuse_page_v2(container, tbl, entry + i); -- cgit