| Message ID | 1584035607-23166-6-git-send-email-kwankhede@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KABIs to support migration for VFIO devices | expand |
On Thu, 12 Mar 2020 23:23:25 +0530 Kirti Wankhede <kwankhede@nvidia.com> wrote: > Pages, pinned by external interface for requested IO virtual address > range, might get unpinned and unmapped while migration is active and "DMA mapped pages, including those pinned by mdev vendor drivers, might get..." > device is still running, that is, in pre-copy phase while guest driver "...running. For example, in pre-copy..." > still could access those pages. Host device can write to these pages while > those were mapped. "...those pages, host device or vendor driver can dirty these mapped pages." > Such pages should be marked dirty so that after > migration guest driver should still be able to complete the operation. Complete what operation? We need to report these dirty pages in order to maintain memory consistency for a user making use of dirty page tracking. > To get bitmap during unmap, user should set flag > VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP, bitmap memory should be allocated and > zeroed by user space application. Bitmap size and page size should be set > by user application. It seems like zeroed pages are no longer strictly necessary now that we require requests to match existing mappings, right? > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> > Reviewed-by: Neo Jia <cjia@nvidia.com> > --- > drivers/vfio/vfio_iommu_type1.c | 63 +++++++++++++++++++++++++++++++++++++---- > include/uapi/linux/vfio.h | 12 ++++++++ > 2 files changed, 70 insertions(+), 5 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 435e84269a28..4037b82c6db0 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -976,7 +976,8 @@ static int verify_bitmap_size(unsigned long npages, unsigned long bitmap_size) > } > > static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > - struct vfio_iommu_type1_dma_unmap *unmap) > + struct vfio_iommu_type1_dma_unmap *unmap, > + unsigned long *bitmap) > { > uint64_t mask; > struct vfio_dma *dma, *dma_last = NULL; > @@ -1027,6 +1028,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > * will be returned if these conditions are not met. The v2 interface > * will only return success and a size of zero if there were no > * mappings within the range. > + * > + * When VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP flag is set, unmap request > + * must be for single mapping. Multiple mappings with this flag set is > + * not supported. > */ > if (iommu->v2) { > dma = vfio_find_dma(iommu, unmap->iova, 1); > @@ -1034,6 +1039,13 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > ret = -EINVAL; > goto unlock; > } > + > + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && > + (dma->iova != unmap->iova || dma->size != unmap->size)) { > + ret = -EINVAL; > + goto unlock; > + } > + > dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); > if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { > ret = -EINVAL; > @@ -1051,6 +1063,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > if (dma->task->mm != current->mm) > break; > > + if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) > + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, > + unmap->bitmap_pgsize, > + (unsigned char __user *) bitmap); > + > if (!RB_EMPTY_ROOT(&dma->pfn_list)) { > struct vfio_iommu_type1_dma_unmap nb_unmap; > > @@ -1076,6 +1093,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, > &nb_unmap); > goto again; > } > + > unmapped += dma->size; > vfio_remove_dma(iommu, dma); > } Spurious white space. > @@ -2406,22 +2424,57 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, > > } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { > struct vfio_iommu_type1_dma_unmap unmap; > - long ret; > + unsigned long *bitmap = NULL; Shouldn't this have a __user attribute? Also long doesn't seem the right type. void would be ok here. > + long ret, bsize; > > minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); > > if (copy_from_user(&unmap, (void __user *)arg, minsz)) > return -EFAULT; > > - if (unmap.argsz < minsz || unmap.flags) > + if (unmap.argsz < minsz || > + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) > return -EINVAL; > > - ret = vfio_dma_do_unmap(iommu, &unmap); > + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { > + unsigned long pgshift; > + uint64_t iommu_pgsizes = vfio_pgsize_bitmap(iommu); > + uint64_t iommu_pgmask = > + ((uint64_t)1 << __ffs(iommu_pgsizes)) - 1; > + Need to test that unmap.argsz includes this. > + if (copy_from_user(&unmap, (void __user *)arg, > + sizeof(unmap))) > + return -EFAULT; > + > + pgshift = __ffs(unmap.bitmap_pgsize); > + > + if (((unmap.bitmap_pgsize - 1) & iommu_pgmask) != > + (unmap.bitmap_pgsize - 1)) > + return -EINVAL; > + > + if ((unmap.bitmap_pgsize & iommu_pgsizes) != > + unmap.bitmap_pgsize) > + return -EINVAL; > + if (unmap.iova + unmap.size < unmap.iova) > + return -EINVAL; > + if (!access_ok((void __user *)unmap.bitmap, > + unmap.bitmap_size)) > + return -EINVAL; These tests should be identical to the previous patch. > + > + bsize = verify_bitmap_size(unmap.size >> pgshift, > + unmap.bitmap_size); > + if (bsize < 0) > + return bsize; > + bitmap = unmap.bitmap; > + } > + > + ret = vfio_dma_do_unmap(iommu, &unmap, bitmap); > if (ret) > return ret; > > - return copy_to_user((void __user *)arg, &unmap, minsz) ? > + ret = copy_to_user((void __user *)arg, &unmap, minsz) ? > -EFAULT : 0; > + return ret; Why? Leftover debugging? > } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { > struct vfio_iommu_type1_dirty_bitmap dirty; > uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 02d555cc7036..12b2094f887e 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -1004,12 +1004,24 @@ struct vfio_iommu_type1_dma_map { > * field. No guarantee is made to the user that arbitrary unmaps of iova > * or size different from those used in the original mapping call will > * succeed. > + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap > + * before unmapping IO virtual addresses. When this flag is set, user should > + * allocate memory to get bitmap, clear the bitmap memory by setting zero and > + * should set size of allocated memory in bitmap_size field. One bit in bitmap > + * represents per page , page of user provided page size in 'bitmap_pgsize', > + * consecutively starting from iova offset. Bit set indicates page at that > + * offset from iova is dirty. Bitmap of pages in the range of unmapped size is > + * returned in bitmap. > */ > struct vfio_iommu_type1_dma_unmap { > __u32 argsz; > __u32 flags; > +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) > __u64 iova; /* IO virtual address */ > __u64 size; /* Size of mapping (bytes) */ > + __u64 bitmap_pgsize; /* page size for bitmap */ > + __u64 bitmap_size; /* in bytes */ > + void __user *bitmap; /* one bit per page */ This suggests to me that we should further split struct vfio_iommu_type1_dirty_bitmap_get so that we can use the same sub-structure here. For example: struct vfio_bitmap { __u64 pgsize; __u64 size; __u64 __user *data; }; Note we still have a void* rather than __u64* in original above. Also, why wouldn't we take the same data[] approach as the previous patch, defining this as the data when the GET_DIRTY_BITMAP flag is set? Previous patch would be updated to something like: struct vfio_iommu_type1_dirty_bitmap_get { __u64 iova; __u64 size; struct vfio_bitmap bitmap; }; > }; > > #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)
On 3/14/2020 12:15 AM, Alex Williamson wrote: > On Thu, 12 Mar 2020 23:23:25 +0530 > Kirti Wankhede <kwankhede@nvidia.com> wrote: > >> Pages, pinned by external interface for requested IO virtual address >> range, might get unpinned and unmapped while migration is active and > > "DMA mapped pages, including those pinned by mdev vendor drivers, might > get..." > >> device is still running, that is, in pre-copy phase while guest driver > > "...running. For example, in pre-copy..." > >> still could access those pages. Host device can write to these pages while >> those were mapped. > > "...those pages, host device or vendor driver can dirty these mapped > pages." > >> Such pages should be marked dirty so that after >> migration guest driver should still be able to complete the operation. > > Complete what operation? For whatever operation guest driver was using that memory for. > We need to report these dirty pages in order > to maintain memory consistency for a user making use of dirty page > tracking. > >> To get bitmap during unmap, user should set flag >> VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP, bitmap memory should be allocated and >> zeroed by user space application. Bitmap size and page size should be set >> by user application. > > It seems like zeroed pages are no longer strictly necessary now that we > require requests to match existing mappings, right? > Right. >> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com> >> Reviewed-by: Neo Jia <cjia@nvidia.com> >> --- >> drivers/vfio/vfio_iommu_type1.c | 63 +++++++++++++++++++++++++++++++++++++---- >> include/uapi/linux/vfio.h | 12 ++++++++ >> 2 files changed, 70 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c >> index 435e84269a28..4037b82c6db0 100644 >> --- a/drivers/vfio/vfio_iommu_type1.c >> +++ b/drivers/vfio/vfio_iommu_type1.c >> @@ -976,7 +976,8 @@ static int verify_bitmap_size(unsigned long npages, unsigned long bitmap_size) >> } >> >> static int vfio_dma_do_unmap(struct vfio_iommu *iommu, >> - struct vfio_iommu_type1_dma_unmap *unmap) >> + struct vfio_iommu_type1_dma_unmap *unmap, >> + unsigned long *bitmap) >> { >> uint64_t mask; >> struct vfio_dma *dma, *dma_last = NULL; >> @@ -1027,6 +1028,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, >> * will be returned if these conditions are not met. The v2 interface >> * will only return success and a size of zero if there were no >> * mappings within the range. >> + * >> + * When VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP flag is set, unmap request >> + * must be for single mapping. Multiple mappings with this flag set is >> + * not supported. >> */ >> if (iommu->v2) { >> dma = vfio_find_dma(iommu, unmap->iova, 1); >> @@ -1034,6 +1039,13 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, >> ret = -EINVAL; >> goto unlock; >> } >> + >> + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && >> + (dma->iova != unmap->iova || dma->size != unmap->size)) { >> + ret = -EINVAL; >> + goto unlock; >> + } >> + >> dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); >> if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { >> ret = -EINVAL; >> @@ -1051,6 +1063,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, >> if (dma->task->mm != current->mm) >> break; >> >> + if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) >> + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, >> + unmap->bitmap_pgsize, >> + (unsigned char __user *) bitmap); >> + >> if (!RB_EMPTY_ROOT(&dma->pfn_list)) { >> struct vfio_iommu_type1_dma_unmap nb_unmap; >> >> @@ -1076,6 +1093,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, >> &nb_unmap); >> goto again; >> } >> + >> unmapped += dma->size; >> vfio_remove_dma(iommu, dma); >> } > > Spurious white space. > >> @@ -2406,22 +2424,57 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, >> >> } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { >> struct vfio_iommu_type1_dma_unmap unmap; >> - long ret; >> + unsigned long *bitmap = NULL; > > Shouldn't this have a __user attribute? Also long doesn't seem the > right type. void would be ok here. > Removed this with the use of vfio_bitmap structure. >> + long ret, bsize; >> >> minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); >> >> if (copy_from_user(&unmap, (void __user *)arg, minsz)) >> return -EFAULT; >> >> - if (unmap.argsz < minsz || unmap.flags) >> + if (unmap.argsz < minsz || >> + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) >> return -EINVAL; >> >> - ret = vfio_dma_do_unmap(iommu, &unmap); >> + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { >> + unsigned long pgshift; >> + uint64_t iommu_pgsizes = vfio_pgsize_bitmap(iommu); >> + uint64_t iommu_pgmask = >> + ((uint64_t)1 << __ffs(iommu_pgsizes)) - 1; >> + > > Need to test that unmap.argsz includes this. > Added. >> + if (copy_from_user(&unmap, (void __user *)arg, >> + sizeof(unmap))) >> + return -EFAULT; >> + >> + pgshift = __ffs(unmap.bitmap_pgsize); >> + >> + if (((unmap.bitmap_pgsize - 1) & iommu_pgmask) != >> + (unmap.bitmap_pgsize - 1)) >> + return -EINVAL; >> + >> + if ((unmap.bitmap_pgsize & iommu_pgsizes) != >> + unmap.bitmap_pgsize) >> + return -EINVAL; >> + if (unmap.iova + unmap.size < unmap.iova) >> + return -EINVAL; >> + if (!access_ok((void __user *)unmap.bitmap, >> + unmap.bitmap_size)) >> + return -EINVAL; > > These tests should be identical to the previous patch. > Updating tests here. Removing redundant tests which are already in vfio_dma_do_unmap() >> + >> + bsize = verify_bitmap_size(unmap.size >> pgshift, >> + unmap.bitmap_size); >> + if (bsize < 0) >> + return bsize; >> + bitmap = unmap.bitmap; >> + } >> + >> + ret = vfio_dma_do_unmap(iommu, &unmap, bitmap); >> if (ret) >> return ret; >> >> - return copy_to_user((void __user *)arg, &unmap, minsz) ? >> + ret = copy_to_user((void __user *)arg, &unmap, minsz) ? >> -EFAULT : 0; >> + return ret; > > Why? Leftover debugging? > Yeah, keeping the original one. >> } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { >> struct vfio_iommu_type1_dirty_bitmap dirty; >> uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | >> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h >> index 02d555cc7036..12b2094f887e 100644 >> --- a/include/uapi/linux/vfio.h >> +++ b/include/uapi/linux/vfio.h >> @@ -1004,12 +1004,24 @@ struct vfio_iommu_type1_dma_map { >> * field. No guarantee is made to the user that arbitrary unmaps of iova >> * or size different from those used in the original mapping call will >> * succeed. >> + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap >> + * before unmapping IO virtual addresses. When this flag is set, user should >> + * allocate memory to get bitmap, clear the bitmap memory by setting zero and >> + * should set size of allocated memory in bitmap_size field. One bit in bitmap >> + * represents per page , page of user provided page size in 'bitmap_pgsize', >> + * consecutively starting from iova offset. Bit set indicates page at that >> + * offset from iova is dirty. Bitmap of pages in the range of unmapped size is >> + * returned in bitmap. >> */ >> struct vfio_iommu_type1_dma_unmap { >> __u32 argsz; >> __u32 flags; >> +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) >> __u64 iova; /* IO virtual address */ >> __u64 size; /* Size of mapping (bytes) */ >> + __u64 bitmap_pgsize; /* page size for bitmap */ >> + __u64 bitmap_size; /* in bytes */ >> + void __user *bitmap; /* one bit per page */ > > This suggests to me that we should further split struct > vfio_iommu_type1_dirty_bitmap_get so that we can use the same > sub-structure here. For example: > > struct vfio_bitmap { > __u64 pgsize; > __u64 size; > __u64 __user *data; > }; > > Note we still have a void* rather than __u64* in original above. > > Also, why wouldn't we take the same data[] approach as the previous > patch, defining this as the data when the GET_DIRTY_BITMAP flag is set? > > Previous patch would be updated to something like: > > struct vfio_iommu_type1_dirty_bitmap_get { > __u64 iova; > __u64 size; > struct vfio_bitmap bitmap; > }; > >> }; >> >> #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14) > Ok. Updating. Thanks, Kirti
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 435e84269a28..4037b82c6db0 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -976,7 +976,8 @@ static int verify_bitmap_size(unsigned long npages, unsigned long bitmap_size) } static int vfio_dma_do_unmap(struct vfio_iommu *iommu, - struct vfio_iommu_type1_dma_unmap *unmap) + struct vfio_iommu_type1_dma_unmap *unmap, + unsigned long *bitmap) { uint64_t mask; struct vfio_dma *dma, *dma_last = NULL; @@ -1027,6 +1028,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, * will be returned if these conditions are not met. The v2 interface * will only return success and a size of zero if there were no * mappings within the range. + * + * When VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP flag is set, unmap request + * must be for single mapping. Multiple mappings with this flag set is + * not supported. */ if (iommu->v2) { dma = vfio_find_dma(iommu, unmap->iova, 1); @@ -1034,6 +1039,13 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, ret = -EINVAL; goto unlock; } + + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + (dma->iova != unmap->iova || dma->size != unmap->size)) { + ret = -EINVAL; + goto unlock; + } + dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { ret = -EINVAL; @@ -1051,6 +1063,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma->task->mm != current->mm) break; + if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) + vfio_iova_dirty_bitmap(iommu, dma->iova, dma->size, + unmap->bitmap_pgsize, + (unsigned char __user *) bitmap); + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -1076,6 +1093,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, &nb_unmap); goto again; } + unmapped += dma->size; vfio_remove_dma(iommu, dma); } @@ -2406,22 +2424,57 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { struct vfio_iommu_type1_dma_unmap unmap; - long ret; + unsigned long *bitmap = NULL; + long ret, bsize; minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); if (copy_from_user(&unmap, (void __user *)arg, minsz)) return -EFAULT; - if (unmap.argsz < minsz || unmap.flags) + if (unmap.argsz < minsz || + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) return -EINVAL; - ret = vfio_dma_do_unmap(iommu, &unmap); + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { + unsigned long pgshift; + uint64_t iommu_pgsizes = vfio_pgsize_bitmap(iommu); + uint64_t iommu_pgmask = + ((uint64_t)1 << __ffs(iommu_pgsizes)) - 1; + + if (copy_from_user(&unmap, (void __user *)arg, + sizeof(unmap))) + return -EFAULT; + + pgshift = __ffs(unmap.bitmap_pgsize); + + if (((unmap.bitmap_pgsize - 1) & iommu_pgmask) != + (unmap.bitmap_pgsize - 1)) + return -EINVAL; + + if ((unmap.bitmap_pgsize & iommu_pgsizes) != + unmap.bitmap_pgsize) + return -EINVAL; + if (unmap.iova + unmap.size < unmap.iova) + return -EINVAL; + if (!access_ok((void __user *)unmap.bitmap, + unmap.bitmap_size)) + return -EINVAL; + + bsize = verify_bitmap_size(unmap.size >> pgshift, + unmap.bitmap_size); + if (bsize < 0) + return bsize; + bitmap = unmap.bitmap; + } + + ret = vfio_dma_do_unmap(iommu, &unmap, bitmap); if (ret) return ret; - return copy_to_user((void __user *)arg, &unmap, minsz) ? + ret = copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; + return ret; } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { struct vfio_iommu_type1_dirty_bitmap dirty; uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 02d555cc7036..12b2094f887e 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1004,12 +1004,24 @@ struct vfio_iommu_type1_dma_map { * field. No guarantee is made to the user that arbitrary unmaps of iova * or size different from those used in the original mapping call will * succeed. + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap + * before unmapping IO virtual addresses. When this flag is set, user should + * allocate memory to get bitmap, clear the bitmap memory by setting zero and + * should set size of allocated memory in bitmap_size field. One bit in bitmap + * represents per page , page of user provided page size in 'bitmap_pgsize', + * consecutively starting from iova offset. Bit set indicates page at that + * offset from iova is dirty. Bitmap of pages in the range of unmapped size is + * returned in bitmap. */ struct vfio_iommu_type1_dma_unmap { __u32 argsz; __u32 flags; +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) __u64 iova; /* IO virtual address */ __u64 size; /* Size of mapping (bytes) */ + __u64 bitmap_pgsize; /* page size for bitmap */ + __u64 bitmap_size; /* in bytes */ + void __user *bitmap; /* one bit per page */ }; #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)