diff options
Diffstat (limited to 'hw/vfio/container-legacy.c')
| -rw-r--r-- | hw/vfio/container-legacy.c | 20 |
1 files changed, 1 insertions, 19 deletions
diff --git a/hw/vfio/container-legacy.c b/hw/vfio/container-legacy.c index c0f87f774a..25a15ea867 100644 --- a/hw/vfio/container-legacy.c +++ b/hw/vfio/container-legacy.c @@ -147,25 +147,7 @@ static int vfio_legacy_dma_unmap_one(const VFIOContainer *bcontainer, need_dirty_sync = true; } - while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) { - /* - * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c - * v4.15) where an overflow in its wrap-around check prevents us from - * unmapping the last page of the address space. Test for the error - * condition and re-try the unmap excluding the last page. The - * expectation is that we've never mapped the last page anyway and this - * unmap request comes via vIOMMU support which also makes it unlikely - * that this page is used. This bug was introduced well after type1 v2 - * support was introduced, so we shouldn't need to test for v1. A fix - * is queued for kernel v5.0 so this workaround can be removed once - * affected kernels are sufficiently deprecated. - */ - if (errno == EINVAL && unmap.size && !(unmap.iova + unmap.size) && - container->iommu_type == VFIO_TYPE1v2_IOMMU) { - trace_vfio_legacy_dma_unmap_overflow_workaround(); - unmap.size -= 1ULL << ctz64(bcontainer->pgsizes); - continue; - } + if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) { return -errno; } |