vfio/iommufd: Support unmap all in one ioctl()

IOMMUFD kernel uAPI supports unmapping whole address space in one call with
[iova, size] set to [0, UINT64_MAX], this can simplify iommufd_cdev_unmap()
a bit. See iommufd_ioas_unmap() in kernel for details.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20251009040134.334251-3-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 24a99efa87f4df268d0df7198f26bba37976874b..fc9cd9d22ff2d6f126d3c0964d7033eee33ed9f2 100644 (file)
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -62,21 +62,8 @@ static int iommufd_cdev_unmap(const VFIOContainer *bcontainer,
 {
     const VFIOIOMMUFDContainer *container = VFIO_IOMMU_IOMMUFD(bcontainer);
 
-    /* unmap in halves */
     if (unmap_all) {
-        Int128 llsize = int128_rshift(int128_2_64(), 1);
-        int ret;
-
-        ret = iommufd_backend_unmap_dma(container->be, container->ioas_id,
-                                        0, int128_get64(llsize));
-
-        if (ret == 0) {
-            ret = iommufd_backend_unmap_dma(container->be, container->ioas_id,
-                                            int128_get64(llsize),
-                                            int128_get64(llsize));
-        }
-
-        return ret;
+        size = UINT64_MAX;
     }
 
     /* TODO: Handle dma_unmap_bitmap with iotlb args (migration) */