On Tue, Aug 15, 2023 at 9:45 AM Si-Wei Liu <si-wei.liu@xxxxxxxxxx> wrote:
>
> Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> ---
> drivers/vhost/vdpa.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index b43e868..62b0a01 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -131,6 +131,15 @@ static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(struct vhost_vdpa *v,
> return vhost_vdpa_alloc_as(v, asid);
> }
>
> +static void vhost_vdpa_reset_map(struct vhost_vdpa *v, u32 asid)
> +{
> + struct vdpa_device *vdpa = v->vdpa;
> + const struct vdpa_config_ops *ops = vdpa->config;
> +
> + if (ops->reset_map)
> + ops->reset_map(vdpa, asid);
> +}
> +
> static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
> {
> struct vhost_vdpa_as *as = asid_to_as(v, asid);
> @@ -140,6 +149,14 @@ static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
>
> hlist_del(&as->hash_link);
> vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1, asid);
> + /*
> + * Devices with on-chip IOMMU need to restore iotlb
> + * to 1:1 identity mapping before vhost-vdpa is going
> + * to be removed and detached from the device. Give
> + * them a chance to do so, as this cannot be done
> + * efficiently via the whole-range unmap call above.
> + */
Same question as before, if 1:1 is restored and the userspace doesn't
do any IOTLB updating. It looks like a security issue? (Assuming IOVA
is PA)
Thanks
> + vhost_vdpa_reset_map(v, asid);
> kfree(as);
>
> return 0;
> --
> 1.8.3.1
>
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