Si-Wei Liu
2023-Oct-10 09:02 UTC
[PATCH 2/4] vhost-vdpa: reset vendor specific mapping to initial state in .release
Devices with on-chip IOMMU or vendor specific IOTLB implementation
may need to restore iotlb mapping to the initial or default state
using the .reset_map op, as it's desirable for some parent devices
to solely manipulate mappings by its own, independent of virtio device
state. For instance, device reset does not cause mapping go away on
such IOTLB model in need of persistent mapping. Before vhost-vdpa
is going away, give them a chance to reset iotlb back to the initial
state in vhost_vdpa_cleanup().
Signed-off-by: Si-Wei Liu <si-wei.liu at oracle.com>
---
drivers/vhost/vdpa.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 851535f..a3f8160 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 +149,13 @@ 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 vendor specific IOMMU may need to restore
+ * iotlb to the initial or default state which is not done
+ * through device reset, as the IOTLB mapping manipulation
+ * could be decoupled from the virtio device life cycle.
+ */
+ vhost_vdpa_reset_map(v, asid);
kfree(as);
return 0;
--
1.8.3.1
Jason Wang
2023-Oct-13 03:01 UTC
[PATCH 2/4] vhost-vdpa: reset vendor specific mapping to initial state in .release
On Tue, Oct 10, 2023 at 5:05?PM Si-Wei Liu <si-wei.liu at oracle.com> wrote:> > Devices with on-chip IOMMU or vendor specific IOTLB implementation > may need to restore iotlb mapping to the initial or default state > using the .reset_map op, as it's desirable for some parent devices > to solely manipulate mappings by its own, independent of virtio device > state. For instance, device reset does not cause mapping go away on > such IOTLB model in need of persistent mapping. Before vhost-vdpa > is going away, give them a chance to reset iotlb back to the initial > state in vhost_vdpa_cleanup(). > > Signed-off-by: Si-Wei Liu <si-wei.liu at oracle.com> > --- > drivers/vhost/vdpa.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 851535f..a3f8160 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 +149,13 @@ 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 vendor specific IOMMU may need to restore > + * iotlb to the initial or default state which is not done > + * through device reset, as the IOTLB mapping manipulation > + * could be decoupled from the virtio device life cycle. > + */Should we do this according to whether IOTLB_PRESIST is set? Otherwise we may break old userspace. Thanks> + vhost_vdpa_reset_map(v, asid); > kfree(as); > > return 0; > -- > 1.8.3.1 >