vfio-user: set up container access to the proxy

The user container will shortly need access to the underlying vfio-user
proxy; set this up.

Originally-by: John Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250625193012.2316242-12-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio-user/container.c

@@ -49,15 +49,28 @@ static int vfio_user_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
 
 static bool vfio_user_setup(VFIOContainerBase *bcontainer, Error **errp)
 {
-    error_setg_errno(errp, ENOTSUP, "Not supported");
-    return -ENOTSUP;
+    VFIOUserContainer *container = container_of(bcontainer, VFIOUserContainer,
+                                                bcontainer);
+
+    assert(container->proxy->dma_pgsizes != 0);
+    bcontainer->pgsizes = container->proxy->dma_pgsizes;
+    bcontainer->dma_max_mappings = container->proxy->max_dma;
+
+    /* No live migration support yet. */
+    bcontainer->dirty_pages_supported = false;
+    bcontainer->max_dirty_bitmap_size = container->proxy->max_bitmap;
+    bcontainer->dirty_pgsizes = container->proxy->migr_pgsize;
+
+    return true;
 }
 
-static VFIOUserContainer *vfio_user_create_container(Error **errp)
+static VFIOUserContainer *vfio_user_create_container(VFIODevice *vbasedev,
+                                                     Error **errp)
 {
     VFIOUserContainer *container;
 
     container = VFIO_IOMMU_USER(object_new(TYPE_VFIO_IOMMU_USER));
+    container->proxy = vbasedev->proxy;
     return container;
 }
 
@@ -65,16 +78,18 @@ static VFIOUserContainer *vfio_user_create_container(Error **errp)
  * Try to mirror vfio_container_connect() as much as possible.
  */
 static VFIOUserContainer *
-vfio_user_container_connect(AddressSpace *as, Error **errp)
+vfio_user_container_connect(AddressSpace *as, VFIODevice *vbasedev,
+                            Error **errp)
 {
     VFIOContainerBase *bcontainer;
     VFIOUserContainer *container;
     VFIOAddressSpace *space;
     VFIOIOMMUClass *vioc;
+    int ret;
 
     space = vfio_address_space_get(as);
 
-    container = vfio_user_create_container(errp);
+    container = vfio_user_create_container(vbasedev, errp);
     if (!container) {
         goto put_space_exit;
     }
@@ -85,11 +100,17 @@ vfio_user_container_connect(AddressSpace *as, Error **errp)
         goto free_container_exit;
     }
 
+    ret = ram_block_uncoordinated_discard_disable(true);
+    if (ret) {
+        error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
+        goto unregister_container_exit;
+    }
+
     vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
     assert(vioc->setup);
 
     if (!vioc->setup(bcontainer, errp)) {
-        goto unregister_container_exit;
+        goto enable_discards_exit;
     }
 
     vfio_address_space_insert(space, bcontainer);
@@ -108,6 +129,9 @@ listener_release_exit:
         vioc->release(bcontainer);
     }
 
+enable_discards_exit:
+    ram_block_uncoordinated_discard_disable(false);
+
 unregister_container_exit:
     vfio_cpr_unregister_container(bcontainer);
 
@@ -124,14 +148,15 @@ static void vfio_user_container_disconnect(VFIOUserContainer *container)
 {
     VFIOContainerBase *bcontainer = &container->bcontainer;
     VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
+    VFIOAddressSpace *space = bcontainer->space;
+
+    ram_block_uncoordinated_discard_disable(false);
 
     vfio_listener_unregister(bcontainer);
     if (vioc->release) {
         vioc->release(bcontainer);
     }
 
-    VFIOAddressSpace *space = bcontainer->space;
-
     vfio_cpr_unregister_container(bcontainer);
     object_unref(container);
 
@@ -163,7 +188,7 @@ static bool vfio_user_device_attach(const char *name, VFIODevice *vbasedev,
 {
     VFIOUserContainer *container;
 
-    container = vfio_user_container_connect(as, errp);
+    container = vfio_user_container_connect(as, vbasedev, errp);
     if (container == NULL) {
         error_prepend(errp, "failed to connect proxy");
         return false;

hw/vfio-user/container.h

@@ -10,10 +10,12 @@
 #include "qemu/osdep.h"
 
 #include "hw/vfio/vfio-container-base.h"
+#include "hw/vfio-user/proxy.h"
 
 /* MMU container sub-class for vfio-user. */
 typedef struct VFIOUserContainer {
     VFIOContainerBase bcontainer;
+    VFIOUserProxy *proxy;
 } VFIOUserContainer;
 
 OBJECT_DECLARE_SIMPLE_TYPE(VFIOUserContainer, VFIO_IOMMU_USER);