Let's add vhost_get_max_memslots(), to perform a similar task as
kvm_get_max_memslots().

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/virtio/vhost-stub.c    |  5 +++++
 hw/virtio/vhost.c         | 11 +++++++++++
 include/hw/virtio/vhost.h |  1 +
 3 files changed, 17 insertions(+)

diff --git a/hw/virtio/vhost-stub.c b/hw/virtio/vhost-stub.c
index c175148fce..2722af5580 100644
--- a/hw/virtio/vhost-stub.c
+++ b/hw/virtio/vhost-stub.c
@@ -2,6 +2,11 @@
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
 
+unsigned int vhost_get_max_memslots(void)
+{
+    return UINT_MAX;
+}
+
 bool vhost_has_free_slot(void)
 {
     return true;
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b2c1646ca4..4b912709e8 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -55,6 +55,17 @@ static unsigned int used_shared_memslots;
 static QLIST_HEAD(, vhost_dev) vhost_devices =
     QLIST_HEAD_INITIALIZER(vhost_devices);
 
+unsigned int vhost_get_max_memslots(void)
+{
+    unsigned int max = UINT_MAX;
+    struct vhost_dev *hdev;
+
+    QLIST_FOREACH(hdev, &vhost_devices, entry) {
+        max = MIN(max, hdev->vhost_ops->vhost_backend_memslots_limit(hdev));
+    }
+    return max;
+}
+
 bool vhost_has_free_slot(void)
 {
     unsigned int free = UINT_MAX;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index f7f10c8fb7..fb8fdf07f9 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -315,6 +315,7 @@ uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits,
  */
 void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
                         uint64_t features);
+unsigned int vhost_get_max_memslots(void);
 bool vhost_has_free_slot(void);
 
 int vhost_net_set_backend(struct vhost_dev *hdev,
-- 
2.40.1