vhost: Return number of free memslots

Let's return the number of free slots instead of only checking if there
is a free slot. Required to support memory devices that consume multiple
memslots.

This is a preparation for memory devices that consume multiple memslots.

Message-ID: <20230926185738.277351-6-david@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>

diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
index 98e355c96045ecb4e9ed57f47872c3e837a16c2e..e09960744d7b2c140ed46947b6cf6bf7d61f7211 100644 (file)
--- a/hw/mem/memory-device.c
+++ b/hw/mem/memory-device.c
@@ -63,7 +63,7 @@ static void memory_device_check_addable(MachineState *ms, MemoryRegion *mr,
         error_setg(errp, "hypervisor has no free memory slots left");
         return;
     }
-    if (!vhost_has_free_slot()) {
+    if (!vhost_get_free_memslots()) {
         error_setg(errp, "a used vhost backend has no free memory slots left");
         return;
     }

diff --git a/hw/virtio/vhost-stub.c b/hw/virtio/vhost-stub.c
index aa858ef3fbdbdfcac34d19cff9b9430d46b3da64..d53dd9d288a45f119998c50cb7b57ac819027354 100644 (file)
--- a/hw/virtio/vhost-stub.c
+++ b/hw/virtio/vhost-stub.c
@@ -2,9 +2,9 @@
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-user.h"
 
-bool vhost_has_free_slot(void)
+unsigned int vhost_get_free_memslots(void)
 {
-    return true;
+    return UINT_MAX;
 }
 
 bool vhost_user_init(VhostUserState *user, CharBackend *chr, Error **errp)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 530a65c1b4f3a039c0dab65420edbfc6a0a23375..82c3d20521ffa1dfb7969aa0d14e4d0d2a3d0e44 100644 (file)
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -54,7 +54,7 @@ static unsigned int used_shared_memslots;
 static QLIST_HEAD(, vhost_dev) vhost_devices =
     QLIST_HEAD_INITIALIZER(vhost_devices);
 
-bool vhost_has_free_slot(void)
+unsigned int vhost_get_free_memslots(void)
 {
     unsigned int free = UINT_MAX;
     struct vhost_dev *hdev;
@@ -71,7 +71,7 @@ bool vhost_has_free_slot(void)
         }
         free = MIN(free, cur_free);
     }
-    return free > 0;
+    return free;
 }
 
 static void vhost_dev_sync_region(struct vhost_dev *dev,

diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 6a173cb9fa3b9445b685e228d27e0a95a6a7e305..603bf834be0cdfd15aad4cadedbea0b8599a4bf1 100644 (file)
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -315,7 +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);
-bool vhost_has_free_slot(void);
+unsigned int vhost_get_free_memslots(void);
 
 int vhost_net_set_backend(struct vhost_dev *hdev,
                           struct vhost_vring_file *file);