libvhost-user: Dynamically allocate memory for memory slots

Let's prepare for increasing VHOST_USER_MAX_RAM_SLOTS by dynamically
allocating dev->regions. We don't have any ABI guarantees (not
dynamically linked), so we can simply change the layout of VuDev.

Let's zero out the memory, just as we used to do.

Reviewed-by: Raphael Norwitz <raphael@enfabrica.net>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20240214151701.29906-2-david@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
index a3b158c671..360c5366d6 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -2171,6 +2171,8 @@ vu_deinit(VuDev *dev)
 
     free(dev->vq);
     dev->vq = NULL;
+    free(dev->regions);
+    dev->regions = NULL;
 }
 
 bool
@@ -2205,9 +2207,18 @@ vu_init(VuDev *dev,
     dev->backend_fd = -1;
     dev->max_queues = max_queues;
 
+    dev->regions = malloc(VHOST_USER_MAX_RAM_SLOTS * sizeof(dev->regions[0]));
+    if (!dev->regions) {
+        DPRINT("%s: failed to malloc mem regions\n", __func__);
+        return false;
+    }
+    memset(dev->regions, 0, VHOST_USER_MAX_RAM_SLOTS * sizeof(dev->regions[0]));
+
     dev->vq = malloc(max_queues * sizeof(dev->vq[0]));
     if (!dev->vq) {
         DPRINT("%s: failed to malloc virtqueues\n", __func__);
+        free(dev->regions);
+        dev->regions = NULL;
         return false;
     }