virtio-net: Avoid QemuOpts in failover_find_primary_device()

Don't go through the global QemuOptsList, it is state of the legacy
command line parser and we will create devices that are not contained
in it. It is also just the command line configuration and not
necessarily the current runtime state.

Instead, look at the qdev device tree which has the current state of all
existing devices.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211008133442.141332-14-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 19 insertions, 33 deletions

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index ed9a901..f503f28 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -796,23 +796,28 @@ static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
 
 typedef struct {
     VirtIONet *n;
-    char *id;
-} FailoverId;
+    DeviceState *dev;
+} FailoverDevice;
 
 /**
- * Set the id of the failover primary device
+ * Set the failover primary device
  *
  * @opaque: FailoverId to setup
  * @opts: opts for device we are handling
  * @errp: returns an error if this function fails
  */
-static int failover_set_primary(void *opaque, QemuOpts *opts, Error **errp)
+static int failover_set_primary(DeviceState *dev, void *opaque)
 {
-    FailoverId *fid = opaque;
-    const char *standby_id = qemu_opt_get(opts, "failover_pair_id");
+    FailoverDevice *fdev = opaque;
+    PCIDevice *pci_dev = (PCIDevice *)
+        object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE);
 
-    if (g_strcmp0(standby_id, fid->n->netclient_name) == 0) {
-        fid->id = g_strdup(opts->id);
+    if (!pci_dev) {
+        return 0;
+    }
+
+    if (!g_strcmp0(pci_dev->failover_pair_id, fdev->n->netclient_name)) {
+        fdev->dev = dev;
         return 1;
     }
 
@@ -820,25 +825,6 @@ static int failover_set_primary(void *opaque, QemuOpts *opts, Error **errp)
 }
 
 /**
- * Find the primary device id for this failover virtio-net
- *
- * @n: VirtIONet device
- * @errp: returns an error if this function fails
- */
-static char *failover_find_primary_device_id(VirtIONet *n)
-{
-    Error *err = NULL;
-    FailoverId fid;
-
-    fid.n = n;
-    if (!qemu_opts_foreach(qemu_find_opts("device"),
-                           failover_set_primary, &fid, &err)) {
-        return NULL;
-    }
-    return fid.id;
-}
-
-/**
  * Find the primary device for this failover virtio-net
  *
  * @n: VirtIONet device
@@ -846,13 +832,13 @@ static char *failover_find_primary_device_id(VirtIONet *n)
  */
 static DeviceState *failover_find_primary_device(VirtIONet *n)
 {
-    char *id = failover_find_primary_device_id(n);
-
-    if (!id) {
-        return NULL;
-    }
+    FailoverDevice fdev = {
+        .n = n,
+    };
 
-    return qdev_find_recursive(sysbus_get_default(), id);
+    qbus_walk_children(sysbus_get_default(), failover_set_primary, NULL,
+                       NULL, NULL, &fdev);
+    return fdev.dev;
 }
 
 static void failover_add_primary(VirtIONet *n, Error **errp)