Add multiple-device support virtio-loopback-adapter

Updates [v1]:
- The adapter supports multiple vhost-user devices running in
  parallel.
- Redesign the devices interfaces. Unified their common functionality
  and add it into vhost-user-loopback lib. This eases the addition of
  new vhost-user devices and makes the virtio-loopback adapter more
  device agnostic.

Bug-AGL: SPEC-4834
Change-Id: I9aff91dce0207ccdd8c2d1c5d0769a13b4e9ae04
Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/include/virtio_rng.h b/include/virtio_rng.h
new file mode 100644
index 0000000..6e97294
--- /dev/null
+++ b/include/virtio_rng.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2022-2023 Virtual Open Systems SAS.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef VIRTIO_RNG_DEV
+#define VIRTIO_RNG_DEV
+
+#include "virtio_loopback.h"
+#include "vhost_user_loopback.h"
+
+extern const char test_str[64];
+
+typedef struct VirtIORNGConf {
+    uint64_t max_bytes;
+    uint32_t period_ms;
+} VirtIORNGConf;
+
+typedef struct VirtIORNG {
+    VirtIODevice *parent_obj;
+
+    /* Only one vq - guest puts buffer(s) on it when it needs entropy */
+    VirtQueue *vq;
+    VirtIORNGConf conf;
+
+    /*
+     * We purposefully don't migrate this state.  The quota will reset on the
+     * destination as a result.  Rate limiting is host state, not guest state.
+     */
+    int64_t quota_remaining;
+    bool activate_timer;
+
+} VirtIORNG;
+
+bool is_guest_ready(VirtIORNG *vrng);
+size_t get_request_size(VirtQueue *vq, unsigned quota);
+void virtio_rng_set_status(VirtIODevice *vdev, uint8_t status);
+void virtio_rng_process(VirtIORNG *vrng);
+void chr_read(VirtIORNG *vrng, const char *buf, size_t size);
+void virtio_rng_realize(struct adapter_dev *adev);
+void virtio_rng_init(VirtIODevice *vdev);
+
+#endif /* VIRTIO_RNG */