[PATCH RFC 13/15] hw/virtio/vhost-user: add shadow virtqueues and eventfd intercepts

Adds shadow virtqueues that will eventually be used to transfer data
between device and host via bounce buffers when isolation mode is
active.  The svqs are initalized, and eventfd assignments are
intercepted so that notifications come to svqs first before
the guest or backend receive them.

Signed-off-by: Connor Kite <[email protected]>
---
 hw/virtio/vhost-user.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index acabfb7f1c..75858289a2 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -18,6 +18,7 @@
 #include "hw/virtio/vhost-backend.h"
 #include "hw/virtio/virtio.h"
 #include "hw/virtio/virtio-net.h"
+#include "hw/virtio/vhost-shadow-virtqueue.h"
 #include "hw/virtio/vhost-iova-tree.h"
 #include "chardev/char-fe.h"
 #include "io/channel-socket.h"
@@ -365,7 +366,9 @@ struct vhost_user {
 
     /* Isolated memory data*/
     struct IsolationRegion iso_memory;
+    GPtrArray *shadow_vqs;
     VhostIOVATree *iso_iova_tree;
+    bool svqs_allocated;
 };
 
 struct scrub_regions {
@@ -1693,6 +1696,24 @@ static int vhost_set_vring_file(struct vhost_dev *dev,
 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
                                      struct vhost_vring_file *file)
 {
+    struct vhost_user *u = dev->opaque;
+    int svq_idx = file->index - dev->vq_index;
+    if (u->user->memory_isolation) {
+        VhostShadowVirtqueue *svq = g_ptr_array_index(u->shadow_vqs,
+                                                      svq_idx);
+        vhost_svq_set_svq_kick_fd(svq, file->fd);
+
+        if (svq->hdev_kick.initialized == false) {
+            int r = event_notifier_init(&svq->hdev_kick, 0);
+            if (r) {
+                error_report("Failed to create kick event notifier");
+                return r;
+            }
+        }
+
+        file->fd = event_notifier_get_fd(&svq->hdev_kick);
+    }
+
     int ret = vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
     if (ret < 0) {
         return ret;
@@ -1721,6 +1742,24 @@ static int vhost_user_set_vring_kick(struct vhost_dev *dev,
 static int vhost_user_set_vring_call(struct vhost_dev *dev,
                                      struct vhost_vring_file *file)
 {
+    struct vhost_user *u = dev->opaque;
+    int svq_idx = file->index - dev->vq_index;
+    if (u->user->memory_isolation) {
+        VhostShadowVirtqueue *svq = g_ptr_array_index(u->shadow_vqs,
+                                                      svq_idx);
+        vhost_svq_set_svq_call_fd(svq, file->fd);
+
+        if (svq->hdev_call.initialized == false) {
+            int r = event_notifier_init(&svq->hdev_call, 0);
+            if (r) {
+                error_report("Failed to create call event notifier");
+                return r;
+            }
+        }
+
+        file->fd = event_notifier_get_fd(&svq->hdev_call);
+    }
+
     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
 }
 
@@ -2715,6 +2754,17 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
     return 0;
 }
 
+static void vhost_user_init_svq(struct vhost_dev *dev, struct vhost_user *u)
+{
+    /*Modified from vhost-vdpa*/
+    u->shadow_vqs = g_ptr_array_new_full(dev->nvqs, vhost_svq_free);
+    for (int i = 0; i < dev->nvqs; i++) {
+        VhostShadowVirtqueue *svq;
+        svq = vhost_svq_new(NULL, NULL);
+        g_ptr_array_add(u->shadow_vqs, svq);
+    }
+}
+
 static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
                                    Error **errp)
 {
@@ -2859,6 +2909,10 @@ static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque,
     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
     postcopy_add_notifier(&u->postcopy_notifier);
 
+    if (vus->memory_isolation) {
+        vhost_user_init_svq(dev, u);
+    }
+
     return 0;
 }
 

-- 
2.43.0