[PATCH RFC 05/19] vfio-user: connect vfio proxy to remote server

[Elena Ufimtseva <elena.ufimtseva@oracle.com>]

From: John G Johnson <john.g.johnson@oracle.com>

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
---
 hw/vfio/user.h |  2 ++
 hw/vfio/pci.c  | 16 ++++++++++
 hw/vfio/user.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 105 insertions(+)

diff --git a/hw/vfio/user.h b/hw/vfio/user.h
index cdbc074579..12106ccb6a 100644
--- a/hw/vfio/user.h
+++ b/hw/vfio/user.h
@@ -117,4 +117,6 @@ typedef struct VFIOProxy {
 
 void vfio_user_recv(void *opaque);
 void vfio_user_send_reply(VFIOProxy *proxy, char *buf, int ret);
+VFIOProxy *vfio_user_connect_dev(char *sockname, Error **errp);
+void vfio_user_disconnect(VFIOProxy *proxy);
 #endif /* VFIO_USER_H */
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 554b562769..1effdcd5c0 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3332,16 +3332,32 @@ static void vfio_user_pci_realize(PCIDevice *pdev, Error **errp)
 {
     ERRP_GUARD();
     VFIOUserPCIDevice *udev = VFIO_USER_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIOProxy *proxy;
+    Error *err = NULL;
 
     if (!udev->sock_name) {
         error_setg(errp, "No socket specified");
         error_append_hint(errp, "Use -device vfio-user-pci,socket=<name>\n");
         return;
     }
+    proxy = vfio_user_connect_dev(udev->sock_name, &err);
+    if (!proxy) {
+        error_setg(errp, "Remote proxy not found");
+        return;
+    }
+    vbasedev->proxy = proxy;
 }
 
 static void vfio_user_instance_finalize(Object *obj)
 {
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(obj);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+
+    vfio_put_device(vdev);
+
+    vfio_user_disconnect(vbasedev->proxy);
 }
 
 static Property vfio_user_pci_dev_properties[] = {
diff --git a/hw/vfio/user.c b/hw/vfio/user.c
index 021d5540e0..371ee9cd8b 100644
--- a/hw/vfio/user.c
+++ b/hw/vfio/user.c
@@ -284,3 +284,90 @@ static void vfio_user_send(VFIOProxy *proxy, vfio_user_hdr_t *msg,
         qemu_mutex_lock_iothread();
     }
 }
+
+static QLIST_HEAD(, VFIOProxy) vfio_user_sockets =
+    QLIST_HEAD_INITIALIZER(vfio_user_sockets);
+
+VFIOProxy *vfio_user_connect_dev(char *sockname, Error **errp)
+{
+    VFIOProxy *proxy;
+    struct QIOChannel *ioc;
+    int sockfd;
+
+    sockfd = unix_connect(sockname, errp);
+    if (sockfd == -1) {
+        return NULL;
+    }
+
+    ioc = qio_channel_new_fd(sockfd, errp);
+    if (ioc == NULL) {
+        close(sockfd);
+        return NULL;
+    }
+    qio_channel_set_blocking(ioc, true, NULL);
+
+    proxy = g_malloc0(sizeof(VFIOProxy));
+    proxy->sockname = sockname;
+    proxy->ioc = ioc;
+    proxy->flags = VFIO_PROXY_CLIENT;
+    proxy->state = CONNECTED;
+    qemu_cond_init(&proxy->close_cv);
+
+    if (vfio_user_iothread == NULL) {
+        vfio_user_iothread = iothread_create("VFIO user", errp);
+    }
+
+    qemu_mutex_init(&proxy->lock);
+    QTAILQ_INIT(&proxy->free);
+    QTAILQ_INIT(&proxy->pending);
+    QLIST_INSERT_HEAD(&vfio_user_sockets, proxy, next);
+
+    return proxy;
+}
+
+void vfio_user_disconnect(VFIOProxy *proxy)
+{
+    VFIOUserReply *r1, *r2;
+
+    qemu_mutex_lock(&proxy->lock);
+
+    /* our side is quitting */
+    if (proxy->state == CONNECTED) {
+        vfio_user_shutdown(proxy);
+        if (!QTAILQ_EMPTY(&proxy->pending)) {
+            error_printf("vfio_user_disconnect: outstanding requests\n");
+        }
+    }
+    qio_channel_close(proxy->ioc, NULL);
+    proxy->state = CLOSING;
+
+    QTAILQ_FOREACH_SAFE(r1, &proxy->pending, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->pending, r1, next);
+        g_free(r1);
+    }
+    QTAILQ_FOREACH_SAFE(r1, &proxy->free, next, r2) {
+        qemu_cond_destroy(&r1->cv);
+        QTAILQ_REMOVE(&proxy->free, r1, next);
+        g_free(r1);
+    }
+
+    /* drop locks so the iothread can make progress */
+    qemu_mutex_unlock_iothread();
+    qemu_cond_wait(&proxy->close_cv, &proxy->lock);
+
+    /* we now hold the only ref to proxy */
+    qemu_mutex_unlock(&proxy->lock);
+    qemu_cond_destroy(&proxy->close_cv);
+    qemu_mutex_destroy(&proxy->lock);
+
+    qemu_mutex_lock_iothread();
+
+    QLIST_REMOVE(proxy, next);
+    if (QLIST_EMPTY(&vfio_user_sockets)) {
+        iothread_destroy(vfio_user_iothread);
+        vfio_user_iothread = NULL;
+    }
+
+    g_free(proxy);
+}
-- 
2.25.1