[Qemu-devel] [RFC v2 3/4] libvhost-user: support VFIO container message

[Tiwei Bie]

This patch introduces the VFIO container message support
in libvhost-user. A new API is added to support setting
the VFIO container for the vhost device.

Signed-off-by: Tiwei Bie <tiwei....@intel.com>
---
 contrib/libvhost-user/libvhost-user.c | 29 ++++++++++++++++++++++++++-
 contrib/libvhost-user/libvhost-user.h | 12 +++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/contrib/libvhost-user/libvhost-user.c 
b/contrib/libvhost-user/libvhost-user.c
index a6b46cdc03..b960449f9e 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -979,6 +979,32 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, 
int fd,
     return vu_process_message_reply(dev, &vmsg);
 }
 
+bool vu_set_vfio_container(VuDev *dev, int fd)
+{
+    int fd_num = 0;
+    VhostUserMsg vmsg = {
+        .request = VHOST_USER_SLAVE_VFIO_CONTAINER_MSG,
+        .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
+        .size = 0,
+    };
+
+    if (fd != -1) {
+        vmsg.fds[fd_num++] = fd;
+    }
+
+    vmsg.fd_num = fd_num;
+
+    if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) == 0) {
+        return false;
+    }
+
+    if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
+        return false;
+    }
+
+    return vu_process_message_reply(dev, &vmsg);
+}
+
 static bool
 vu_set_vring_call_exec(VuDev *dev, VhostUserMsg *vmsg)
 {
@@ -1033,7 +1059,8 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg 
*vmsg)
     uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
                         1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ |
                         1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |
-                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD;
+                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD |
+                        1ULL << VHOST_USER_PROTOCOL_F_VFIO_CONTAINER;
 
     if (have_userfault()) {
         features |= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
diff --git a/contrib/libvhost-user/libvhost-user.h 
b/contrib/libvhost-user/libvhost-user.h
index 4aa55b4d2d..5232bd85ab 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -53,6 +53,7 @@ enum VhostUserProtocolFeature {
     VHOST_USER_PROTOCOL_F_CONFIG = 9,
     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
+    VHOST_USER_PROTOCOL_F_VFIO_CONTAINER = 12,
 
     VHOST_USER_PROTOCOL_F_MAX
 };
@@ -99,6 +100,7 @@ typedef enum VhostUserSlaveRequest {
     VHOST_USER_SLAVE_IOTLB_MSG = 1,
     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
+    VHOST_USER_SLAVE_VFIO_CONTAINER_MSG = 4,
     VHOST_USER_SLAVE_MAX
 }  VhostUserSlaveRequest;
 
@@ -401,6 +403,16 @@ void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
 bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
                                 int size, int offset);
 
+/**
+ * vu_set_vfio_container:
+ * @dev: a VuDev context
+ * @fd: a VFIO container file descriptor
+ *
+ * Set device's VFIO container file descriptor. If called with
+ * -1 @fd, the container is destroyed.
+ */
+bool vu_set_vfio_container(VuDev *dev, int fd);
+
 /**
  * vu_queue_set_notification:
  * @dev: a VuDev context
-- 
2.18.0