[PATCH 6/7] libvhost-user: rename message names from "SLAVE" to "BACKEND"

[Paolo Bonzini <pbonzini@redhat.com>]

Follow the terminology that is used in the specification.  The old names
are preserved for API compatibility.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 subprojects/libvhost-user/libvhost-user.c | 20 ++++++------
 subprojects/libvhost-user/libvhost-user.h | 39 ++++++++++++++++-------
 2 files changed, 37 insertions(+), 22 deletions(-)

diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c
index fab7ca17ee..b7aef17e4e 100644
--- a/subprojects/libvhost-user/libvhost-user.c
+++ b/subprojects/libvhost-user/libvhost-user.c
@@ -125,7 +125,7 @@ vu_request_to_string(unsigned int req)
         REQ(VHOST_USER_SET_VRING_ENABLE),
         REQ(VHOST_USER_SEND_RARP),
         REQ(VHOST_USER_NET_SET_MTU),
-        REQ(VHOST_USER_SET_SLAVE_REQ_FD),
+        REQ(VHOST_USER_SET_BACKEND_REQ_FD),
         REQ(VHOST_USER_IOTLB_MSG),
         REQ(VHOST_USER_SET_VRING_ENDIAN),
         REQ(VHOST_USER_GET_CONFIG),
@@ -1313,7 +1313,7 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
     int qidx = vq - dev->vq;
     int fd_num = 0;
     VhostUserMsg vmsg = {
-        .request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
+        .request = VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG,
         .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
         .size = sizeof(vmsg.payload.area),
         .payload.area = {
@@ -1331,7 +1331,7 @@ bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
 
     vmsg.fd_num = fd_num;
 
-    if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) {
+    if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD)) {
         return false;
     }
 
@@ -1409,9 +1409,9 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
      */
     uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_MQ |
                         1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD |
-                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ |
+                        1ULL << VHOST_USER_PROTOCOL_F_BACKEND_REQ |
                         1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER |
-                        1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD |
+                        1ULL << VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD |
                         1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |
                         1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS;
 
@@ -1442,7 +1442,7 @@ vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
 
     if (vu_has_protocol_feature(dev,
                                 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
-        (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ) ||
+        (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ) ||
          !vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
         /*
          * The use case for using messages for kick/call is simulation, to make
@@ -1455,7 +1455,7 @@ vu_set_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg)
          * that actually enables the simulation case.
          */
         vu_panic(dev,
-                 "F_IN_BAND_NOTIFICATIONS requires F_SLAVE_REQ && F_REPLY_ACK");
+                 "F_IN_BAND_NOTIFICATIONS requires F_BACKEND_REQ && F_REPLY_ACK");
         return false;
     }
 
@@ -1864,7 +1864,7 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
         return vu_get_queue_num_exec(dev, vmsg);
     case VHOST_USER_SET_VRING_ENABLE:
         return vu_set_vring_enable_exec(dev, vmsg);
-    case VHOST_USER_SET_SLAVE_REQ_FD:
+    case VHOST_USER_SET_BACKEND_REQ_FD:
         return vu_set_slave_req_fd(dev, vmsg);
     case VHOST_USER_GET_CONFIG:
         return vu_get_config(dev, vmsg);
@@ -2370,9 +2370,9 @@ static void _vu_queue_notify(VuDev *dev, VuVirtq *vq, bool sync)
     if (vq->call_fd < 0 &&
         vu_has_protocol_feature(dev,
                                 VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
-        vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
+        vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_BACKEND_REQ)) {
         VhostUserMsg vmsg = {
-            .request = VHOST_USER_SLAVE_VRING_CALL,
+            .request = VHOST_USER_BACKEND_VRING_CALL,
             .flags = VHOST_USER_VERSION,
             .size = sizeof(vmsg.payload.state),
             .payload.state = {
diff --git a/subprojects/libvhost-user/libvhost-user.h b/subprojects/libvhost-user/libvhost-user.h
index 3d13dfadde..eba3e1fc05 100644
--- a/subprojects/libvhost-user/libvhost-user.h
+++ b/subprojects/libvhost-user/libvhost-user.h
@@ -54,18 +54,20 @@ enum VhostUserProtocolFeature {
     VHOST_USER_PROTOCOL_F_RARP = 2,
     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
-    VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
+    VHOST_USER_PROTOCOL_F_BACKEND_REQ = 5,
     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
     VHOST_USER_PROTOCOL_F_CONFIG = 9,
-    VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
+    VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD = 10,
     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
     VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
     VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS = 14,
     VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15,
+    VHOST_USER_PROTOCOL_F_MAX,
 
-    VHOST_USER_PROTOCOL_F_MAX
+    VHOST_USER_PROTOCOL_F_SLAVE_REQ = VHOST_USER_PROTOCOL_F_BACKEND_REQ,
+    VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD
 };
 
 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
@@ -92,7 +94,7 @@ typedef enum VhostUserRequest {
     VHOST_USER_SET_VRING_ENABLE = 18,
     VHOST_USER_SEND_RARP = 19,
     VHOST_USER_NET_SET_MTU = 20,
-    VHOST_USER_SET_SLAVE_REQ_FD = 21,
+    VHOST_USER_SET_BACKEND_REQ_FD = 21,
     VHOST_USER_IOTLB_MSG = 22,
     VHOST_USER_SET_VRING_ENDIAN = 23,
     VHOST_USER_GET_CONFIG = 24,
@@ -109,16 +111,29 @@ typedef enum VhostUserRequest {
     VHOST_USER_GET_MAX_MEM_SLOTS = 36,
     VHOST_USER_ADD_MEM_REG = 37,
     VHOST_USER_REM_MEM_REG = 38,
-    VHOST_USER_MAX
+    VHOST_USER_MAX,
+
+    VHOST_USER_SET_SLAVE_REQ_FD = VHOST_USER_SET_BACKEND_REQ_FD,
 } VhostUserRequest;
 
+typedef enum VhostUserBackendRequest {
+    VHOST_USER_BACKEND_NONE = 0,
+    VHOST_USER_BACKEND_IOTLB_MSG = 1,
+    VHOST_USER_BACKEND_CONFIG_CHANGE_MSG = 2,
+    VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG = 3,
+    VHOST_USER_BACKEND_VRING_CALL = 4,
+    VHOST_USER_BACKEND_VRING_ERR = 5,
+    VHOST_USER_BACKEND_MAX
+}  VhostUserBackendRequest;
+
+
 typedef enum VhostUserSlaveRequest {
-    VHOST_USER_SLAVE_NONE = 0,
-    VHOST_USER_SLAVE_IOTLB_MSG = 1,
-    VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
-    VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
-    VHOST_USER_SLAVE_VRING_CALL = 4,
-    VHOST_USER_SLAVE_VRING_ERR = 5,
+    VHOST_USER_SLAVE_NONE = VHOST_USER_BACKEND_NONE,
+    VHOST_USER_SLAVE_IOTLB_MSG = VHOST_USER_BACKEND_IOTLB_MSG,
+    VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = VHOST_USER_BACKEND_CONFIG_CHANGE_MSG,
+    VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = VHOST_USER_BACKEND_VRING_HOST_NOTIFIER_MSG,
+    VHOST_USER_SLAVE_VRING_CALL = VHOST_USER_BACKEND_VRING_CALL,
+    VHOST_USER_SLAVE_VRING_ERR = VHOST_USER_BACKEND_VRING_ERR,
     VHOST_USER_SLAVE_MAX
 }  VhostUserSlaveRequest;
 
@@ -295,7 +310,7 @@ typedef struct VuVirtqInflight {
     uint16_t version;
 
     /* The size of VuDescStateSplit array. It's equal to the virtqueue
-     * size. Slave could get it from queue size field of VhostUserInflight. */
+     * size. The backend could get it from queue size field of VhostUserInflight. */
     uint16_t desc_num;
 
     /* The head of list that track the last batch of used descriptors. */
-- 
2.26.2