[PATCH v4 21/22] tests/qtest: add a get_features op to vhost-user-test

["Alex Bennée" <alex.bennee@linaro.org>]

As we expand this test for more virtio devices we will need to support
different feature sets. Add a mandatory op field to fetch the list of
features needed for the test itself.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tests/qtest/vhost-user-test.c | 37 +++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/tests/qtest/vhost-user-test.c b/tests/qtest/vhost-user-test.c
index 61980bfc6a..fe46e28cf2 100644
--- a/tests/qtest/vhost-user-test.c
+++ b/tests/qtest/vhost-user-test.c
@@ -171,10 +171,11 @@ struct vhost_user_ops {
             const char *chr_opts);
 
     /* VHOST-USER commands. */
+    uint64_t (*get_features)(TestServer *s);
     void (*set_features)(TestServer *s, CharBackend *chr,
-            VhostUserMsg *msg);
+                         VhostUserMsg *msg);
     void (*get_protocol_features)(TestServer *s,
-            CharBackend *chr, VhostUserMsg *msg);
+                                  CharBackend *chr, VhostUserMsg *msg);
 };
 
 static const char *init_hugepagefs(void);
@@ -338,20 +339,22 @@ static void chr_read(void *opaque, const uint8_t *buf, int size)
 
     switch (msg.request) {
     case VHOST_USER_GET_FEATURES:
+        /* Mandatory for tests to define get_features */
+        g_assert(s->vu_ops->get_features);
+
         /* send back features to qemu */
         msg.flags |= VHOST_USER_REPLY_MASK;
         msg.size = sizeof(m.payload.u64);
-        msg.payload.u64 = 0x1ULL << VHOST_F_LOG_ALL |
-            0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
-        if (s->queues > 1) {
-            msg.payload.u64 |= 0x1ULL << VIRTIO_NET_F_MQ;
-        }
+
         if (s->test_flags >= TEST_FLAGS_BAD) {
             msg.payload.u64 = 0;
             s->test_flags = TEST_FLAGS_END;
+        } else {
+            msg.payload.u64 = s->vu_ops->get_features(s);
         }
-        p = (uint8_t *) &msg;
-        qemu_chr_fe_write_all(chr, p, VHOST_USER_HDR_SIZE + msg.size);
+
+        qemu_chr_fe_write_all(chr, (uint8_t *) &msg,
+                              VHOST_USER_HDR_SIZE + msg.size);
         break;
 
     case VHOST_USER_SET_FEATURES:
@@ -993,8 +996,21 @@ static void test_multiqueue(void *obj, void *arg, QGuestAllocator *alloc)
     wait_for_rings_started(s, s->queues * 2);
 }
 
+
+static uint64_t vu_net_get_features(TestServer *s)
+{
+    uint64_t features = 0x1ULL << VHOST_F_LOG_ALL |
+        0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
+
+    if (s->queues > 1) {
+        features |= 0x1ULL << VIRTIO_NET_F_MQ;
+    }
+
+    return features;
+}
+
 static void vu_net_set_features(TestServer *s, CharBackend *chr,
-        VhostUserMsg *msg)
+                                VhostUserMsg *msg)
 {
     g_assert(msg->payload.u64 & (0x1ULL << VHOST_USER_F_PROTOCOL_FEATURES));
     if (s->test_flags == TEST_FLAGS_DISCONNECT) {
@@ -1023,6 +1039,7 @@ static struct vhost_user_ops g_vu_net_ops = {
 
     .append_opts = append_vhost_net_opts,
 
+    .get_features = vu_net_get_features,
     .set_features = vu_net_set_features,
     .get_protocol_features = vu_net_get_protocol_features,
 };
-- 
2.30.2