@@ -6,9 +6,11 @@
/* Message flags */
#define VHOST_USER_FLAG_REPLY BIT(2)
+#define VHOST_USER_FLAG_NEED_REPLY BIT(3)
/* Feature bits */
#define VHOST_USER_F_PROTOCOL_FEATURES 30
/* Protocol feature bits */
+#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
#define VHOST_USER_PROTOCOL_F_CONFIG 9
/* Vring state index masks */
@@ -20,7 +22,8 @@
/* Supported transport features */
#define VHOST_USER_SUPPORTED_F BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)
/* Supported protocol features */
-#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
+#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \
+ BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG))
enum vhost_user_request {
@@ -160,30 +160,64 @@ static int vhost_user_recv_req(struct virtio_uml_device *vu_dev,
if (rc)
return rc;
- if (msg->header.flags != VHOST_USER_VERSION)
+ if ((msg->header.flags & ~VHOST_USER_FLAG_NEED_REPLY) !=
+ VHOST_USER_VERSION)
return -EPROTO;
return 0;
}
static int vhost_user_send(struct virtio_uml_device *vu_dev,
- struct vhost_user_msg *msg,
+ bool need_response, struct vhost_user_msg *msg,
int *fds, size_t num_fds)
{
size_t size = sizeof(msg->header) + msg->header.size;
+ bool request_ack;
+ int rc;
msg->header.flags |= VHOST_USER_VERSION;
- return full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
+
+ /*
+ * The need_response flag indicates that we already need a response,
+ * e.g. to read the features. In these cases, don't request an ACK as
+ * it is meaningless. Also request an ACK only if supported.
+ */
+ request_ack = !need_response;
+ if (!(vu_dev->protocol_features &
+ BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK)))
+ request_ack = false;
+
+ if (request_ack)
+ msg->header.flags |= VHOST_USER_FLAG_NEED_REPLY;
+
+ rc = full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
+ if (rc < 0)
+ return rc;
+
+ if (request_ack) {
+ uint64_t status;
+
+ rc = vhost_user_recv_u64(vu_dev, &status);
+ if (rc)
+ return rc;
+
+ if (status) {
+ vu_err(vu_dev, "slave reports error: %llu\n", status);
+ return -EIO;
+ }
+ }
+
+ return 0;
}
static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev,
- u32 request)
+ bool need_response, u32 request)
{
struct vhost_user_msg msg = {
.header.request = request,
};
- return vhost_user_send(vu_dev, &msg, NULL, 0);
+ return vhost_user_send(vu_dev, need_response, &msg, NULL, 0);
}
static int vhost_user_send_no_payload_fd(struct virtio_uml_device *vu_dev,
@@ -193,7 +227,7 @@ static int vhost_user_send_no_payload_fd(struct virtio_uml_device *vu_dev,
.header.request = request,
};
- return vhost_user_send(vu_dev, &msg, &fd, 1);
+ return vhost_user_send(vu_dev, false, &msg, &fd, 1);
}
static int vhost_user_send_u64(struct virtio_uml_device *vu_dev,
@@ -205,18 +239,19 @@ static int vhost_user_send_u64(struct virtio_uml_device *vu_dev,
.payload.integer = value,
};
- return vhost_user_send(vu_dev, &msg, NULL, 0);
+ return vhost_user_send(vu_dev, false, &msg, NULL, 0);
}
static int vhost_user_set_owner(struct virtio_uml_device *vu_dev)
{
- return vhost_user_send_no_payload(vu_dev, VHOST_USER_SET_OWNER);
+ return vhost_user_send_no_payload(vu_dev, false, VHOST_USER_SET_OWNER);
}
static int vhost_user_get_features(struct virtio_uml_device *vu_dev,
u64 *features)
{
- int rc = vhost_user_send_no_payload(vu_dev, VHOST_USER_GET_FEATURES);
+ int rc = vhost_user_send_no_payload(vu_dev, true,
+ VHOST_USER_GET_FEATURES);
if (rc)
return rc;
@@ -232,7 +267,7 @@ static int vhost_user_set_features(struct virtio_uml_device *vu_dev,
static int vhost_user_get_protocol_features(struct virtio_uml_device *vu_dev,
u64 *protocol_features)
{
- int rc = vhost_user_send_no_payload(vu_dev,
+ int rc = vhost_user_send_no_payload(vu_dev, true,
VHOST_USER_GET_PROTOCOL_FEATURES);
if (rc)
@@ -247,9 +282,32 @@ static int vhost_user_set_protocol_features(struct virtio_uml_device *vu_dev,
protocol_features);
}
+static void vhost_user_reply(struct virtio_uml_device *vu_dev,
+ struct vhost_user_msg *msg, int response)
+{
+ struct vhost_user_msg reply = {
+ .payload.integer = response,
+ };
+ size_t size = sizeof(reply.header) + sizeof(reply.payload.integer);
+ int rc;
+
+ reply.header = msg->header;
+ reply.header.flags &= ~VHOST_USER_FLAG_NEED_REPLY;
+ reply.header.flags |= VHOST_USER_FLAG_REPLY;
+ reply.header.size = sizeof(reply.payload.integer);
+
+ rc = full_sendmsg_fds(vu_dev->req_fd, &reply, size, NULL, 0);
+
+ if (rc)
+ vu_err(vu_dev,
+ "sending reply to slave request failed: %d (size %zu)\n",
+ rc, size);
+}
+
static irqreturn_t vu_req_interrupt(int irq, void *data)
{
struct virtio_uml_device *vu_dev = data;
+ int response = 1;
struct {
struct vhost_user_msg msg;
u8 extra_payload[512];
@@ -266,6 +324,7 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
switch (msg.msg.header.request) {
case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG:
virtio_config_changed(&vu_dev->vdev);
+ response = 0;
break;
case VHOST_USER_SLAVE_IOTLB_MSG:
/* not supported - VIRTIO_F_IOMMU_PLATFORM */
@@ -276,6 +335,9 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
msg.msg.header.request);
}
+ if (msg.msg.header.flags & VHOST_USER_FLAG_NEED_REPLY)
+ vhost_user_reply(vu_dev, &msg.msg, response);
+
return IRQ_HANDLED;
}
@@ -365,7 +427,7 @@ static void vhost_user_get_config(struct virtio_uml_device *vu_dev,
msg->payload.config.offset = 0;
msg->payload.config.size = cfg_size;
- rc = vhost_user_send(vu_dev, msg, NULL, 0);
+ rc = vhost_user_send(vu_dev, true, msg, NULL, 0);
if (rc) {
vu_err(vu_dev, "sending VHOST_USER_GET_CONFIG failed: %d\n",
rc);
@@ -416,7 +478,7 @@ static void vhost_user_set_config(struct virtio_uml_device *vu_dev,
msg->payload.config.size = len;
memcpy(msg->payload.config.payload, buf, len);
- rc = vhost_user_send(vu_dev, msg, NULL, 0);
+ rc = vhost_user_send(vu_dev, false, msg, NULL, 0);
if (rc)
vu_err(vu_dev, "sending VHOST_USER_SET_CONFIG failed: %d\n",
rc);
@@ -506,7 +568,8 @@ static int vhost_user_set_mem_table(struct virtio_uml_device *vu_dev)
return rc;
}
- return vhost_user_send(vu_dev, &msg, fds, msg.payload.mem_regions.num);
+ return vhost_user_send(vu_dev, false, &msg, fds,
+ msg.payload.mem_regions.num);
}
static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev,
@@ -519,7 +582,7 @@ static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev,
.payload.vring_state.num = num,
};
- return vhost_user_send(vu_dev, &msg, NULL, 0);
+ return vhost_user_send(vu_dev, false, &msg, NULL, 0);
}
static int vhost_user_set_vring_num(struct virtio_uml_device *vu_dev,
@@ -550,7 +613,7 @@ static int vhost_user_set_vring_addr(struct virtio_uml_device *vu_dev,
.payload.vring_addr.log = log,
};
- return vhost_user_send(vu_dev, &msg, NULL, 0);
+ return vhost_user_send(vu_dev, false, &msg, NULL, 0);
}
static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev,
@@ -566,9 +629,9 @@ static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev,
return -EINVAL;
if (fd < 0) {
msg.payload.integer |= VHOST_USER_VRING_POLL_MASK;
- return vhost_user_send(vu_dev, &msg, NULL, 0);
+ return vhost_user_send(vu_dev, false, &msg, NULL, 0);
}
- return vhost_user_send(vu_dev, &msg, &fd, 1);
+ return vhost_user_send(vu_dev, false, &msg, &fd, 1);
}
static int vhost_user_set_vring_call(struct virtio_uml_device *vu_dev,