When the slave cannot add queues dynamically, it needs to know for
how many queues to wait to be initialized.
This patch introduce new vhost-user protocol feature & request for
the master to send the number of queue pairs allocated by the
driver.
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
docs/interop/vhost-user.txt | 16 ++++++++++++++++
hw/virtio/vhost-user.c | 24 ++++++++++++++++++++++++
include/hw/virtio/vhost-backend.h | 3 +++
3 files changed, 43 insertions(+)
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index 8a14191a1e..85c0e03a95 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -218,6 +218,9 @@ The max number of queue pairs the slave supports can be
queried with message
VHOST_USER_GET_QUEUE_NUM. Master should stop when the number of
requested queues is bigger than that.
+When VHOST_USER_PROTOCOL_F_SET_QUEUE_NUM is negotiated, the master must send
+the number of queue pairs initialized with message VHOST_USER_SET_QUEUE_NUM.
+
As all queues share one connection, the master uses a unique index for each
queue in the sent message to identify a specified queue. One queue pair
is enabled initially. More queues are enabled dynamically, by sending
@@ -354,6 +357,7 @@ Protocol features
#define VHOST_USER_PROTOCOL_F_MTU 4
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
#define VHOST_USER_PROTOCOL_F_CROSS_ENDIAN 6
+#define VHOST_USER_PROTOCOL_F_SET_QUEUE_NUM 7
Master message types
--------------------
@@ -623,6 +627,18 @@ Master message types
and expect this message once (per VQ) during device configuration
(ie. before the master starts the VQ).
+ * VHOST_USER_SET_QUEUE_NUM
+
+ Id: 24
+ Equivalent ioctl: N/A
+ Master payload: u64
+
+ Set the number of queue pairs initialized.
+ Master sends such request to notify the slave the number of queue pairs
+ that have been initialized.
+ This request should only be sent if VHOST_USER_PROTOCOL_F_SET_QUEUE_NUM
+ feature has been successfully negotiated.
+
Slave message types
-------------------
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 093675ed98..9e7728d2da 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -34,6 +34,7 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_NET_MTU = 4,
VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
+ VHOST_USER_PROTOCOL_F_SET_QUEUE_NUM = 7,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -65,6 +66,7 @@ typedef enum VhostUserRequest {
VHOST_USER_SET_SLAVE_REQ_FD = 21,
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
+ VHOST_USER_SET_QUEUE_NUM = 24,
VHOST_USER_MAX
} VhostUserRequest;
@@ -922,6 +924,27 @@ static void vhost_user_set_iotlb_callback(struct vhost_dev
*dev, int enabled)
/* No-op as the receive channel is not dedicated to IOTLB messages. */
}
+static int vhost_user_set_queue_num(struct vhost_dev *dev, uint64_t queues)
+{
+ VhostUserMsg msg = {
+ .request = VHOST_USER_SET_QUEUE_NUM,
+ .size = sizeof(msg.payload.u64),
+ .flags = VHOST_USER_VERSION,
+ .payload.u64 = queues,
+ };
+
+ if (!(dev->protocol_features &
+ (1ULL << VHOST_USER_PROTOCOL_F_SET_QUEUE_NUM))) {
+ return 0;
+ }
+
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
@@ -948,4 +971,5 @@ const VhostOps user_ops = {
.vhost_net_set_mtu = vhost_user_net_set_mtu,
.vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
.vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
+ .vhost_set_queue_num = vhost_user_set_queue_num,
};
diff --git a/include/hw/virtio/vhost-backend.h
b/include/hw/virtio/vhost-backend.h
index a7a5f22bc6..1dd3e4bbf3 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -84,6 +84,8 @@ typedef void (*vhost_set_iotlb_callback_op)(struct vhost_dev
*dev,
int enabled);
typedef int (*vhost_send_device_iotlb_msg_op)(struct vhost_dev *dev,
struct vhost_iotlb_msg *imsg);
+typedef int (*vhost_set_queue_num_op)(struct vhost_dev *dev,
+ uint64_t queues);
typedef struct VhostOps {
VhostBackendType backend_type;
@@ -118,6 +120,7 @@ typedef struct VhostOps {
vhost_vsock_set_running_op vhost_vsock_set_running;
vhost_set_iotlb_callback_op vhost_set_iotlb_callback;
vhost_send_device_iotlb_msg_op vhost_send_device_iotlb_msg;
+ vhost_set_queue_num_op vhost_set_queue_num;
} VhostOps;
extern const VhostOps user_ops;
--
2.14.3
