From: xiongweimin <[email protected]>
This commit implements CQ (Completion Queue) notification functionality
for virtio RDMA devices:
1. Notification types:
- Solicited completion notifications (IB_CQ_SOLICITED)
- Next completion notifications (IB_CQ_NEXT_COMP)
- Error handling for unsupported flags
2. Backend communication:
- VIRTIO_RDMA_CMD_REQ_NOTIFY_CQ command implementation
- Command/response buffer management
- Error handling for virtqueue operations
3. Resource management:
- Dynamic memory allocation for command/response structs
- Guaranteed cleanup on error paths
- Rate-limited error logging
4. Feature limitations:
- REPORT_MISSED_EVENTS currently returns -EOPNOTSUPP
(to be implemented in future work)
Signed-off-by: Xiong Weimin <[email protected]>
---
.../drivers/infiniband/hw/virtio/vrdma_abi.h | 6 +
.../infiniband/hw/virtio/vrdma_dev_api.h | 9 ++
.../drivers/infiniband/hw/virtio/vrdma_ib.c | 121 +++++++++++++++++-
3 files changed, 135 insertions(+), 1 deletion(-)
diff --git a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_abi.h
b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_abi.h
index 0a9404057..ff4b2505f 100644
--- a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_abi.h
+++ b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_abi.h
@@ -9,6 +9,12 @@
#define VRDMA_ABI_VERSION 1
+enum {
+ VIRTIO_RDMA_NOTIFY_NOT = (0),
+ VIRTIO_RDMA_NOTIFY_SOLICITED = (1 << 0),
+ VIRTIO_RDMA_NOTIFY_NEXT_COMPLETION = (1 << 1)
+};
+
/**
* struct vrdma_cqe - Virtio-RDMA Completion Queue Entry (CQE)
*
diff --git a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_dev_api.h
b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_dev_api.h
index 86b5ecade..d9a65531e 100644
--- a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_dev_api.h
+++ b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_dev_api.h
@@ -243,6 +243,15 @@ struct vrdma_rsp_query_qp {
struct vrdma_qp_attr attr;
};
+struct vrdma_cmd_req_notify {
+ __u32 cqn;
+ __u32 flags;
+};
+
+struct vrdma_rsp_req_notify {
+ __u32 missed;
+};
+
struct vrdma_cmd_reg_user_mr {
__u32 pdn;
__u32 access_flags;
diff --git a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_ib.c
b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_ib.c
index b1429e072..6f97c6bdc 100644
--- a/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_ib.c
+++ b/linux-6.16.8/drivers/infiniband/hw/virtio/vrdma_ib.c
@@ -2849,6 +2849,116 @@ static struct ib_mr *vrdma_reg_user_mr(struct ib_pd
*pd, u64 start,
return ERR_PTR(rc);
}
+/**
+ * vrdma_req_notify_cq - Request notification for CQ events
+ * @ibcq: Completion queue
+ * @flags: Notification flags (e.g., solicited only, report missed)
+ *
+ * Requests that the next completion (or next solicited completion) trigger
+ * an interrupt/event. Also supports checking if events were missed.
+ *
+ * Context: Process context (may sleep). Called from user or kernel path.
+ * Return:
+ * * 0 on success
+ * * -EOPNOTSUPP if unsupported flag (e.g., REPORT_MISSED_EVENTS)
+ * * -ENOMEM if command allocation fails
+ * * -EIO if communication with backend fails
+ */
+static int vrdma_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags
flags)
+{
+ struct vrdma_cq *vcq = to_vcq(ibcq);
+ struct vrdma_dev *vdev = to_vdev(ibcq->device);
+ struct vrdma_cmd_req_notify *cmd;
+ struct vrdma_rsp_req_notify *rsp;
+ struct scatterlist in, out;
+ int rc = 0;
+
+ /* Handle solicited-only or any-completion notification */
+ if (flags & IB_CQ_SOLICITED_MASK) {
+ cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+ if (!cmd)
+ return -ENOMEM;
+
+ rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
+ if (!rsp) {
+ kfree(cmd);
+ return -ENOMEM;
+ }
+
+ cmd->cqn = cpu_to_le32(vcq->cq_handle);
+
+ if ((flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED)
+ cmd->flags = VIRTIO_RDMA_NOTIFY_SOLICITED;
+ else
+ cmd->flags = VIRTIO_RDMA_NOTIFY_NEXT_COMPLETION;
+
+ sg_init_one(&in, cmd, sizeof(*cmd));
+ sg_init_one(&out, rsp, sizeof(*rsp));
+
+ rc = vrdma_exec_verbs_cmd(vdev, VIRTIO_RDMA_CMD_REQ_NOTIFY_CQ,
+ &in, &out);
+
+ if (rc) {
+ dev_err(&vdev->vdev->dev,
+ "VIRTIO_RDMA_CMD_REQ_NOTIFY_CQ failed: cqn=%u,
rc=%d\n",
+ vcq->cq_handle, rc);
+ rc = -EIO;
+ }
+
+ kfree(rsp);
+ kfree(cmd);
+
+ if (rc)
+ return rc;
+ }
+
+ /*
+ * Check for missed events: this requires querying backend state
+ * Currently not supported in most virtio-rdma implementations.
+ */
+ if (flags & IB_CQ_REPORT_MISSED_EVENTS) {
+ /*
+ * Ideally we'd query the host whether an event has occurred
+ * since last notify, but this is often unimplemented.
+ */
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static ssize_t hca_type_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "VIRTIO-RDMA-%s\n", VIRTIO_RDMA_DRIVER_VER);
+}
+static DEVICE_ATTR_RO(hca_type);
+
+static ssize_t hw_rev_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", VIRTIO_RDMA_HW_REV);
+}
+static DEVICE_ATTR_RO(hw_rev);
+
+static ssize_t board_id_show(struct device *device,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", VIRTIO_RDMA_BOARD_ID);
+}
+static DEVICE_ATTR_RO(board_id);
+
+static struct attribute *vrdma_class_attributes[] = {
+ &dev_attr_hw_rev.attr,
+ &dev_attr_hca_type.attr,
+ &dev_attr_board_id.attr,
+ NULL,
+};
+
+static const struct attribute_group vrdma_attr_group = {
+ .attrs = vrdma_class_attributes,
+};
+
static const struct ib_device_ops vrdma_dev_ops = {
.owner = THIS_MODULE,
.uverbs_abi_ver = VIRTIO_RDMA_ABI_VERSION,
@@ -2885,7 +2995,16 @@ static const struct ib_device_ops vrdma_dev_ops = {
.post_send = vrdma_post_send,
.query_pkey = vrdma_query_pkey,
.query_qp = vrdma_query_qp,
- .reg_user_mr = vrdma_reg_user_mr,
+ .reg_user_mr = vrdma_reg_user_mr,
+ .req_notify_cq = vrdma_req_notify_cq,
+
+ .device_group = &vrdma_attr_group,
+
+ INIT_RDMA_OBJ_SIZE(ib_ah, vrdma_ah, ibah),
+ INIT_RDMA_OBJ_SIZE(ib_cq, vrdma_cq, ibcq),
+ INIT_RDMA_OBJ_SIZE(ib_pd, vrdma_pd, ibpd),
+ INIT_RDMA_OBJ_SIZE(ib_qp, vrdma_qp, ibqp),
+ INIT_RDMA_OBJ_SIZE(ib_ucontext, vrdma_ucontext, ibucontext),
};
/**
--
2.43.0
