hw/pvrdma: Add support to allow guest to configure GID table

The control over the RDMA device's GID table is done by updating the
device's Ethernet function addresses.
Usually the first GID entry is determined by the MAC address, the second
by the first IPv6 address and the third by the IPv4 address. Other
entries can be added by adding more IP addresses. The opposite is the
same, i.e. whenever an address is removed, the corresponding GID entry
is removed.

The process is done by the network and RDMA stacks. Whenever an address
is added the ib_core driver is notified and calls the device driver
add_gid function which in turn update the device.

To support this in pvrdma device we need to hook into the create_bind
and destroy_bind HW commands triggered by pvrdma driver in guest.
Whenever a change is made to the pvrdma port's GID table a special QMP
message is sent to be processed by libvirt to update the address of the
backend Ethernet device.

Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Marcel Apfelbaum<marcel.apfelbaum@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>

1 files changed, 100 insertions, 4 deletions

diff --git a/hw/rdma/rdma_rm.c b/hw/rdma/rdma_rm.c
index 4f10fcabcc..250254561c 100644
--- a/hw/rdma/rdma_rm.c
+++ b/hw/rdma/rdma_rm.c
@@ -391,7 +391,7 @@ out_dealloc_qp:
 }
 
 int rdma_rm_modify_qp(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
-                      uint32_t qp_handle, uint32_t attr_mask,
+                      uint32_t qp_handle, uint32_t attr_mask, uint8_t sgid_idx,
                       union ibv_gid *dgid, uint32_t dqpn,
                       enum ibv_qp_state qp_state, uint32_t qkey,
                       uint32_t rq_psn, uint32_t sq_psn)
@@ -400,6 +400,7 @@ int rdma_rm_modify_qp(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
     int ret;
 
     pr_dbg("qpn=0x%x\n", qp_handle);
+    pr_dbg("qkey=0x%x\n", qkey);
 
     qp = rdma_rm_get_qp(dev_res, qp_handle);
     if (!qp) {
@@ -430,9 +431,19 @@ int rdma_rm_modify_qp(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
         }
 
         if (qp->qp_state == IBV_QPS_RTR) {
+            /* Get backend gid index */
+            pr_dbg("Guest sgid_idx=%d\n", sgid_idx);
+            sgid_idx = rdma_rm_get_backend_gid_index(dev_res, backend_dev,
+                                                     sgid_idx);
+            if (sgid_idx <= 0) { /* TODO check also less than bk.max_sgid */
+                pr_dbg("Fail to get bk sgid_idx for sgid_idx %d\n", sgid_idx);
+                return -EIO;
+            }
+
             ret = rdma_backend_qp_state_rtr(backend_dev, &qp->backend_qp,
-                                            qp->qp_type, dgid, dqpn, rq_psn,
-                                            qkey, attr_mask & IBV_QP_QKEY);
+                                            qp->qp_type, sgid_idx, dgid, dqpn,
+                                            rq_psn, qkey,
+                                            attr_mask & IBV_QP_QKEY);
             if (ret) {
                 return -EIO;
             }
@@ -523,11 +534,91 @@ void rdma_rm_dealloc_cqe_ctx(RdmaDeviceResources *dev_res, uint32_t cqe_ctx_id)
     res_tbl_dealloc(&dev_res->cqe_ctx_tbl, cqe_ctx_id);
 }
 
+int rdma_rm_add_gid(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
+                    const char *ifname, union ibv_gid *gid, int gid_idx)
+{
+    int rc;
+
+    rc = rdma_backend_add_gid(backend_dev, ifname, gid);
+    if (rc) {
+        pr_dbg("Fail to add gid\n");
+        return -EINVAL;
+    }
+
+    memcpy(&dev_res->ports[0].gid_tbl[gid_idx].gid, gid, sizeof(*gid));
+
+    return 0;
+}
+
+int rdma_rm_del_gid(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
+                    const char *ifname, int gid_idx)
+{
+    int rc;
+
+    rc = rdma_backend_del_gid(backend_dev, ifname,
+                              &dev_res->ports[0].gid_tbl[gid_idx].gid);
+    if (rc) {
+        pr_dbg("Fail to delete gid\n");
+        return -EINVAL;
+    }
+
+    memset(dev_res->ports[0].gid_tbl[gid_idx].gid.raw, 0,
+           sizeof(dev_res->ports[0].gid_tbl[gid_idx].gid));
+    dev_res->ports[0].gid_tbl[gid_idx].backend_gid_index = -1;
+
+    return 0;
+}
+
+int rdma_rm_get_backend_gid_index(RdmaDeviceResources *dev_res,
+                                  RdmaBackendDev *backend_dev, int sgid_idx)
+{
+    if (unlikely(sgid_idx < 0 || sgid_idx > MAX_PORT_GIDS)) {
+        pr_dbg("Got invalid sgid_idx %d\n", sgid_idx);
+        return -EINVAL;
+    }
+
+    if (unlikely(dev_res->ports[0].gid_tbl[sgid_idx].backend_gid_index == -1)) {
+        dev_res->ports[0].gid_tbl[sgid_idx].backend_gid_index =
+        rdma_backend_get_gid_index(backend_dev,
+                                   &dev_res->ports[0].gid_tbl[sgid_idx].gid);
+    }
+
+    pr_dbg("backend_gid_index=%d\n",
+           dev_res->ports[0].gid_tbl[sgid_idx].backend_gid_index);
+
+    return dev_res->ports[0].gid_tbl[sgid_idx].backend_gid_index;
+}
+
 static void destroy_qp_hash_key(gpointer data)
 {
     g_bytes_unref(data);
 }
 
+static void init_ports(RdmaDeviceResources *dev_res)
+{
+    int i, j;
+
+    memset(dev_res->ports, 0, sizeof(dev_res->ports));
+
+    for (i = 0; i < MAX_PORTS; i++) {
+        dev_res->ports[i].state = IBV_PORT_DOWN;
+        for (j = 0; j < MAX_PORT_GIDS; j++) {
+            dev_res->ports[i].gid_tbl[j].backend_gid_index = -1;
+        }
+    }
+}
+
+static void fini_ports(RdmaDeviceResources *dev_res,
+                       RdmaBackendDev *backend_dev, const char *ifname)
+{
+    int i;
+
+    dev_res->ports[0].state = IBV_PORT_DOWN;
+    for (i = 0; i < MAX_PORT_GIDS; i++) {
+        rdma_rm_del_gid(dev_res, backend_dev, ifname, i);
+    }
+}
+
 int rdma_rm_init(RdmaDeviceResources *dev_res, struct ibv_device_attr *dev_attr,
                  Error **errp)
 {
@@ -545,11 +636,16 @@ int rdma_rm_init(RdmaDeviceResources *dev_res, struct ibv_device_attr *dev_attr,
                        dev_attr->max_qp_wr, sizeof(void *));
     res_tbl_init("UC", &dev_res->uc_tbl, MAX_UCS, sizeof(RdmaRmUC));
 
+    init_ports(dev_res);
+
     return 0;
 }
 
-void rdma_rm_fini(RdmaDeviceResources *dev_res)
+void rdma_rm_fini(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
+                  const char *ifname)
 {
+    fini_ports(dev_res, backend_dev, ifname);
+
     res_tbl_free(&dev_res->uc_tbl);
     res_tbl_free(&dev_res->cqe_ctx_tbl);
     res_tbl_free(&dev_res->qp_tbl);