Drivers: hv: vss: convert to hv_utils_transport

Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_vss communication methods.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 27 insertions, 25 deletions

diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index ddb1cda4b2fc..2c8c246d09eb 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -25,6 +25,7 @@
 #include <linux/hyperv.h>
 
 #include "hyperv_vmbus.h"
+#include "hv_utils_transport.h"
 
 #define VSS_MAJOR  5
 #define VSS_MINOR  0
@@ -58,9 +59,9 @@ static struct {
 
 static void vss_respond_to_host(int error);
 
-static struct cb_id vss_id = { CN_VSS_IDX, CN_VSS_VAL };
-static const char vss_name[] = "vss_kernel_module";
+static const char vss_devname[] = "vmbus/hv_vss";
 static __u8 *recv_buffer;
+static struct hvutil_transport *hvt;
 
 static void vss_send_op(struct work_struct *dummy);
 static void vss_timeout_func(struct work_struct *dummy);
@@ -88,12 +89,12 @@ static void vss_timeout_func(struct work_struct *dummy)
                         hv_vss_onchannelcallback);
 }
 
-static void
-vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
+static int vss_on_msg(void *msg, int len)
 {
-        struct hv_vss_msg *vss_msg;
+        struct hv_vss_msg *vss_msg = (struct hv_vss_msg *)msg;
 
-        vss_msg = (struct hv_vss_msg *)msg->data;
+        if (len != sizeof(*vss_msg))
+                return -EINVAL;
 
         /*
          * Don't process registration messages if we're in the middle of
@@ -101,7 +102,7 @@ vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
          */
         if (vss_transaction.state > HVUTIL_READY &&
             vss_msg->vss_hdr.operation == VSS_OP_REGISTER)
-                return;
+                return -EINVAL;
 
         if (vss_transaction.state == HVUTIL_DEVICE_INIT &&
             vss_msg->vss_hdr.operation == VSS_OP_REGISTER) {
@@ -119,8 +120,9 @@ vss_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
         } else {
                 /* This is a spurious call! */
                 pr_warn("VSS: Transaction not active\n");
-                return;
+                return -EINVAL;
         }
+        return 0;
 }
 
 
@@ -128,27 +130,20 @@ static void vss_send_op(struct work_struct *dummy)
 {
         int op = vss_transaction.msg->vss_hdr.operation;
         int rc;
-        struct cn_msg *msg;
         struct hv_vss_msg *vss_msg;
 
         /* The transaction state is wrong. */
         if (vss_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
                 return;
 
-        msg = kzalloc(sizeof(*msg) + sizeof(*vss_msg), GFP_ATOMIC);
-        if (!msg)
+        vss_msg = kzalloc(sizeof(*vss_msg), GFP_KERNEL);
+        if (!vss_msg)
                 return;
 
-        vss_msg = (struct hv_vss_msg *)msg->data;
-
-        msg->id.idx =  CN_VSS_IDX;
-        msg->id.val = CN_VSS_VAL;
-
         vss_msg->vss_hdr.operation = op;
-        msg->len = sizeof(struct hv_vss_msg);
 
         vss_transaction.state = HVUTIL_USERSPACE_REQ;
-        rc = cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
+        rc = hvutil_transport_send(hvt, vss_msg, sizeof(*vss_msg));
         if (rc) {
                 pr_warn("VSS: failed to communicate to the daemon: %d\n", rc);
                 if (cancel_delayed_work_sync(&vss_timeout_work)) {
@@ -157,7 +152,7 @@ static void vss_send_op(struct work_struct *dummy)
                 }
         }
 
-        kfree(msg);
+        kfree(vss_msg);
 
         return;
 }
@@ -308,14 +303,16 @@ void hv_vss_onchannelcallback(void *context)
 
 }
 
+static void vss_on_reset(void)
+{
+        if (cancel_delayed_work_sync(&vss_timeout_work))
+                vss_respond_to_host(HV_E_FAIL);
+        vss_transaction.state = HVUTIL_DEVICE_INIT;
+}
+
 int
 hv_vss_init(struct hv_util_service *srv)
 {
-        int err;
-
-        err = cn_add_callback(&vss_id, vss_name, vss_cn_callback);
-        if (err)
-                return err;
         recv_buffer = srv->recv_buffer;
 
         /*
@@ -326,13 +323,18 @@ hv_vss_init(struct hv_util_service *srv)
          */
         vss_transaction.state = HVUTIL_DEVICE_INIT;
 
+        hvt = hvutil_transport_init(vss_devname, CN_VSS_IDX, CN_VSS_VAL,
+                                    vss_on_msg, vss_on_reset);
+        if (!hvt)
+                return -EFAULT;
+
         return 0;
 }
 
 void hv_vss_deinit(void)
 {
         vss_transaction.state = HVUTIL_DEVICE_DYING;
-        cn_del_callback(&vss_id);
         cancel_delayed_work_sync(&vss_timeout_work);
         cancel_work_sync(&vss_send_op_work);
+        hvutil_transport_destroy(hvt);
 }