Drivers: hv: vss: full handshake support
Introduce VSS_OP_REGISTER1 to support kernel replying to the negotiation
message with its own version.
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>
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 2c8c246..ee1762b 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -59,6 +59,11 @@
static void vss_respond_to_host(int error);
+/*
+ * This state maintains the version number registered by the daemon.
+ */
+static int dm_reg_value;
+
static const char vss_devname[] = "vmbus/hv_vss";
static __u8 *recv_buffer;
static struct hvutil_transport *hvt;
@@ -89,6 +94,29 @@
hv_vss_onchannelcallback);
}
+static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
+{
+ u32 our_ver = VSS_OP_REGISTER1;
+
+ switch (vss_msg->vss_hdr.operation) {
+ case VSS_OP_REGISTER:
+ /* Daemon doesn't expect us to reply */
+ dm_reg_value = VSS_OP_REGISTER;
+ break;
+ case VSS_OP_REGISTER1:
+ /* Daemon expects us to reply with our own version*/
+ if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver)))
+ return -EFAULT;
+ dm_reg_value = VSS_OP_REGISTER1;
+ break;
+ default:
+ return -EINVAL;
+ }
+ vss_transaction.state = HVUTIL_READY;
+ pr_info("VSS daemon registered\n");
+ return 0;
+}
+
static int vss_on_msg(void *msg, int len)
{
struct hv_vss_msg *vss_msg = (struct hv_vss_msg *)msg;
@@ -96,18 +124,15 @@
if (len != sizeof(*vss_msg))
return -EINVAL;
- /*
- * Don't process registration messages if we're in the middle of
- * a transaction processing.
- */
- if (vss_transaction.state > HVUTIL_READY &&
- vss_msg->vss_hdr.operation == VSS_OP_REGISTER)
- return -EINVAL;
-
- if (vss_transaction.state == HVUTIL_DEVICE_INIT &&
- vss_msg->vss_hdr.operation == VSS_OP_REGISTER) {
- pr_info("VSS daemon registered\n");
- vss_transaction.state = HVUTIL_READY;
+ if (vss_msg->vss_hdr.operation == VSS_OP_REGISTER ||
+ vss_msg->vss_hdr.operation == VSS_OP_REGISTER1) {
+ /*
+ * Don't process registration messages if we're in the middle
+ * of a transaction processing.
+ */
+ if (vss_transaction.state > HVUTIL_READY)
+ return -EINVAL;
+ return vss_handle_handshake(vss_msg);
} else if (vss_transaction.state == HVUTIL_USERSPACE_REQ) {
vss_transaction.state = HVUTIL_USERSPACE_RECV;
if (cancel_delayed_work_sync(&vss_timeout_work)) {