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Commit cd8dc054 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Greg Kroah-Hartman
Browse files

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: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: default avatarAlex Ng <alexng@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f5722b9b

drivers/hv/hv_snapshot.c

+37 −12
Original line number Diff line number Diff line
@@ -59,6 +59,11 @@ static struct { 


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 @@ static void vss_timeout_func(struct work_struct *dummy) 
			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 @@ static int vss_on_msg(void *msg, int len) 
	if (len != sizeof(*vss_msg))

		return -EINVAL;



	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.

		 * 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)

		if (vss_transaction.state > HVUTIL_READY)

			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;

		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)) {

include/uapi/linux/hyperv.h

+5 −0
Original line number Diff line number Diff line
@@ -45,6 +45,11 @@ 


#define VSS_OP_REGISTER 128



/*

  Daemon code with full handshake support.

 */

#define VSS_OP_REGISTER1 129



enum hv_vss_op {

	VSS_OP_CREATE = 0,

	VSS_OP_DELETE,

tools/hv/hv_vss_daemon.c

+14 −0
Original line number Diff line number Diff line
@@ -148,6 +148,8 @@ int main(int argc, char *argv[]) 
	int	op;

	struct hv_vss_msg vss_msg[1];

	int daemonize = 1, long_index = 0, opt;

	int in_handshake = 1;

	__u32 kernel_modver;



	static struct option long_options[] = {

		{"help",	no_argument,	   0,  'h' },
@@ -211,6 +213,18 @@ int main(int argc, char *argv[]) 


		len = read(vss_fd, vss_msg, sizeof(struct hv_vss_msg));



		if (in_handshake) {

			if (len != sizeof(kernel_modver)) {

				syslog(LOG_ERR, "invalid version negotiation");

				exit(EXIT_FAILURE);

			}

			kernel_modver = *(__u32 *)vss_msg;

			in_handshake = 0;

			syslog(LOG_INFO, "VSS: kernel module version: %d",

			       kernel_modver);

			continue;

		}



		if (len != sizeof(struct hv_vss_msg)) {

			syslog(LOG_ERR, "read failed; error:%d %s",

			       errno, strerror(errno));