svn commit: r314840 - in head/sys: dev/xen/blkfront dev/xen/control dev/xen/netfront xen xen/xenbus

[Roger Pau Monné]

Author: royger
Date: Tue Mar  7 09:16:51 2017
New Revision: 314840
URL: https://svnweb.freebsd.org/changeset/base/314840

Log:
  xen: add support for canceled suspend
  
  When running on Xen, it's possible that a suspend request to the hypervisor
  fails (return from HYPERVISOR_suspend different than 0). This means that the
  suspend hasn't succeed, and the resume procedure needs to properly handle this
  case.
  
  First of all, when such situation happens there's no need to reset the vector
  callback, hypercall page, shared info, event channels or grant table, because
  it's state is preserved. Also, the PV drivers don't need to be reset to the
  initial state, since the connection with the backed has not been interrupted.
  
  Submitted by:		Liuyingdong <liuyingdong at huawei.com>
  Reviewed by:		royger
  MFC after:		2 weeks
  Differential revision:	https://reviews.freebsd.org/D9635

Modified:
  head/sys/dev/xen/blkfront/blkfront.c
  head/sys/dev/xen/control/control.c
  head/sys/dev/xen/netfront/netfront.c
  head/sys/xen/xen-os.h
  head/sys/xen/xenbus/xenbusb.c

Modified: head/sys/dev/xen/blkfront/blkfront.c
==============================================================================
--- head/sys/dev/xen/blkfront/blkfront.c	Tue Mar  7 07:49:25 2017	(r314839)
+++ head/sys/dev/xen/blkfront/blkfront.c	Tue Mar  7 09:16:51 2017	(r314840)
@@ -1537,6 +1537,11 @@ xbd_resume(device_t dev)
 {
 	struct xbd_softc *sc = device_get_softc(dev);
 
+	if (xen_suspend_cancelled) {
+		sc->xbd_state = XBD_STATE_CONNECTED;
+		return (0);
+	}
+
 	DPRINTK("xbd_resume: %s\n", xenbus_get_node(dev));
 
 	xbd_free(sc);

Modified: head/sys/dev/xen/control/control.c
==============================================================================
--- head/sys/dev/xen/control/control.c	Tue Mar  7 07:49:25 2017	(r314839)
+++ head/sys/dev/xen/control/control.c	Tue Mar  7 09:16:51 2017	(r314840)
@@ -148,6 +148,7 @@ __FBSDID("$FreeBSD$");
 
 #include <xen/xenbus/xenbusvar.h>
 
+bool xen_suspend_cancelled;
 /*--------------------------- Forward Declarations --------------------------*/
 /** Function signature for shutdown event handlers. */
 typedef	void (xctrl_shutdown_handler_t)(void);
@@ -196,7 +197,6 @@ xctrl_suspend()
 #ifdef SMP
 	cpuset_t cpu_suspend_map;
 #endif
-	int suspend_cancelled;
 
 	EVENTHANDLER_INVOKE(power_suspend_early);
 	stop_all_proc();
@@ -267,16 +267,20 @@ xctrl_suspend()
 	intr_suspend();
 	xen_hvm_suspend();
 
-	suspend_cancelled = HYPERVISOR_suspend(0);
+	xen_suspend_cancelled = !!HYPERVISOR_suspend(0);
 
-	xen_hvm_resume(suspend_cancelled != 0);
-	intr_resume(suspend_cancelled != 0);
+	if (!xen_suspend_cancelled) {
+		xen_hvm_resume(false);
+	}
+	intr_resume(xen_suspend_cancelled != 0);
 	enable_intr();
 
 	/*
 	 * Reset grant table info.
 	 */
-	gnttab_resume(NULL);
+	if (!xen_suspend_cancelled) {
+		gnttab_resume(NULL);
+	}
 
 #ifdef SMP
 	if (!CPU_EMPTY(&cpu_suspend_map)) {

Modified: head/sys/dev/xen/netfront/netfront.c
==============================================================================
--- head/sys/dev/xen/netfront/netfront.c	Tue Mar  7 07:49:25 2017	(r314839)
+++ head/sys/dev/xen/netfront/netfront.c	Tue Mar  7 09:16:51 2017	(r314840)
@@ -439,6 +439,20 @@ static int
 netfront_resume(device_t dev)
 {
 	struct netfront_info *info = device_get_softc(dev);
+	u_int i;
+
+	if (xen_suspend_cancelled) {
+		for (i = 0; i < info->num_queues; i++) {
+			XN_RX_LOCK(&info->rxq[i]);
+			XN_TX_LOCK(&info->txq[i]);
+		}
+		netfront_carrier_on(info);
+		for (i = 0; i < info->num_queues; i++) {
+			XN_RX_UNLOCK(&info->rxq[i]);
+			XN_TX_UNLOCK(&info->txq[i]);
+		}
+		return (0);
+	}
 
 	netif_disconnect_backend(info);
 	return (0);

Modified: head/sys/xen/xen-os.h
==============================================================================
--- head/sys/xen/xen-os.h	Tue Mar  7 07:49:25 2017	(r314839)
+++ head/sys/xen/xen-os.h	Tue Mar  7 09:16:51 2017	(r314840)
@@ -56,6 +56,8 @@ extern char *console_page;
 extern int xen_disable_pv_disks;
 extern int xen_disable_pv_nics;
 
+extern bool xen_suspend_cancelled;
+
 enum xen_domain_type {
 	XEN_NATIVE,             /* running on bare hardware    */
 	XEN_PV_DOMAIN,          /* running in a PV domain      */

Modified: head/sys/xen/xenbus/xenbusb.c
==============================================================================
--- head/sys/xen/xenbus/xenbusb.c	Tue Mar  7 07:49:25 2017	(r314839)
+++ head/sys/xen/xenbus/xenbusb.c	Tue Mar  7 09:16:51 2017	(r314840)
@@ -791,6 +791,11 @@ xenbusb_resume(device_t dev)
 			if (device_get_state(kids[i]) == DS_NOTPRESENT)
 				continue;
 
+			if (xen_suspend_cancelled) {
+				DEVICE_RESUME(kids[i]);
+				continue;
+			}
+
 			ivars = device_get_ivars(kids[i]);
 
 			xs_unregister_watch(&ivars->xd_otherend_watch);