[PATCH v4 10/24] xen/arm: compile and run xenbus

[Stefano Stabellini]

bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not
an error.

If Linux is running as an HVM domain and is running as Dom0, use
xenstored_local_init to initialize the xenstore page and event channel.


Changes in v4:

- do not xs_reset_watches on dom0.


Changes in v2:

- refactor xenbus_init.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
 drivers/xen/xenbus/xenbus_comms.c |    2 +-
 drivers/xen/xenbus/xenbus_probe.c |   62 +++++++++++++++++++++++++-----------
 drivers/xen/xenbus/xenbus_xs.c    |    3 +-
 3 files changed, 46 insertions(+), 21 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index 52fe7ad..c5aa55c 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -224,7 +224,7 @@ int xb_init_comms(void)
 		int err;
 		err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting,
 						0, "xenbus", &xb_waitq);
-		if (err <= 0) {
+		if (err < 0) {
 			printk(KERN_ERR "XENBUS request irq failed %i\n", err);
 			return err;
 		}
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index b793723..a67ccc0 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -719,37 +719,61 @@ static int __init xenstored_local_init(void)
 	return err;
 }
 
+enum xenstore_init {
+	UNKNOWN,
+	PV,
+	HVM,
+	LOCAL,
+};
 static int __init xenbus_init(void)
 {
 	int err = 0;
+	enum xenstore_init usage = UNKNOWN;
+	uint64_t v = 0;
 
 	if (!xen_domain())
 		return -ENODEV;
 
 	xenbus_ring_ops_init();
 
-	if (xen_hvm_domain()) {
-		uint64_t v = 0;
-		err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
-		if (err)
-			goto out_error;
-		xen_store_evtchn = (int)v;
-		err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
-		if (err)
-			goto out_error;
-		xen_store_mfn = (unsigned long)v;
-		xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
-	} else {
-		xen_store_evtchn = xen_start_info->store_evtchn;
-		xen_store_mfn = xen_start_info->store_mfn;
-		if (xen_store_evtchn)
-			xenstored_ready = 1;
-		else {
+	if (xen_pv_domain())
+		usage = PV;
+	if (xen_hvm_domain())
+		usage = HVM;
+	if (xen_hvm_domain() && xen_initial_domain())
+		usage = LOCAL;
+	if (xen_pv_domain() && !xen_start_info->store_evtchn)
+		usage = LOCAL;
+	if (xen_pv_domain() && xen_start_info->store_evtchn)
+		xenstored_ready = 1;
+
+	switch (usage) {
+		case LOCAL:
 			err = xenstored_local_init();
 			if (err)
 				goto out_error;
-		}
-		xen_store_interface = mfn_to_virt(xen_store_mfn);
+			xen_store_interface = mfn_to_virt(xen_store_mfn);
+			break;
+		case PV:
+			xen_store_evtchn = xen_start_info->store_evtchn;
+			xen_store_mfn = xen_start_info->store_mfn;
+			xen_store_interface = mfn_to_virt(xen_store_mfn);
+			break;
+		case HVM:
+			err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
+			if (err)
+				goto out_error;
+			xen_store_evtchn = (int)v;
+			err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
+			if (err)
+				goto out_error;
+			xen_store_mfn = (unsigned long)v;
+			xen_store_interface =
+				ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
+			break;
+		default:
+			pr_warn("Xenstore state unknown\n");
+			break;
 	}
 
 	/* Initialize the interface to xenstore. */
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c
index bce15cf..131dec0 100644
--- a/drivers/xen/xenbus/xenbus_xs.c
+++ b/drivers/xen/xenbus/xenbus_xs.c
@@ -44,6 +44,7 @@
 #include <linux/rwsem.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <asm/xen/hypervisor.h>
 #include <xen/xenbus.h>
 #include <xen/xen.h>
 #include "xenbus_comms.h"
@@ -622,7 +623,7 @@ static void xs_reset_watches(void)
 {
 	int err, supported = 0;
 
-	if (!xen_hvm_domain())
+	if (!xen_hvm_domain() || xen_initial_domain())
 		return;
 
 	err = xenbus_scanf(XBT_NIL, "control",
-- 
1.7.2.5

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