Merge pull request #66 from alexngmsft/lis-next

Fix Kdump hang with multiple vCPUs configured.
LIS · Feb 9, 2016 · 9395e1f · 9395e1f
2 parents 4d5ddb2 + 15d41f5
commit 9395e1f
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Showing 2 changed files with 31 additions and 12 deletions.
diff --git a/hv-rhel6.x/hv/connection.c b/hv-rhel6.x/hv/connection.c
@@ -82,13 +82,23 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
 	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
 	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
+
 	/*
-	 * We want all channel messages to be delivered on CPU 0.
-	 * This has been the behavior pre-win8. This is not a
-	 * perf issue and having all channel messages delivered on
-	 * CPU 0 would be OK.
+	 * For Win8 and below, we want all channel messages to be delivered 
+	 * on CPU 0. This is not a perf issue and having all channel messages
+	 * delivered on CPU 0 would be OK.
+	 *
+	 * For Win 8.1 and above, we want messages delivered on current 
+	 * CPU, as this is necessary when a connection already exists.
+	 * For example, in the case of a crash kernel coming up.
 	 */
-	msg->target_vcpu = 0;
+	if (version >= VERSION_WIN8_1) {
+		msg->target_vcpu = hv_context.vp_index[get_cpu()];
+		put_cpu();
+	}
+	else {
+		msg->target_vcpu = 0;
+	}
 
 	/*
 	 * Add to list before we send the request since we may

diff --git a/hv-rhel7.x/hv/connection.c b/hv-rhel7.x/hv/connection.c
@@ -84,13 +84,22 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
 	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
 
-	/*
- 	 * We want all channel messages to be delivered on CPU 0.
- 	 * This has been the behavior pre-win8. This is not
- 	 * perf issue and having all channel messages delevered on
- 	 * CPU 0 would be OK.
- 	 */
-	msg->target_vcpu = 0;
+        /*
+         * For Win8 and below, we want all channel messages to be delivered
+         * on CPU 0. This is not a perf issue and having all channel messages
+         * delivered on CPU 0 would be OK.
+         *
+         * For Win 8.1 and above, we want messages delivered on current
+         * CPU, as this is necessary when a connection already exists.
+         * For example, in the case of a crash kernel coming up.
+         */
+        if (version >= VERSION_WIN8_1) {
+                msg->target_vcpu = hv_context.vp_index[get_cpu()];
+                put_cpu();
+        }
+        else {
+                msg->target_vcpu = 0;
+        }
 
 	/*
 	 * Add to list before we send the request since we may