svn commit: r301916 - stable/10/sys/dev/hyperv/vmbus

[Sepherosa Ziehau]

Author: sephe
Date: Wed Jun 15 06:08:05 2016
New Revision: 301916
URL: https://svnweb.freebsd.org/changeset/base/301916

Log:
  MFC 296291,301109
  
  296291
      hyperv/chan: Factor out the vcpu setting
  
      And use it for cpu0 assignment; it does not sound right to assume that
      cpu0 maps to vcpu0.  And this factored out function will be exposed to
      drivers, if driver specific CPU binding is needed, e.g. hn(4).
  
      Move default cpu select after saving channel offer message. This makes
      sure that all useful information of the channel has been setup.
  
      MFC after:  1 week
      Sponsored by:       Microsoft OSTC
      Differential Revision:      https://reviews.freebsd.org/D5504
  
  301109
      hyperv/channel: Only cpu0 is supported as channel target cpu on WIN7
  
      MFC after:  1 week
      Sponsored by:       Microsoft OSTC

Modified:
  stable/10/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
==============================================================================
--- stable/10/sys/dev/hyperv/vmbus/hv_channel_mgmt.c	Wed Jun 15 05:57:06 2016	(r301915)
+++ stable/10/sys/dev/hyperv/vmbus/hv_channel_mgmt.c	Wed Jun 15 06:08:05 2016	(r301916)
@@ -277,6 +277,27 @@ vmbus_channel_process_offer(hv_vmbus_cha
 	}
 }
 
+static void
+vmbus_channel_cpu_set(struct hv_vmbus_channel *chan, int cpu)
+{
+	KASSERT(cpu >= 0 && cpu < mp_ncpus, ("invalid cpu %d", cpu));
+
+	if (hv_vmbus_protocal_version == HV_VMBUS_VERSION_WS2008 ||
+	    hv_vmbus_protocal_version == HV_VMBUS_VERSION_WIN7) {
+		/* Only cpu0 is supported */
+		cpu = 0;
+	}
+
+	chan->target_cpu = cpu;
+	chan->target_vcpu = hv_vmbus_g_context.hv_vcpu_index[cpu];
+
+	if (bootverbose) {
+		printf("vmbus_chan%u: assigned to cpu%u [vcpu%u]\n",
+		    chan->offer_msg.child_rel_id,
+		    chan->target_cpu, chan->target_vcpu);
+	}
+}
+
 /**
  * Array of device guids that are performance critical. We try to distribute
  * the interrupt load for these devices across all online cpus. 
@@ -309,11 +330,12 @@ static uint32_t next_vcpu;
  * distributed across all available CPUs.
  */
 static void
-vmbus_channel_select_cpu(hv_vmbus_channel *channel, hv_guid *guid)
+vmbus_channel_select_defcpu(struct hv_vmbus_channel *channel)
 {
 	uint32_t current_cpu;
 	int i;
 	boolean_t is_perf_channel = FALSE;
+	const hv_guid *guid = &channel->offer_msg.offer.interface_type;
 
 	for (i = PERF_CHN_NIC; i < MAX_PERF_CHN; i++) {
 		if (memcmp(guid->data, high_perf_devices[i].data,
@@ -323,24 +345,14 @@ vmbus_channel_select_cpu(hv_vmbus_channe
 		}
 	}
 
-	if ((hv_vmbus_protocal_version == HV_VMBUS_VERSION_WS2008) ||
-	    (hv_vmbus_protocal_version == HV_VMBUS_VERSION_WIN7) ||
-	    (!is_perf_channel)) {
-		/* Host's view of guest cpu */
-		channel->target_vcpu = 0;
-		/* Guest's own view of cpu */
-		channel->target_cpu = 0;
+	if (!is_perf_channel) {
+		/* Stick to cpu0 */
+		vmbus_channel_cpu_set(channel, 0);
 		return;
 	}
 	/* mp_ncpus should have the number cpus currently online */
 	current_cpu = (++next_vcpu % mp_ncpus);
-	channel->target_cpu = current_cpu;
-	channel->target_vcpu =
-	    hv_vmbus_g_context.hv_vcpu_index[current_cpu];
-	if (bootverbose)
-		printf("VMBUS: Total online cpus %d, assign perf channel %d "
-		    "to vcpu %d, cpu %d\n", mp_ncpus, i, channel->target_vcpu,
-		    current_cpu);
+	vmbus_channel_cpu_set(channel, current_cpu);
 }
 
 /**
@@ -411,17 +423,14 @@ vmbus_channel_on_offer_internal(void* co
 		    offer->connection_id;
 	}
 
-	/*
-	 * Bind the channel to a chosen cpu.
-	 */
-	vmbus_channel_select_cpu(new_channel,
-	    &offer->offer.interface_type);
-
 	memcpy(&new_channel->offer_msg, offer,
 	    sizeof(hv_vmbus_channel_offer_channel));
 	new_channel->monitor_group = (uint8_t) offer->monitor_id / 32;
 	new_channel->monitor_bit = (uint8_t) offer->monitor_id % 32;
 
+	/* Select default cpu for this channel. */
+	vmbus_channel_select_defcpu(new_channel);
+
 	vmbus_channel_process_offer(new_channel);
 
 	free(offer, M_DEVBUF);