svn commit: r296291 - head/sys/dev/hyperv/vmbus

[Sepherosa Ziehau]

Author: sephe
Date: Wed Mar  2 01:40:47 2016
New Revision: 296291
URL: https://svnweb.freebsd.org/changeset/base/296291

Log:
  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

Modified:
  head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c

Modified: head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
==============================================================================
--- head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c	Wed Mar  2 01:33:30 2016	(r296290)
+++ head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c	Wed Mar  2 01:40:47 2016	(r296291)
@@ -274,6 +274,21 @@ 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));
+
+	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. 
@@ -306,11 +321,12 @@ 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,
@@ -323,21 +339,13 @@ 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;
+		/* 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);
 }
 
 /**
@@ -408,17 +416,14 @@ 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);