summaryrefslogtreecommitdiff
path: root/drivers/hv/channel_mgmt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/hv/channel_mgmt.c')
-rw-r--r--drivers/hv/channel_mgmt.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 2f84c5cff8d4..53a8600162a5 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -257,6 +257,70 @@ static void vmbus_process_offer(struct work_struct *work)
}
}
+enum {
+ IDE = 0,
+ SCSI,
+ NIC,
+ MAX_PERF_CHN,
+};
+
+/*
+ * This is an array of device_ids (device types) that are performance critical.
+ * We attempt to distribute the interrupt load for these devices across
+ * all available CPUs.
+ */
+static const struct hv_vmbus_device_id hp_devs[] = {
+ /* IDE */
+ { HV_IDE_GUID, },
+ /* Storage - SCSI */
+ { HV_SCSI_GUID, },
+ /* Network */
+ { HV_NIC_GUID, },
+};
+
+
+/*
+ * We use this state to statically distribute the channel interrupt load.
+ */
+static u32 next_vp;
+
+/*
+ * Starting with Win8, we can statically distribute the incoming
+ * channel interrupt load by binding a channel to VCPU. We
+ * implement here a simple round robin scheme for distributing
+ * the interrupt load.
+ * We will bind channels that are not performance critical to cpu 0 and
+ * performance critical channels (IDE, SCSI and Network) will be uniformly
+ * distributed across all available CPUs.
+ */
+static u32 get_vp_index(uuid_le *type_guid)
+{
+ u32 cur_cpu;
+ int i;
+ bool perf_chn = false;
+ u32 max_cpus = num_online_cpus();
+
+ for (i = IDE; i < MAX_PERF_CHN; i++) {
+ if (!memcmp(type_guid->b, hp_devs[i].guid,
+ sizeof(uuid_le))) {
+ perf_chn = true;
+ break;
+ }
+ }
+ if ((vmbus_proto_version == VERSION_WS2008) ||
+ (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
+ /*
+ * Prior to win8, all channel interrupts are
+ * delivered on cpu 0.
+ * Also if the channel is not a performance critical
+ * channel, bind it to cpu 0.
+ */
+ return 0;
+ }
+ cur_cpu = (++next_vp % max_cpus);
+ return 0;
+}
+
/*
* vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
*
@@ -275,6 +339,35 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
return;
}
+ /*
+ * By default we setup state to enable batched
+ * reading. A specific service can choose to
+ * disable this prior to opening the channel.
+ */
+ newchannel->batched_reading = true;
+
+ /*
+ * Setup state for signalling the host.
+ */
+ newchannel->sig_event = (struct hv_input_signal_event *)
+ (ALIGN((unsigned long)
+ &newchannel->sig_buf,
+ HV_HYPERCALL_PARAM_ALIGN));
+
+ newchannel->sig_event->connectionid.asu32 = 0;
+ newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
+ newchannel->sig_event->flag_number = 0;
+ newchannel->sig_event->rsvdz = 0;
+
+ if (vmbus_proto_version != VERSION_WS2008) {
+ newchannel->is_dedicated_interrupt =
+ (offer->is_dedicated_interrupt != 0);
+ newchannel->sig_event->connectionid.u.id =
+ offer->connection_id;
+ }
+
+ newchannel->target_vp = get_vp_index(&offer->offer.if_type);
+
memcpy(&newchannel->offermsg, offer,
sizeof(struct vmbus_channel_offer_channel));
newchannel->monitor_grp = (u8)offer->monitorid / 32;