From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH 2/4] bus/vmbus: add host latency tuning function Date: Thu, 9 Aug 2018 10:50:06 -0700 Message-ID: <20180809175008.5787-3-stephen@networkplumber.org> References: <20180809175008.5787-1-stephen@networkplumber.org> Cc: Stephen Hemminger , Stephen Hemminger To: dev@dpdk.org Return-path: Received: from mail-pg1-f194.google.com (mail-pg1-f194.google.com [209.85.215.194]) by dpdk.org (Postfix) with ESMTP id 1133D2BCD for ; Thu, 9 Aug 2018 19:50:21 +0200 (CEST) Received: by mail-pg1-f194.google.com with SMTP id w10-v6so3099202pgv.2 for ; Thu, 09 Aug 2018 10:50:20 -0700 (PDT) In-Reply-To: <20180809175008.5787-1-stephen@networkplumber.org> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Add vmbus API to allow tuning the scan interval on the host side. Signed-off-by: Stephen Hemminger --- drivers/bus/vmbus/rte_bus_vmbus.h | 15 ++++++++++++ drivers/bus/vmbus/rte_bus_vmbus_version.map | 1 + drivers/bus/vmbus/vmbus_channel.c | 26 +++++++++++++++++++++ 3 files changed, 42 insertions(+) diff --git a/drivers/bus/vmbus/rte_bus_vmbus.h b/drivers/bus/vmbus/rte_bus_vmbus.h index 4a2c1f6fd918..2839fef5b27a 100644 --- a/drivers/bus/vmbus/rte_bus_vmbus.h +++ b/drivers/bus/vmbus/rte_bus_vmbus.h @@ -364,6 +364,21 @@ void rte_vmbus_chan_signal_read(struct vmbus_channel *chan, uint32_t bytes_read) */ uint16_t rte_vmbus_sub_channel_index(const struct vmbus_channel *chan); +/** + * Set the host monitor latency hint + * + * @param dev + * VMBUS device + * @param chan + * Pointer to vmbus_channel structure. + * @param latency + * Approximate wait period between hypervisor examinations of + * the trigger page (in nanoseconds). + */ +void rte_vmbus_set_latency(const struct rte_vmbus_device *dev, + const struct vmbus_channel *chan, + uint32_t latency); + /** * Register a VMBUS driver. * diff --git a/drivers/bus/vmbus/rte_bus_vmbus_version.map b/drivers/bus/vmbus/rte_bus_vmbus_version.map index dabb9203104b..5b01ff30d7b0 100644 --- a/drivers/bus/vmbus/rte_bus_vmbus_version.map +++ b/drivers/bus/vmbus/rte_bus_vmbus_version.map @@ -20,6 +20,7 @@ DPDK_18.08 { rte_vmbus_probe; rte_vmbus_register; rte_vmbus_scan; + rte_vmbus_set_latency; rte_vmbus_sub_channel_index; rte_vmbus_subchan_open; rte_vmbus_unmap_device; diff --git a/drivers/bus/vmbus/vmbus_channel.c b/drivers/bus/vmbus/vmbus_channel.c index cc5f3e8379a5..bd14c0662b46 100644 --- a/drivers/bus/vmbus/vmbus_channel.c +++ b/drivers/bus/vmbus/vmbus_channel.c @@ -59,6 +59,32 @@ vmbus_set_event(const struct rte_vmbus_device *dev, vmbus_set_monitor(dev, chan->monitor_id); } +/* + * Set the wait between when hypervisor examines the trigger. + */ +void +rte_vmbus_set_latency(const struct rte_vmbus_device *dev, + const struct vmbus_channel *chan, + uint32_t latency) +{ + uint32_t trig_idx = chan->monitor_id / VMBUS_MONTRIG_LEN; + uint32_t trig_offs = chan->monitor_id % VMBUS_MONTRIG_LEN; + + if (latency >= UINT16_MAX * 100) { + VMBUS_LOG(ERR, "invalid latency value %u", latency); + return; + } + + if (trig_idx >= VMBUS_MONTRIGS_MAX) { + VMBUS_LOG(ERR, "invalid monitor trigger %u", + trig_idx); + return; + } + + /* Host value is expressed in 100 nanosecond units */ + dev->monitor_page->lat[trig_idx][trig_offs] = latency / 100; +} + /* * Notify host that there are data pending on our TX bufring. * -- 2.18.0