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* [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove
@ 2021-01-09  0:53 Long Li
  2021-01-09  0:53 ` [PATCH v2 1/3] hv_netvsc: Check VF datapath when sending traffic to VF Long Li
                   ` (4 more replies)
  0 siblings, 5 replies; 7+ messages in thread
From: Long Li @ 2021-01-09  0:53 UTC (permalink / raw)
  To: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, Jakub Kicinski, linux-hyperv, netdev,
	linux-kernel
  Cc: Long Li

From: Long Li <longli@microsoft.com>

This patch set fixes issues with packet loss on VF add/remove.

Long Li (3):
  hv_netvsc: Check VF datapath when sending traffic to VF
  hv_netvsc: Wait for completion on request SWITCH_DATA_PATH
  hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove

 drivers/net/hyperv/netvsc.c     | 37 ++++++++++++++++++++++++++++++---
 drivers/net/hyperv/netvsc_drv.c | 14 ++++++++-----
 2 files changed, 43 insertions(+), 8 deletions(-)

-- 
2.27.0


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH v2 1/3] hv_netvsc: Check VF datapath when sending traffic to VF
  2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
@ 2021-01-09  0:53 ` Long Li
  2021-01-09  0:53 ` [PATCH v2 2/3] hv_netvsc: Wait for completion on request SWITCH_DATA_PATH Long Li
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2021-01-09  0:53 UTC (permalink / raw)
  To: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, Jakub Kicinski, linux-hyperv, netdev,
	linux-kernel
  Cc: Long Li

From: Long Li <longli@microsoft.com>

The driver needs to check if the datapath has been switched to VF before
sending traffic to VF.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index f32f28311d57..5dd4f37afa3d 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -539,7 +539,8 @@ static int netvsc_xmit(struct sk_buff *skb, struct net_device *net, bool xdp_tx)
 	 */
 	vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev);
 	if (vf_netdev && netif_running(vf_netdev) &&
-	    netif_carrier_ok(vf_netdev) && !netpoll_tx_running(net))
+	    netif_carrier_ok(vf_netdev) && !netpoll_tx_running(net) &&
+	    net_device_ctx->data_path_is_vf)
 		return netvsc_vf_xmit(net, vf_netdev, skb);
 
 	/* We will atmost need two pages to describe the rndis
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH v2 2/3] hv_netvsc: Wait for completion on request SWITCH_DATA_PATH
  2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
  2021-01-09  0:53 ` [PATCH v2 1/3] hv_netvsc: Check VF datapath when sending traffic to VF Long Li
@ 2021-01-09  0:53 ` Long Li
  2021-01-09  0:53 ` [PATCH v2 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove Long Li
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2021-01-09  0:53 UTC (permalink / raw)
  To: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, Jakub Kicinski, linux-hyperv, netdev,
	linux-kernel
  Cc: Long Li

From: Long Li <longli@microsoft.com>

The completion indicates if NVSP_MSG4_TYPE_SWITCH_DATA_PATH has been
processed by the VSP. The traffic is steered to VF or synthetic after we
receive this completion.

Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
---
Change from v1:
Fixed warnings from kernel test robot.

 drivers/net/hyperv/netvsc.c     | 37 ++++++++++++++++++++++++++++++---
 drivers/net/hyperv/netvsc_drv.c |  1 -
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 2350342b961f..3a3db2f0134d 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -37,6 +37,10 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
 	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
 
+	/* Block sending traffic to VF if it's about to be gone */
+	if (!vf)
+		net_device_ctx->data_path_is_vf = vf;
+
 	memset(init_pkt, 0, sizeof(struct nvsp_message));
 	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
 	if (vf)
@@ -50,8 +54,11 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 
 	vmbus_sendpacket(dev->channel, init_pkt,
 			       sizeof(struct nvsp_message),
-			       VMBUS_RQST_ID_NO_RESPONSE,
-			       VM_PKT_DATA_INBAND, 0);
+			       (unsigned long)init_pkt,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	wait_for_completion(&nv_dev->channel_init_wait);
+	net_device_ctx->data_path_is_vf = vf;
 }
 
 /* Worker to setup sub channels on initial setup
@@ -754,8 +761,31 @@ static void netvsc_send_completion(struct net_device *ndev,
 				   const struct vmpacket_descriptor *desc,
 				   int budget)
 {
-	const struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
+	const struct nvsp_message *nvsp_packet;
 	u32 msglen = hv_pkt_datalen(desc);
+	struct nvsp_message *pkt_rqst;
+	u64 cmd_rqst;
+
+	/* First check if this is a VMBUS completion without data payload */
+	if (!msglen) {
+		cmd_rqst = vmbus_request_addr(&incoming_channel->requestor,
+					      (u64)desc->trans_id);
+		if (cmd_rqst == VMBUS_RQST_ERROR) {
+			netdev_err(ndev, "Invalid transaction id\n");
+			return;
+		}
+
+		pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;
+		switch (pkt_rqst->hdr.msg_type) {
+		case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
+			complete(&net_device->channel_init_wait);
+			break;
+
+		default:
+			netdev_err(ndev, "Unexpected VMBUS completion!!\n");
+		}
+		return;
+	}
 
 	/* Ensure packet is big enough to read header fields */
 	if (msglen < sizeof(struct nvsp_message_header)) {
@@ -763,6 +793,7 @@ static void netvsc_send_completion(struct net_device *ndev,
 		return;
 	}
 
+	nvsp_packet = hv_pkt_data(desc);
 	switch (nvsp_packet->hdr.msg_type) {
 	case NVSP_MSG_TYPE_INIT_COMPLETE:
 		if (msglen < sizeof(struct nvsp_message_header) +
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 5dd4f37afa3d..64ae5f4e974e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2400,7 +2400,6 @@ static int netvsc_vf_changed(struct net_device *vf_netdev)
 
 	if (net_device_ctx->data_path_is_vf == vf_is_up)
 		return NOTIFY_OK;
-	net_device_ctx->data_path_is_vf = vf_is_up;
 
 	netvsc_switch_datapath(ndev, vf_is_up);
 	netdev_info(ndev, "Data path switched %s VF: %s\n",
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH v2 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove
  2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
  2021-01-09  0:53 ` [PATCH v2 1/3] hv_netvsc: Check VF datapath when sending traffic to VF Long Li
  2021-01-09  0:53 ` [PATCH v2 2/3] hv_netvsc: Wait for completion on request SWITCH_DATA_PATH Long Li
@ 2021-01-09  0:53 ` Long Li
  2021-01-12  2:07 ` [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Jakub Kicinski
  2021-01-13  4:10 ` patchwork-bot+netdevbpf
  4 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2021-01-09  0:53 UTC (permalink / raw)
  To: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, Jakub Kicinski, linux-hyperv, netdev,
	linux-kernel
  Cc: Long Li

From: Long Li <longli@microsoft.com>

On VF hot remove, NETDEV_GOING_DOWN is sent to notify the VF is about to
go down. At this time, the VF is still sending/receiving traffic and we
request the VSP to switch datapath.

On completion, the datapath is switched to synthetic and we can proceed
with VF hot remove.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 64ae5f4e974e..75b4d6703cf1 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2382,12 +2382,15 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
  * During hibernation, if a VF NIC driver (e.g. mlx5) preserves the network
  * interface, there is only the CHANGE event and no UP or DOWN event.
  */
-static int netvsc_vf_changed(struct net_device *vf_netdev)
+static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event)
 {
 	struct net_device_context *net_device_ctx;
 	struct netvsc_device *netvsc_dev;
 	struct net_device *ndev;
-	bool vf_is_up = netif_running(vf_netdev);
+	bool vf_is_up = false;
+
+	if (event != NETDEV_GOING_DOWN)
+		vf_is_up = netif_running(vf_netdev);
 
 	ndev = get_netvsc_byref(vf_netdev);
 	if (!ndev)
@@ -2716,7 +2719,8 @@ static int netvsc_netdev_event(struct notifier_block *this,
 	case NETDEV_UP:
 	case NETDEV_DOWN:
 	case NETDEV_CHANGE:
-		return netvsc_vf_changed(event_dev);
+	case NETDEV_GOING_DOWN:
+		return netvsc_vf_changed(event_dev, event);
 	default:
 		return NOTIFY_DONE;
 	}
-- 
2.27.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove
  2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
                   ` (2 preceding siblings ...)
  2021-01-09  0:53 ` [PATCH v2 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove Long Li
@ 2021-01-12  2:07 ` Jakub Kicinski
  2021-01-12 21:31   ` Long Li
  2021-01-13  4:10 ` patchwork-bot+netdevbpf
  4 siblings, 1 reply; 7+ messages in thread
From: Jakub Kicinski @ 2021-01-12  2:07 UTC (permalink / raw)
  To: Long Li
  Cc: K. Y. Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, linux-hyperv, netdev, linux-kernel, Long Li

On Fri,  8 Jan 2021 16:53:40 -0800 Long Li wrote:
> From: Long Li <longli@microsoft.com>
> 
> This patch set fixes issues with packet loss on VF add/remove.

These patches are for net-next? They just optimize the amount of packet
loss on switch, not fix bugs, right?

^ permalink raw reply	[flat|nested] 7+ messages in thread

* RE: [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove
  2021-01-12  2:07 ` [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Jakub Kicinski
@ 2021-01-12 21:31   ` Long Li
  0 siblings, 0 replies; 7+ messages in thread
From: Long Li @ 2021-01-12 21:31 UTC (permalink / raw)
  To: Jakub Kicinski, Long Li
  Cc: KY Srinivasan, Haiyang Zhang, Stephen Hemminger, Wei Liu,
	David S. Miller, linux-hyperv, netdev, linux-kernel

> Subject: Re: [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF
> add/remove
> 
> On Fri,  8 Jan 2021 16:53:40 -0800 Long Li wrote:
> > From: Long Li <longli@microsoft.com>
> >
> > This patch set fixes issues with packet loss on VF add/remove.
> 
> These patches are for net-next? They just optimize the amount of packet
> loss on switch, not fix bugs, right?

Yes, those patches are for net-next.

They eliminate the packet loss introduced from Linux side during VF changes. They can be seen as optimizations.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove
  2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
                   ` (3 preceding siblings ...)
  2021-01-12  2:07 ` [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Jakub Kicinski
@ 2021-01-13  4:10 ` patchwork-bot+netdevbpf
  4 siblings, 0 replies; 7+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-01-13  4:10 UTC (permalink / raw)
  To: Long Li
  Cc: kys, haiyangz, sthemmin, wei.liu, davem, kuba, linux-hyperv,
	netdev, linux-kernel, longli

Hello:

This series was applied to netdev/net-next.git (refs/heads/master):

On Fri,  8 Jan 2021 16:53:40 -0800 you wrote:
> From: Long Li <longli@microsoft.com>
> 
> This patch set fixes issues with packet loss on VF add/remove.
> 
> Long Li (3):
>   hv_netvsc: Check VF datapath when sending traffic to VF
>   hv_netvsc: Wait for completion on request SWITCH_DATA_PATH
>   hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove
> 
> [...]

Here is the summary with links:
  - [v2,1/3] hv_netvsc: Check VF datapath when sending traffic to VF
    https://git.kernel.org/netdev/net-next/c/69d25a6cf4ca
  - [v2,2/3] hv_netvsc: Wait for completion on request SWITCH_DATA_PATH
    https://git.kernel.org/netdev/net-next/c/8b31f8c982b7
  - [v2,3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove
    https://git.kernel.org/netdev/net-next/c/34b06a2eee44

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-01-13  4:11 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-09  0:53 [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Long Li
2021-01-09  0:53 ` [PATCH v2 1/3] hv_netvsc: Check VF datapath when sending traffic to VF Long Li
2021-01-09  0:53 ` [PATCH v2 2/3] hv_netvsc: Wait for completion on request SWITCH_DATA_PATH Long Li
2021-01-09  0:53 ` [PATCH v2 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove Long Li
2021-01-12  2:07 ` [PATCH v2 0/3] hv_netvsc: Prevent packet loss during VF add/remove Jakub Kicinski
2021-01-12 21:31   ` Long Li
2021-01-13  4:10 ` patchwork-bot+netdevbpf

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