[PATCH 1/3] hv_netvsc: Check VF datapath when sending traffic to VF

[PATCH 1/3] hv_netvsc: Check VF datapath when sending traffic to VF

[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>
---
 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

[PATCH 2/3] hv_netvsc: Wait for completion on request NVSP_MSG4_TYPE_SWITCH_DATA_PATH

[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>
---
 drivers/net/hyperv/netvsc.c     | 34 +++++++++++++++++++++++++++++++--
 drivers/net/hyperv/netvsc_drv.c |  1 -
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 2350342b961f..237e998d21d1 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
@@ -756,6 +763,29 @@ static void netvsc_send_completion(struct net_device *ndev,
 {
 	const struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
 	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 *)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)) {
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

RE: [PATCH 2/3] hv_netvsc: Wait for completion on request NVSP_MSG4_TYPE_SWITCH_DATA_PATH

[Haiyang Zhang]

> -----Original Message-----
> From: Long Li <longli@linuxonhyperv.com>
> Sent: Tuesday, January 5, 2021 8:16 PM
> To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Wei Liu <wei.liu@kernel.org>; David S. Miller
> <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; linux-
> hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: Long Li <longli@microsoft.com>
> Subject: [PATCH 2/3] hv_netvsc: Wait for completion on request
> NVSP_MSG4_TYPE_SWITCH_DATA_PATH
> 
> 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>

Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>

RE: [PATCH 2/3] hv_netvsc: Wait for completion on request NVSP_MSG4_TYPE_SWITCH_DATA_PATH

[Long Li]

> Subject: Re: [PATCH 2/3] hv_netvsc: Wait for completion on request
> NVSP_MSG4_TYPE_SWITCH_DATA_PATH
> 
> Hi Long,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on linus/master] [also build test WARNING on
> v5.11-rc2 next-20210104] [If your patch is applied to the wrong git tree, kindly
> drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit-
> scm.com%2Fdocs%2Fgit-format-
> patch&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468
> b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6
> 37455042608743102%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMD
> AiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=
> 90AgH9HlZumRZ4UNC4uD2WIRpZ6ZEnvIdOKOfzYcXpI%3D&reserved=0]
> 
> url:
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> ub.com%2F0day-ci%2Flinux%2Fcommits%2FLong-Li%2Fhv_netvsc-Check-VF-
> datapath-when-sending-traffic-to-VF%2F20210106-
> 092237&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb46
> 8b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C
> 637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM
> DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata
> =vtVJ8pXIOxIYeKdaqT9pD1%2BEuOM3wz4yqsHh8uWsGP4%3D&reserv
> ed=0
> base:
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&
> amp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468b85fb0
> 8d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6374550
> 42608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQ
> IjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=FXMG
> CFODFoq3KLklxr17iVHiq%2FWmJ3c0fM7vIZRfNmc%3D&reserved=0
> e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62
> config: i386-allyesconfig (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> reproduce (this is a W=1 build):
>         #
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> ub.com%2F0day-
> ci%2Flinux%2Fcommit%2F8c92b5574da1b0c2aee3eab7da2c4dad8d92572c&a
> mp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468b85fb08
> d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C63745504
> 2608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIj
> oiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=MMXkQ
> KENGpyfW0NJs2khBSKTuBExFSZaWHgWyyIj6UU%3D&reserved=0
>         git remote add linux-review
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> ub.com%2F0day-
> ci%2Flinux&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454e
> b468b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0
> %7C637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjA
> wMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&s
> data=uge6PX2NyAe%2BjRtvgOhR5xzN2ltBctZXeZwn0hoYco0%3D&reser
> ved=0
>         git fetch --no-tags linux-review Long-Li/hv_netvsc-Check-VF-datapath-
> when-sending-traffic-to-VF/20210106-092237
>         git checkout 8c92b5574da1b0c2aee3eab7da2c4dad8d92572c
>         # save the attached .config to linux build tree
>         make W=1 ARCH=i386
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/net/hyperv/netvsc.c: In function 'netvsc_send_completion':
> >> drivers/net/hyperv/netvsc.c:778:14: warning: cast to pointer from
> >> integer of different size [-Wint-to-pointer-cast]
>      778 |   pkt_rqst = (struct nvsp_message *)cmd_rqst;
>          |              ^

I think this warning can be safely ignored.

When sending packets over vmbus, the address is passed as u64 and stored internally as u64 in vmbus_next_request_id(). Passing a 32 bit address will not lose any data. Later the address is retrieved from vmbus_request_addr() as a u64. Again, it will not lose data when casting to a 32 bit address.

This method of storing and retrieving addresses are used throughout other hyper-v drivers. If we want to not to trigger this warning, I suggest making a patch to convert all those usages in all hyper-v drivers.

Thanks,
Long

> 
> 
> vim +778 drivers/net/hyperv/netvsc.c
> 
>    757
>    758	static void netvsc_send_completion(struct net_device *ndev,
>    759					   struct netvsc_device *net_device,
>    760					   struct vmbus_channel
> *incoming_channel,
>    761					   const struct vmpacket_descriptor
> *desc,
>    762					   int budget)
>    763	{
>    764		const struct nvsp_message *nvsp_packet =
> hv_pkt_data(desc);
>    765		u32 msglen = hv_pkt_datalen(desc);
>    766		struct nvsp_message *pkt_rqst;
>    767		u64 cmd_rqst;
>    768
>    769		/* First check if this is a VMBUS completion without data
> payload */
>    770		if (!msglen) {
>    771			cmd_rqst =
> vmbus_request_addr(&incoming_channel->requestor,
>    772						      (u64)desc->trans_id);
>    773			if (cmd_rqst == VMBUS_RQST_ERROR) {
>    774				netdev_err(ndev, "Invalid transaction id\n");
>    775				return;
>    776			}
>    777
>  > 778			pkt_rqst = (struct nvsp_message *)cmd_rqst;
>    779			switch (pkt_rqst->hdr.msg_type) {
>    780			case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
>    781				complete(&net_device->channel_init_wait);
>    782				break;
>    783
>    784			default:
>    785				netdev_err(ndev, "Unexpected VMBUS
> completion!!\n");
>    786			}
>    787			return;
>    788		}
>    789
>    790		/* Ensure packet is big enough to read header fields */
>    791		if (msglen < sizeof(struct nvsp_message_header)) {
>    792			netdev_err(ndev, "nvsp_message length too
> small: %u\n", msglen);
>    793			return;
>    794		}
>    795
>    796		switch (nvsp_packet->hdr.msg_type) {
>    797		case NVSP_MSG_TYPE_INIT_COMPLETE:
>    798			if (msglen < sizeof(struct nvsp_message_header) +
>    799					sizeof(struct
> nvsp_message_init_complete)) {
>    800				netdev_err(ndev, "nvsp_msg length too
> small: %u\n",
>    801					   msglen);
>    802				return;
>    803			}
>    804			fallthrough;
>    805
>    806		case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
>    807			if (msglen < sizeof(struct nvsp_message_header) +
>    808					sizeof(struct
> nvsp_1_message_send_receive_buffer_complete)) {
>    809				netdev_err(ndev, "nvsp_msg1 length too
> small: %u\n",
>    810					   msglen);
>    811				return;
>    812			}
>    813			fallthrough;
>    814
>    815		case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
>    816			if (msglen < sizeof(struct nvsp_message_header) +
>    817					sizeof(struct
> nvsp_1_message_send_send_buffer_complete)) {
>    818				netdev_err(ndev, "nvsp_msg1 length too
> small: %u\n",
>    819					   msglen);
>    820				return;
>    821			}
>    822			fallthrough;
>    823
>    824		case NVSP_MSG5_TYPE_SUBCHANNEL:
>    825			if (msglen < sizeof(struct nvsp_message_header) +
>    826					sizeof(struct
> nvsp_5_subchannel_complete)) {
>    827				netdev_err(ndev, "nvsp_msg5 length too
> small: %u\n",
>    828					   msglen);
>    829				return;
>    830			}
>    831			/* Copy the response back */
>    832			memcpy(&net_device->channel_init_pkt,
> nvsp_packet,
>    833			       sizeof(struct nvsp_message));
>    834			complete(&net_device->channel_init_wait);
>    835			break;
>    836
>    837		case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
>    838			netvsc_send_tx_complete(ndev, net_device,
> incoming_channel,
>    839						desc, budget);
>    840			break;
>    841
>    842		default:
>    843			netdev_err(ndev,
>    844				   "Unknown send completion type %d
> received!!\n",
>    845				   nvsp_packet->hdr.msg_type);
>    846		}
>    847	}
>    848
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.
> 01.org%2Fhyperkitty%2Flist%2Fkbuild-
> all%40lists.01.org&amp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3
> d454eb468b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1
> %7C0%7C637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC
> 4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&
> amp;sdata=AKWfmJrn1C%2BwaqX6wlu95HcPys9K0ju%2FlC%2Bu3O20jAg%3
> D&amp;reserved=0

RE: [PATCH 2/3] hv_netvsc: Wait for completion on request NVSP_MSG4_TYPE_SWITCH_DATA_PATH

[Long Li]

> Subject: RE: [PATCH 2/3] hv_netvsc: Wait for completion on request
> NVSP_MSG4_TYPE_SWITCH_DATA_PATH
> 
> > Subject: Re: [PATCH 2/3] hv_netvsc: Wait for completion on request
> > NVSP_MSG4_TYPE_SWITCH_DATA_PATH
> >
> > Hi Long,
> >
> > Thank you for the patch! Perhaps something to improve:
> >
> > [auto build test WARNING on linus/master] [also build test WARNING on
> > v5.11-rc2 next-20210104] [If your patch is applied to the wrong git
> > tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit-
> > scm.com%2Fdocs%2Fgit-format-
> >
> patch&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468
> >
> b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6
> >
> 37455042608743102%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMD
> >
> AiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=
> >
> 90AgH9HlZumRZ4UNC4uD2WIRpZ6ZEnvIdOKOfzYcXpI%3D&reserved=0]
> >
> > url:
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> > ub.com%2F0day-ci%2Flinux%2Fcommits%2FLong-Li%2Fhv_netvsc-Check-
> VF-
> > datapath-when-sending-traffic-to-VF%2F20210106-
> >
> 092237&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb46
> >
> 8b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C
> >
> 637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM
> >
> DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata
> >
> =vtVJ8pXIOxIYeKdaqT9pD1%2BEuOM3wz4yqsHh8uWsGP4%3D&reserv
> > ed=0
> > base:
> > https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.
> > k
> ernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&
> >
> amp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468b85fb0
> >
> 8d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6374550
> >
> 42608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQ
> >
> IjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=FXMG
> > CFODFoq3KLklxr17iVHiq%2FWmJ3c0fM7vIZRfNmc%3D&reserved=0
> > e71ba9452f0b5b2e8dc8aa5445198cd9214a6a62
> > config: i386-allyesconfig (attached as .config)
> > compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1
> > build):
> >         #
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> > ub.com%2F0day-
> >
> ci%2Flinux%2Fcommit%2F8c92b5574da1b0c2aee3eab7da2c4dad8d92572c&a
> >
> mp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454eb468b85fb08
> >
> d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C63745504
> >
> 2608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIj
> >
> oiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=MMXkQ
> > KENGpyfW0NJs2khBSKTuBExFSZaWHgWyyIj6UU%3D&reserved=0
> >         git remote add linux-review
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> > ub.com%2F0day-
> >
> ci%2Flinux&data=04%7C01%7Clongli%40microsoft.com%7C695cf3d454e
> >
> b468b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0
> > %7C637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wL
> jA
> >
> wMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&s
> >
> data=uge6PX2NyAe%2BjRtvgOhR5xzN2ltBctZXeZwn0hoYco0%3D&reser
> > ved=0
> >         git fetch --no-tags linux-review
> > Long-Li/hv_netvsc-Check-VF-datapath-
> > when-sending-traffic-to-VF/20210106-092237
> >         git checkout 8c92b5574da1b0c2aee3eab7da2c4dad8d92572c
> >         # save the attached .config to linux build tree
> >         make W=1 ARCH=i386
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> >    drivers/net/hyperv/netvsc.c: In function 'netvsc_send_completion':
> > >> drivers/net/hyperv/netvsc.c:778:14: warning: cast to pointer from
> > >> integer of different size [-Wint-to-pointer-cast]
> >      778 |   pkt_rqst = (struct nvsp_message *)cmd_rqst;
> >          |              ^
> 
> I think this warning can be safely ignored.
> 
> When sending packets over vmbus, the address is passed as u64 and stored
> internally as u64 in vmbus_next_request_id(). Passing a 32 bit address will
> not lose any data. Later the address is retrieved from vmbus_request_addr()
> as a u64. Again, it will not lose data when casting to a 32 bit address.
> 
> This method of storing and retrieving addresses are used throughout other
> hyper-v drivers. If we want to not to trigger this warning, I suggest making a
> patch to convert all those usages in all hyper-v drivers.
> 
> Thanks,
> Long

Please discard this patch. I'm sending v2 to fix the warnings.

> 
> >
> >
> > vim +778 drivers/net/hyperv/netvsc.c
> >
> >    757
> >    758	static void netvsc_send_completion(struct net_device *ndev,
> >    759					   struct netvsc_device *net_device,
> >    760					   struct vmbus_channel
> > *incoming_channel,
> >    761					   const struct vmpacket_descriptor
> > *desc,
> >    762					   int budget)
> >    763	{
> >    764		const struct nvsp_message *nvsp_packet =
> > hv_pkt_data(desc);
> >    765		u32 msglen = hv_pkt_datalen(desc);
> >    766		struct nvsp_message *pkt_rqst;
> >    767		u64 cmd_rqst;
> >    768
> >    769		/* First check if this is a VMBUS completion without data
> > payload */
> >    770		if (!msglen) {
> >    771			cmd_rqst =
> > vmbus_request_addr(&incoming_channel->requestor,
> >    772						      (u64)desc->trans_id);
> >    773			if (cmd_rqst == VMBUS_RQST_ERROR) {
> >    774				netdev_err(ndev, "Invalid transaction id\n");
> >    775				return;
> >    776			}
> >    777
> >  > 778			pkt_rqst = (struct nvsp_message *)cmd_rqst;
> >    779			switch (pkt_rqst->hdr.msg_type) {
> >    780			case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
> >    781				complete(&net_device->channel_init_wait);
> >    782				break;
> >    783
> >    784			default:
> >    785				netdev_err(ndev, "Unexpected VMBUS
> > completion!!\n");
> >    786			}
> >    787			return;
> >    788		}
> >    789
> >    790		/* Ensure packet is big enough to read header fields */
> >    791		if (msglen < sizeof(struct nvsp_message_header)) {
> >    792			netdev_err(ndev, "nvsp_message length too
> > small: %u\n", msglen);
> >    793			return;
> >    794		}
> >    795
> >    796		switch (nvsp_packet->hdr.msg_type) {
> >    797		case NVSP_MSG_TYPE_INIT_COMPLETE:
> >    798			if (msglen < sizeof(struct nvsp_message_header) +
> >    799					sizeof(struct
> > nvsp_message_init_complete)) {
> >    800				netdev_err(ndev, "nvsp_msg length too
> > small: %u\n",
> >    801					   msglen);
> >    802				return;
> >    803			}
> >    804			fallthrough;
> >    805
> >    806		case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
> >    807			if (msglen < sizeof(struct nvsp_message_header) +
> >    808					sizeof(struct
> > nvsp_1_message_send_receive_buffer_complete)) {
> >    809				netdev_err(ndev, "nvsp_msg1 length too
> > small: %u\n",
> >    810					   msglen);
> >    811				return;
> >    812			}
> >    813			fallthrough;
> >    814
> >    815		case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
> >    816			if (msglen < sizeof(struct nvsp_message_header) +
> >    817					sizeof(struct
> > nvsp_1_message_send_send_buffer_complete)) {
> >    818				netdev_err(ndev, "nvsp_msg1 length too
> > small: %u\n",
> >    819					   msglen);
> >    820				return;
> >    821			}
> >    822			fallthrough;
> >    823
> >    824		case NVSP_MSG5_TYPE_SUBCHANNEL:
> >    825			if (msglen < sizeof(struct nvsp_message_header) +
> >    826					sizeof(struct
> > nvsp_5_subchannel_complete)) {
> >    827				netdev_err(ndev, "nvsp_msg5 length too
> > small: %u\n",
> >    828					   msglen);
> >    829				return;
> >    830			}
> >    831			/* Copy the response back */
> >    832			memcpy(&net_device->channel_init_pkt,
> > nvsp_packet,
> >    833			       sizeof(struct nvsp_message));
> >    834			complete(&net_device->channel_init_wait);
> >    835			break;
> >    836
> >    837		case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
> >    838			netvsc_send_tx_complete(ndev, net_device,
> > incoming_channel,
> >    839						desc, budget);
> >    840			break;
> >    841
> >    842		default:
> >    843			netdev_err(ndev,
> >    844				   "Unknown send completion type %d
> > received!!\n",
> >    845				   nvsp_packet->hdr.msg_type);
> >    846		}
> >    847	}
> >    848
> >
> > ---
> > 0-DAY CI Kernel Test Service, Intel Corporation
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.
> > 01.org%2Fhyperkitty%2Flist%2Fkbuild-
> >
> all%40lists.01.org&amp;data=04%7C01%7Clongli%40microsoft.com%7C695cf3
> >
> d454eb468b85fb08d8b1fb3ddd%7C72f988bf86f141af91ab2d7cd011db47%7C1
> > %7C0%7C637455042608753098%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> C
> >
> 4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&
> >
> amp;sdata=AKWfmJrn1C%2BwaqX6wlu95HcPys9K0ju%2FlC%2Bu3O20jAg%3
> > D&amp;reserved=0

[PATCH 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove

[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>
---
 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

RE: [PATCH 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot remove

[Haiyang Zhang]

> -----Original Message-----
> From: Long Li <longli@linuxonhyperv.com>
> Sent: Tuesday, January 5, 2021 8:16 PM
> To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Wei Liu <wei.liu@kernel.org>; David S. Miller
> <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; linux-
> hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: Long Li <longli@microsoft.com>
> Subject: [PATCH 3/3] hv_netvsc: Process NETDEV_GOING_DOWN on VF hot
> remove
> 
> 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>

RE: [PATCH 1/3] hv_netvsc: Check VF datapath when sending traffic to VF

[Haiyang Zhang]

> -----Original Message-----
> From: Long Li <longli@linuxonhyperv.com>
> Sent: Tuesday, January 5, 2021 8:16 PM
> To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
> <haiyangz@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Wei Liu <wei.liu@kernel.org>; David S. Miller
> <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; linux-
> hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: Long Li <longli@microsoft.com>
> Subject: [PATCH 1/3] hv_netvsc: Check VF datapath when sending traffic to
> VF
> 
> 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>