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

From: Long Li
Date: Thu Jan 07 2021 - 13:37:28 EST

> 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@xxxxxxxxx>
> >
> > 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