linux.git/drivers/net/hyperv/netvsc.c, branch v5.8 Linux kernel source tree hv_netvsc: Disable NAPI before closing the VMBus channel 2020-04-23T13:17:11+00:00 Andrea Parri (Microsoft) parri.andrea@gmail.com 2020-04-06T00:15:07+00:00 ac5047671758ad4be9f93898247b3a8b6dfde4c7 vmbus_chan_sched() might call the netvsc driver callback function that ends up scheduling NAPI work. This "work" can access the channel ring buffer, so we must ensure that any such work is completed and that the ring buffer is no longer being accessed before freeing the ring buffer data structure in the channel closure path. To this end, disable NAPI before calling vmbus_close() in netvsc_device_remove(). Suggested-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: <netdev@vger.kernel.org> Link: https://lore.kernel.org/r/20200406001514.19876-5-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> 
vmbus_chan_sched() might call the netvsc driver callback function that
ends up scheduling NAPI work.  This "work" can access the channel ring
buffer, so we must ensure that any such work is completed and that the
ring buffer is no longer being accessed before freeing the ring buffer
data structure in the channel closure path.  To this end, disable NAPI
before calling vmbus_close() in netvsc_device_remove().

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406001514.19876-5-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
hv_netvsc: Remove unnecessary round_up for recv_completion_cnt 2020-03-31T02:43:42+00:00 Haiyang Zhang haiyangz@microsoft.com 2020-03-30T19:29:13+00:00 f87238d30c0d550553a37585d0e27a8052952bb4 The vzalloc_node(), already rounds the total size to whole pages, and sizeof(u64) is smaller than sizeof(struct recv_comp_data). So round_up of recv_completion_cnt is not necessary, and may cause extra memory allocation. To save memory, remove this unnecessary round_up for recv_completion_cnt. Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The vzalloc_node(), already rounds the total size to whole pages, and
sizeof(u64) is smaller than sizeof(struct recv_comp_data). So
round_up of recv_completion_cnt is not necessary, and may cause extra
memory allocation.

To save memory, remove this unnecessary round_up for recv_completion_cnt.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hv_netvsc: Fix unwanted wakeup in netvsc_attach() 2020-02-24T00:32:37+00:00 Haiyang Zhang haiyangz@microsoft.com 2020-02-21T16:32:18+00:00 f6f13c125e05603f68f5bf31f045b95e6d493598 When netvsc_attach() is called by operations like changing MTU, etc., an extra wakeup may happen while netvsc_attach() calling rndis_filter_device_add() which sends rndis messages when queue is stopped in netvsc_detach(). The completion message will wake up queue 0. We can reproduce the issue by changing MTU etc., then the wake_queue counter from "ethtool -S" will increase beyond stop_queue counter: stop_queue: 0 wake_queue: 1 The issue causes queue wake up, and counter increment, no other ill effects in current code. So we didn't see any network problem for now. To fix this, initialize tx_disable to true, and set it to false when the NIC is ready to be attached or registered. Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic") Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When netvsc_attach() is called by operations like changing MTU, etc.,
an extra wakeup may happen while netvsc_attach() calling
rndis_filter_device_add() which sends rndis messages when queue is
stopped in netvsc_detach(). The completion message will wake up queue 0.

We can reproduce the issue by changing MTU etc., then the wake_queue
counter from "ethtool -S" will increase beyond stop_queue counter:
     stop_queue: 0
     wake_queue: 1
The issue causes queue wake up, and counter increment, no other ill
effects in current code. So we didn't see any network problem for now.

To fix this, initialize tx_disable to true, and set it to false when
the NIC is ready to be attached or registered.

Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hv_netvsc: Add XDP support 2020-01-25T09:43:19+00:00 Haiyang Zhang haiyangz@microsoft.com 2020-01-23T21:52:34+00:00 351e1581395fcc7fb952bbd7dda01238f69968fd This patch adds support of XDP in native mode for hv_netvsc driver, and transparently sets the XDP program on the associated VF NIC as well. Setting / unsetting XDP program on synthetic NIC (netvsc) propagates to VF NIC automatically. Setting / unsetting XDP program on VF NIC directly is not recommended, also not propagated to synthetic NIC, and may be overwritten by setting of synthetic NIC. The Azure/Hyper-V synthetic NIC receive buffer doesn't provide headroom for XDP. We thought about re-use the RNDIS header space, but it's too small. So we decided to copy the packets to a page buffer for XDP. And, most of our VMs on Azure have Accelerated Network (SRIOV) enabled, so most of the packets run on VF NIC. The synthetic NIC is considered as a fallback data-path. So the data copy on netvsc won't impact performance significantly. XDP program cannot run with LRO (RSC) enabled, so you need to disable LRO before running XDP: ethtool -K eth0 lro off XDP actions not yet supported: XDP_REDIRECT Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
This patch adds support of XDP in native mode for hv_netvsc driver, and
transparently sets the XDP program on the associated VF NIC as well.

Setting / unsetting XDP program on synthetic NIC (netvsc) propagates to
VF NIC automatically. Setting / unsetting XDP program on VF NIC directly
is not recommended, also not propagated to synthetic NIC, and may be
overwritten by setting of synthetic NIC.

The Azure/Hyper-V synthetic NIC receive buffer doesn't provide headroom
for XDP. We thought about re-use the RNDIS header space, but it's too
small. So we decided to copy the packets to a page buffer for XDP. And,
most of our VMs on Azure have Accelerated  Network (SRIOV) enabled, so
most of the packets run on VF NIC. The synthetic NIC is considered as a
fallback data-path. So the data copy on netvsc won't impact performance
significantly.

XDP program cannot run with LRO (RSC) enabled, so you need to disable LRO
before running XDP:
        ethtool -K eth0 lro off

XDP actions not yet supported:
        XDP_REDIRECT

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hv_netvsc: Fix send_table offset in case of a host bug 2019-11-22T03:32:23+00:00 Haiyang Zhang haiyangz@microsoft.com 2019-11-21T21:33:41+00:00 171c1fd98df3d5948d9a9eb755274850fa5e59c6 If negotiated NVSP version <= NVSP_PROTOCOL_VERSION_6, the offset may be wrong (too small) due to a host bug. This can cause missing the end of the send indirection table, and add multiple zero entries from leading zeros before the data region. This bug adds extra burden on channel 0. So fix the offset by computing it from the data structure sizes. This will ensure netvsc driver runs normally on unfixed hosts, and future fixed hosts. Fixes: 5b54dac856cb ("hyperv: Add support for virtual Receive Side Scaling (vRSS)") Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
If negotiated NVSP version <= NVSP_PROTOCOL_VERSION_6, the offset may
be wrong (too small) due to a host bug. This can cause missing the
end of the send indirection table, and add multiple zero entries from
leading zeros before the data region. This bug adds extra burden on
channel 0.

So fix the offset by computing it from the data structure sizes. This
will ensure netvsc driver runs normally on unfixed hosts, and future
fixed hosts.

Fixes: 5b54dac856cb ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hv_netvsc: Fix offset usage in netvsc_send_table() 2019-11-22T03:32:23+00:00 Haiyang Zhang haiyangz@microsoft.com 2019-11-21T21:33:40+00:00 71f21959dd5516031db4f011e15e9a9508b93a7d To reach the data region, the existing code adds offset in struct nvsp_5_send_indirect_table on the beginning of this struct. But the offset should be based on the beginning of its container, struct nvsp_message. This bug causes the first table entry missing, and adds an extra zero from the zero pad after the data region. This can put extra burden on the channel 0. So, correct the offset usage. Also add a boundary check to ensure not reading beyond data region. Fixes: 5b54dac856cb ("hyperv: Add support for virtual Receive Side Scaling (vRSS)") Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
To reach the data region, the existing code adds offset in struct
nvsp_5_send_indirect_table on the beginning of this struct. But the
offset should be based on the beginning of its container,
struct nvsp_message. This bug causes the first table entry missing,
and adds an extra zero from the zero pad after the data region.
This can put extra burden on the channel 0.

So, correct the offset usage. Also add a boundary check to ensure
not reading beyond data region.

Fixes: 5b54dac856cb ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30T18:29:52+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-28T17:10:04+00:00 9952f6918daa4ab5fc81307a9f90e31a4df3b200 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 228 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-08T00:22:09+00:00 David S. Miller davem@davemloft.net 2019-05-08T00:22:09+00:00 a9e41a529681b38087c91ebc0bb91e12f510ca2d Minor conflict with the DSA legacy code removal. Signed-off-by: David S. Miller <davem@davemloft.net> 
Minor conflict with the DSA legacy code removal.

Signed-off-by: David S. Miller <davem@davemloft.net>
hv_netvsc: fix race that may miss tx queue wakeup 2019-05-04T03:50:25+00:00 Haiyang Zhang haiyangz@microsoft.com 2019-04-30T19:29:07+00:00 93aa4792c3908eac87ddd368ee0fe0564148232b When the ring buffer is almost full due to RX completion messages, a TX packet may reach the "low watermark" and cause the queue stopped. If the TX completion arrives earlier than queue stopping, the wakeup may be missed. This patch moves the check for the last pending packet to cover both EAGAIN and success cases, so the queue will be reliably waked up when necessary. Reported-and-tested-by: Stephan Klein <stephan.klein@wegfinder.at> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When the ring buffer is almost full due to RX completion messages, a
TX packet may reach the "low watermark" and cause the queue stopped.
If the TX completion arrives earlier than queue stopping, the wakeup
may be missed.

This patch moves the check for the last pending packet to cover both
EAGAIN and success cases, so the queue will be reliably waked up when
necessary.

Reported-and-tested-by: Stephan Klein <stephan.klein@wegfinder.at>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-05T21:14:19+00:00 David S. Miller davem@davemloft.net 2019-04-05T21:14:19+00:00 f83f7151950dd9e0f6b4a1a405bf5e55c5294e4d Minor comment merge conflict in mlx5. Staging driver has a fixup due to the skb->xmit_more changes in 'net-next', but was removed in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net> 
Minor comment merge conflict in mlx5.

Staging driver has a fixup due to the skb->xmit_more changes
in 'net-next', but was removed in 'net'.

Signed-off-by: David S. Miller <davem@davemloft.net>