When doing the following test steps, an error was found:
  step 1: modprobe virtio_net succeeded
    # modprobe virtio_net        <-- OK

  step 2: fault injection in register_netdevice()
    # modprobe -r virtio_net     <-- OK
    # ...
      FAULT_INJECTION: forcing a failure.
      name failslab, interval 1, probability 0, space 0, times 0
      CPU: 0 PID: 3521 Comm: modprobe
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
      Call Trace:
       <TASK>
       ...
       should_failslab+0xa/0x20
       ...
       dev_set_name+0xc0/0x100
       netdev_register_kobject+0xc2/0x340
       register_netdevice+0xbb9/0x1320
       virtnet_probe+0x1d72/0x2658 [virtio_net]
       ...
       </TASK>
      virtio_net: probe of virtio0 failed with error -22

  step 3: modprobe virtio_net failed
    # modprobe virtio_net        <-- failed
      virtio_net: probe of virtio0 failed with error -2

The root cause of the problem is that the queues are not
disable on the error handling path when register_netdevice()
fails in virtnet_probe(), resulting in an error "-ENOENT"
returned in the next modprobe call in setup_vq().

virtio_pci_modern_device uses virtqueues to send or
receive message, and "queue_enable" records whether the
queues are available. In vp_modern_find_vqs(), all queues
will be selected and activated, but once queues are enabled
there is no way to go back except reset.

Fix it by reset virtio device on error handling path. This
makes error handling follow the same order as normal device
cleanup in virtnet_remove() which does: unregister, destroy
failover, then reset. And that flow is better tested than
error handling so we can be reasonably sure it works well.

Fixes: 024655555021 ("virtio_net: fix use after free on allocation failure")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20221122150046.3910638-1-lizetao1@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Pull virtio updates from Michael Tsirkin:

 - 9k mtu perf improvements

 - vdpa feature provisioning

 - virtio blk SECURE ERASE support

 - fixes and cleanups all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_pci: don't try to use intxif pin is zero
  vDPA: conditionally read MTU and MAC in dev cfg space
  vDPA: fix spars cast warning in vdpa_dev_net_mq_config_fill
  vDPA: check virtio device features to detect MQ
  vDPA: check VIRTIO_NET_F_RSS for max_virtqueue_paris's presence
  vDPA: only report driver features if FEATURES_OK is set
  vDPA: allow userspace to query features of a vDPA device
  virtio_blk: add SECURE ERASE command support
  vp_vdpa: support feature provisioning
  vdpa_sim_net: support feature provisioning
  vdpa: device feature provisioning
  virtio-net: use mtu size as buffer length for big packets
  virtio-net: introduce and use helper function for guest gso support checks
  virtio: drop vp_legacy_set_queue_size
  virtio_ring: make vring_alloc_queue_packed prettier
  virtio_ring: split: Operators use unified style
  vhost: add __init/__exit annotations to module init/exit funcs

Currently add_recvbuf_big() allocates MAX_SKB_FRAGS segments for big
packets even when GUEST_* offloads are not present on the device.
However, if guest GSO is not supported, it would be sufficient to
allocate segments to cover just up the MTU size and no further.
Allocating the maximum amount of segments results in a large waste of
buffer space in the queue, which limits the number of packets that can
be buffered and can result in reduced performance.

Therefore, if guest GSO is not supported, use the MTU to calculate the
optimal amount of segments required.

Below is the iperf TCP test results over a Mellanox NIC, using vDPA for
1 VQ, queue size 1024, before and after the change, with the iperf
server running over the virtio-net interface.

MTU(Bytes)/Bandwidth (Gbit/s)
             Before   After
  1500        22.5     22.4
  9000        12.8     25.9

And result of queue size 256.
MTU(Bytes)/Bandwidth (Gbit/s)
             Before   After
  9000        2.15     11.9

With this patch no degradation is observed with multiple below tests and
feature bit combinations. Results are summarized below for q depth of
1024. Interface MTU is 1500 if MTU feature is disabled. MTU is set to 9000
in other tests.

Features/              Bandwidth (Gbit/s)
                         Before   After
mtu off                   20.1     20.2
mtu/indirect on           17.4     17.3
mtu/indirect/packed on    17.2     17.2

Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Gavi Teitz <gavi@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
Message-Id: <20220914144911.56422-3-gavinl@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

Probe routine is already several hundred lines.
Use helper function for guest gso support check.

Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Gavi Teitz <gavi@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
Message-Id: <20220914144911.56422-2-gavinl@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for CAN
Link: https://lore.kernel.org/r/20220830201457.7984-1-wsa+renesas@sang-engineering.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter.

  Current release - regressions:

   - tcp: fix cleanup and leaks in tcp_read_skb() (the new way BPF
     socket maps get data out of the TCP stack)

   - tls: rx: react to strparser initialization errors

   - netfilter: nf_tables: fix scheduling-while-atomic splat

   - net: fix suspicious RCU usage in bpf_sk_reuseport_detach()

  Current release - new code bugs:

   - mlxsw: ptp: fix a couple of races, static checker warnings and
     error handling

  Previous releases - regressions:

   - netfilter:
      - nf_tables: fix possible module reference underflow in error path
      - make conntrack helpers deal with BIG TCP (skbs > 64kB)
      - nfnetlink: re-enable conntrack expectation events

   - net: fix potential refcount leak in ndisc_router_discovery()

  Previous releases - always broken:

   - sched: cls_route: disallow handle of 0

   - neigh: fix possible local DoS due to net iface start/stop loop

   - rtnetlink: fix module refcount leak in rtnetlink_rcv_msg

   - sched: fix adding qlen to qcpu->backlog in gnet_stats_add_queue_cpu

   - virtio_net: fix endian-ness for RSS

   - dsa: mv88e6060: prevent crash on an unused port

   - fec: fix timer capture timing in `fec_ptp_enable_pps()`

   - ocelot: stats: fix races, integer wrapping and reading incorrect
     registers (the change of register definitions here accounts for
     bulk of the changed LoC in this PR)"

* tag 'net-6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits)
  net: moxa: MAC address reading, generating, validity checking
  tcp: handle pure FIN case correctly
  tcp: refactor tcp_read_skb() a bit
  tcp: fix tcp_cleanup_rbuf() for tcp_read_skb()
  tcp: fix sock skb accounting in tcp_read_skb()
  igb: Add lock to avoid data race
  dt-bindings: Fix incorrect "the the" corrections
  net: genl: fix error path memory leak in policy dumping
  stmmac: intel: Add a missing clk_disable_unprepare() call in intel_eth_pci_remove()
  net: ethernet: mtk_eth_soc: fix possible NULL pointer dereference in mtk_xdp_run
  net/mlx5e: Allocate flow steering storage during uplink initialization
  net: mscc: ocelot: report ndo_get_stats64 from the wraparound-resistant ocelot->stats
  net: mscc: ocelot: keep ocelot_stat_layout by reg address, not offset
  net: mscc: ocelot: make struct ocelot_stat_layout array indexable
  net: mscc: ocelot: fix race between ndo_get_stats64 and ocelot_check_stats_work
  net: mscc: ocelot: turn stats_lock into a spinlock
  net: mscc: ocelot: fix address of SYS_COUNT_TX_AGING counter
  net: mscc: ocelot: fix incorrect ndo_get_stats64 packet counters
  net: dsa: felix: fix ethtool 256-511 and 512-1023 TX packet counters
  net: dsa: don't warn in dsa_port_set_state_now() when driver doesn't support it
  ...

This reverts commit 762faee5a2678559d3dc09d95f8f2c54cd0466a7.

This has been reported to trip up guests on GCP (Google Cloud).
The reason is that virtio_find_vqs_ctx_size is broken on legacy
devices. We can in theory fix virtio_find_vqs_ctx_size but
in fact the patch itself has several other issues:

- It treats unknown speed as < 10G
- It leaves userspace no way to find out the ring size set by hypervisor
- It tests speed when link is down
- It ignores the virtio spec advice:
        Both \field{speed} and \field{duplex} can change, thus the driver
        is expected to re-read these values after receiving a
        configuration change notification.
- It is not clear the performance impact has been tested properly

Revert the patch for now.

Reported-by: Andres Freund <andres@anarazel.de>
Link: https://lore.kernel.org/r/20220814212610.GA3690074%40roeck-us.net
Link: https://lore.kernel.org/r/20220815070203.plwjx7b3cyugpdt7%40awork3.anarazel.de
Link: https://lore.kernel.org/r/3df6bb82-1951-455d-a768-e9e1513eb667%40www.fastmail.com
Link: https://lore.kernel.org/r/FCDC5DDE-3CDD-4B8A-916F-CA7D87B547CE%40anarazel.de
Fixes: 762faee5a267 ("virtio_net: set the default max ring size by find_vqs()")
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Andres Freund <andres@anarazel.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-Id: <20220816053602.173815-2-mst@redhat.com>

Pull virtio updates from Michael Tsirkin:

 - A huge patchset supporting vq resize using the new vq reset
   capability

 - Features, fixes, and cleanups all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (88 commits)
  vdpa/mlx5: Fix possible uninitialized return value
  vdpa_sim_blk: add support for discard and write-zeroes
  vdpa_sim_blk: add support for VIRTIO_BLK_T_FLUSH
  vdpa_sim_blk: make vdpasim_blk_check_range usable by other requests
  vdpa_sim_blk: check if sector is 0 for commands other than read or write
  vdpa_sim: Implement suspend vdpa op
  vhost-vdpa: uAPI to suspend the device
  vhost-vdpa: introduce SUSPEND backend feature bit
  vdpa: Add suspend operation
  virtio-blk: Avoid use-after-free on suspend/resume
  virtio_vdpa: support the arg sizes of find_vqs()
  vhost-vdpa: Call ida_simple_remove() when failed
  vDPA: fix 'cast to restricted le16' warnings in vdpa.c
  vDPA: !FEATURES_OK should not block querying device config space
  vDPA/ifcvf: support userspace to query features and MQ of a management device
  vDPA/ifcvf: get_config_size should return a value no greater than dev implementation
  vhost scsi: Allow user to control num virtqueues
  vhost-scsi: Fix max number of virtqueues
  vdpa/mlx5: Support different address spaces for control and data
  vdpa/mlx5: Implement susupend virtqueue callback
  ...

Using native endian-ness for device supplied fields is wrong
on BE platforms. Sparse warns about this.

Fixes: 91f41f01d219 ("drivers/net/virtio_net: Added RSS hash report.")
Cc: "Andrew Melnychenko" <andrew@daynix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

New VirtIO network feature: VIRTIO_NET_F_NOTF_COAL.

Control a Virtio network device notifications coalescing parameters
using the control virtqueue.

A device that supports this fetature can receive
VIRTIO_NET_CTRL_NOTF_COAL control commands.

- VIRTIO_NET_CTRL_NOTF_COAL_TX_SET:
  Ask the network device to change the following parameters:
  - tx_usecs: Maximum number of usecs to delay a TX notification.
  - tx_max_packets: Maximum number of packets to send before a
    TX notification.

- VIRTIO_NET_CTRL_NOTF_COAL_RX_SET:
  Ask the network device to change the following parameters:
  - rx_usecs: Maximum number of usecs to delay a RX notification.
  - rx_max_packets: Maximum number of packets to receive before a
    RX notification.

VirtIO spec. patch:
https://lists.oasis-open.org/archives/virtio-comment/202206/msg00100.html

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20220718091102.498774-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jason Wang <jasowang@redhat.com>