Today netfront will trust the backend to send only sane response data.
In order to avoid privilege escalations or crashes in case of malicious
backends verify the data to be within expected limits. Especially make
sure that the response always references an outstanding request.
Note that only the tx queue needs special id handling, as for the rx
queue the id is equal to the index in the ring page.
Introduce a new indicator for the device whether it is broken and let
the device stop working when it is set. Set this indicator in case the
backend sets any weird data.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tx_skb_freelist elements are in a single linked list with the
request id used as link reference. The per element link field is in a
union with the skb pointer of an in use request.
Move the link reference out of the union in order to enable a later
reuse of it for requests which need a populated skb pointer.
Rename add_id_to_freelist() and get_id_from_freelist() to
add_id_to_list() and get_id_from_list() in order to prepare using
those for other lists as well. Define ~0 as value to indicate the end
of a list and place that value into the link for a request not being
on the list.
When freeing a skb zero the skb pointer in the request. Use a NULL
value of the skb pointer instead of skb_entry_is_link() for deciding
whether a request has a skb linked to it.
Remove skb_entry_set_link() and open code it instead as it is really
trivial now.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to avoid a malicious backend being able to influence the local
processing of a request build the request locally first and then copy
it to the ring page. Any reading from the request influencing the
processing in the frontend needs to be done on the local instance.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to avoid problems in case the backend is modifying a response
on the ring page while the frontend has already seen it, just read the
response into a local buffer in one go and then operate on that buffer
only.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is working
towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error
path handling from each XDP ethernet driver to devmap code. According to
the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx
loop whenever the hw reports a tx error and it will just return to devmap
caller the number of successfully transmitted frames. It will be devmap
responsibility to free dropped frames.
Move each XDP ndo_xdp_xmit capable driver to the new APIs:
- veth
- virtio-net
- mvneta
- mvpp2
- socionext
- amazon ena
- bnxt
- freescale (dpaa2, dpaa)
- xen-frontend
- qede
- ice
- igb
- ixgbe
- i40e
- mlx5
- ti (cpsw, cpsw-new)
- tun
- sfc
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org
Fix the following coccicheck warnings:
./drivers/net/xen-netfront.c:1816:52-54: WARNING !A || A && B is
equivalent to !A || B.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/1612261069-13315-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fixes the following W=1 kernel build warning(s):
from drivers/net/ethernet/ibm/ibmvnic.c:35:
inlined from ‘handle_vpd_rsp’ at drivers/net/ethernet/ibm/ibmvnic.c:4124:3:
drivers/net/ethernet/ibm/ibmvnic.c:1362: warning: Function parameter or member 'hdr_field' not described in 'build_hdr_data'
drivers/net/ethernet/ibm/ibmvnic.c:1362: warning: Function parameter or member 'skb' not described in 'build_hdr_data'
drivers/net/ethernet/ibm/ibmvnic.c:1362: warning: Function parameter or member 'hdr_len' not described in 'build_hdr_data'
drivers/net/ethernet/ibm/ibmvnic.c:1362: warning: Function parameter or member 'hdr_data' not described in 'build_hdr_data'
drivers/net/ethernet/ibm/ibmvnic.c:1423: warning: Function parameter or member 'hdr_field' not described in 'create_hdr_descs'
drivers/net/ethernet/ibm/ibmvnic.c:1423: warning: Function parameter or member 'hdr_data' not described in 'create_hdr_descs'
drivers/net/ethernet/ibm/ibmvnic.c:1423: warning: Function parameter or member 'len' not described in 'create_hdr_descs'
drivers/net/ethernet/ibm/ibmvnic.c:1423: warning: Function parameter or member 'hdr_len' not described in 'create_hdr_descs'
drivers/net/ethernet/ibm/ibmvnic.c:1423: warning: Function parameter or member 'scrq_arr' not described in 'create_hdr_descs'
drivers/net/ethernet/ibm/ibmvnic.c:1474: warning: Function parameter or member 'txbuff' not described in 'build_hdr_descs_arr'
drivers/net/ethernet/ibm/ibmvnic.c:1474: warning: Function parameter or member 'num_entries' not described in 'build_hdr_descs_arr'
drivers/net/ethernet/ibm/ibmvnic.c:1474: warning: Function parameter or member 'hdr_field' not described in 'build_hdr_descs_arr'
drivers/net/ethernet/ibm/ibmvnic.c:1832: warning: Function parameter or member 'adapter' not described in 'do_change_param_reset'
drivers/net/ethernet/ibm/ibmvnic.c:1832: warning: Function parameter or member 'rwi' not described in 'do_change_param_reset'
drivers/net/ethernet/ibm/ibmvnic.c:1832: warning: Function parameter or member 'reset_state' not described in 'do_change_param_reset'
drivers/net/ethernet/ibm/ibmvnic.c:1911: warning: Function parameter or member 'adapter' not described in 'do_reset'
drivers/net/ethernet/ibm/ibmvnic.c:1911: warning: Function parameter or member 'rwi' not described in 'do_reset'
drivers/net/ethernet/ibm/ibmvnic.c:1911: warning: Function parameter or member 'reset_state' not described in 'do_reset'
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add napi_id to the xdp_rxq_info structure, and make sure the XDP
socket pick up the napi_id in the Rx path. The napi_id is used to find
the corresponding NAPI structure for socket busy polling.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-7-bjorn.topel@gmail.com
drivers/net/xen-netfront.c:2416:16: warning: variable ‘target’ set but not used [-Wunused-but-set-variable]
2416 | unsigned long target;
Remove target and just discard the return value from simple_strtoul().
This patch does give a checkpatch warning, but the warning was there
before anyway, as this file has lots of checkpatch warnings.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20201031180435.1081127-1-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now that BPF program/link management is centralized in generic net_device
code, kernel code never queries program id from drivers, so
XDP_QUERY_PROG/XDP_QUERY_PROG_HW commands are unnecessary.
This patch removes all the implementations of those commands in kernel, along
the xdp_attachment_query().
This patch was compile-tested on allyesconfig.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200722064603.3350758-10-andriin@fb.com
The UDP reuseport conflict was a little bit tricky.
The net-next code, via bpf-next, extracted the reuseport handling
into a helper so that the BPF sk lookup code could invoke it.
At the same time, the logic for reuseport handling of unconnected
sockets changed via commit efc6b6f6c3
which changed the logic to carry on the reuseport result into the
rest of the lookup loop if we do not return immediately.
This requires moving the reuseport_has_conns() logic into the callers.
While we are here, get rid of inline directives as they do not belong
in foo.c files.
The other changes were cases of more straightforward overlapping
modifications.
Signed-off-by: David S. Miller <davem@davemloft.net>
There's a potential race in xennet_remove(); this is what the driver is
doing upon unregistering a network device:
1. state = read bus state
2. if state is not "Closed":
3. request to set state to "Closing"
4. wait for state to be set to "Closing"
5. request to set state to "Closed"
6. wait for state to be set to "Closed"
If the state changes to "Closed" immediately after step 1 we are stuck
forever in step 4, because the state will never go back from "Closed" to
"Closing".
Make sure to check also for state == "Closed" in step 4 to prevent the
deadlock.
Also add a 5 sec timeout any time we wait for the bus state to change,
to avoid getting stuck forever in wait_event().
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds kernel TX timestamps to the xen-netfront driver. Tested with chrony
on an AWS EC2 instance.
Signed-off-by: Daniel Drown <dan-netdev@drown.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The variable act is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch adds a basic XDP processing to xen-netfront driver.
We ran an XDP program for an RX response received from netback
driver. Also we request xen-netback to adjust data offset for
bpf_xdp_adjust_head() header space for custom headers.
synchronization between frontend and backend parts is done
by using xenbus state switching:
Reconfiguring -> Reconfigured- > Connected
UDP packets drop rate using xdp program is around 310 kpps
using ./pktgen_sample04_many_flows.sh and 160 kpps without the patch.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
xennet_fill_frags() uses ~0U as return value when the sk_buff is not able
to cache extra fragments. This is incorrect because the return type of
xennet_fill_frags() is RING_IDX and 0xffffffff is an expected value for
ring buffer index.
In the situation when the rsp_cons is approaching 0xffffffff, the return
value of xennet_fill_frags() may become 0xffffffff which xennet_poll() (the
caller) would regard as error. As a result, queue->rx.rsp_cons is set
incorrectly because it is updated only when there is error. If there is no
error, xennet_poll() would be responsible to update queue->rx.rsp_cons.
Finally, queue->rx.rsp_cons would point to the rx ring buffer entries whose
queue->rx_skbs[i] and queue->grant_rx_ref[i] are already cleared to NULL.
This leads to NULL pointer access in the next iteration to process rx ring
buffer entries.
The symptom is similar to the one fixed in
commit 00b368502d ("xen-netfront: do not assume sk_buff_head list is
empty in error handling").
This patch changes the return type of xennet_fill_frags() to indicate
whether it is successful or failed. The queue->rx.rsp_cons will be
always updated inside this function.
Fixes: ad4f15dc2c ("xen/netfront: don't bug in case of too many frags")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When skb_shinfo(skb) is not able to cache extra fragment (that is,
skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS), xennet_fill_frags() assumes
the sk_buff_head list is already empty. As a result, cons is increased only
by 1 and returns to error handling path in xennet_poll().
However, if the sk_buff_head list is not empty, queue->rx.rsp_cons may be
set incorrectly. That is, queue->rx.rsp_cons would point to the rx ring
buffer entries whose queue->rx_skbs[i] and queue->grant_rx_ref[i] are
already cleared to NULL. This leads to NULL pointer access in the next
iteration to process rx ring buffer entries.
Below is how xennet_poll() does error handling. All remaining entries in
tmpq are accounted to queue->rx.rsp_cons without assuming how many
outstanding skbs are remained in the list.
985 static int xennet_poll(struct napi_struct *napi, int budget)
... ...
1032 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1033 __skb_queue_head(&tmpq, skb);
1034 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1035 goto err;
1036 }
It is better to always have the error handling in the same way.
Fixes: ad4f15dc2c ("xen/netfront: don't bug in case of too many frags")
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use accessor functions for skb fragment's page_offset instead
of direct references, in preparation for bvec conversion.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.
This patch fixes the following warning:
drivers/net/xen-netfront.c: In function ‘netback_changed’:
drivers/net/xen-netfront.c:2038:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dev->state == XenbusStateClosed)
^
drivers/net/xen-netfront.c:2041:2: note: here
case XenbusStateClosing:
^~~~
Warning level 3 was used: -Wimplicit-fallthrough=3
Notice that, in this particular case, the code comment is modified
in accordance with what GCC is expecting to find.
This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the previous patch, all the callers of ndo_select_queue()
provide as a 'fallback' argument netdev_pick_tx.
The only exceptions are nested calls to ndo_select_queue(),
which pass down the 'fallback' available in the current scope
- still netdev_pick_tx.
We can drop such argument and replace fallback() invocation with
netdev_pick_tx(). This avoids an indirect call per xmit packet
in some scenarios (TCP syn, UDP unconnected, XDP generic, pktgen)
with device drivers implementing such ndo. It also clean the code
a bit.
Tested with ixgbe and CONFIG_FCOE=m
With pktgen using queue xmit:
threads vanilla patched
(kpps) (kpps)
1 2334 2428
2 4166 4278
4 7895 8100
v1 -> v2:
- rebased after helper's name change
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Lots of conflicts, by happily all cases of overlapping
changes, parallel adds, things of that nature.
Thanks to Stephen Rothwell, Saeed Mahameed, and others
for their guidance in these resolutions.
Signed-off-by: David S. Miller <davem@davemloft.net>
At least old Xen net backends seem to send frags with no real data
sometimes. In case such a fragment happens to occur with the frag limit
already reached the frontend will BUG currently even if this situation
is easily recoverable.
Modify the BUG_ON() condition accordingly.
Tested-by: Dietmar Hahn <dietmar.hahn@ts.fujitsu.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
requests before req_prod is updated.
Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 57f230ab04 ("xen/netfront: raise max number of slots in
xennet_get_responses()") raised the max number of allowed slots by one.
This seems to be problematic in some configurations with netback using
a larger MAX_SKB_FRAGS value (e.g. old Linux kernel with MAX_SKB_FRAGS
defined as 18 instead of nowadays 17).
Instead of BUG_ON() in this case just fall back to retransmission.
Fixes: 57f230ab04 ("xen/netfront: raise max number of slots in xennet_get_responses()")
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 822fb18a82 ("xen-netfront: wait xenbus state change when load
module manually") added a new wait queue to wait on for a state change
when the module is loaded manually. Unfortunately there is no wakeup
anywhere to stop that waiting.
Instead of introducing a new wait queue rename the existing
module_unload_q to module_wq and use it for both purposes (loading and
unloading).
As any state change of the backend might be intended to stop waiting
do the wake_up_all() in any case when netback_changed() is called.
Fixes: 822fb18a82 ("xen-netfront: wait xenbus state change when load module manually")
Cc: <stable@vger.kernel.org> #4.18
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_shinfo() can change when calling __pskb_pull_tail(): Don't cache
its return value.
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The BTF conflicts were simple overlapping changes.
The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.
Signed-off-by: David S. Miller <davem@davemloft.net>
When loading module manually, after call xenbus_switch_state to initializes
the state of the netfront device, the driver state did not change so fast
that may lead no dev created in latest kernel. This patch adds wait to make
sure xenbus knows the driver is not in closed/unknown state.
Current state:
[vm]# ethtool eth0
Settings for eth0:
Link detected: yes
[vm]# modprobe -r xen_netfront
[vm]# modprobe xen_netfront
[vm]# ethtool eth0
Settings for eth0:
Cannot get device settings: No such device
Cannot get wake-on-lan settings: No such device
Cannot get message level: No such device
Cannot get link status: No such device
No data available
With the patch installed.
[vm]# ethtool eth0
Settings for eth0:
Link detected: yes
[vm]# modprobe -r xen_netfront
[vm]# modprobe xen_netfront
[vm]# ethtool eth0
Settings for eth0:
Link detected: yes
Signed-off-by: Xiao Liang <xiliang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit f599c64fdf ("xen-netfront: Fix race between device setup and
open") changed the initialization order: xennet_create_queues() now
happens before we do register_netdev() so using netdev->name in
xennet_init_queue() is incorrect, we end up with the following in
/proc/interrupts:
60: 139 0 xen-dyn -event eth%d-q0-tx
61: 265 0 xen-dyn -event eth%d-q0-rx
62: 234 0 xen-dyn -event eth%d-q1-tx
63: 1 0 xen-dyn -event eth%d-q1-rx
and this looks ugly. Actually, using early netdev name (even when it's
already set) is also not ideal: nowadays we tend to rename eth devices
and queue name may end up not corresponding to the netdev name.
Use nodename from xenbus device for queue naming: this can't change in VM's
lifetime. Now /proc/interrupts looks like
62: 202 0 xen-dyn -event device/vif/0-q0-tx
63: 317 0 xen-dyn -event device/vif/0-q0-rx
64: 262 0 xen-dyn -event device/vif/0-q1-tx
65: 17 0 xen-dyn -event device/vif/0-q1-rx
Fixes: f599c64fdf ("xen-netfront: Fix race between device setup and open")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes it so that instead of passing a void pointer as the
accel_priv we instead pass a net_device pointer as sb_dev. Making this
change allows us to pass the subordinate device through to the fallback
function eventually so that we can keep the actual code in the
ndo_select_queue call as focused on possible on the exception cases.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Update the features after calling register_netdev() otherwise the
device features are not set up correctly and it not possible to change
the MTU of the device. After this change, the features reported by
ethtool match the device's features before the commit which introduced
the issue and it is possible to change the device's MTU.
Fixes: f599c64fdf ("xen-netfront: Fix race between device setup and open")
Reported-by: Liam Shepherd <liam@dancer.es>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes: f599c64fdf ("xen-netfront: Fix race between device setup and open")
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The max number of slots used in xennet_get_responses() is set to
MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD).
In old kernel-xen MAX_SKB_FRAGS was 18, while nowadays it is 17. This
difference is resulting in frequent messages "too many slots" and a
reduced network throughput for some workloads (factor 10 below that of
a kernel-xen based guest).
Replacing MAX_SKB_FRAGS by XEN_NETIF_NR_SLOTS_MIN for calculation of
the max number of slots to use solves that problem (tests showed no
more messages "too many slots" and throughput was as high as with the
kernel-xen based guest system).
Replace MAX_SKB_FRAGS-2 by XEN_NETIF_NR_SLOTS_MIN-1 in
netfront_tx_slot_available() for making it clearer what is really being
tested without actually modifying the tested value.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.
Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Prefer the direct use of octal for permissions.
Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace
and some typing.
Miscellanea:
o Whitespace neatening around these conversions.
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A toolstack may delete the vif frontend and backend xenstore entries
while xen-netfront is in the removal code path. In that case, the
checks for xenbus_read_driver_state would return XenbusStateUnknown, and
xennet_remove would hang indefinitely. This hang prevents system
shutdown.
xennet_remove must be able to handle XenbusStateUnknown, and
netback_changed must also wake up the wake_queue for that state as well.
Fixes: 5b5971df3b ("xen-netfront: remove warning when unloading module")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Cc: Eduardo Otubo <otubo@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
When a netfront device is set up it registers a netdev fairly early on,
before it has set up the queues and is actually usable. A userspace tool
like NetworkManager will immediately try to open it and access its state
as soon as it appears. The bug can be reproduced by hotplugging VIFs
until the VM runs out of grant refs. It registers the netdev but fails
to set up any queues (since there are no more grant refs). In the
meantime, NetworkManager opens the device and the kernel crashes trying
to access the queues (of which there are none).
Fix this in two ways:
* For initial setup, register the netdev much later, after the queues
are setup. This avoids the race entirely.
* During a suspend/resume cycle, the frontend reconnects to the backend
and the queues are recreated. It is possible (though highly unlikely) to
race with something opening the device and accessing the queues after
they have been destroyed but before they have been recreated. Extend the
region covered by the rtnl semaphore to protect against this race. There
is a possibility that we fail to recreate the queues so check for this
in the open function.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
When loading the module after unloading it, the network interface would
not be enabled and thus wouldn't have a backend counterpart and unable
to be used by the guest.
The guest would face errors like:
[root@guest ~]# ethtool -i eth0
Cannot get driver information: No such device
[root@guest ~]# ifconfig eth0
eth0: error fetching interface information: Device not found
This patch initializes the state of the netfront device whenever it is
loaded manually, this state would communicate the netback to create its
device and establish the connection between them.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) The forcedeth conversion from pci_*() DMA interfaces to dma_*() ones
missed one spot. From Zhu Yanjun.
2) Missing CRYPTO_SHA256 Kconfig dep in cfg80211, from Johannes Berg.
3) Fix checksum offloading in thunderx driver, from Sunil Goutham.
4) Add SPDX to vm_sockets_diag.h, from Stephen Hemminger.
5) Fix use after free of packet headers in TIPC, from Jon Maloy.
6) "sizeof(ptr)" vs "sizeof(*ptr)" bug in i40e, from Gustavo A R Silva.
7) Tunneling fixes in mlxsw driver, from Petr Machata.
8) Fix crash in fanout_demux_rollover() of AF_PACKET, from Mike
Maloney.
9) Fix race in AF_PACKET bind() vs. NETDEV_UP notifier, from Eric
Dumazet.
10) Fix regression in sch_sfq.c due to one of the timer_setup()
conversions. From Paolo Abeni.
11) SCTP does list_for_each_entry() using wrong struct member, fix from
Xin Long.
12) Don't use big endian netlink attribute read for
IFLA_BOND_AD_ACTOR_SYSTEM, it is in cpu endianness. Also from Xin
Long.
13) Fix mis-initialization of q->link.clock in CBQ scheduler, preventing
adding filters there. From Jiri Pirko.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits)
ethernet: dwmac-stm32: Fix copyright
net: via: via-rhine: use %p to format void * address instead of %x
net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit
myri10ge: Update MAINTAINERS
net: sched: cbq: create block for q->link.block
atm: suni: remove extraneous space to fix indentation
atm: lanai: use %p to format kernel addresses instead of %x
VSOCK: Don't set sk_state to TCP_CLOSE before testing it
atm: fore200e: use %pK to format kernel addresses instead of %x
ambassador: fix incorrect indentation of assignment statement
vxlan: use __be32 type for the param vni in __vxlan_fdb_delete
bonding: use nla_get_u64 to extract the value for IFLA_BOND_AD_ACTOR_SYSTEM
sctp: use right member as the param of list_for_each_entry
sch_sfq: fix null pointer dereference at timer expiration
cls_bpf: don't decrement net's refcount when offload fails
net/packet: fix a race in packet_bind() and packet_notifier()
packet: fix crash in fanout_demux_rollover()
sctp: remove extern from stream sched
sctp: force the params with right types for sctp csum apis
sctp: force SCTP_ERROR_INV_STRM with __u32 when calling sctp_chunk_fail
...
v2:
* Replace busy wait with wait_event()/wake_up_all()
* Cannot garantee that at the time xennet_remove is called, the
xen_netback state will not be XenbusStateClosed, so added a
condition for that
* There's a small chance for the xen_netback state is
XenbusStateUnknown by the time the xen_netfront switches to Closed,
so added a condition for that.
When unloading module xen_netfront from guest, dmesg would output
warning messages like below:
[ 105.236836] xen:grant_table: WARNING: g.e. 0x903 still in use!
[ 105.236839] deferring g.e. 0x903 (pfn 0x35805)
This problem relies on netfront and netback being out of sync. By the time
netfront revokes the g.e.'s netback didn't have enough time to free all of
them, hence displaying the warnings on dmesg.
The trick here is to make netfront to wait until netback frees all the g.e.'s
and only then continue to cleanup for the module removal, and this is done by
manipulating both device states.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC791 specifies the minimum MTU to be 68, while xen-net{front|back}
drivers use a minimum value of 0.
When set MTU to 0~67 with xen_net{front|back} driver, the network
will become unreachable immediately, the guest can no longer be pinged.
xen_net{front|back} should not allow the user to set this value which causes
network problems.
Reported-by: Chen Shi <cheshi@redhat.com>
Signed-off-by: Mohammed Gamal <mgamal@redhat.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
xennet_start_xmit() might copy skb with inappropriate layout
into a fresh one.
Old skb is freed, and at this point it is not a drop, but
a consume. New skb will then be either consumed or dropped.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unavoidable crashes in netfront_resume() and netback_changed() after a
previous fail in talk_to_netback() (e.g. when we fail to read MAC from
xenstore) were discovered. The failure path in talk_to_netback() does
unregister/free for netdev but we don't reset drvdata and we try accessing
it after resume.
Fix the bug by removing the whole xen device completely with
device_unregister(), this guarantees we won't have any calls into netfront
after a failure.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
