For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V
has sent to the guest.  Ensure that invalid values cannot cause indexing
off the end of an array, or subvert an existing validation via integer
overflow.  Ensure that outgoing packets do not have any leftover guest
memory that has not been zeroed out.
Reported-by: NJuan Vazquez <juvazq@microsoft.com>
Signed-off-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20210114202628.119541-1-parri.andrea@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

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: NLong Li <longli@microsoft.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NJakub 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: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NTariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-7-bjorn.topel@gmail.com

Currently, pointers to guest memory are passed to Hyper-V as
transaction IDs in netvsc. In the face of errors or malicious
behavior in Hyper-V, netvsc should not expose or trust the transaction
IDs returned by Hyper-V to be valid guest memory addresses. Instead,
use small integers generated by vmbus_requestor as requests
(transaction) IDs.
Signed-off-by: NAndres Beltran <lkmlabelt@gmail.com>
Co-developed-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Acked-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NWei Liu <wei.liu@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20201109100402.8946-4-parri.andrea@gmail.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

When communicating with Hyper-V, HV_HYP_PAGE_SIZE should be used since
that's the page size used by Hyper-V and Hyper-V expects all
page-related data using the unit of HY_HYP_PAGE_SIZE, for example, the
"pfn" in hv_page_buffer is actually the HV_HYP_PAGE (i.e. the Hyper-V
page) number.

In order to support guest whose page size is not 4k, we need to make
hv_netvsc always use HV_HYP_PAGE_SIZE for Hyper-V communication.
Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-8-boqun.feng@gmail.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V
has sent to the guest in the host-to-guest ring buffer. Ensure that
invalid values cannot cause indexing off the end of an array, or
subvert an existing validation via integer overflow. Ensure that
outgoing packets do not have any leftover guest memory that has not
been zeroed out.
Signed-off-by: NAndres Beltran <lkmlabelt@gmail.com>
Co-developed-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Acked-by: NStephen 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.comReviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>

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: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid 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: 7b2ee50c ("hv_netvsc: common detach logic")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid 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: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid 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: 5b54dac8 ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid 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: 5b54dac8 ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NSteve Winslow <swinslow@gmail.com>
Reviewed-by: NRichard Fontana <rfontana@redhat.com>
Reviewed-by: NAlexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NStephan Klein <stephan.klein@wegfinder.at>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two reasons for this.

First, the xmit_more flag conceptually doesn't fit into the skb, as
xmit_more is not a property related to the skb.
Its only a hint to the driver that the stack is about to transmit another
packet immediately.

Second, it was only done this way to not have to pass another argument
to ndo_start_xmit().

We can place xmit_more in the softnet data, next to the device recursion.
The recursion counter is already written to on each transmit. The "more"
indicator is placed right next to it.

Drivers can use the netdev_xmit_more() helper instead of skb->xmit_more
to check the "more packets coming" hint.

skb->xmit_more is retained (but always 0) to not cause build breakage.

This change takes care of the simple s/skb->xmit_more/netdev_xmit_more()/
conversions.  Remaining drivers are converted in the next patches.
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After queue stopped, the wakeup mechanism may wake it up again
when ring buffer usage is lower than a threshold. This may cause
send path panic on NULL pointer when we stopped all tx queues in
netvsc_detach and start removing the netvsc device.

This patch fix it by adding a tx_disable flag to prevent unwanted
queue wakeup.

Fixes: 7b2ee50c ("hv_netvsc: common detach logic")
Reported-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix all typos from hyperv netvsc code comments.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Alessandro Pilotti" <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Changing mtu, channels, or buffer sizes ops call to netvsc_attach(),
rndis_set_subchannel(), which always reset the hash key to default
value. That will override hash key changed previously. This patch
fixes the problem by save the hash key, then restore it when we re-
add the netvsc device.

Fixes: ff4a4419 ("netvsc: allow get/set of RSS indirection table")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
[sl: fix up subject line]
Signed-off-by: NSasha Levin <sashal@kernel.org>

LRO/RSC in the vSwitch is a feature available in Windows Server 2019
hosts and later. It reduces the per packet processing overhead by
coalescing multiple TCP segments when possible. This patch adds netvsc
driver support for this feature.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Matching network device based on MAC address is problematic
since a non VF network device can be creted with a duplicate MAC
address causing confusion and problems.  The VMBus API does provide
a serial number that is a better matching method.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If out ring is full temporarily and receive completion cannot go out,
we may still need to reschedule napi if certain conditions are met.
Otherwise the napi poll might be stopped forever, and cause network
disconnect.

Fixes: 7426b1a5 ("netvsc: optimize receive completions")
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When doing device hotplug the sub channel must be async to avoid
deadlock issues because device is discovered in softirq context.

When doing changes to MTU and number of channels, the setup
must be synchronous to avoid races such as when MTU and device
settings are done in a single ip command.
Reported-by: NThomas Walker <Thomas.Walker@twosigma.com>
Fixes: 8195b139 ("hv_netvsc: fix deadlock on hotplug")
Fixes: 732e4985 ("netvsc: fix race on sub channel creation")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The calls up from the napi poll reading the receive ring had many
places where an argument was being recreated. I.e the caller already
had the value and wasn't passing it, then the callee would use
known relationship to determine the same value. Simpler and faster
to just pass arguments needed.

Also, add const in a couple places where message is being only read.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the NetVSP v6 and 6.1 message structures, and includes
these versions into NetVSC/NetVSP version negotiation process.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In Vmbus, we have defined a function to calculate available ring buffer
percentage to write.

Use that function and remove netvsc's private version.

[mkp: typo]
Signed-off-by: NLong Li <longli@microsoft.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The callers to netvsc_revoke_*_buf() and netvsc_teardown_*_gpadl()
already have their net_device instances. Pass them as a paramaeter to
the function instead of obtaining them from netvsc_device struct
everytime
Signed-off-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prior to commit 0cf73780 ("hv_netvsc: netvsc_teardown_gpadl() split")
the call sequence in netvsc_device_remove() was as follows (as
implemented in netvsc_destroy_buf()):
1- Send NVSP_MSG1_TYPE_REVOKE_RECV_BUF message
2- Teardown receive buffer GPADL
3- Send NVSP_MSG1_TYPE_REVOKE_SEND_BUF message
4- Teardown send buffer GPADL
5- Close vmbus

This didn't work for WS2016 hosts. Commit 0cf73780
("hv_netvsc: netvsc_teardown_gpadl() split") rearranged the
teardown sequence as follows:
1- Send NVSP_MSG1_TYPE_REVOKE_RECV_BUF message
2- Send NVSP_MSG1_TYPE_REVOKE_SEND_BUF message
3- Close vmbus
4- Teardown receive buffer GPADL
5- Teardown send buffer GPADL

That worked well for WS2016 hosts, but it prevented guests on older hosts from
shutting down after changing network settings. Commit 0ef58b0a
("hv_netvsc: change GPAD teardown order on older versions") ensured the
following message sequence for older hosts
1- Send NVSP_MSG1_TYPE_REVOKE_RECV_BUF message
2- Send NVSP_MSG1_TYPE_REVOKE_SEND_BUF message
3- Teardown receive buffer GPADL
4- Teardown send buffer GPADL
5- Close vmbus

However, with this sequence calling `ip link set eth0 mtu 1000` hangs and the
process becomes uninterruptible. On futher analysis it turns out that on tearing
down the receive buffer GPADL the kernel is waiting indefinitely
in vmbus_teardown_gpadl() for a completion to be signaled.

Here is a snippet of where this occurs:
int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
{
        struct vmbus_channel_gpadl_teardown *msg;
        struct vmbus_channel_msginfo *info;
        unsigned long flags;
        int ret;

        info = kmalloc(sizeof(*info) +
                       sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        init_completion(&info->waitevent);
        info->waiting_channel = channel;
[....]
        ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
                             true);

        if (ret)
                goto post_msg_err;

        wait_for_completion(&info->waitevent);
[....]
}

The completion is signaled from vmbus_ongpadl_torndown(), which gets called when
the corresponding message is received from the host, which apparently never happens
in that case.
This patch works around the issue by restoring the first mentioned message sequence
for older hosts

Fixes: 0ef58b0a ("hv_netvsc: change GPAD teardown order on older versions")
Signed-off-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split each of the functions into two for each of send/recv buffers.
This will be needed in order to implement a fine-grained messaging
sequence to the host so that we accommodate the requirements of
different Windows versions

Fixes: 0ef58b0a ("hv_netvsc: change GPAD teardown order on older versions")
Signed-off-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When changing network interface settings, Windows guests
older than WS2016 can no longer shutdown. This was addressed
by commit 0ef58b0a ("hv_netvsc: change GPAD teardown order
on older versions"), however the issue also occurs on WS2012
guests that share NVSP protocol versions with WS2016 guests.
Hence we use Windows version directly to differentiate them.

Fixes: 0ef58b0a ("hv_netvsc: change GPAD teardown order on older versions")
Signed-off-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds range checking for rx packet offset and length.
It may only happen if there is a host side bug.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As defined in hyperv_net.h, the NVSP_STAT_SUCCESS is one not zero.
Some functions returns 0 when it actually means NVSP_STAT_SUCCESS.
This patch fixes them.

In netvsc_receive(), it puts the last RNDIS packet's receive status
for all packets in a vmxferpage which may contain multiple RNDIS
packets.
This patch puts NVSP_STAT_FAIL in the receive completion if one of
the packets in a vmxferpage fails.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make common function for detaching internals of device
during changes to MTU and RSS. Make sure no more packets
are transmitted and all packets have been received before
doing device teardown.

Change the wait logic to be common and use usleep_range().

Changes transmit enabling logic so that transmit queues are disabled
during the period when lower device is being changed. And enabled
only after sub channels are setup. This avoids issue where it could
be that a packet was being sent while subchannel was not initialized.

Fixes: 8195b139 ("hv_netvsc: fix deadlock on hotplug")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On older versions of Windows, the host ignores messages after
vmbus channel is closed.

Workaround this by doing what Windows does and send the teardown
before close on older versions of NVSP protocol.
Reported-by: NMohammed Gamal <mgamal@redhat.com>
Fixes: 0cf73780 ("hv_netvsc: netvsc_teardown_gpadl() split")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The receive processing may continue to happen while the
internal network device state is in RCU grace period.
The internal RNDIS structure is associated with the
internal netvsc_device structure; both have the same
RCU lifetime.

Defer freeing all associated parts until after grace
period.

Fixes: 0cf73780 ("hv_netvsc: netvsc_teardown_gpadl() split")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This makes sure that no CPU is still process packets when
the channel is closed.

Fixes: 76bb5db5 ("netvsc: fix use after free on module removal")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds tracepoints to the driver which has proved useful in
debugging startup and shutdown race conditions.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the netvsc_channel_cb is already called in interrupt
context from vmbus, there is no need to do irqsave/restore.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a race between napi_reschedule and re-enabling interrupts
which could lead to missed host interrrupts.  This occurs when
interrupts are re-enabled (hv_end_read) and vmbus irq callback
(netvsc_channel_cb) has already scheduled NAPI.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Need to delete NAPI association if vmbus_open fails.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change the initialization order so that the device is ready to transmit
(ie connect vsp is completed) before setting the internal reference
to the device with RCU.

This avoids any races on initialization and prevents retry issues
on shutdown.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>