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  1. 03 10月, 2017 13 次提交
  3. 30 9月, 2017 15 次提交
  5. 27 9月, 2017 2 次提交
    • D
      bpf, ixgbe: add meta data support · 366a88fe
      由 Daniel Borkmann 提交于 
      Implement support for transferring XDP meta data into skb for
ixgbe driver; before calling into the program, xdp.data_meta points
to xdp.data, where on program return with pass verdict, we call
into skb_metadata_set().

We implement this for the default ixgbe_build_skb() variant. For the
ixgbe_construct_skb() that is used when legacy-rx buffer mananagement
mode is turned on via ethtool, I found that XDP gets 0 headroom, so
neither xdp_adjust_head() nor xdp_adjust_meta() can be used with this.
Just add a comment with explanation for this operating mode.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      366a88fe
    • D
      bpf: add meta pointer for direct access · de8f3a83
      由 Daniel Borkmann 提交于 
      This work enables generic transfer of metadata from XDP into skb. The
basic idea is that we can make use of the fact that the resulting skb
must be linear and already comes with a larger headroom for supporting
bpf_xdp_adjust_head(), which mangles xdp->data. Here, we base our work
on a similar principle and introduce a small helper bpf_xdp_adjust_meta()
for adjusting a new pointer called xdp->data_meta. Thus, the packet has
a flexible and programmable room for meta data, followed by the actual
packet data. struct xdp_buff is therefore laid out that we first point
to data_hard_start, then data_meta directly prepended to data followed
by data_end marking the end of packet. bpf_xdp_adjust_head() takes into
account whether we have meta data already prepended and if so, memmove()s
this along with the given offset provided there's enough room.

xdp->data_meta is optional and programs are not required to use it. The
rationale is that when we process the packet in XDP (e.g. as DoS filter),
we can push further meta data along with it for the XDP_PASS case, and
give the guarantee that a clsact ingress BPF program on the same device
can pick this up for further post-processing. Since we work with skb
there, we can also set skb->mark, skb->priority or other skb meta data
out of BPF, thus having this scratch space generic and programmable
allows for more flexibility than defining a direct 1:1 transfer of
potentially new XDP members into skb (it's also more efficient as we
don't need to initialize/handle each of such new members). The facility
also works together with GRO aggregation. The scratch space at the head
of the packet can be multiple of 4 byte up to 32 byte large. Drivers not
yet supporting xdp->data_meta can simply be set up with xdp->data_meta
as xdp->data + 1 as bpf_xdp_adjust_meta() will detect this and bail out,
such that the subsequent match against xdp->data for later access is
guaranteed to fail.

The verifier treats xdp->data_meta/xdp->data the same way as we treat
xdp->data/xdp->data_end pointer comparisons. The requirement for doing
the compare against xdp->data is that it hasn't been modified from it's
original address we got from ctx access. It may have a range marking
already from prior successful xdp->data/xdp->data_end pointer comparisons
though.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      de8f3a83
  7. 22 9月, 2017 4 次提交
  9. 06 9月, 2017 2 次提交
    • J
      i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq · 3c8f3e96
      由 Jacob Keller 提交于 
      When introducing the functions to read the NVM through the AdminQ, we
did not correctly mark the wb_desc.

Fixes: 7073f46e ("i40e: Add AQ commands for NVM Update for X722", 2015-06-05)
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      3c8f3e96
    • A
      i40e: avoid NVM acquire deadlock during NVM update · 09f79fd4
      由 Anjali Singhai Jain 提交于 
      X722 devices use the AdminQ to access the NVM, and this requires taking
the AdminQ lock. Because of this, we lock the AdminQ during
i40e_read_nvm(), which is also called in places where the lock is
already held, such as the firmware update path which wants to lock once
and then unlock when finished after performing several tasks.

Although this should have only affected X722 devices, commit
96a39aed ("i40e: Acquire NVM lock before reads on all devices",
2016-12-02) added locking for all NVM reads, regardless of device
family.

This resulted in us accidentally causing NVM acquire timeouts on all
devices, causing failed firmware updates which left the eeprom in
a corrupt state.

Create unsafe non-locked variants of i40e_read_nvm_word and
i40e_read_nvm_buffer, __i40e_read_nvm_word and __i40e_read_nvm_buffer
respectively. These variants will not take the NVM lock and are expected
to only be called in places where the NVM lock is already held if
needed.

Since the only caller of i40e_read_nvm_buffer() was in such a path,
remove it entirely in favor of the unsafe version. If necessary we can
always add it back in the future.

Additionally, we now need to hold the NVM lock in i40e_validate_checksum
because the call to i40e_calc_nvm_checksum now assumes that the NVM lock
is held. We can further move the call to read I40E_SR_SW_CHECKSUM_WORD
up a bit so that we do not need to acquire the NVM lock twice.

This should resolve firmware updates and also fix potential raise that
could have caused the driver to report an invalid NVM checksum upon
driver load.
Reported-by: NStefan Assmann <sassmann@kpanic.de>
Fixes: 96a39aed ("i40e: Acquire NVM lock before reads on all devices", 2016-12-02)
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      09f79fd4
  11. 28 8月, 2017 4 次提交
    • J
      i40e/i40evf: avoid dynamic ITR updates when polling or low packet rate · 742c9875
      由 Jacob Keller 提交于 
      The dynamic ITR algorithm depends on a calculation of usecs which
assumes that the interrupts have been firing constantly at the interrupt
throttle rate. This is not guaranteed because we could have a low packet
rate, or have been polling in software.

We'll estimate whether this is the case by using jiffies to determine if
we've been too long. If the time difference of jiffies is larger we are
guaranteed to have an incorrect calculation. If the time difference of
jiffies is smaller we might have been polling some but the difference
shouldn't affect the calculation too much.

This ensures that we don't get stuck in BULK latency during certain rare
situations where we receive bursts of packets that force us into NAPI
polling.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      742c9875
    • J
      i40e/i40evf: remove ULTRA latency mode · 0a2c7722
      由 Jacob Keller 提交于 
      Since commit c56625d5 ("i40e/i40evf: change dynamic interrupt
thresholds") a new higher latency ITR setting called I40E_ULTRA_LATENCY
was added with a cryptic comment about how it was meant for adjusting Rx
more aggressively when streaming small packets.

This mode was attempting to calculate packets per second and then kick
in when we have a huge number of small packets.

Unfortunately, the ULTRA setting was kicking in for workloads it wasn't
intended for including single-thread UDP_STREAM workloads.

This wasn't caught for a variety of reasons. First, the ip_defrag
routines were improved somewhat which makes the UDP_STREAM test still
reasonable at 10GbE, even when dropped down to 8k interrupts a second.
Additionally, some other obvious workloads appear to work fine, such
as TCP_STREAM.

The number 40k doesn't make sense for a number of reasons. First, we
absolutely can do more than 40k packets per second. Second, we calculate
the value inline in an integer, which sometimes can overflow resulting
in using incorrect values.

If we fix this overflow it makes it even more likely that we'll enter
ULTRA mode which is the opposite of what we want.

The ULTRA mode was added originally as a way to reduce CPU utilization
during a small packet workload where we weren't keeping up anyways. It
should never have been kicking in during these other workloads.

Given the issues outlined above, let's remove the ULTRA latency mode. If
necessary, a better solution to the CPU utilization issue for small
packet workloads will be added in a future patch.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      0a2c7722
    • J
      i40e: invert logic for checking incorrect cpu vs irq affinity · 6d977729
      由 Jacob Keller 提交于 
      In commit 96db776a ("i40e/vf: fix interrupt affinity bug")
we added some code to force exit of polling in case we did
not have the correct CPU. This is important since it was possible for
the IRQ affinity to be changed while the CPU is pegged at 100%. This can
result in the polling routine being stuck on the wrong CPU until
traffic finally stops.

Unfortunately, the implementation, "if the CPU is correct, exit as
normal, otherwise, fall-through to the end-polling exit" is incredibly
confusing to reason about. In this case, the normal flow looks like the
exception, while the exception actually occurs far away from the if
statement and comment.

We recently discovered and fixed a bug in this code because we were
incorrectly initializing the affinity mask.

Re-write the code so that the exceptional case is handled at the check,
rather than having the logic be spread through the regular exit flow.
This does end up with minor code duplication, but the resulting code is
much easier to reason about.

The new logic is identical, but inverted. If we are running on a CPU not
in our affinity mask, we'll exit polling. However, the code flow is much
easier to understand.

Note that we don't actually have to check for MSI-X, because in the MSI
case we'll only have one q_vector, but its default affinity mask should
be correct as it includes all CPUs when it's initialized. Further, we
could at some point add code to setup the notifier for the non-MSI-X
case and enable this workaround for that case too, if desired, though
there isn't much gain since its unlikely to be the common case.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      6d977729
    • J
      i40e: initialize our affinity_mask based on cpu_possible_mask · 759dc4a7
      由 Jacob Keller 提交于 
      On older kernels a call to irq_set_affinity_hint does not guarantee that
the IRQ affinity will be set. If nothing else on the system sets the IRQ
affinity this can result in a bug in the i40e_napi_poll() routine where
we notice that our interrupt fired on the "wrong" CPU according to our
internal affinity_mask variable.

This results in a bug where we continuously tell NAPI to stop polling to
move the interrupt to a new CPU, but the CPU never changes because our
affinity mask does not match the actual mask setup for the IRQ.

The root problem is a mismatched affinity mask value. So lets initialize
the value to cpu_possible_mask instead. This ensures that prior to the
first time we get an IRQ affinity notification we'll have the mask set
to include every possible CPU.

We use cpu_possible_mask instead of cpu_online_mask since the former is
almost certainly never going to change, while the later might change
after we've made a copy.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
      759dc4a7