net: Remove unneeded NULL check for the allocated ifnet

Change 4787572d0580 made if_alloc_domain() never fail, then also do the
wrappers if_alloc(), if_alloc_dev(), and if_gethandle().

No functiona

net: Remove unneeded NULL check for the allocated ifnet

Change 4787572d0580 made if_alloc_domain() never fail, then also do the
wrappers if_alloc(), if_alloc_dev(), and if_gethandle().

No functional change intended.

Reviewed by: kp, imp, glebius, stevek
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D45740

(cherry picked from commit aa3860851b9f6a6002d135b1cac7736e0995eedc)

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netmap: Use device_set_descf()

No functional change intended.

MFC after: 1 week

(cherry picked from commit 44d36c9731c172977ad8a95a09c0d6fbddcc9b2f)

sys: Remove $FreeBSD$: one-line .c comment pattern

Remove /^/[*/]\s*\$FreeBSD\$.*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

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netmap: Handle packet batches in generic mode

ifnets are allowed to pass batches of multiple packets to if_input,
linked by the m_nextpkt pointer. iflib_rxeof() sometimes does this, for
example. N

netmap: Handle packet batches in generic mode

ifnets are allowed to pass batches of multiple packets to if_input,
linked by the m_nextpkt pointer. iflib_rxeof() sometimes does this, for
example. Netmap's generic mode did not handle this and would only
deliver the first packet in the batch, leaking the rest.

PR: 270636
Reviewed by: vmaffione
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D39426

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netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf

netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf headers to which netmap buffers are attached. When transmitting,
the mbuf refcount is initialized to 2, and when the counter value has
been decremented to 1 netmap infers that the driver has freed the mbuf
and thus transmission is complete.

This scheme does not generalize to the situation where netmap is
attaching to a software interface which may transmit packets among
multiple "queues", as is the case with bridge or lagg interfaces. In
that case, we would be relying on backing hardware drivers to free
transmitted mbufs promptly, but this isn't guaranteed; a driver may
reasonably defer freeing a small number of transmitted buffers
indefinitely. If such a buffer ends up at the tail of a netmap transmit
ring, further transmits can end up blocked indefinitely.

Fix the problem by removing the zero-copy scheme (which is also not
implemented in the Linux port of netmap). Instead, the kernel ring is
populated with regular mbuf clusters into which netmap buffers are
copied by nm_os_generic_xmit_frame(). The refcounting scheme is
preserved, and this lets us avoid allocating a fresh cluster per
transmitted packet in the common case. If the transmit ring is full, a
callout is used to free the "stuck" mbuf, avoiding the queue deadlock
described above.

Furthermore, when recycling mbuf clusters, be sure to fully reinitialize
the mbuf header instead of simply re-setting M_PKTHDR. Some software
interfaces, like if_vlan, may set fields in the header which should be
reset before the mbuf is reused.

Reviewed by: vmaffione
MFC after: 1 month
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38065

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netmap: get rid of save_if_input for emulated adapters

The save_if_input function pointer was meant to save the previous
value of ifp->if_input before replacing it with the emulated
adapter hook.
Ho

netmap: get rid of save_if_input for emulated adapters

The save_if_input function pointer was meant to save the previous
value of ifp->if_input before replacing it with the emulated
adapter hook.
However, the same pointer value is already stored in the if_input
field of the netmap_adapter struct, to be used for host TX ring processing.

Reuse the netmap_adapter if_input field to simplify the code
and save some space.

MFC after: 14 days

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netmap: Remove obsolete compatibility defines

No functional change intended.

Reviewed by: vmaffione
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D39001

Mechanically convert netmap(4) to IfAPI

Reviewed by: vmaffione, zlei
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D37814

netmap: drop redundant if_mtu assignment

Reported by: zlei
MFC after 3 days

if_lagg: Allow lagg interfaces to be used with netmap

Reviewed by: zlei
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D37

if_lagg: Allow lagg interfaces to be used with netmap

Reviewed by: zlei
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D37436

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netmap: drop compatibility FreeBSD code

Netmap users on FreeBSD are not supposed to import code from the
github netmap repository anymore. They should use the code that
is available in the src repo.

netmap: drop compatibility FreeBSD code

Netmap users on FreeBSD are not supposed to import code from the
github netmap repository anymore. They should use the code that
is available in the src repo. We can therefore drop the compatibility
code.

MFC after: 7 days

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netmap: Remove unused devclass arguments to DRIVER_MODULE.

netmap: several typo fixes

No functional changes intended.

netmap: add kernel support for the "offsets" feature

This feature enables applications to ask netmap to transmit or
receive packets starting at a user-specified offset from the
beginning of the netm

netmap: add kernel support for the "offsets" feature

This feature enables applications to ask netmap to transmit or
receive packets starting at a user-specified offset from the
beginning of the netmap buffer. This is meant to ease those
packet manipulation operations such as pushing or popping packet
headers, that may be useful to implement software switches,
routers and other packet processors.
To use the feature, drivers (e.g., iflib, vtnet, etc.) must have
explicit support. This change does not add support for any driver,
but introduces the necessary kernel changes. However, offsets support
is already included for VALE ports and pipes.

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netmap: fix issues in nm_os_extmem_create()

- Call vm_object_reference() before vm_map_lookup_done().
- Use vm_mmap_to_errno() to convert vm_map_* return values to errno.
- Fix memory leak of e->obj

netmap: fix issues in nm_os_extmem_create()

- Call vm_object_reference() before vm_map_lookup_done().
- Use vm_mmap_to_errno() to convert vm_map_* return values to errno.
- Fix memory leak of e->obj.

Reported by: markj
Reviewed by: markj
MFC after: 1 week

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Make page busy state deterministic on free. Pages must be xbusy when
removed from objects including calls to free. Pages must not be xbusy
when freed and not on an object. Strengthen assertions to

Make page busy state deterministic on free. Pages must be xbusy when
removed from objects including calls to free. Pages must not be xbusy
when freed and not on an object. Strengthen assertions to match these
expectations. In practice very little code had to change busy handling
to meet these rules but we can now make stronger guarantees to busy
holders and avoid conditionally dropping busy in free.

Refine vm_page_remove() and vm_page_replace() semantics now that we have
stronger guarantees about busy state. This removes redundant and
potentially problematic code that has proliferated.

Discussed with: markj
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22822

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(4/6) Protect page valid with the busy lock.

Atomics are used for page busy and valid state when the shared busy is
held. The details of the locking protocol and valid and dirty
synchronization are

(4/6) Protect page valid with the busy lock.

Atomics are used for page busy and valid state when the shared busy is
held. The details of the locking protocol and valid and dirty
synchronization are in the updated vm_page.h comments.

Reviewed by: kib, markj
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D21594

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Change synchonization rules for vm_page reference counting.

There are several mechanisms by which a vm_page reference is held,
preventing the page from being freed back to the page allocator. In
pa

Change synchonization rules for vm_page reference counting.

There are several mechanisms by which a vm_page reference is held,
preventing the page from being freed back to the page allocator. In
particular, holding the page's object lock is sufficient to prevent the
page from being freed; holding the busy lock or a wiring is sufficent as
well. These references are protected by the page lock, which must
therefore be acquired for many per-page operations. This results in
false sharing since the page locks are external to the vm_page
structures themselves and each lock protects multiple structures.

Transition to using an atomically updated per-page reference counter.
The object's reference is counted using a flag bit in the counter. A
second flag bit is used to atomically block new references via
pmap_extract_and_hold() while removing managed mappings of a page.
Thus, the reference count of a page is guaranteed not to increase if the
page is unbusied, unmapped, and the object's write lock is held. As
a consequence of this, the page lock no longer protects a page's
identity; operations which move pages between objects are now
synchronized solely by the objects' locks.

The vm_page_wire() and vm_page_unwire() KPIs are changed. The former
requires that either the object lock or the busy lock is held. The
latter no longer has a return value and may free the page if it releases
the last reference to that page. vm_page_unwire_noq() behaves the same
as before; the caller is responsible for checking its return value and
freeing or enqueuing the page as appropriate. vm_page_wire_mapped() is
introduced for use in pmap_extract_and_hold(). It fails if the page is
concurrently being unmapped, typically triggering a fallback to the
fault handler. vm_page_wire() no longer requires the page lock and
vm_page_unwire() now internally acquires the page lock when releasing
the last wiring of a page (since the page lock still protects a page's
queue state). In particular, synchronization details are no longer
leaked into the caller.

The change excises the page lock from several frequently executed code
paths. In particular, vm_object_terminate() no longer bounces between
page locks as it releases an object's pages, and direct I/O and
sendfile(SF_NOCACHE) completions no longer require the page lock. In
these latter cases we now get linear scalability in the common scenario
where different threads are operating on different files.

__FreeBSD_version is bumped. The DRM ports have been updated to
accomodate the KPI changes.

Reviewed by: jeff (earlier version)
Tested by: gallatin (earlier version), pho
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20486

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netmap: fix two panics with emulated adapter

This patch fixes 2 panics. The first one is due to the current VNET not
being set in the emulated adapter transmission path. The second one
is caused by

netmap: fix two panics with emulated adapter

This patch fixes 2 panics. The first one is due to the current VNET not
being set in the emulated adapter transmission path. The second one
is caused by the M_PKTHDR flag not being set when preallocated mbufs
are recycled in the transmit path.

Submitted by: [email protected]
Reviewed by: vmaffione
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20824

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Add two missing eventhandler.h headers

These are obviously missing from the .c files, but don't show up in any
tinderbox configuration (due to latent header pollution of some kind). It
seems some c

Add two missing eventhandler.h headers

These are obviously missing from the .c files, but don't show up in any
tinderbox configuration (due to latent header pollution of some kind). It
seems some configurations don't have this pollution, and the includes are
obviously missing, so go ahead and add them.

Reported by: Peter Jeremy <peter AT rulingia.com>
X-MFC-With: r347984

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netmap: don't schedule kqueue notify task when kqueue is not used

This change adds a counter (kqueue_users) to keep track of how many
kqueue users are referencing a given struct nm_selinfo.
In this

netmap: don't schedule kqueue notify task when kqueue is not used

This change adds a counter (kqueue_users) to keep track of how many
kqueue users are referencing a given struct nm_selinfo.
In this way, nm_os_selwakeup() can schedule the kevent notification
task only when kqueue is actually being used.
This is important to avoid wasting CPU in the common case where
kqueue is not used.

Reviewed by: Aleksandr Fedorov <[email protected]>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D19177

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netmap: refactor logging macros and pipes

Changelist:
- Replace ND, D and RD macros with nm_prdis, nm_prinf, nm_prerr
and nm_prlim, to avoid possible naming conflicts.
- Add netmap_kri

netmap: refactor logging macros and pipes

Changelist:
- Replace ND, D and RD macros with nm_prdis, nm_prinf, nm_prerr
and nm_prlim, to avoid possible naming conflicts.
- Add netmap_krings_mode_commit() helper function and use that
to reduce code duplication.
- Refactor pipes control code to export some functions that
can be reused by the veth driver (on Linux) and epair(4).
- Add check to reject API requests with version less than 11.
- Small code refactoring for the null adapter.

MFC after: 1 week

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netmap: fix lock order reversal related to kqueue usage

When using poll(), select() or kevent() on netmap file descriptors,
netmap executes the equivalent of NIOCTXSYNC and NIOCRXSYNC commands,
befo

netmap: fix lock order reversal related to kqueue usage

When using poll(), select() or kevent() on netmap file descriptors,
netmap executes the equivalent of NIOCTXSYNC and NIOCRXSYNC commands,
before collecting the events that are ready. In other words, the
poll/kevent callback has side effects. This is done to avoid the
overhead of two system call per iteration (e.g., poll() + ioctl(NIOC*XSYNC)).

When the kqueue subsystem invokes the kqueue(9) f_event callback
(netmap_knrw), it holds the lock of the struct knlist object associated
to the netmap port (the lock is provided at initialization, by calling
knlist_init_mtx).
However, netmap_knrw() may need to wake up another netmap port (or even
the same one), which means that it may need to call knote().
Since knote() needs the lock of the struct knlist object associated to
the to-be-wake-up netmap port, it is possible to have a lock order reversal
problem (AB/BA deadlock).

This change prevents the deadlock by executing the knote() call in a
per-selinfo taskqueue, where it is possible to hold a mutex.

Reviewed by: aleksandr.fedorov_itglobal.com
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D18956

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netmap: add notifications on kloop stop

On sync-kloop stop, send a wake-up signal to the kloop, so that
waiting for the timeout is not needed.
Also, improve logging in netmap_freebsd.c.

MFC after:

netmap: add notifications on kloop stop

On sync-kloop stop, send a wake-up signal to the kloop, so that
waiting for the timeout is not needed.
Also, improve logging in netmap_freebsd.c.

MFC after: 3 days

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