The only thing is used from this code is ipip_output() function, that does
IPIP encapsulation. Other parts of XF_IP4 code were removed in r275133.
Also it isn't possible to configure the use of XF_IP4, nor from userland
via setkey(8), nor from the kernel.
Simplify the ipip_output() function and rename it to ipsec_encap().
* move IP_DF handling from ipsec4_process_packet() into ipsec_encap();
* since ipsec_encap() called from ipsec[64]_process_packet(), it
is safe to assume that mbuf is contiguous at least to IP header
for used IP version. Remove all unneeded m_pullup(), m_copydata
and related checks.
* use V_ip_defttl and V_ip6_defhlim for outer headers;
* use V_ip4_ipsec_ecn and V_ip6_ipsec_ecn for outer headers;
* move all diagnostic messages to the ipsec_encap() callers;
* simplify handling of ipsec_encap() results: if it returns non zero
value, print diagnostic message and free mbuf.
* some style(9) fixes.
Differential Revision: https://reviews.freebsd.org/D2303
Reviewed by: glebius
Sponsored by: Yandex LLC
discontinued by its initial authors. In FreeBSD the code was already
slightly edited during the pf(4) SMP project. It is about to be edited
more in the projects/ifnet. Moving out of contrib also allows to remove
several hacks to the make glue.
Reviewed by: net@
function names have changed and comments are reformatted or added, but
there is no functional change.
Claim copyright for me and Adrian.
Sponsored by: Nginx, Inc.
Handle the VIRQ_DEBUG signal and print a stack trace of each vCPU on the Xen
console. This is only used for debug purposes and is triggered by the
administrator of the Xen host.
Sponsored by: Citrix Systems R&D
MFC after: 1 week
Many thanks to ian who gently provided me the DS1307 breakout board.
Tested on: Raspberry pi
Differential Revision: https://reviews.freebsd.org/D2022
Reviewed by: rpaulo
- Split the driver into independent pf and vf loadables. This is
in preparation for SRIOV support which will be following shortly.
This also allows us to keep a seperate revision control over the
two parts, making for easier sustaining.
- Make the TX/RX code a shared/seperated file, in the old code base
the ixv code would miss fixes that went into ixgbe, this model
will eliminate that problem.
- The driver loadables will now match the device names, something that
has been requested for some time.
- Rather than a modules/ixgbe there is now modules/ix and modules/ixv
- It will also be possible to make your static kernel with only one
or the other for streamlined installs, or both.
Enjoy!
Submitted by: jfv and erj
drivers can use it. This avoids some code duplication. Add missing
default case to all switch statements while at it. Also move the
hashing of the IPv6 flow field to layer 4 because the IPv6 flow field
is constant on a per L4 connection basis and not on a per L3 network.
Differential Revision: https://reviews.freebsd.org/D1987
Sponsored by: Mellanox Technologies
MFC after: 1 month
Implement the interace to create SR-IOV Virtual Functions (VFs).
When a driver registers that they support SR-IOV by calling
pci_setup_iov(), the SR-IOV code creates a new node in /dev/iov
for that device. An ioctl can be invoked on that device to
create VFs and have the driver initialize them.
At this point, allocating memory I/O windows (BARs) is not
supported.
Differential Revision: https://reviews.freebsd.org/D76
Reviewed by: jhb
MFC after: 1 month
Sponsored by: Sandvine Inc.
I2C real-time clock (RTC).
The DS3231 has an integrated temperature-compensated crystal oscillator
(TXCO) and crystal.
DS3231 has a temperature sensor, an independent 32kHz output (which can be
turned on and off by the driver) and another output that can be used as
interrupt for alarms or as a second square-wave output, which frequency and
operation mode can be set by driver sysctl(8) knobs.
Differential Revision: https://reviews.freebsd.org/D1016
Reviewed by: ian, rpaulo
Tested on: Raspberry pi model B
this option from all modules that enable it theirselves.
In C mode -fms-extensions option enables anonymous structs and unions,
allowing us to use this C11 feature in kernel. Of course, clang supports
it without any extra options.
Reviewed by: dim
Highlights:
- Multiple verbs API updates
- Support for RoCE, RDMA over ethernet
All hardware drivers depending on the common infiniband stack has been
updated aswell.
Discussed with: np @
Sponsored by: Mellanox Technologies
MFC after: 1 month
has been removed and the driver has been greatly simplified and
optimised for FreeBSD. The driver is currently not built by default.
Requested by: Bruce Simpson <bms@fastmail.net>
bits.
The motivation here is to eventually teach netisr and potentially
other networking subsystems a bit more about how RSS work queues / buckets
are configured so things have a hope of auto-configuring in the future.
* net/rss_config.[ch] takes care of the generic bits for doing
configuration, hash function selection, etc;
* topelitz.[ch] is now in net/ rather than netinet/;
* (and would be in libkern if it didn't directly include RSS_KEYSIZE;
that's a later thing to fix up.)
* netinet/in_rss.[ch] now just contains the IPv4 specific methods;
* and netinet/in6_rss.[ch] now just contains the IPv6 specific methods.
This should have no functional impact on anyone currently using
the RSS support.
Differential Revision: D1383
Reviewed by: gnn, jfv (intel driver bits)
amd64. Until further we need some custom C-flags when building the
Linux compat API.
MFC after: 1 month
Sponsored by: Mellanox Technologies
Reported by: bz@
by dumbbell@ to be able to compile this layer as a dependency module.
Clean up some Makefiles and remove the no longer used OFED define.
Currently only i386 and amd64 targets are supported.
MFC after: 1 month
Sponsored by: Mellanox Technologies
code in sys/kern/kern_dump.c. Most dumpsys() implementations are nearly
identical and simply redefine a number of constants and helper subroutines;
a generic implementation will make it easier to implement features around
kernel core dumps. This change does not alter any minidump code and should
have no functional impact.
PR: 193873
Differential Revision: https://reviews.freebsd.org/D904
Submitted by: Conrad Meyer <conrad.meyer@isilon.com>
Reviewed by: jhibbits (earlier version)
Sponsored by: EMC / Isilon Storage Division
of the scan API.
The eventual aim is to have 'ieee80211_scan.c' have the net80211 and
driver facing scan API to start, finish and continue doing scanning
while 'ieee80211_swscan.c' implements the software scanner that
runs the scan task, handles probe request/reply bits, configures
the VAP off-channel, changes channel and does the scanning bits.
For NICs that do no scanning at all, the existing code is needed.
ath(4) and most of the other NICs (dumb USB ones in particular)
do little to no scan offload - it's all done in software.
Some NICs may do single channel at a time scanning; I haven't really
checked them out in detail.
iwn(4), the upcoming 7260 driver stuff, the new Qualcomm Atheros
11ac chipsets and the Atheros mobile/USB full-offload chips all
have complete scan engines in firmware. We don't have to drive
any of it at all - the firmware just needs to be told what to scan,
when to scan, how long to scan. It'll take care of going off
channel, pausing TX/RX appropriately, sending sleep notification
to the AP, sending probe requests and handling probe responses.
It'll do passive/active scan itself. It's almost completely
transparent to the network stack - all we see are scan notifications
when it finishes scanning each channel and beacons/probe responses
when it does its thing. Once it's done we get a final notification
that the scan is complete, with some scan results in the message.
The iwn(4) NICs handle doing active scanning too as an option
and will handle waiting appropriately on 5GHz passive channels
before active scanning.
There's some more refactoring, tidying up and lock assertions to
sprinkle around to tidy this whole thing up before I turn swscan.c
into another set of ic methods to override by the driver or
alternate scan module. So in theory this is all one big no-op
commit. In theory.
Tested:
* iwn(4) 5200, STA mode
* ath(4) 6205, STA mode
* ath(4) - various NICs, AP mode
CWARNFALGS.$file centrally so we don't have to have it in all the
places. Remove a few warning flags that are no longer needed.
Also, always use -Wno-unknown-pragma to (hopefully temporarily) work
around #pragma ident in debug.h in the opensolaris code. Remove some
stale warning suppression that's no longer necessary.
roughly 10 years, and the driver has not enjoyed any significant maintenance
since long before that. Despite well-meaning efforts from a number of
people, myself included, it never made the jump to 64-bit and was relegated
to the back-corners of i386. Now its frailty is hampering forward progress
with Clang. Any renewed engineering efforts are of course welcome and can
happen outside of the tree. No MFC of this is planned.
a) Front load as much work as possible in if_transmit, before any driver
lock or software queue has to get involved.
b) Replace buf_ring with a brand new mp_ring (multiproducer ring). This
is specifically for the tx multiqueue model where one of the if_transmit
producer threads becomes the consumer and other producers carry on as
usual. mp_ring is implemented as standalone code and it should be
possible to use it in any driver with tx multiqueue. It also has:
- the ability to enqueue/dequeue multiple items. This might become
significant if packet batching is ever implemented.
- an abdication mechanism to allow a thread to give up writing tx
descriptors and have another if_transmit thread take over. A thread
that's writing tx descriptors can end up doing so for an unbounded
time period if a) there are other if_transmit threads continuously
feeding the sofware queue, and b) the chip keeps up with whatever the
thread is throwing at it.
- accurate statistics about interesting events even when the stats come
at the expense of additional branches/conditional code.
The NIC txq lock is uncontested on the fast path at this point. I've
left it there for synchronization with the control events (interface
up/down, modload/unload).
c) Add support for "type 1" coalescing work request in the normal NIC tx
path. This work request is optimized for frames with a single item in
the DMA gather list. These are very common when forwarding packets.
Note that netmap tx in cxgbe already uses these "type 1" work requests.
d) Do not request automatic cidx updates every 32 descriptors. Instead,
request updates via bits in individual work requests (still every 32
descriptors approximately). Also, request an automatic final update
when the queue idles after activity. This means NIC tx reclaim is still
performed lazily but it will catch up quickly as soon as the queue
idles. This seems to be the best middle ground and I'll probably do
something similar for netmap tx as well.
e) Implement a faster tx path for WRQs (used by TOE tx and control
queues, _not_ by the normal NIC tx). Allow work requests to be written
directly to the hardware descriptor ring if room is available. I will
convert t4_tom and iw_cxgbe modules to this faster style gradually.
MFC after: 2 months
images into the kernel as currently included into iwn6000g2{a,b}fw.ko
and delete the old files, missed in r254199 and r259135 respectively.
MFC after: 3 days
which means that the NFSCLIENT and NFSSERVER
kernel options will no longer work. This commit
only removes the kernel components. Removal of
unused code in the user utilities will be done
later. This commit does not include an addition
to UPDATING, but that will be committed in a
few minutes.
Discussed on: freebsd-fs
the orphaned descendants. Base of the API is modelled after the same
feature from the DragonFlyBSD.
Requested by: bapt
Reviewed by: jilles (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
for counter mode), and AES-GCM. Both of these modes have been added to
the aesni module.
Included is a set of tests to validate that the software and aesni
module calculate the correct values. These use the NIST KAT test
vectors. To run the test, you will need to install a soon to be
committed port, nist-kat that will install the vectors. Using a port
is necessary as the test vectors are around 25MB.
All the man pages were updated. I have added a new man page, crypto.7,
which includes a description of how to use each mode. All the new modes
and some other AES modes are present. It would be good for someone
else to go through and document the other modes.
A new ioctl was added to support AEAD modes which AES-GCM is one of them.
Without this ioctl, it is not possible to test AEAD modes from userland.
Add a timing safe bcmp for use to compare MACs. Previously we were using
bcmp which could leak timing info and result in the ability to forge
messages.
Add a minor optimization to the aesni module so that single segment
mbufs don't get copied and instead are updated in place. The aesni
module needs to be updated to support blocked IO so segmented mbufs
don't have to be copied.
We require that the IV be specified for all calls for both GCM and ICM.
This is to ensure proper use of these functions.
Obtained from: p4: //depot/projects/opencrypto
Relnotes: yes
Sponsored by: FreeBSD Foundation
Sponsored by: NetGate
Mave the grant table code into the dev/xen folder in preparation for turning
it into a device using the newbus interface. This is just code motion, no
functional changes.
Sponsored by: Citrix Systems R&D
partitions. Several utilities still use this interface and require
additional information since gpart was activated than before. This
allows fsck of a UFS partition without having to specify it is UFS,
per historic behavior.
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.
No objections from: net@
Split it into two modules: if_gre(4) for GRE encapsulation and
if_me(4) for minimal encapsulation within IP.
gre(4) changes:
* convert to if_transmit;
* rework locking: protect access to softc with rmlock,
protect from concurrent ioctls with sx lock;
* correct interface accounting for outgoing datagramms (count only payload size);
* implement generic support for using IPv6 as delivery header;
* make implementation conform to the RFC 2784 and partially to RFC 2890;
* add support for GRE checksums - calculate for outgoing datagramms and check
for inconming datagramms;
* add support for sending sequence number in GRE header;
* remove support of cached routes. This fixes problem, when gre(4) doesn't
work at system startup. But this also removes support for having tunnels with
the same addresses for inner and outer header.
* deprecate support for various GREXXX ioctls, that doesn't used in FreeBSD.
Use our standard ioctls for tunnels.
me(4):
* implementation conform to RFC 2004;
* use if_transmit;
* use the same locking model as gre(4);
PR: 164475
Differential Revision: D1023
No objections from: net@
Relnotes: yes
Sponsored by: Yandex LLC
This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources.
The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people.
The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway.
Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to.
My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise.
My Nomex pants are on. Let the feedback commence!
Reviewed by: trasz,des(partial),imp(partial?),rwatson(partial?)
Approved by: so(des)
This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.
Sponsored by: Citrix Systems R&D
i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
- Introduce a function to make generic hypercalls into Xen.
xen/interface/xen.h:
xen/interface/memory.h:
- Import the new hypercall XENMEM_add_to_physmap_range used by
auto-translated guests to map memory from foreign domains.
dev/xen/privcmd/privcmd.c:
- This device has the following functions:
- Allow user-space applications to make hypercalls into Xen.
- Allow user-space applications to map memory from foreign domains,
this is accomplished using the newly introduced hypercall
(XENMEM_add_to_physmap_range).
xen/privcmd.h:
- Public ioctl interface for the privcmd device.
x86/xen/hvm.c:
- Remove declaration of hypercall_page, now it's declared in
hypercall.h.
conf/files:
- Add the privcmd device to the build process.
The user-space event channel device is used by applications to receive
and send event channel interrupts. This device is based on the Linux
evtchn device.
Sponsored by: Citrix Systems R&D
xen/evtchn/evtchn_dev.c:
- Remove the old event channel device, which was already disabled in
the build system.
dev/xen/evtchn/evtchn_dev.c:
- Import a new event channel device based on the one present in
Linux.
- This device allows the following operations:
- Bind VIRQ event channels (ioctl).
- Bind regular event channels (ioctl).
- Create and bind new event channels (ioctl).
- Unbind event channels (ioctl).
- Send notifications to event channels (ioctl).
- Reset the device shared memory ring (ioctl).
- Unmask event channels (write).
- Receive event channel upcalls (read).
- The new code is MP safe, and can be used concurrently.
conf/files:
- Add the new device to the build system.
vxlan creates a virtual LAN by encapsulating the inner Ethernet frame in
a UDP packet. This implementation is based on RFC7348.
Currently, the IPv6 support is not fully compliant with the specification:
we should be able to receive UPDv6 packets with a zero checksum, but we
need to support RFC6935 first. Patches for this should come soon.
Encapsulation protocols such as vxlan emphasize the need for the FreeBSD
network stack to support batching, GRO, and GSO. Each frame has to make
two trips through the network stack, and each frame will be at most MTU
sized. Performance suffers accordingly.
Some latest generation NICs have begun to support vxlan HW offloads that
we should also take advantage of. VIMAGE support should also be added soon.
Differential Revision: https://reviews.freebsd.org/D384
Reviewed by: gnn
Relnotes: yes
syscalls themselves are tightly coupled with the network stack and
therefore should not be in the generic socket code.
The following four syscalls have been marked as NOSTD so they can be
dynamically registered in sctp_syscalls_init() function:
sys_sctp_peeloff
sys_sctp_generic_sendmsg
sys_sctp_generic_sendmsg_iov
sys_sctp_generic_recvmsg
The syscalls are also set up to be dynamically registered when COMPAT32
option is configured.
As a side effect of moving the SCTP syscalls, getsock_cap needs to be
made available outside of the uipc_syscalls.c source file. A proper
prototype has been added to the sys/socketvar.h header file.
API tests from the SCTP reference implementation have been run to ensure
compatibility. (http://code.google.com/p/sctp-refimpl/source/checkout)
Submitted by: Steve Kiernan <stevek@juniper.net>
Reviewed by: tuexen, rrs
Obtained from: Juniper Networks, Inc.
This device is used by the user-space daemon that runs xenstore
(xenstored). It allows xenstored to map the xenstore memory page, and
reports the event channel xenstore is using.
Sponsored by: Citrix Systems R&D
dev/xen/xenstore/xenstored_dev.c:
- Add the xenstored character device that's used to map the xenstore
memory into user-space, and to report the event channel used by
xenstore.
conf/files:
- Add the device to the build process.
Move xenstore related devices (xenstore.c and xenstore_dev.c) from
xen/xenstore to dev/xen/xenstore. This is just code motion, no
functional changes.
Sponsored by: Citrix Systems R&D
- Use bus_*() instead of bus_space_*().
- Use device_printf().
- Remove unused global variables and the extra warning suppression
they required.
- Use callout() instead of timeout().
Reviewed by: se
For now restrict it to amd64. Other architectures might be
re-added later once tested.
Remove the drivers from the global NOTES and files files and move
them to the amd64 specifics.
Remove the drivers from the i386 modules build and only leave the
amd64 version.
Rather than depending on "inet" depend on "pci" and make sure that
ixl(4) and ixlv(4) can be compiled independently [2]. This also
allows the drivers to build properly on IPv4-only or IPv6-only
kernels.
PR: 193824 [2]
Reviewed by: eric.joyner intel.com
MFC after: 3 days
References:
[1] http://lists.freebsd.org/pipermail/svn-src-all/2014-August/090470.html
The flowdirector feature shares on-chip memory with other things
such as the RX buffers. In theory it should be configured in a way
that doesn't interfere with the rest of operation. In practice,
the RX buffer calculation didn't take the flow-director allocation
into account and there'd be overlap. This lead to various garbage
frames being received containing what looks like internal NIC state.
What _I_ saw was traffic ending up in the wrong RX queues.
If I was doing a UDP traffic test with only one NIC ring receiving
traffic, everything is fine. If I fired up a second UDP stream
which came in on another ring, there'd be a few percent of traffic
from both rings ending up in the wrong ring. Ie, the RSS hash would
indicate it was supposed to come in ring X, but it'd come in ring Y.
However, when the allocation was fixed up, the developers at Verisign
still saw traffic stalls.
The flowdirector feature ends up fiddling with the NIC to do various
attempts at load balancing connections by populating flow table rules
based on sampled traffic. It's likely that all of that has to be
carefully reviewed and made less "magic".
So for now the flow director feature is disabled (which fixes both
what I was seeing and what they were seeing) until it's all much
more debugged and verified.
Tested:
* (me) 82599EB 2x10G NIC, RSS UDP testing.
* (verisign) not sure on the NIC (but likely 82599), 100k-200k/sec TCP
transaction tests.
Submitted by: Marc De La Gueronniere <mdelagueronniere@verisign.com>
MFC after: 1 week
Sponsored by: Verisign, Inc.
PCI IDs into quirks, which mostly fit (though you'd get no argument
from me that AHCI_Q_SATA1_UNIT0 is oddly specific). Set these quirks
in the PCI attachment. Make some shared functions public so that PCI
and possibly other bus attachments can use them.
The split isn't perfect yet, but it is functional. The split will be
perfected as other bus attachments for AHCI are written.
Sponsored by: Netflix
Reviewed by: kan, mav
Differential Revision: https://reviews.freebsd.org/D699
friendliness. This should restore old-fashioned kernel building in a
cross environment, though this has only had limited testing.
Sponsored by: Netflix
in the clocks=<...> properties of their FDT data. The clock properties
consist of 2-cell tuples, each containing a clock device node reference and
a clock number. A clock device driver can register itself as providing
this interface, then other drivers can turn the FDT clock node reference
into the corresponding device_t so that they can use the interface to query
and manipulate their clocks.
This provides convenience functions to enable or disable all the clocks
listed in the properties for a device, so most drivers will be able to
manage their clocks with a single call to fdt_clock_enable_all(dev).
This is the last major change in given branch.
Kernel changes:
* Use 64-bytes structures to hold multi-value variables.
* Use shared array to hold values from all tables (assume
each table algo is capable of holding 32-byte variables).
* Add some placeholders to support per-table value arrays in future.
* Use simple eventhandler-style API to ease the process of adding new
table items. Currently table addition may required multiple UH drops/
acquires which is quite tricky due to atomic table modificatio/swap
support, shared array resize, etc. Deal with it by calling special
notifier capable of rolling back state before actually performing
swap/resize operations. Original operation then restarts itself after
acquiring UH lock.
* Bump all objhash users default values to at least 64
* Fix custom hashing inside objhash.
Userland changes:
* Add support for dumping shared value array via "vlist" internal cmd.
* Some small print/fill_flags dixes to support u32 values.
* valtype is now bitmask of
<skipto|pipe|fib|nat|dscp|tag|divert|netgraph|limit|ipv4|ipv6>.
New values can hold distinct values for each of this types.
* Provide special "legacy" type which assumes all values are the same.
* More helpers/docs following..
Some examples:
3:41 [1] zfscurr0# ipfw table mimimi create valtype skipto,limit,ipv4,ipv6
3:41 [1] zfscurr0# ipfw table mimimi info
+++ table(mimimi), set(0) +++
kindex: 2, type: addr
references: 0, valtype: skipto,limit,ipv4,ipv6
algorithm: addr:radix
items: 0, size: 296
3:42 [1] zfscurr0# ipfw table mimimi add 10.0.0.5 3000,10,10.0.0.1,2a02:978:2::1
added: 10.0.0.5/32 3000,10,10.0.0.1,2a02:978:2::1
3:42 [1] zfscurr0# ipfw table mimimi list
+++ table(mimimi), set(0) +++
10.0.0.5/32 3000,0,10.0.0.1,2a02:978:2::1
- It was decided to change the driver name to if_ixl for FreeBSD
- This release adds the VF Driver to the tree, it can be built into
the kernel or as the if_ixlv module
- The VF driver is independent for the first time, this will be
desireable when full SRIOV capability is added to the OS.
- Thanks to my new coworker Eric Joyner for his superb work in
both the core and vf driver code.
Enjoy everyone!
Submitted by: jack.vogel@intel.com and eric.joyner@intel.com
MFC after: 3 days (hoping to make 10.1)
UNIX systems, eg. MacOS X and Solaris. It uses Sun-compatible map format,
has proper kernel support, and LDAP integration.
There are still a few outstanding problems; they will be fixed shortly.
Reviewed by: allanjude@, emaste@, kib@, wblock@ (earlier versions)
Phabric: D523
MFC after: 2 weeks
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Mostly bugfixes or features developed in the past 6 months,
so this is a 10.1 candidate.
Basically no user API changes (some bugfixes in sys/net/netmap_user.h).
In detail:
1. netmap support for virtio-net, including in netmap mode.
Under bhyve and with a netmap backend [2] we reach over 1Mpps
with standard APIs (e.g. libpcap), and 5-8 Mpps in netmap mode.
2. (kernel) add support for multiple memory allocators, so we can
better partition physical and virtual interfaces giving access
to separate users. The most visible effect is one additional
argument to the various kernel functions to compute buffer
addresses. All netmap-supported drivers are affected, but changes
are mechanical and trivial
3. (kernel) simplify the prototype for *txsync() and *rxsync()
driver methods. All netmap drivers affected, changes mostly mechanical.
4. add support for netmap-monitor ports. Think of it as a mirroring
port on a physical switch: a netmap monitor port replicates traffic
present on the main port. Restrictions apply. Drive carefully.
5. if_lem.c: support for various paravirtualization features,
experimental and disabled by default.
Most of these are described in our ANCS'13 paper [1].
Paravirtualized support in netmap mode is new, and beats the
numbers in the paper by a large factor (under qemu-kvm,
we measured gues-host throughput up to 10-12 Mpps).
A lot of refactoring and additional documentation in the files
in sys/dev/netmap, but apart from #2 and #3 above, almost nothing
of this stuff is visible to other kernel parts.
Example programs in tools/tools/netmap have been updated with bugfixes
and to support more of the existing features.
This is meant to go into 10.1 so we plan an MFC before the Aug.22 deadline.
A lot of this code has been contributed by my colleagues at UNIPI,
including Giuseppe Lettieri, Vincenzo Maffione, Stefano Garzarella.
MFC after: 3 days.
* Rewrite interface tables to use interface indexes
Kernel changes:
* Add generic interface tracking API:
- ipfw_iface_ref (must call unlocked, performs lazy init if needed, allocates
state & bumps ref)
- ipfw_iface_add_ntfy(UH_WLOCK+WLOCK, links comsumer & runs its callback to
update ifindex)
- ipfw_iface_del_ntfy(UH_WLOCK+WLOCK, unlinks consumer)
- ipfw_iface_unref(unlocked, drops reference)
Additionally, consumer callbacks are called in interface withdrawal/departure.
* Rewrite interface tables to use iface tracking API. Currently tables are
implemented the following way:
runtime data is stored as sorted array of {ifidx, val} for existing interfaces
full data is stored inside namedobj instance (chained hashed table).
* Add IP_FW_XIFLIST opcode to dump status of tracked interfaces
* Pass @chain ptr to most non-locked algorithm callbacks:
(prepare_add, prepare_del, flush_entry ..). This may be needed for better
interaction of given algorithm an other ipfw subsystems
* Add optional "change_ti" algorithm handler to permit updating of
cached table_info pointer (happens in case of table_max resize)
* Fix small bug in ipfw_list_tables()
* Add badd (insert into sorted array) and bdel (remove from sorted array) funcs
Userland changes:
* Add "iflist" cmd to print status of currently tracked interface
* Add stringnum_cmp for better interface/table names sorting
so it really should not be under "optional inet". The fact that uipc_accf.c
lives under kern/ lends some weight to making it a "standard" file.
Moving kern/uipc_accf.c from "optional inet" to "standard" eliminates the
need for #ifdef INET in kern/uipc_socket.c.
Also, this meant the net.inet.accf.unloadable sysctl needed to move, as
net.inet does not exist without networking compiled in (as it lives in
netinet/in_proto.c.) The new sysctl has been named net.accf.unloadable.
In order to support existing accept filter sysctls, the net.inet.accf node
has been added netinet/in_proto.c.
Submitted by: Steve Kiernan <stevek@juniper.net>
Obtained from: Juniper Networks, Inc.
This allows to clone VMs and move them between LUNs inside one storage
host without generating extra network traffic to the initiator and back,
and without being limited by network bandwidth.
LUNs participating in copy operation should have UNIQUE NAA or EUI IDs set.
For LUNs without these IDs VMWare will use traditional copy operations.
Beware: the above LUN IDs explicitly set to values non-unique from the VM
cluster point of view may cause data corruption if wrong LUN is addressed!
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
into head. The code is not believed to have any effect
on the semantics of non-NFSv4.1 server behaviour.
It is a rather large merge, but I am hoping that there will
not be any regressions for the NFS server.
MFC after: 1 month
Since there's no ACPI on PVH guests, we need to create a dummy CPU
device in order to fill the pcpu->pc_device field.
Sponsored by: Citrix Systems R&D
Approved by: gibbs
dev/xen/pvcpu/pvcpu.c:
- Create a dummy CPU device for PVH guests in order to fill the
per-cpu pc_device field.
conf/files:
- Add the pvcpu device to kernels using XEN or XENHVM options.
Kernel-side changelog:
* Split general tables code and algorithm-specific table data.
Current algorithms (IPv4/IPv6 radix and interface tables radix) moved to
new ip_fw_table_algo.c file.
Tables code now supports any algorithm implementing the following callbacks:
+struct table_algo {
+ char name[64];
+ int idx;
+ ta_init *init;
+ ta_destroy *destroy;
+ table_lookup_t *lookup;
+ ta_prepare_add *prepare_add;
+ ta_prepare_del *prepare_del;
+ ta_add *add;
+ ta_del *del;
+ ta_flush_entry *flush_entry;
+ ta_foreach *foreach;
+ ta_dump_entry *dump_entry;
+ ta_dump_xentry *dump_xentry;
+};
* Change ->state, ->xstate, ->tabletype fields of ip_fw_chain to
->tablestate pointer (array of 32 bytes structures necessary for
runtime lookups (can be probably shrinked to 16 bytes later):
+struct table_info {
+ table_lookup_t *lookup; /* Lookup function */
+ void *state; /* Lookup radix/other structure */
+ void *xstate; /* eXtended state */
+ u_long data; /* Hints for given func */
+};
* Add count method for namedobj instance to ease size calculations
* Bump ip_fw3 buffer in ipfw_clt 128->256 bytes.
* Improve bitmask resizing on tables_max change.
* Remove table numbers checking from most places.
* Fix wrong nesting in ipfw_rewrite_table_uidx().
* Add IP_FW_OBJ_LIST opcode (list all objects of given type, currently
implemented for IPFW_OBJTYPE_TABLE).
* Add IP_FW_OBJ_LISTSIZE (get buffer size to hold IP_FW_OBJ_LIST data,
currenly implemented for IPFW_OBJTYPE_TABLE).
* Add IP_FW_OBJ_INFO (requests info for one object of given type).
Some name changes:
s/ipfw_xtable_tlv/ipfw_obj_tlv/ (no table specifics)
s/ipfw_xtable_ntlv/ipfw_obj_ntlv/ (no table specifics)
Userland changes:
* Add do_set3() cmd to ipfw2 to ease dealing with op3-embeded opcodes.
* Add/improve support for destroy/info cmds.
using a direct hook called from kern_vfs_bio_buffer_alloc().
Mark ffs_rawread.c as requiring both ffs and directio options to be
compiled into the kernel. Add ffs_rawread.c to the list of ufs.ko
module' sources.
In addition to stopping breaking the layering violation, it also
allows to link kernel when FFS is configured as module and DIRECTIO is
enabled.
One consequence of the change is that ffs_rawread.o is always linked
into the module regardless of the DIRECTIO option. This is similar to
the option QUOTA and ufs_quota.c.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
- Update FDT file for BERI DE4 boards.
- Add needed kernel configuration keywords.
- Rename module to saf1761otg so that the device unit number does not
interfere with the hardware ID in dmesg.
Sponsored by: DARPA, AFRL
Netmap gets its own hardware-assisted virtual interface and won't take
over or disrupt the "normal" interface in any way. You can use both
simultaneously.
For kernels with DEV_NETMAP, cxgbe(4) carves out an ncxl<N> interface
(note the 'n' prefix) in the hardware to accompany each cxl<N>
interface. These two ifnet's per port share the same wire but really
are separate interfaces in the hardware and software. Each gets its own
L2 MAC addresses (unicast and multicast), MTU, checksum caps, etc. You
should run netmap on the 'n' interfaces only, that's what they are for.
With this, pkt-gen is able to transmit > 45Mpps out of a single 40G port
of a T580 card. 2 port tx is at ~56Mpps total (28M + 28M) as of now.
Single port receive is at 33Mpps but this is very much a work in
progress. I expect it to be closer to 40Mpps once done. In any case
the current effort can already saturate multiple 10G ports of a T5 card
at the smallest legal packet size. T4 gear is totally untested.
trantor:~# ./pkt-gen -i ncxl0 -f tx -D 00:07:43🆎cd:ef
881.952141 main [1621] interface is ncxl0
881.952250 extract_ip_range [275] range is 10.0.0.1:0 to 10.0.0.1:0
881.952253 extract_ip_range [275] range is 10.1.0.1:0 to 10.1.0.1:0
881.962540 main [1804] mapped 334980KB at 0x801dff000
Sending on netmap:ncxl0: 4 queues, 1 threads and 1 cpus.
10.0.0.1 -> 10.1.0.1 (00:00:00:00:00:00 -> 00:07:43🆎cd:ef)
881.962562 main [1882] Sending 512 packets every 0.000000000 s
881.962563 main [1884] Wait 2 secs for phy reset
884.088516 main [1886] Ready...
884.088535 nm_open [457] overriding ifname ncxl0 ringid 0x0 flags 0x1
884.088607 sender_body [996] start
884.093246 sender_body [1064] drop copy
885.090435 main_thread [1418] 45206353 pps (45289533 pkts in 1001840 usec)
886.091600 main_thread [1418] 45322792 pps (45375593 pkts in 1001165 usec)
887.092435 main_thread [1418] 45313992 pps (45351784 pkts in 1000834 usec)
888.094434 main_thread [1418] 45315765 pps (45406397 pkts in 1002000 usec)
889.095434 main_thread [1418] 45333218 pps (45378551 pkts in 1001000 usec)
890.097434 main_thread [1418] 45315247 pps (45405877 pkts in 1002000 usec)
891.099434 main_thread [1418] 45326515 pps (45417168 pkts in 1002000 usec)
892.101434 main_thread [1418] 45333039 pps (45423705 pkts in 1002000 usec)
893.103434 main_thread [1418] 45324105 pps (45414708 pkts in 1001999 usec)
894.105434 main_thread [1418] 45318042 pps (45408723 pkts in 1002001 usec)
895.106434 main_thread [1418] 45332430 pps (45377762 pkts in 1001000 usec)
896.107434 main_thread [1418] 45338072 pps (45383410 pkts in 1001000 usec)
...
Relnotes: Yes
Sponsored by: Chelsio Communications.
The CUSE library is a wrapper for the devfs kernel functionality which
is exposed through /dev/cuse . In order to function the CUSE kernel
code must either be enabled in the kernel configuration file or loaded
separately as a module. Currently none of the committed items are
connected to the default builds, except for installing the needed
header files. The CUSE code will be connected to the default world and
kernel builds in a follow-up commit.
The CUSE module was written by Hans Petter Selasky, somewhat inspired
by similar functionality found in FUSE. The CUSE library can be used
for many purposes. Currently CUSE is used when running Linux kernel
drivers in user-space, which need to create a character device node to
communicate with its applications. CUSE has full support for almost
all devfs functionality found in the kernel:
- kevents
- read
- write
- ioctl
- poll
- open
- close
- mmap
- private per file handle data
Requested by several people. Also see "multimedia/cuse4bsd-kmod" in
ports.
ismt(4) supports the SMBus Message Transport controller found on Intel
C2000 series (Avoton) and S1200 series (Briarwood) Atom SoCs.
Sponsored by: Intel
Intel 40G Ethernet Controller XL710 Family. This is
the core driver, a VF driver called i40evf, will be
following soon. Questions or comments to myself or
my co-developer Eric Joyner. Cheers!
This driver supports the low and high precision models (9 and 11 bits) and
it will auto-detect the both variants.
The driver expose the temperature registers (actual temperature, shutdown
and hysteresys temperature) and also the configuration register.
It was tested on FDT systems: RPi, BBB and on non-FDT systems: AR71xx, with
both, hardware i2c controllers (when available) and gpioiic(4).
This provides a simple and cheap way for verifying the i2c bus on embedded
systems.
cards. LSI has been maintaining this driver outside of the FreeBSD
tree. It overlaps support of ThunderBolt and Invader cards that mfi(4)
supports. By default mfi(4) will attach to cards. If the tunable:
hw.mfi.mrsas_enable=1
is set then mfi(4) will not probe and attach to these newer cards and
allow mrsas(4) to attach. So by default this driver will not effect
a FreeBSD system unless mfi(4) is removed from the kernel or the
tunable is enabled.
mrsas(4) attaches disks to the CAM layer so it depends on CAM and devices
show up as /dev/daX. mfiutil(8) does not work with mrsas. The FreeBSD
version of MegaCli and StorCli from LSI do work with mrsas. It appears
that StorCli only works with mrsas. MegaCli appears to work with mfi(4)
and mrsas(4).
It would be good to add mfiutil(4) support to mrsas, emulations modes,
kernel logging, device aliases to ease the transition between mfi(4)
and mrsas(4).
Style issues should be resolved by LSI when they get committers approved.
The plan is get this driver in FreeBSD 9.3 to improve HW support.
Thanks to LSI for developing, testing and working with FreeBSD to
make this driver co-exist in FreeBSD. This improves the overall
support of MegaRAID SAS.
Submitted by: Kashyap Desai <Kashyap.Desai@lsi.com>
Reviewed by: scottl
MFC after: 3 days
Sponsored by: LSI
This is derived from the mps(4) driver, but it supports only the 12Gb
IT and IR hardware including the SAS 3004, SAS 3008 and SAS 3108.
Some notes about this driver:
o The 12Gb hardware can do "FastPath" I/O, and that capability is included in
this driver.
o WarpDrive functionality has been removed, since it isn't supported in
the 12Gb driver interface.
o The Scatter/Gather list handling code is significantly different between
the 6Gb and 12Gb hardware. The 12Gb boards support IEEE Scatter/Gather
lists.
Thanks to LSI for developing and testing this driver for FreeBSD.
share/man/man4/mpr.4:
mpr(4) man page.
sys/dev/mpr/*:
mpr(4) driver files.
sys/modules/Makefile,
sys/modules/mpr/Makefile:
Add a module Makefile for the mpr(4) driver.
sys/conf/files:
Add the mpr(4) driver.
sys/amd64/conf/GENERIC,
sys/i386/conf/GENERIC,
sys/mips/conf/OCTEON1,
sys/sparc64/conf/GENERIC:
Add the mpr(4) driver to all config files that currently
have the mps(4) driver.
sys/ia64/conf/GENERIC:
Add the mps(4) and mpr(4) drivers to the ia64 GENERIC
config file.
sys/i386/conf/XEN:
Exclude the mpr module from building here.
Submitted by: Steve McConnell <Stephen.McConnell@lsi.com>
MFC after: 3 days
Tested by: Chris Reeves <chrisr@spectralogic.com>
Sponsored by: LSI, Spectra Logic
Relnotes: LSI 12Gb SAS driver mpr(4) added
kernel config file. If you also want to have a static DTB compiled
into your kernel, however, it cannot be a list. We have no mechanism
in the kernel for picking one, so that doesn't make sense and will
result in a compile-time error.
systems need fine-grained control over what's in and what's out.
That's ideal. For now, separate GPT labels from the rest and allow
g_label to be built with just GPT labels.
Obtained from: Juniper Networks, Inc.
My PCI RID changes somehow got intermixed with my PCI ARI patch when I
committed it. I may have accidentally applied a patch to a non-clean
working tree. Revert everything while I figure out what went wrong.
Pointy hat to: rstone
my tests, it is faster ~20%, even on an old IXP425 533MHz it is ~45%
faster... This is partly due to loop unrolling, so the code size does
significantly increase... I do plan on committing a version that
rolls up the loops again for smaller code size for embedded systems
where size is more important than absolute performance (it'll save ~6k
code)...
The kernel implementation is now shared w/ userland's libcrypt and
libmd...
We drop support for sha256 from sha2.c, so now sha2.c only contains
sha384 and sha512...
Reviewed by: secteam@
linking NIC Receive Side Scaling (RSS) to the network stack's
connection-group implementation. This prototype (and derived patches)
are in use at Juniper and several other FreeBSD-using companies, so
despite some reservations about its maturity, merge the patch to the
base tree so that it can be iteratively refined in collaboration rather
than maintained as a set of gradually diverging patch sets.
(1) Merge a software implementation of the Toeplitz hash specified in
RSS implemented by David Malone. This is used to allow suitable
pcbgroup placement of connections before the first packet is
received from the NIC. Software hashing is generally avoided,
however, due to high cost of the hash on general-purpose CPUs.
(2) In in_rss.c, maintain authoritative versions of RSS state intended
to be pushed to each NIC, including keying material, hash
algorithm/ configuration, and buckets. Provide software-facing
interfaces to hash 2- and 4-tuples for IPv4 and IPv6 using both
the RSS standardised Toeplitz and a 'naive' variation with a hash
efficient in software but with poor distribution properties.
Implement rss_m2cpuid()to be used by netisr and other load
balancing code to look up the CPU on which an mbuf should be
processed.
(3) In the Ethernet link layer, allow netisr distribution using RSS as
a source of policy as an alternative to source ordering; continue
to default to direct dispatch (i.e., don't try and requeue packets
for processing on the 'right' CPU if they arrive in a directly
dispatchable context).
(4) Allow RSS to control tuning of connection groups in order to align
groups with RSS buckets. If a packet arrives on a protocol using
connection groups, and contains a suitable hardware-generated
hash, use that hash value to select the connection group for pcb
lookup for both IPv4 and IPv6. If no hardware-generated Toeplitz
hash is available, we fall back on regular PCB lookup risking
contention rather than pay the cost of Toeplitz in software --
this is a less scalable but, at my last measurement, faster
approach. As core counts go up, we may want to revise this
strategy despite CPU overhead.
Where device drivers suitably configure NICs, and connection groups /
RSS are enabled, this should avoid both lock and line contention during
connection lookup for TCP. This commit does not modify any device
drivers to tune device RSS configuration to the global RSS
configuration; patches are in circulation to do this for at least
Chelsio T3 and Intel 1G/10G drivers. Currently, the KPI for device
drivers is not particularly robust, nor aware of more advanced features
such as runtime reconfiguration/rebalancing. This will hopefully prove
a useful starting point for refinement.
No MFC is scheduled as we will first want to nail down a more mature
and maintainable KPI/KBI for device drivers.
Sponsored by: Juniper Networks (original work)
Sponsored by: EMC/Isilon (patch update and merge)
AppleTalk was a network transport protocol for Apple Macintosh devices
in 80s and then 90s. Starting with Mac OS X in 2000 the AppleTalk was
a legacy protocol and primary networking protocol is TCP/IP. The last
Mac OS X release to support AppleTalk happened in 2009. The same year
routing equipment vendors (namely Cisco) end their support.
Thus, AppleTalk won't be supported in FreeBSD 11.0-RELEASE.
IPX was a network transport protocol in Novell's NetWare network operating
system from late 80s and then 90s. The NetWare itself switched to TCP/IP
as default transport in 1998. Later, in this century the Novell Open
Enterprise Server became successor of Novell NetWare. The last release
that claimed to still support IPX was OES 2 in 2007. Routing equipment
vendors (e.g. Cisco) discontinued support for IPX in 2011.
Thus, IPX won't be supported in FreeBSD 11.0-RELEASE.
This adds and enables the PV console used on XEN kernels to
GENERIC/XENHVM kernels in order for it to be used on PVH.
Approved by: gibbs
Sponsored by: Citrix Systems R&D
dev/xen/console/console.c:
- Define console_page.
- Move xc_printf debug function from i386 XEN code to generic console
code.
- Rework xc_printf.
- Use xen_initial_domain instead of open-coded checks for Dom0.
- Gate the attach of the PV console to PV(H) guests.
dev/xen/console/xencons_ring.c:
- Allow the PV Xen console to output earlier by directly signaling
the event channel in start_info if the event channel is not yet
initialized.
- Use HYPERVISOR_start_info instead of xen_start_info.
i386/include/xen/xen-os.h:
- Remove prototype for xc_printf since it's now declared in global
xen-os.h
i386/xen/xen_machdep.c:
- Remove previous version of xc_printf.
- Remove definition of console_page (now it's defined in the console
itself).
- Fix some printf formatting errors.
x86/xen/pv.c:
- Add some early boot debug messages using xc_printf.
- Set console_page based on the value passed in start_info.
xen/xen-os.h:
- Declare console_page and add prototype for xc_printf.
(1) Invoke cpp to bring in files via #include (although the old
/include/ stuff is supported still).
(2) bring in files from either vendor tree or freebsd-custom files
when building.
(3) move all dts* files from sys/boot/fdt/dts to
sys/boot/fdt/dts/${MACHINE} as appropriate.
(4) encode all the magic to do the build in sys/tools/fdt/make_dtb.sh
so that the different places in the tree use the exact same logic.
(5) switch back to gpl dtc by default. the bsdl one in the tree has
significant issues not easily addressed by those unfamiliar with
the code.
This is (almost!) enough to actually probe, attach, configure a default
port group and do some basic work. It's also totally hard-coded for
the Qualcomm Atheros DB120 board - it doesn't yet have any of the code
from OpenWRT which parses extra configuration data to know how to program
the switch. The LED stuff is also missing.
But, it's enough to facilitate board, PHY, switch and VLAN bringup,
so I am committing it now.
Tested:
* Qualcomm Atheros DB120
Obtained from: OpenWRT
- netmap pipes, providing bidirectional blocking I/O while moving
100+ Mpps between processes using shared memory channels
(no mistake: over one hundred million. But mind you, i said
*moving* not *processing*);
- kqueue support (BHyVe needs it);
- improved user library. Just the interface name lets you select a NIC,
host port, VALE switch port, netmap pipe, and individual queues.
The upcoming netmap-enabled libpcap will use this feature.
- optional extra buffers associated to netmap ports, for applications
that need to buffer data yet don't want to make copies.
- segmentation offloading for the VALE switch, useful between VMs.
and a number of bug fixes and performance improvements.
My colleagues Giuseppe Lettieri and Vincenzo Maffione did a substantial
amount of work on these features so we owe them a big thanks.
There are some external repositories that can be of interest:
https://code.google.com/p/netmap
our public repository for netmap/VALE code, including
linux versions and other stuff that does not belong here,
such as python bindings.
https://code.google.com/p/netmap-libpcap
a clone of the libpcap repository with netmap support.
With this any libpcap client has access to most netmap
feature with no recompilation. E.g. tcpdump can filter
packets at 10-15 Mpps.
https://code.google.com/p/netmap-ipfw
a userspace version of ipfw+dummynet which uses netmap
to send/receive packets. Speed is up in the 7-10 Mpps
range per core for simple rulesets.
Both netmap-libpcap and netmap-ipfw will be merged upstream at some
point, but while this happens it is useful to have access to them.
And yes, this code will be merged soon. It is infinitely better
than the version currently in 10 and 9.
MFC after: 3 days
describe GPIO bindings in the system.
Move the GPIOBUS lock macros to gpiobusvar.h as they are now shared between
the OFW and the non OFW versions of GPIO bus.
Export gpiobus_print_pins() so it can also be used on the OFW GPIO bus.
Approved by: adrian (mentor, implicit)
Useful for so-called USB tethering.
- Imported code from OpenBSD
- Adapted code to FreeBSD
- Removed some unused functions
- Fixed some buffer encoding and decoding issues
- Optimised data transport path a bit, by sending multiple packets at a time
- Increased receive buffer to 16K
Obtained from: OpenBSD
Requested by: eadler @
MFC after: 2 weeks
a sub-node of nexus (ofwbus) rather than direct attach under nexus. This
fixes FDT on x86 and will make coexistence with ACPI on ARM systems easier.
SPARC is unchanged.
Reviewed by: imp, ian
get the Routerboard 800 up and running with the vendor device tree. This
does not implement some BERI-specific features (which hopefully won't be
necessary soon), so move the old code to mips/beri, with a higher attach
priority when built, until MIPS interrupt domain support is rearranged.
drivers and their firmware were under active development, but those days
have passed. The firmware now exists in pre-compiled form, no longer
dependent on it's sources or on aicasm. If you wish to rebuild the
firmware from source, the glue still exists under the 'make firmware'
target in sys/modules/aic7xxx.
This also fixes the problem introduced with r257777 et al with building
kernels the old fashioned way in sys/$arch/compile/$CONFIG when the
ahc/ahd drivers were included.
related to setting up static device mappings. Since it was only used by
arm/mv/mv_pci.c, it's now just static functions within that file, plus
one public function that gets called only from arm/mv/mv_machdep.c.
