This bring huge amount of changes, I'll enumerate only user-visible changes:
- Delegated Administration
Allows regular users to perform ZFS operations, like file system
creation, snapshot creation, etc.
- L2ARC
Level 2 cache for ZFS - allows to use additional disks for cache.
Huge performance improvements mostly for random read of mostly
static content.
- slog
Allow to use additional disks for ZFS Intent Log to speed up
operations like fsync(2).
- vfs.zfs.super_owner
Allows regular users to perform privileged operations on files stored
on ZFS file systems owned by him. Very careful with this one.
- chflags(2)
Not all the flags are supported. This still needs work.
- ZFSBoot
Support to boot off of ZFS pool. Not finished, AFAIK.
Submitted by: dfr
- Snapshot properties
- New failure modes
Before if write requested failed, system paniced. Now one
can select from one of three failure modes:
- panic - panic on write error
- wait - wait for disk to reappear
- continue - serve read requests if possible, block write requests
- Refquota, refreservation properties
Just quota and reservation properties, but don't count space consumed
by children file systems, clones and snapshots.
- Sparse volumes
ZVOLs that don't reserve space in the pool.
- External attributes
Compatible with extattr(2).
- NFSv4-ACLs
Not sure about the status, might not be complete yet.
Submitted by: trasz
- Creation-time properties
- Regression tests for zpool(8) command.
Obtained from: OpenSolaris
controller. The controller is also known as L1E(AR8121) and
L2E(AR8113/AR8114). Unlike its predecessor Attansic L1,
AR8121/AR8113/AR8114 uses completely different Rx logic such that
it requires separate driver. Datasheet for AR81xx is not available
to open source driver writers but it shares large part of Tx and
PHY logic of L1. I still don't understand some part of register
meaning and some MAC statistics counters but the driver seems to
have no critical issues for performance and stability.
The AR81xx requires copy operation to pass received frames to upper
stack such that ale(4) consumes a lot of CPU cycles than that of
other controller. A couple of silicon bugs also adds more CPU
cycles to address the known hardware bug. However, if you have fast
CPU you can still saturate the link.
Currently ale(4) supports the following hardware features.
- MSI.
- TCP Segmentation offload.
- Hardware VLAN tag insertion/stripping with checksum offload.
- Tx TCP/UDP checksum offload and Rx IP/TCP/UDP checksum offload.
- Tx/Rx interrupt moderation.
- Hardware statistics counters.
- Jumbo frame.
- WOL.
AR81xx PCIe ethernet controllers are mainly found on ASUS EeePC or
P5Q series of ASUS motherboards. Special thanks to Jeremy Chadwick
who sent the hardware to me. Without his donation writing a driver
for AR81xx would never have been possible. Big thanks to all people
who reported feedback or tested patches.
HW donated by: koitsu
Tested by: bsam, Joao Barros <joao.barros <> gmail DOT com >
Jan Henrik Sylvester <me <> janh DOT de >
Ivan Brawley < ivan <> brawley DOT id DOT au >,
CURRENT ML
dependencies. A 'struct pmc_classdep' structure describes operations
on PMCs; 'struct pmc_mdep' contains one or more 'struct pmc_classdep'
structures depending on the CPU in question.
Inside PMC class dependent code, row indices are relative to the
PMCs supported by the PMC class; MI code in "hwpmc_mod.c" translates
global row indices before invoking class dependent operations.
- Augment the OP_GETCPUINFO request with the number of PMCs present
in a PMC class.
- Move code common to Intel CPUs to file "hwpmc_intel.c".
- Move TSC handling to file "hwpmc_tsc.c".
Because the TTY hooks interface was not finished when I imported the
MPSAFE TTY layer, I had to disconnect the snp(4) driver. This snp(4)
implementation has been sitting in my P4 branch for some time now.
Unfortunately it still doesn't use the same error handling as snp(4)
(returning codes through FIONREAD), but it should already be usable.
I'm committing this to SVN, hoping someone else could polish off its
rough edges. It's always better than having a broken driver sitting in
the tree.
that includes significant features and SMP safety.
This commit includes a more or less complete rewrite of the *BSD USB
stack, including Host Controller and Device Controller drivers and
updating all existing USB drivers to use the new USB API:
1) A brief feature list:
- A new and mutex enabled USB API.
- Many USB drivers are now running Giant free.
- Linux USB kernel compatibility layer.
- New UGEN backend and libusb library, finally solves the "driver
unloading" problem. The new BSD licensed libusb20 library is fully
compatible with libusb-0.1.12 from sourceforge.
- New "usbconfig" utility, for easy configuration of USB.
- Full support for Split transactions, which means you can use your
full speed USB audio device on a high speed USB HUB.
- Full support for HS ISOC transactions, which makes writing drivers
for various HS webcams possible, for example.
- Full support for USB on embedded platforms, mostly cache flushing
and buffer invalidating stuff.
- Safer parsing of USB descriptors.
- Autodetect of annoying USB install disks.
- Support for USB device side mode, also called USB gadget mode,
using the same API like the USB host side. In other words the new
USB stack is symmetric with regard to host and device side.
- Support for USB transfers like I/O vectors, means more throughput
and less interrupts.
- ... see the FreeBSD quarterly status reports under "USB project"
2) To enable the driver in the default kernel build:
2.a) Remove all existing USB device options from your kernel config
file.
2.b) Add the following USB device options to your kernel configuration
file:
# USB core support
device usb2_core
# USB controller support
device usb2_controller
device usb2_controller_ehci
device usb2_controller_ohci
device usb2_controller_uhci
# USB mass storage support
device usb2_storage
device usb2_storage_mass
# USB ethernet support, requires miibus
device usb2_ethernet
device usb2_ethernet_aue
device usb2_ethernet_axe
device usb2_ethernet_cdce
device usb2_ethernet_cue
device usb2_ethernet_kue
device usb2_ethernet_rue
device usb2_ethernet_dav
# USB wireless LAN support
device usb2_wlan
device usb2_wlan_rum
device usb2_wlan_ral
device usb2_wlan_zyd
# USB serial device support
device usb2_serial
device usb2_serial_ark
device usb2_serial_bsa
device usb2_serial_bser
device usb2_serial_chcom
device usb2_serial_cycom
device usb2_serial_foma
device usb2_serial_ftdi
device usb2_serial_gensa
device usb2_serial_ipaq
device usb2_serial_lpt
device usb2_serial_mct
device usb2_serial_modem
device usb2_serial_moscom
device usb2_serial_plcom
device usb2_serial_visor
device usb2_serial_vscom
# USB bluetooth support
device usb2_bluetooth
device usb2_bluetooth_ng
# USB input device support
device usb2_input
device usb2_input_hid
device usb2_input_kbd
device usb2_input_ms
# USB sound and MIDI device support
device usb2_sound
2) To enable the driver at runtime:
2.a) Unload all existing USB modules. If USB is compiled into the
kernel then you might have to build a new kernel.
2.b) Load the "usb2_xxx.ko" modules under /boot/kernel having the same
base name like the kernel device option.
Submitted by: Hans Petter Selasky hselasky at c2i dot net
Reviewed by: imp, alfred
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager. I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.
The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.
To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.
As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.
Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.
The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.
Sponsored by: Isilon Systems
MFC after: 1 month
compiled into the main AMR driver. It's code that is nice to have but not
required for normal operation, and it is reported to cause problems for some
people.
cable tuning. This has helped in some installations for hardware
deployed by a former employer. Made optional because the lists aren't
full of complaints about these cards... even when they were wildly
popular.
Reviewed by: attilio@, jhb@, trhodes@ (all an older version of the patch)
control logic and policy registration remaining in that file, and access
control checks broken out into other files by class of check.
Obtained from: TrustedBSD Project
Driver supports PCI devices with class 8 and subclass 5 according to
SD Host Controller Specification.
Update NOTES, enable module and static build.
Enable related mmc and mmcsd modules build.
Discussed on: mobile@, current@
This was located in the ubsa driver, but should be moved into a separate
driver:
- 3G modems provide multiple serial ports to allow AT commands while the PPP
connection is up.
- 3G modems do not provide baud rate or other serial port settings.
- Huawei cards need specific initialisation.
- ubsa is for Belkin adapters, an Linuxy choice for another device like 3G.
Speeds achieved here with a weak signal at best is ~40kb/s (UMTS). No spooky
STALLED messages as well.
Next: Move over all entries for Sierra and Novatel cards once I have found
testers, and implemented serial port enumeration for Sierra (or rather have
Andrea Guzzo do it). They list all endpoints in 1 iface instead of 4 ifaces.
Submitted by: aguzzo@anywi.com
MFC after: 3 weeks
If you just config KERNEL as usual there should be no apparent changes, you'll get all chipset support code compiled in.
However there is now a way to only compile in code for chipsets needed on a pr vendor basis. ATA now has the following "device" entries:
atacore: ATA core functionality, always needed for any ATA setup
atacard: CARDBUS support
atacbus: PC98 cbus support
ataisa: ISA bus support
atapci: PCI bus support only generic chipset support.
ataahci: AHCI support, also pulled in by some vendor modules.
ataacard, ataacerlabs, ataadaptec, ataamd, ataati, atacenatek, atacypress, atacyrix, atahighpoint, ataintel, ataite, atajmicron, atamarvell, atamicron, atanational, atanetcell, atanvidia, atapromise, ataserverworks, atasiliconimage, atasis, atavia; Vendor support, ie atavia for VIA chipsets
atadisk: ATA disk driver
ataraid: ATA softraid driver
atapicd: ATAPI cd/dvd driver
atapifd: ATAPI floppy/flashdisk driver
atapist: ATAPI tape driver
atausb: ATA<>USB bridge
atapicam: ATA<>CAM bridge
This makes it possible to config a kernel with just VIA chipset support by having the following ATA lines in the kernel config file:
device atacore
device atapci
device atavia
And then you need the atadisk, atapicd etc lines in there just as usual.
If you use ATA as modules loaded at boot there is few changes except the rename of the "ata" module to "atacore", things looks just as usual.
However under atapci you now have a whole bunch of vendor specific drivers, that you can kldload individually depending on you needs. Drivers have the same names as used in the kernel config explained above.
It seems we only depend on COMPAT_43 to implement the send() and recv()
routines. We can easily implement them using sendto() and recvfrom(),
just like we do inside our very own C library.
I wasn't able to really test it, apart from simple compilation testing.
I've heard rumours that COMPAT_SVR4 is broken inside execve() anyway.
It's still worth to fix this, because I suspect we'll get rid of
COMPAT_43 somewhere in the future...
Reviewed by: rdivacky
Discussed with: jhb
This is a sync to mesa/drm pre-gem, with a few fixes on top of that.
It also contains one local patch supplied by kib@ that I can't apply to
git.master shared code.
Approved by: flz
Obtained from: mesa/drm git.master
MFC after: 2 weeks
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
This driver supports GW3887 based chipsets and works on
x86/powerpc/sparc64. You need upgtfw kernel module before loading
upgt(4). Please see the manpage.
Obtained from: OpenBSD
found in Soekris hardware, for instance). The hardware supports acceleration
of AES-128-CBC accessible through crypto(4) and supplies entropy to random(4).
TODO:
o Implement rndtest(4) support
o Performance enhancements
Submitted by: Patrick Lamaizière <patfbsd -at- davenulle.org>
Reviewed by: jhb, sam
MFC after: 1 week
features of CPUs like reading/writing machine-specific registers,
retrieving cpuid data, and updating microcode.
- Add cpucontrol(8) utility, that provides userland access to
the features of cpuctl(4).
- Add subsequent manpages.
The cpuctl(4) device operates as follows. The pseudo-device node cpuctlX
is created for each cpu present in the systems. The pseudo-device minor
number corresponds to the cpu number in the system. The cpuctl(4) pseudo-
device allows a number of ioctl to be preformed, namely RDMSR/WRMSR/CPUID
and UPDATE. The first pair alows the caller to read/write machine-specific
registers from the correspondent CPU. cpuid data could be retrieved using
the CPUID call, and microcode updates are applied via UPDATE.
The permissions are inforced based on the pseudo-device file permissions.
RDMSR/CPUID will be allowed when the caller has read access to the device
node, while WRMSR/UPDATE will be granted only when the node is opened
for writing. There're also a number of priv(9) checks.
The cpucontrol(8) utility is intened to provide userland access to
the cpuctl(4) device features. The utility also allows one to apply
cpu microcode updates.
Currently only Intel and AMD cpus are supported and were tested.
Approved by: kib
Reviewed by: rpaulo, cokane, Peter Jeremy
MFC after: 1 month
As clearly mentioned on the mailing lists, there is a list of drivers
that have not been ported to the MPSAFE TTY layer yet. Remove them from
the kernel configuration files. This means people can now still use
these drivers if they explicitly put them in their kernel configuration
file, which is good.
People should keep in mind that after August 10, these drivers will not
work anymore. Even though owners of the hardware are capable of getting
these drivers working again, I will see if I can at least get them to a
compilable state (if time permits).
MPSAFE patches on current@ and stable@. This driver also has a fundamental
issue in that it sleeps when sending commands to the card including in the
if_init/if_start routines (which can be called from interrupt context). As
such, the driver shouldn't be working reliably even on 4.x.
and stable@. It also is a driver for an older non-802.11 wireless PC card
that is quite slow in comparison to say, wi(4). I know Warner wants this
driver axed as well.
current@ and stable@ for the locking patches. The driver can always be
revived if someone tests it.
This driver also sleeps in its if_init routine, so it likely doesn't really
work at all anyway in modern releases.
semaphores. Specifically, semaphores are now represented as new file
descriptor type that is set to close on exec. This removes the need for
all of the manual process reference counting (and fork, exec, and exit
event handlers) as the normal file descriptor operations handle all of
that for us nicely. It is also suggested as one possible implementation
in the spec and at least one other OS (OS X) uses this approach.
Some bugs that were fixed as a result include:
- References to a named semaphore whose name is removed still work after
the sem_unlink() operation. Prior to this patch, if a semaphore's name
was removed, valid handles from sem_open() would get EINVAL errors from
sem_getvalue(), sem_post(), etc. This fixes that.
- Unnamed semaphores created with sem_init() were not cleaned up when a
process exited or exec'd. They were only cleaned up if the process
did an explicit sem_destroy(). This could result in a leak of semaphore
objects that could never be cleaned up.
- On the other hand, if another process guessed the id (kernel pointer to
'struct ksem' of an unnamed semaphore (created via sem_init)) and had
write access to the semaphore based on UID/GID checks, then that other
process could manipulate the semaphore via sem_destroy(), sem_post(),
sem_wait(), etc.
- As part of the permission check (UID/GID), the umask of the proces
creating the semaphore was not honored. Thus if your umask denied group
read/write access but the explicit mode in the sem_init() call allowed
it, the semaphore would be readable/writable by other users in the
same group, for example. This includes access via the previous bug.
- If the module refused to unload because there were active semaphores,
then it might have deregistered one or more of the semaphore system
calls before it noticed that there was a problem. I'm not sure if
this actually happened as the order that modules are discovered by the
kernel linker depends on how the actual .ko file is linked. One can
make the order deterministic by using a single module with a mod_event
handler that explicitly registers syscalls (and deregisters during
unload after any checks). This also fixes a race where even if the
sem_module unloaded first it would have destroyed locks that the
syscalls might be trying to access if they are still executing when
they are unloaded.
XXX: By the way, deregistering system calls doesn't do any blocking
to drain any threads from the calls.
- Some minor fixes to errno values on error. For example, sem_init()
isn't documented to return ENFILE or EMFILE if we run out of semaphores
the way that sem_open() can. Instead, it should return ENOSPC in that
case.
Other changes:
- Kernel semaphores now use a hash table to manage the namespace of
named semaphores nearly in a similar fashion to the POSIX shared memory
object file descriptors. Kernel semaphores can now also have names
longer than 14 chars (up to MAXPATHLEN) and can include subdirectories
in their pathname.
- The UID/GID permission checks for access to a named semaphore are now
done via vaccess() rather than a home-rolled set of checks.
- Now that kernel semaphores have an associated file object, the various
MAC checks for POSIX semaphores accept both a file credential and an
active credential. There is also a new posixsem_check_stat() since it
is possible to fstat() a semaphore file descriptor.
- A small set of regression tests (using the ksem API directly) is present
in src/tools/regression/posixsem.
Reported by: kris (1)
Tested by: kris
Reviewed by: rwatson (lightly)
MFC after: 1 month
provides the correct semantics for flock(2) style locks which are used by the
lockf(1) command line tool and the pidfile(3) library. It also implements
recovery from server restarts and ensures that dirty cache blocks are written
to the server before obtaining locks (allowing multiple clients to use file
locking to safely share data).
Sponsored by: Isilon Systems
PR: 94256
MFC after: 2 weeks
NET_NEEDS_GIANT. netatm has been disconnected from the build for ten
months in HEAD/RELENG_7. Specifics:
- netatm include files
- netatm command line management tools
- libatm
- ATM parts in rescue and sysinstall
- sample configuration files and documents
- kernel support as a module or in NOTES
- netgraph wrapper nodes for netatm
- ctags data for netatm.
- netatm-specific device drivers.
MFC after: 3 weeks
Reviewed by: bz
Discussed with: bms, bz, harti
-It has new hardware support
-It uses a new method of TX cleanup called Head Write Back
-It includes the provisional generic TCP LRO feature contributed
by Myricom and made general purpose by me. This should move into
the stack upon approval but for this driver drop its in here.
-Also bug fixes and etc...
MFC in a week if no serious issues arise.
perform various operations on a controller. Specifically, for each mpt(4)
device, create a character device in devfs which accepts ioctl requests for
reading and writing configuration pages and performing RAID actions.
MFC after: 1 week
Reviewed by: scottl
which are also likely to be irrelevant for sun4v (there's no SBus on sun4v
and only some EBus devices). While at it fix some style bugs according to
style.Makefile(5) where appropriate.
MFC after: 3 days
PR 122839 is fixed in both em and in igb
Second, the issue on building modules since the static kernel
build changes is now resolved. I was not able to get the fancier
directory hierarchy working, but this works, both em and igb
build as modules now.
Third, there is now support in em for two new NICs, Hartwell
(or 82574) is a low cost PCIE dual port adapter that has MSIX,
for this release it uses 3 vectors only, RX, TX, and LINK. In
the next release I will add a second TX and RX queue. Also, there
is support here for ICH10, the followon to ICH9. Both of these are
early releases, general availability will follow soon.
Fourth: On Hartwell and ICH10 we now have IEEE 1588 PTP support,
I have implemented this in a provisional way so that early adopters
may try and comment on the functionality. The IOCTL structure may
change. This feature is off by default, you need to edit the Makefile
and add the EM_TIMESYNC define to get the code.
Enjoy all!!
Note this includes changes to all drivers and moves some device firmware
loading to use firmware(9) and a separate module (e.g. ral). Also there
no longer are separate wlan_scan* modules; this functionality is now
bundled into the wlan module.
Supported by: Hobnob and Marvell
Reviewed by: many
Obtained from: Atheros (some bits)
move most offload functionality from NIC to TOE
factor out all socket and inpcb direct access
factor out access to locking in incpb, pcbinfo, and sockbuf
and the igb driver static in the kernel. But it also reflects
some other bug fixes in my development stream at Intel.
PR 122373 is also fixed in this code.
src/cddl and src/sys/cddl directories per the core@ decision following
the license review.
This change modifies the affected Makefiles to reference the sources
in their new location.
to detect (or load) kernel NLM support in rpc.lockd. Remove the '-k'
option to rpc.lockd and make kernel NLM the default. A user can still
force the use of the old user NLM by building a kernel without NFSLOCKD
and/or removing the nfslockd.ko module.
just em, there is an igb driver (this follows behavior with our Linux drivers).
All adapters up to the 82575 are supported in em, and new client/desktop support
will continue to be in that adapter.
The igb driver is for new server NICs like the 82575 and its followons.
Advanced features for virtualization and performance will be in this driver.
Also, both drivers now have shared code that is up to the latest we have
released. Some stylistic changes as well.
Enjoy :)
- add support for T3C
- add DDP support (zero-copy receive)
- fix TOE transmit of large requests
- fix shutdown so that sockets don't remain in CLOSING state indefinitely
- register listeners when an interface is brought up after tom is loaded
- fix setting of multicast filter
- enable link at device attach
- exit tick handler if shutdown is in progress
- add helper for logging TCB
- add sysctls for dumping transmit queues
- note that TOE wxill not be MFC'd until after 7.0 has been finalized
MFC after: 3 days
VFS namecache, as is done by the Coda module on Linux. Unlike the Coda
namecache, the global VFS namecache isn't tagged by credential, so use
ore conservative flushing behavior (for now) when CODA_PURGEUSER is
issued by Venus.
This improves overall integration with the FreeBSD VFS, including
allowing __getcwd() to work better, procfs/procstat monitoring, and so
on. This improves shell behavior in many cases, and improves ".."
handling. It may lead to some slowdown until we've implemented a
specific access cache, which should net improve performance, but in the
mean time, lookup access control now always goes to Venus, whereas
previously it didn't.
MFC after: 1 month
DP83847 PHYs. The main reason for using a specific driver for these
PHYs are reset quirks similar to the nsphy(4) driven DP83840A.
PR: 112654
Obtained from: NetBSD
MFC after: 2 weeks
Thanks to: mlaier for testing w/ DP83815
queues (which we call slices). The NIC will steer traffic into up to
hw.mxge.max_slices different receive rings based on a configurable
hash type (hw.mxge.rss_hash_type).
Currently the driver defaults to using a single slice, so the default
behavior is unchanged. Also, transmit from non-zero slices is
disabled currently.
