What it is: vhost net is a character device that can be used to reduce
the number of system calls involved in virtio networking.
Existing virtio net code is used in the guest without modification.
There's similarity with vringfd, with some differences and reduced scope
- uses eventfd for signalling
- structures can be moved around in memory at any time (good for
migration, bug work-arounds in userspace)
- write logging is supported (good for migration)
- support memory table and not just an offset (needed for kvm)
common virtio related code has been put in a separate file vhost.c and
can be made into a separate module if/when more backends appear. I used
Rusty's lguest.c as the source for developing this part : this supplied
me with witty comments I wouldn't be able to write myself.
What it is not: vhost net is not a bus, and not a generic new system
call. No assumptions are made on how guest performs hypercalls.
Userspace hypervisors are supported as well as kvm.
How it works: Basically, we connect virtio frontend (configured by
userspace) to a backend. The backend could be a network device, or a tap
device. Backend is also configured by userspace, including vlan/mac
etc.
Status: This works for me, and I haven't see any crashes.
Compared to userspace, people reported improved latency (as I save up to
4 system calls per packet), as well as better bandwidth and CPU
utilization.
Features that I plan to look at in the future:
- mergeable buffers
- zero copy
- scalability tuning: figure out the best threading model to use
Note on RCU usage (this is also documented in vhost.h, near
private_pointer which is the value protected by this variant of RCU):
what is happening is that the rcu_dereference() is being used in a
workqueue item. The role of rcu_read_lock() is taken on by the start of
execution of the workqueue item, of rcu_read_unlock() by the end of
execution of the workqueue item, and of synchronize_rcu() by
flush_workqueue()/flush_work(). In the future we might need to apply
some gcc attribute or sparse annotation to the function passed to
INIT_WORK(). Paul's ack below is for this RCU usage.
(Includes fixes by Alan Cox <alan@linux.intel.com>,
David L Stevens <dlstevens@us.ibm.com>,
Chris Wright <chrisw@redhat.com>)
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tun device looks similar to a packet socket
in that both pass complete frames from/to userspace.
This patch fills in enough fields in the socket underlying tun driver
to support sendmsg/recvmsg operations, and message flags
MSG_TRUNC and MSG_DONTWAIT, and exports access to this socket
to modules. Regular read/write behaviour is unchanged.
This way, code using raw sockets to inject packets
into a physical device, can support injecting
packets into host network stack almost without modification.
First user of this interface will be vhost virtualization
accelerator.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds error checking of ctrlmode values for CAN devices. As
an example all availabe bits are implemented in the mcp251x driver.
Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert code away from ->read_proc/->write_proc interfaces. Switch to
proc_create()/proc_create_data() which make addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.
Problem with ->read_proc et al is described here commit
786d7e1612 "Fix rmmod/read/write races in
/proc entries"
[akpm@linux-foundation.org: CONFIG_PROC_FS=n build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
To prevent the CAN drivers to operate on invalid socketbuffers the skbs are
now checked and silently dropped at the xmit-function consistently.
Also the netdev stats are consistently using the CAN data length code (dlc)
for [rx|tx]_bytes now.
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the kernel portions needed to implement
RFC 5082 Generalized TTL Security Mechanism (GTSM).
It is a lightweight security measure against forged
packets causing DoS attacks (for BGP).
This is already implemented the same way in BSD kernels.
For the necessary Quagga patch
http://www.gossamer-threads.com/lists/quagga/dev/17389
Description from Cisco
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t7/feature/guide/gt_btsh.html
It does add one byte to each socket structure, but I did
a little rearrangement to reuse a hole (on 64 bit), but it
does grow the structure on 32 bit
This should be documented on ip(4) man page and the Glibc in.h
file also needs update. IPV6_MINHOPLIMIT should also be added
(although BSD doesn't support that).
Only TCP is supported, but could also be added to UDP, DCCP, SCTP
if desired.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is to be used together with switch technologies, like RFC3069,
that where the individual ports are not allowed to communicate with
each other, but they are allowed to talk to the upstream router. As
described in RFC 3069, it is possible to allow these hosts to
communicate through the upstream router by proxy_arp'ing.
This patch basically allow proxy arp replies back to the same
interface (from which the ARP request/solicitation was received).
Tunable per device via proc "proxy_arp_pvlan":
/proc/sys/net/ipv4/conf/*/proxy_arp_pvlan
This switch technology is known by different vendor names:
- In RFC 3069 it is called VLAN Aggregation.
- Cisco and Allied Telesyn call it Private VLAN.
- Hewlett-Packard call it Source-Port filtering or port-isolation.
- Ericsson call it MAC-Forced Forwarding (RFC Draft).
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Send aligned pipe payload if requested to do so. Then, the socket buffer
needs not be fragmented anymore.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Newer Nokia cellular modems can use aligned payload for their GPRS pipe.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we have L3 tunnels with different inner/outer families
(i.e. IPV4/IPV6) which use a multicast address as the outer tunnel
destination address, multicast packets will be loopbacked back to the
sending socket even if IP*_MULTICAST_LOOP is set to disabled.
The mc_loop flag is present in the family specific part of the socket
(e.g. the IPv4 or IPv4 specific part). setsockopt sets the inner
family mc_loop flag. When the packet is pushed through the L3 tunnel
it will eventually be processed by the outer family which if different
will check the flag in a different part of the socket then it was set.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the flag CAN_CTRLMODE_ONE_SHOT. It is used as mask
or flag in the "struct can_ctrlmode".
It allows userspace via netlink to set a CAN controller into the special
"one-shot" mode. In this mode, if supported by the CAN controller, it
tries only once to deliver a CAN frame and aborts it if an error
(e.g.: arbitration lost) happens.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since hibernation assumes power loss, we should fully reinitialize
PHYs (including platform fixups), as if PHYs were just attached.
This patch factors phy_init_hw() out of phy_attach_direct(), then
converts mdio_bus to dev_pm_ops and adds an appropriate restore()
callback.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To make it easier to notice cases of calling sleeping ops in atomic context,
annotate driver-ops.h with appropiate might_sleep() calls. At the same time,
also document in mac80211.h the op functions with missing contexts.
mac80211 doesn't seem to use get_tx_stats anywhere currently. Just to be on
the safe side, I documented it to be atomic, but hopefully the op can be
removed in the future.
Compile-tested only.
Signed-off-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
All its members (vif, mac_addr, type) are now available
in the vif struct directly, so we can pass that instead
of the conf struct. I generated this patch (except the
mac80211 and header file changes) with this semantic
patch:
@@
identifier conf, fn, hw;
type tp;
@@
tp fn(struct ieee80211_hw *hw,
-struct ieee80211_if_init_conf *conf)
+struct ieee80211_vif *vif)
{
<...
(
-conf->type
+vif->type
|
-conf->mac_addr
+vif->addr
|
-conf->vif
+vif
)
...>
}
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When, for instance, a new IBSS peer is found, userspace
wants to be notified. Add events for all new stations
that mac80211 learns about.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Add new commands for requesting the driver to remain awake
on a specified channel for the specified amount of time
(and another command to cancel such an operation). This
can be used to implement userspace-controlled off-channel
operations, like Public Action frame exchange on another
channel than the operation channel.
The off-channel operation should behave similarly to scan,
i.e. the local station (if associated) moves into power
save mode to request the AP to buffer frames for it and
then moves to the other channel to allow the off-channel
operation to be completed. The duration parameter can be
used to request enough time to receive a response from
the target station.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently, we insert all user-specified IEs before the HT
IE for association, and after the HT IE for probe requests.
For association, that's correct only if the user-specified
IEs are RSN only, incorrect in all other cases including
WPA. Change this to split apart the user-specified IEs in
two places for association: before the HT IE (e.g. RSN),
after the HT IE (generally empty right now I think?) and
after WMM (all other vendor-specific IEs). For probes,
split the IEs in different places to be correct according
to the spec.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We've long lacked a good confirmation that frames
have really gone out, e.g. before going off-channel
for a scan. Add a flush() operation that drivers
can implement to provide that confirmation, and use
it in a few places:
* before scanning sends the nullfunc frames
* after scanning sends the nullfunc frames, if any
* when going idle, to send any pending frames
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This removes the remaining users of the rx status
'qual' field and the field itself.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
For the cases where a lot of interfaces are used in conjunction with a
lot of LLC sockets bound to the same SAP, the iteration of the socket
list becomes prohibitively expensive.
Replacing the list with a a local address based hash significantly
improves the bind and listener lookup operations as well as the
datagram delivery.
Connected sockets delivery is also improved, but this patch does not
address the case where we have lots of sockets with the same local
address connected to different remote addresses.
In order to keep the socket sanity checks alive and fast a socket
counter was added to the SAP structure.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a per SAP device based hash table to solve the
multicast delivery scalability issue when we have large number of
interfaces and a large number of sockets bound to the same SAP.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the reclamation phase we use the SLAB_DESTROY_BY_RCU mechanism,
which require some extra checks in the lookup code:
a) If the current socket was released, reallocated & inserted in
another list it will short circuit the iteration for the current list,
thus we need to restart the lookup.
b) If the current socket was released, reallocated & inserted in the
same list we just need to recheck it matches the look-up criteria and
if not we can skip to the next element.
In this case there is no need to restart the lookup, since sockets are
inserted at the start of the list and the worst that will happen is
that we will iterate throught some of the list elements more then
once.
Note that the /proc and multicast delivery was not yet converted to
RCU, it still uses spinlocks for protection.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
when using policy routing and the skb mark:
there are cases where a back path validation requires us
to use a different routing table for src ip validation than
the one used for mapping ingress dst ip.
One such a case is transparent proxying where we pretend to be
the destination system and therefore the local table
is used for incoming packets but possibly a main table would
be used on outbound.
Make the default behavior to allow the above and if users
need to turn on the symmetry via sysctl src_valid_mark
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add rtnetlink init_rcvwnd to set the TCP initial receive window size
advertised by passive and active TCP connections.
The current Linux TCP implementation limits the advertised TCP initial
receive window to the one prescribed by slow start. For short lived
TCP connections used for transaction type of traffic (i.e. http
requests), bounding the advertised TCP initial receive window results
in increased latency to complete the transaction.
Support for setting initial congestion window is already supported
using rtnetlink init_cwnd, but the feature is useless without the
ability to set a larger TCP initial receive window.
The rtnetlink init_rcvwnd allows increasing the TCP initial receive
window, allowing TCP connection to advertise larger TCP receive window
than the ones bounded by slow start.
Signed-off-by: Laurent Chavey <chavey@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_push checks tcp_send_head and calls __tcp_push_pending_frames,
which again checks tcp_send_head, and this unnecessary check is
done for every other caller of __tcp_push_pending_frames.
Remove tcp_send_head check in __tcp_push_pending_frames and add
the check to tcp_push_pending_frames. Other functions call
__tcp_push_pending_frames only when tcp_send_head would evaluate
to true.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
devtmpfs: unlock mutex in case of string allocation error
Driver core: export platform_device_register_data as a GPL symbol
driver core: Prevent reference to freed memory on error path
Driver-core: Fix bogus 0 error return in device_add()
Driver core: driver_attribute parameters can often be const*
Driver core: bin_attribute parameters can often be const*
Driver core: device_attribute parameters can often be const*
Doc/stable rules: add new cherry-pick logic
vfs: get_sb_single() - do not pass options twice
devtmpfs: Convert dirlock to a mutex
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
Staging/vt66*: kconfig, depends on WLAN
Staging: batman-adv: introduce missing kfree
Staging: batman-adv: Add Kconfig dependancies on PROC_FS and PACKET.
Staging: panel: Adjust range for PANEL_KEYPAD in Kconfig
Staging: panel: Fix compilation error with custom lcd charset
Staging: ramzswap: remove ARM specific d-cache hack
Staging: rtl8192x: fix printk formats
Staging: wlan-ng: fix Correct size given to memset
staging: rtl8192su: add USB VID/PID for HWNUm-300
staging: fix rtl8192su compilation errors with mac80211
staging: fix rtl8192e compilation errors with mac80211
Staging: fix rtl8187se compilation errors with mac80211
Staging: rtl8192su: fix test for negative error in rtl8192_rx_isr()
Staging: comedi: jr3_pci: Don't ioremap too much space. Check result.
Staging: comedi: removed "depricated" from COMEDI_CB_BLOCK
Staging: comedi: usbdux.c: fix locking up of the driver when the comedi ringbuffer runs empty
Staging: dst: remove from the tree
Staging: sm7xx: add a new framebuffer driver
Staging: batman: fix debug Kconfig option
DST is dead, no one is using it and upstream
has abandoned it, so remove it from the tree because
it is not going anywhere.
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many struct driver_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore make
the promise not to, which will let those descriptors be put in
a ro section.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many struct bin_attribute descriptors are purely read-only
structures, and there's no need to change them. Therefore
make the promise not to, which will let those descriptors
be put in a ro section.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Most device_attributes are const, and are begging to be
put in a ro section. However, the create and remove
file interfaces were failing to propagate the const promise
which the only functions they call offer.
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix kernel-doc errors and warnings in new header file kfifo.h.
Don't use kernel-doc "/**" for internal functions whose comments
are not in kernel-doc format.
kernel-doc section header names (like "Note:") must be unique
per function. Looks like I need to document that.
Error(include/linux/kfifo.h:76): duplicate section name 'Note'
Warning(include/linux/kfifo.h:88): Excess function parameter 'size' description in 'INIT_KFIFO'
Error(include/linux/kfifo.h:101): duplicate section name 'Note'
Warning(include/linux/kfifo.h:257): No description found for parameter 'fifo'
(many of this last type, from internal functions)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
quota: Improve checking of quota file header
jbd: jbd-debug and jbd2-debug should be writable
ext4: fix sleep inside spinlock issue with quota and dealloc (#14739)
ext4: Fix potential quota deadlock
quota: Fix 64-bit limits setting on 32-bit archs
ext3: Replace lock/unlock_super() with an explicit lock for resizing
ext3: Replace lock/unlock_super() with an explicit lock for the orphan list
ext3: ext3_mark_recovery_complete() doesn't need to use lock_super
ext3: Remove outdated comment about lock_super()
quota: Move duplicated code to separate functions
ext4: Convert to generic reserved quota's space management.
quota: decouple fs reserved space from quota reservation
Add unlocked version of inode_add_bytes() function
ext3: quota macros cleanup [V2]
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (35 commits)
drm/radeon/kms: add definitions for v4 power tables
drm/radeon/kms: never combine LVDS with another encoder
drm/radeon/kms: Check module arguments to be valid V2
drm/radeon/kms: Avoid crash when trying to cleanup uninitialized structure
drm/radeon/kms: add cvt mode if we only have lvds w/h and no edid (v4)
drm/radeon/kms: add 3DC compression support
drm/radeon/kms: allow rendering while no colorbuffer is set on r300
drm/radeon/kms: enable memory clock reading on legacy (V2)
drm/radeon/kms: prevent parallel AtomBIOS calls
drm/radeon/kms: set proper default tv standard
drm/radeon/kms: fix legacy rmx
drm/radeon/kms/atom: fill in proper defines for digital setup
drm/kms: silencing a false positive warning.
drm/mm: fix logic for selection of best fit block
drm/vmwgfx: Use TTM handles instead of SIDs as user-space surface handles.
drm/vmwgfx: Return -ERESTARTSYS when interrupted by a signal.
drm/vmwgfx: Fix unlocked ioctl and add proper access control
drm/radeon: fix build on 64-bit with some compilers.
drivers/gpu: Use kzalloc for allocating only one thing
DRM: Rename clamp variable
...
The USB serial code was a new user of the kfifo API, and it was missed
when porting things to the new kfifo API.
Please make the write_fifo in place. Here is my patch to fix the
regression and full ported version.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use a separate lock to protect s_groups_count and the other block
group descriptors which get changed via an on-line resize operation,
so we can stop overloading the use of lock_super().
Port of ext4 commit 32ed5058ce by
Theodore Ts'o <tytso@mit.edu>.
CC: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Use a separate lock to protect the orphan list, so we can stop
overloading the use of lock_super().
Port of ext4 commit 3b9d4ed266
by Theodore Ts'o <tytso@mit.edu>.
CC: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Currently inode_reservation is managed by fs itself and this
reservation is transfered on dquot_transfer(). This means what
inode_reservation must always be in sync with
dquot->dq_dqb.dqb_rsvspace. Otherwise dquot_transfer() will result
in incorrect quota(WARN_ON in dquot_claim_reserved_space() will be
triggered)
This is not easy because of complex locking order issues
for example http://bugzilla.kernel.org/show_bug.cgi?id=14739
The patch introduce quota reservation field for each fs-inode
(fs specific inode is used in order to prevent bloating generic
vfs inode). This reservation is managed by quota code internally
similar to i_blocks/i_bytes and may not be always in sync with
internal fs reservation.
Also perform some code rearrangement:
- Unify dquot_reserve_space() and dquot_reserve_space()
- Unify dquot_release_reserved_space() and dquot_free_space()
- Also this patch add missing warning update to release_rsv()
dquot_release_reserved_space() must call flush_warnings() as
dquot_free_space() does.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Quota code requires unlocked version of this function. Off course
we can just copy-paste the code, but copy-pasting is always an evil.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
