The for loop in pcistub_match_one will loop forever if the
dev->bus->self links to itself at the uppermost bridge. Adding a
check to prevent linking back in on itself prevents this.
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
This patch adds TSO transmission support to the backend.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Disable for now, as domU->dom0 direction.
Signed-off-by: Keir Fraser <keir@xensource.com>
This patch adds TCP Segmentation Offload (TSO) support to the
frontend.
It also advertises this fact through xenbus so that the frontend can
detect this and send through TSO requests only if it is supported.
This is done using an extra request slot which is indicated by a flag
in the first slot. In future checksum offload can be done in the same
way.
Even though only TSO is supported for now the code actually supports
GSO so it can be applied to any other protocol. The only missing bit
is the detection of host support for a specific GSO protocol. Once
that is added we can advertise all supported protocols to the guest.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Disable for now, as in domU->dom0 direction.
Signed-off-by: Keir Fraser <keir@xensource.com>
This patch adds scatter-and-gather transmission support to the
backend. This allows the MTU to be raised right now and the potential
for TSO in future.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds scatter-and-gather support to the frontend. It also
advertises this fact through xenbus so that the backend can detect
this and send through SG requests only if it is supported.
SG support is required to support skb's larger than one page. This
in turn is needed for either jumbo MTU or TSO. One of these is
required to bring local networking performance up to a level that
is acceptable.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a tx queue to the backend if the frontend supports rx
refill notification. A queue is needed because SG/TSO greatly reduces
the number of packets that can be stored in the rx ring. Given an rx
ring with 256 entries, a maximum TSO packet can occupy as many as 18
entries, meaning that the entire ring can only hold 14 packets. This
is too small at high bandwidths with large TCP RX windows.
Having a tx queue does not present a new security risk as the queue is
a fixed size buffer just like the rx ring. So each guest can only
hold a
fixed amount of memory (proportional to the tx queue length) on the
host.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Cannot BUG_ON netbk_queue_full yet !netbk_can_queue, as this can be
triggered by a misbehaving client. Set req_event appropriately when
stopping the packet queue, or we will not receive a notification.
Signed-off-by: Keir Fraser <keir@xensource.com>
used to be used for sending of vTPM control commands, but now this is
all done with the hotplug scripts.
Signed-off-by: Stefan Berger <stefanb@us.ibm.com>
Added in Kconfig.
On ia64, use ia64 sysdata instead of pcifront genuine one.
Fix a warning on xenbus.c
Signed-off-by: Tristan Gingold <tristan.gingold@bull.net>
This patch adds support to the frontend for notifying the backend whenever
the rx ring is refilled. This is required in order for the backend to
get a tx queue.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Modified to only send notification if req_event index is set
appropriately.
Signed-off-by: Keir Fraser <keir@xensource.com>
The connection status to the frontend can be represented using
netif_carrier_ok instead of netif->status. As a result, we delay
the construction of the dev qdisc until the carrier comes on. This
is a prerequisite for adding a tx queue.
By the same token, netif->active is now simply the conjunction of
netif_running and netif_carrier_ok so it too can be removed.
Because netif_carrier_off/netif_carrier_on and rtnl_lock all entail
memory barriers, there is no need to have extra memory barriers around
them.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch moves all rx request pushing to network_alloc_rx_buffers.
This is needed to reduce churn for TSO. More importantly, this makes
it easier to send notifications when adding rx requests which is
required for having a queue in dom0.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Keir Fraser <keir@xensource.com>
This is an update to c/s
10855:03c8002068d9d60c7bbfc2f41af975e09b2e2211
which should have contained the following changeset message
(rather than 'Merge.').
[NET] front: Stop using rx->id
With the current protocol for transferring packets from dom0 to domU,
the
rx->id field is useless because it can be derived from the rx request
ring
ID. In particular,
rx->id = (ring_id & NET_RX_RING_SIZE - 1) + 1;
This formula works because the rx response to each request always
occupies
the same slot that the request arrived in. This in turn is a
consequence
of the fact that each packet only occupies one slot.
The other important reason that this works for dom0=>domU but not
domU=>dom0
is that the resource associated with the rx->id is freed immediately
while
in the domU=>dom0 case the resource is held until the skb is liberated
by
dom0.
Using this formula we can essentially remove rx->id from the protocol,
freeing up space that could be instead be used by things like TSO.
The
only constraint is that the backend must obey the rule that each id
must
only be used in the response that occupies the same slot as the
request.
The actual field of rx->id is still maintained for compatibility with
older backends.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
configuration space writes, with a goal that was also previously
described by Ryan:
"Permissive mode should only be used as a fall back for unknown
devices.
I think the correct solution for dealing with these device-specific
configuration space registers is to identify them and add the
device-specific fields to the overlay. This patch adds a special
configuration space handler for network cards based on the tg3 linux
network device driver. This handler should allow for reads/writes to
all of the configuration space registers that the tg3 driver requires."
This patch attempts to address concerns with Ryan's original
submission by moving policy from the dom0 kernel into dom0 user-space.
As new quirky devices emerge they can be incorporated into the user-space
policy. An added benefit is that changes to the policy are effective
for domains created after the changes are written (no need rebuild the
hypervisor or restart xend).
Signed-off-by: Chris Bookholt <hap10@tycho.ncsc.mil>
The connection status to the frontend can be represented using
netif_carrier_ok instead of netif->active. As a result, we delay
the construction of the dev qdisc until the carrier comes on. This
is a prerequisite for adding a tx queue.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tasklets have the property that each one is running on only one CPU at
any time. This means that you don't have to worry about the tasklet
racing against itself. Therefore any resources used by just a single
tasklet does not need to be guarded by locks.
Since net_rx_action is the only user of alloc_mfn, we can remove the
mfn_lock that guard it.
The notify_list array is huge by Linux standards so placing it on the
stack is unsafe. Since net_rx_action is not re-entrant, we can simply
make it static.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
xc_ia64_linux_save.c and xc_ia64_linux_restore.c added.
vcpu context has more registers and states (eg: tr registers).
Per cpu irqs are deallocated when cpu is switched off.
#if/#endif added in reboot.c for ia64.
Signed-off-by: Tristan Gingold <tristan.gingold@bull.net>
It must be protected by tty_sem semaphore like con_close() in
drivers/char/vt.c. and prevent re-opening this tty.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Keir Fraser <keir@xensource.com>
When we reconnect to the backend we need to first zero all negotiated
bits as the functions xen_set_sg and xen_set_tso do not (and are not
supposed to) zero bits when they fail to set them.
This patch also permanently enables the NETIF_F_GSO_ROBUST bit as we
never parse any GSO fields ourselves (even if we did the backend could
not trust us so it's wasted effort).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the as-yet unused GSO features which will contain
protocol-independent bits such as the ECN marker.
It also makes the backend check gso_size to ensure that it is non-zero.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The generalised extra request info patch introduced a bug with the use
of netbk_tx_err since it advanced the req_cons pointer by one. This
patch fixes thing by delaying the increment in netbk_tx_err.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Attached patch makes it always create valid devices on tty1-tty63, but
all but the one specified by xencons are dummy devices.
From: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Keir Fraser <keir@xensource.com>
The new method for printing unconnected device status is arguably
cleaner and also does not screw up reference counts (previous code
called bus_find_device() with no put_device() on the result.
Signed-off-by: Keir Fraser <keir@xensource.com>
However xchg of IA64 has acquire semantics so that event
channel notification is lost sometimes. This patch fixes it.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
