If a single descriptor crosses a region, the
second chunk length should be decremented
by size translated so far, instead it includes
the full descriptor length.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We copy head count to a 16 bit field, this works by chance on LE but on
BE guest gets 0. Fix it up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Alexander Graf <agraf@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull scsi target updates from Nicholas Bellinger:
"Things have been calm for the most part with no new fabric drivers in
flight for v3.7 (we're up to eight now !), so this update is primarily
focused on addressing a few long-standing items within target-core and
iscsi-target fabric code.
The highlights include:
- target: Simplify fabric sense data length handling (roland)
- qla2xxx: Fix endianness of task management response code (roland)
- target: fix truncation of mode data, support zero allocation length
(paolo)
- target: Properly support zero-length commands in normal processing
path (paolo)
- iscsi-target: Correctly set 0xffffffff field within ISCSI_OP_REJECT
PDU (ronnie + nab)
- iscsi-target: Add explicit set of cache_dynamic_acls=1 for TPG
demo-mode (ronnie + nab)
- target/file: Re-enable optional fd_buffered_io=1 operation (nab +
hch)
- iscsi-target: Add MaxXmitDataSegmenthLength forr target ->
initiator MDRSL declaration (nab)
- target: Add target_submit_cmd_map_sgls for SGL fabric memory
passthrough (nab + hch)
- tcm_loop: Convert I/O path to use target_submit_cmd_map_sgls (hch +
nab)
- tcm_vhost: Convert I/O path to use target_submit_cmd_map_sgls (nab
+ hch)
The last series for adding a new target_submit_cmd_map_sgls() fabric
caller (as requested by hch) that accepts pre-allocated SGL memory
(using existing logic), along with converting tcm_loop + tcm_vhost has
only been in -next for the last days, but has gotten enough review
+testing and is clear enough a mechanical change that I think it's
reasonable to merge for -rc1 code.
Thanks again to everyone who contributed this round! Extra special
thanks to Roland (PureStorage) for tracking down the qla2xxx target
TMR response code endian issue, and to Paolo (Redhat) for resolving
the long standing zero-length CDB issues within target-core between
virtual and pSCSI backends."
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (44 commits)
iscsi-target: Bump defaults for nopin_timeout + nopin_response_timeout values
iscsit: proper endianess conversions
iscsit: use the itt_t abstract type
iscsit: add missing endianess conversion in iscsit_check_inaddr_any
iscsit: remove incorrect unlock in iscsit_build_sendtargets_resp
iscsit: mark various functions static
target/iscsi: precedence bug in iscsit_set_dataout_sequence_values()
target/usb-gadget: strlen() doesn't count the terminator
target/usb-gadget: remove duplicate initialization
tcm_vhost: Convert I/O path to use target_submit_cmd_map_sgls
target: Add control CDB READ payload zero work-around
tcm_loop: Convert I/O path to use target_submit_cmd_map_sgls
target: Add target_submit_cmd_map_sgls for SGL fabric memory passthrough
iscsi-target: Add explicit set of cache_dynamic_acls=1 for TPG demo-mode
iscsi-target: Change iscsi_target_seq_pdu_list.c to honor MaxXmitDataSegmentLength
iscsi-target: Add MaxXmitDataSegmentLength connection recovery check
iscsi-target: Convert incoming PDU payload checks to MaxXmitDataSegmentLength
iscsi-target: Enable MaxXmitDataSegmentLength operation in login path
iscsi-target: Add base MaxXmitDataSegmentLength code
target/file: Re-enable optional fd_buffered_io=1 operation
...
This patch converts tcm_vhost to use target_submit_cmd_map_sgls() for
I/O submission and mapping of pre-allocated SGL memory from incoming
virtio-scsi SGL memory -> se_cmd descriptors.
This includes removing the original open-coded fabric uses of target
core callers to support transport_generic_map_mem_to_cmd() between
target_setup_cmd_from_cdb() and transport_handle_cdb_direct() logic.
It also includes adding a handful of new tcm_vhost_cmnd member +
assignments in vhost_scsi_allocate_cmd() used from cmwq process
context I/O submission within tcm_vhost_submission_work()
(v2: Use renamed target_submit_cmd_map_sgls)
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Every fabric driver has to supply a se_tfo->set_fabric_sense_len()
method, just so iSCSI can return an offset of 2. However, every fabric
driver is already allocating a sense buffer and passing it into the
target core, either via transport_init_se_cmd() or target_submit_cmd().
So instead of having iSCSI pass the start of its sense buffer into the
core and then later tell the core to skip the first 2 bytes, it seems
easier for iSCSI just to do the offset of 2 when it passes the sense
buffer into the core. Then we can drop the se_tfo->set_fabric_sense_len()
everywhere, and just add a couple of lines of code to iSCSI to set the
sense data length to the beginning of the buffer right before it sends
it over the network.
(nab: Remove .set_fabric_sense_len usage from tcm_qla2xxx_npiv_ops +
change transport_get_sense_buffer to follow v3.6-rc6 code w/o
->set_fabric_sense_len usage)
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
There are no callers of se_tfo->get_fabric_sense_len(), so we should
stop having every fabric driver implement it.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Here TRANSPORT_IQN_LEN is 224, which is a multiple of 4.
Since vhost_tpgt is 2 bytes and abi_version is 4, the total size would
be 230. But gcc needs struct size be aligned to first field size, which
is 4 bytes, so it pads the structure by extra 2 bytes to the total of
232.
This padding is very undesirable in an ABI:
- it can not be initialized easily
- it can not be checked easily
- it can leak information between kernel and userspace
Simplest solution is probably just to make the padding
explicit.
(v2: Add check for zero'ed backend->reserved field for VHOST_SCSI_SET_ENDPOINT
and VHOST_SCSI_CLEAR_ENDPOINT ops as requested by MST)
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch changes the vhost_scsi_target->vhost_wwpn[] type used
by VHOST_SCSI_* ioctls to 'char *' as requested by Blue Swirl in
order to match the latest QEMU vhost-scsi RFC-v3 userspace code.
Queuing this up into target-pending/master for a -rc3 PULL.
Reported-by: Blue Swirl <blauwirbel@gmail.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch contains the post RFC-v5 (post-merge) changes, this includes:
- Add locking comment
- Move vhost_scsi_complete_cmd ahead of TFO callbacks in order to
drop forward declarations
- Drop extra '!= NULL' usage in vhost_scsi_complete_cmd_work()
- Change vhost_scsi_*_handle_kick() to use pr_debug
- Fix possible race in vhost_scsi_set_endpoint() for vs->vs_tpg checking
+ assignment.
- Convert tv_tpg->tpg_vhost_count + ->tv_tpg_port_count from atomic_t ->
int, and make sure reference is protected by ->tv_tpg_mutex.
- Drop unnecessary vhost_scsi->vhost_ref_cnt
- Add 'err:' label for exception path in vhost_scsi_clear_endpoint()
- Add enum for VQ numbers, add usage in vhost_scsi_open()
- Add vhost_scsi_flush() + vhost_scsi_flush_vq() following
drivers/vhost/net.c
- Add smp_wmb() + vhost_scsi_flush() call during vhost_scsi_set_features()
- Drop unnecessary copy_from_user() usage with GET_ABI_VERSION ioctl
- Add missing vhost_scsi_compat_ioctl() caller for vhost_scsi_fops
- Fix function parameter definition first line to follow existing
vhost code style
- Change 'vHost' usage -> 'vhost' in handful of locations
- Change -EPERM -> -EBUSY usage for two failures in tcm_vhost_drop_nexus()
- Add comment for tcm_vhost_workqueue in tcm_vhost_init()
- Make GET_ABI_VERSION return 'int' + add comment in tcm_vhost.h
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch adds the initial code for tcm_vhost, a Vhost level TCM
fabric driver for virtio SCSI initiators into KVM guest.
This code is currently up and running on v3.5-rc2 host+guest
from target-pending/for-next-merge.
Using tcm_vhost requires Zhi's -> Stefan -> nab's qemu vhost-scsi tree here:
http://git.kernel.org/?p=virt/kvm/nab/qemu-kvm.git;a=shortlog;h=refs/heads/vhost-scsi
--
Changelog v4 -> v5:
Expose ABI version via VHOST_SCSI_GET_ABI_VERSION + use Rev 0 as
starting point for v3.6-rc code (Stefan + ALiguori + nab)
Convert vhost_scsi_handle_vq() to vq_err() (nab + MST)
Minor style fixes from checkpatch (nab)
Changelog v3 -> v4:
Rename vhost_vring_target -> vhost_scsi_target (mst + nab)
Use TRANSPORT_IQN_LEN in vhost_scsi_target->vhost_wwpn[] def (nab)
Move back to drivers/vhost/, and just use drivers/vhost/Kconfig.tcm (mst)
Move TCM_VHOST related ioctl defines from include/linux/vhost.h ->
drivers/vhost/tcm_vhost.h as requested by MST (nab)
Move Kbuild.tcm include from drivers/staging -> drivers/vhost/, and
just use 'if STAGING' around 'source drivers/vhost/Kbuild.tcm'
Changelog v2 -> v3:
Unlock on error in tcm_vhost_drop_nexus() (DanC)
Fix strlen() doesn't count the terminator (DanC)
Call kfree() on an error path (DanC)
Convert tcm_vhost_write_pending to use target_execute_cmd (hch + nab)
Fix another strlen() off by one in tcm_vhost_make_tport (DanC)
Add option under drivers/staging/Kconfig, and move to drivers/vhost/tcm/
as requested by MST (nab)
Changelog v1 -> v2:
Fix tv_cmd completion -> release SGL memory leak (nab)
Fix sparse warnings for static variable usage ((Fengguang Wu)
Fix sparse warnings for min() typing + printk format specs (Fengguang Wu)
Convert to cmwq submission for I/O dispatch (nab + hch)
Changelog v0 -> v1:
Merge into single source + header file, and move to drivers/vhost/
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The vhost work queue allows processing to be done in vhost worker thread
context, which uses the owner process mm. Access to the vring and guest
memory is typically only possible from vhost worker context so it is
useful to allow work to be queued directly by users.
Currently vhost_net only uses the poll wrappers which do not expose the
work queue functions. However, for tcm_vhost (vhost_scsi) it will be
necessary to queue custom work.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
In order for other vhost devices to use the VHOST_FEATURES bits the
vhost-net specific bits need to be moved to their own VHOST_NET_FEATURES
constant.
(Asias: Update drivers/vhost/test.c to use VHOST_NET_FEATURES)
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Zhi Yong Wu <wuzhy@cn.ibm.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Asias He <asias@redhat.com>
Signed-off-by: Nicholas A. Bellinger <nab@risingtidesystems.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
On some architectures address spaces are set up in a way that this is
not necessary to work properly but on some others (like s390) it is.
Make sure we operate on the user address space to allow copy_xxx_user()
from the vhost_worker() thread by setting it explicitly before calling
use_mm() and revert it after unuse_mm().
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Take vlan header length into account, when vlan id is stored as
vlan_tci. Otherwise tagged packets coming from macvtap will be
truncated.
Signed-off-by: Basil Gor <basil.gor@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We add used and signal guest in worker thread but did not poll the virtqueue
during the zero copy callback. This may lead the missing of adding and
signalling during zerocopy. Solve this by polling the virtqueue and let it
wakeup the worker during callback.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When a packet were fully copied in zerocopy, we don't wait for the DMA done to
mark the done flag, so after the packet were passed to lower device, we need to
add used and signal guest immediately.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Currently, we restart tx polling unconditionally when sendmsg()
fails. This would cause unnecessary wakeups of vhost wokers and waste
cpu utlization when evil userspace(guest driver) is able to hit EFAULT or
EINVAL.
The polling is only needed when the socket send buffer were exceeded or not
enough memory. So fix this by restarting polling only when sendmsg() returns
EAGAIN/ENOBUFS.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When we want to disable vhost_net backend while there's a tx work, a possible
NULL pointer defernece may happen we we try to deference the vq->bufs after
vhost_net_set_backend() assign a NULL to it.
As suggested by Michael, fix this by checking the vq->bufs instead of
vhost_sock_zcopy().
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull networking fixes from David Miller:
1) Fix namespace init and cleanup in phonet to fix some oopses, from
Eric W. Biederman.
2) Missing kfree_skb() in AF_KEY, from Julia Lawall.
3) Refcount leak and source address handling fix in l2tp from James
Chapman.
4) Memory leak fix in CAIF from Tomasz Gregorek.
5) When routes are cloned from ipv6 addrconf routes, we don't process
expirations properly. Fix from Gao Feng.
6) Fix panic on DMA errors in atl1 driver, from Tony Zelenoff.
7) Only enable interrupts in 8139cp driver after we've registered the
IRQ handler. From Jason Wang.
8) Fix too many reads of KS_CIDER register in ks8851 during probe,
fixing crashes on spurious interrupts. From Matt Renzelmann.
9) Missing include in ath5k driver and missing iounmap on probe
failure, from Jonathan Bither.
10) Fix RX packet handling in smsc911x driver, from Will Deacon.
11) Fix ixgbe WoL on fiber by leaving the laser on during shutdown.
12) ks8851 needs MAX_RECV_FRAMES increased otherwise the internal MAC
buffers are easily overflown. Fix from Davide Cimingahi.
13) Fix memory leaks in peak_usb CAN driver, from Jesper Juhl.
14) gred packet scheduler can dump in WRED more when doing a netlink
dump. Fix from David Ward.
15) Fix MTU in USB smsc75xx driver, from Stephane Fillod.
16) Dummy device needs ->ndo_uninit handler to properly handle
->ndo_init failures. From Hiroaki SHIMODA.
17) Fix TX fragmentation in ath9k driver, from Sujith Manoharan.
18) Missing RTNL lock in ixgbe PM resume, from Benjamin Poirier.
19) Missing iounmap in farsync WAN driver, from Julia Lawall.
20) With LRO/GRO, tcp_grow_window() is easily tricked into not growing
the receive window properly, and this hurts performance. Fix from
Eric Dumazet.
21) Network namespace init failure can leak net_generic data, fix from
Julian Anastasov.
22) Fix skb_over_panic due to mis-accounting in TCP for partially ACK'd
SKBs. From Eric Dumazet.
23) New IDs for qmi_wwan driver, from Bjørn Mork.
24) Fix races in ax25_exit(), from Eric W. Biederman.
25) IPV6 TCP doesn't handle TCP_MAXSEG socket option properly, copy over
logic from the IPV4 side. From Neal Cardwell.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (59 commits)
tcp: fix TCP_MAXSEG for established IPv6 passive sockets
drivers/net: Do not free an IRQ if its request failed
drop_monitor: allow more events per second
ks8851: Fix request_irq/free_irq mismatch
net/hyperv: Adding cancellation to ensure rndis filter is closed
ks8851: Fix mutex deadlock in ks8851_net_stop()
net ax25: Reorder ax25_exit to remove races.
icplus: fix interrupt for IC+ 101A/G and 1001LF
net: qmi_wwan: support Sierra Wireless MC77xx devices in QMI mode
bnx2x: off by one in bnx2x_ets_e3b0_sp_pri_to_cos_set()
ksz884x: don't copy too much in netdev_set_mac_address()
tcp: fix retransmit of partially acked frames
netns: do not leak net_generic data on failed init
net/sock.h: fix sk_peek_off kernel-doc warning
tcp: fix tcp_grow_window() for large incoming frames
drivers/net/wan/farsync.c: add missing iounmap
davinci_mdio: Fix MDIO timeout check
ipv6: clean up rt6_clean_expires
ipv6: fix rt6_update_expires
arcnet: rimi: Fix device name in debug output
...
The skb struct ubuf_info callback gets passed struct ubuf_info
itself, not the arg value as the field name and the function signature
seem to imply. Rename the arg field to ctx to match usage,
add documentation and change the callback argument type
to make usage clear and to have compiler check correctness.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit ea5d404655
broke build for the vhost test module used
by tools/virtio. Fix it up.
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We shouldn't hold any locks on release path. Pass a flag to
vhost_dev_cleanup to use the lockdep info correctly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
This is a tiny, but important, patch to vhost.
Vhost's worker thread only called schedule() when it had no work to do, and
it wanted to go to sleep. But if there's always work to do, e.g., the guest
is running a network-intensive program like netperf with small message sizes,
schedule() was *never* called. This had several negative implications (on
non-preemptive kernels):
1. Passing time was not properly accounted to the "vhost" process (ps and
top would wrongly show it using zero CPU time).
2. Sometimes error messages about RCU timeouts would be printed, if the
core running the vhost thread didn't schedule() for a very long time.
3. Worst of all, a vhost thread would "hog" the core. If several vhost
threads need to share the same core, typically one would get most of the
CPU time (and its associated guest most of the performance), while the
others hardly get any work done.
The trivial solution is to add
if (need_resched())
schedule();
After doing every piece of work. This will not do the heavy schedule() all
the time, just when the timer interrupt decided a reschedule is warranted
(so need_resched returns true).
Thanks to Abel Gordon for this patch.
Signed-off-by: Nadav Har'El <nyh@il.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
By adding some module aliases, programs (or users) won't have to explicitly
call modprobe. Vhost-net will always be available if built into the kernel.
It does require assigning a permanent minor number for depmod to work.
Also:
- use C99 style initialization.
- add missing entry in documentation for loop-control
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-By: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The meth for calculating the # of outstanding buffers gives
incorrect results when vq->upend_idx wraps around zero.
Fix that.
Signed-off-by: Shirley Ma <xma@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
On backend change, we flushed out outstanding skbs
but forgot to update the used ring, so that
done entries were left in the ubuf_info ring.
As a result we lose heads or complete incorrect ones,
crashing the guest or leaking memory.
Fix by updating the used ring.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
As we now only update used ring after enabling
the backend, we can write flags with __put_user:
as that's done on data path, it matters.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fix get/put refcount imbalance with zero copy,
which caused qemu to hang forever on guest driver unload.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We need to log writes when updating used flags and avail event
fields. Otherwise the guest may see a stale value after migration and
miss notifying the host.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Move the used ring initialization after backend was set. This
makes it possible to disable the backend and tweak the used ring,
then restart. This will also make it possible to log the used ring
write correctly.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>From: Shirley Ma <mashirle@us.ibm.com>
This adds experimental zero copy support in vhost-net,
disabled by default. To enable, set
experimental_zcopytx module option to 1.
This patch maintains the outstanding userspace buffers in the
sequence it is delivered to vhost. The outstanding userspace buffers
will be marked as done once the lower device buffers DMA has finished.
This is monitored through last reference of kfree_skb callback. Two
buffer indices are used for this purpose.
The vhost-net device passes the userspace buffers info to lower device
skb through message control. DMA done status check and guest
notification are handled by handle_tx: in the worst case is all buffers
in the vq are in pending/done status, so we need to notify guest to
release DMA done buffers first before we get any new buffers from the
vq.
One known problem is that if the guest stops submitting
buffers, buffers might never get used until some
further action, e.g. device reset. This does not
seem to affect linux guests.
Signed-off-by: Shirley <xma@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support the new event index feature. When acked,
utilize it to reduce the # of interrupts sent to the guest.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
- Documentation/kvm/ to Documentation/virtual/kvm
- Documentation/uml/ to Documentation/virtual/uml
- Documentation/lguest/ to Documentation/virtual/lguest
throughout the kernel source tree.
Signed-off-by: Rob Landley <rob@landley.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Use of skb_queue_empty(&sock->sk->sk_receive_queue)
without taking the sk_receive_queue.lock is unsafe
or useless. Take it out.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vhost takes a sock lock to try and prevent
the skb from being pulled from the receive queue
after skb_peek. However this is not the right lock to use for that,
sk_receive_queue.lock is. Fix that up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Codes duplication were found between the handling of mergeable and big
buffers, so this patch tries to unify them. This could be easily done
by adding a quota to the get_rx_bufs() which is used to limit the
number of buffers it returns (for mergeable buffer, the quota is
simply UIO_MAXIOV, for big buffers, the quota is just 1), and then the
previous handle_rx_mergeable() could be resued also for big buffers.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
No need to check the support of mergeable buffer inside the recevie
loop as the whole handle_rx()_xx is in the read critical region. So
this patch move it ahead of the receiving loop.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
copy_from_user is pretty high on perf top profile,
replacing it with __copy_from_user helps.
It's also safe because we do access_ok checks during setup.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Minor cleanup of vhost.c and net.c to match coding style.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When built with rcu checks enabled, vhost triggers
bogus warnings as vhost features are read without
dev->mutex sometimes, and private pointer is read
with our kind of rcu where work serves as a
read side critical section.
Fixing it properly is not trivial.
Disable the warnings by stubbing out the checks for now.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
To detect that a sequence number is done, we are doing math on unsigned
integers so the result is unsigned too. Not what was intended for the <=
comparison. The result is user stuck forever in flush call.
Convert to int to fix this.
Further, get rid of ({}) to make code clearer.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This adds a test module for vhost infrastructure.
Intentionally not tied to kbuild to prevent people
from installing and loading it accidentally.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We really store a page offset in write_address,
so rename it write_page to avoid confusion.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
