Stash the packet length in a local variable before handing over
ownership of the packet to virtio_transport_recv_pkt() or
virtio_transport_free_pkt().
This patch solves the use-after-free since pkt is no longer guaranteed
to be alive.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull virtio/vhost updates from Michael Tsirkin:
- new vsock device support in host and guest
- platform IOMMU support in host and guest, including compatibility
quirks for legacy systems.
- misc fixes and cleanups.
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
VSOCK: Use kvfree()
vhost: split out vringh Kconfig
vhost: detect 32 bit integer wrap around
vhost: new device IOTLB API
vhost: drop vringh dependency
vhost: convert pre sorted vhost memory array to interval tree
vhost: introduce vhost memory accessors
VSOCK: Add Makefile and Kconfig
VSOCK: Introduce vhost_vsock.ko
VSOCK: Introduce virtio_transport.ko
VSOCK: Introduce virtio_vsock_common.ko
VSOCK: defer sock removal to transports
VSOCK: transport-specific vsock_transport functions
vhost: drop vringh dependency
vop: pull in vhost Kconfig
virtio: new feature to detect IOMMU device quirk
balloon: check the number of available pages in leak balloon
vhost: lockless enqueuing
vhost: simplify work flushing
vringh is pulled in by caif and mic, but the other
vhost config does not need to be there.
In particular, it makes no sense to have vhost net/scsi/sock
under caif/mic.
Create a separate Kconfig file and put vringh bits there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch tries to implement an device IOTLB for vhost. This could be
used with userspace(qemu) implementation of DMA remapping
to emulate an IOMMU for the guest.
The idea is simple, cache the translation in a software device IOTLB
(which is implemented as an interval tree) in vhost and use vhost_net
file descriptor for reporting IOTLB miss and IOTLB
update/invalidation. When vhost meets an IOTLB miss, the fault
address, size and access can be read from the file. After userspace
finishes the translation, it writes the translated address to the
vhost_net file to update the device IOTLB.
When device IOTLB is enabled by setting VIRTIO_F_IOMMU_PLATFORM all vq
addresses set by ioctl are treated as iova instead of virtual address and
the accessing can only be done through IOTLB instead of direct userspace
memory access. Before each round or vq processing, all vq metadata is
prefetched in device IOTLB to make sure no translation fault happens
during vq processing.
In most cases, virtqueues are contiguous even in virtual address space.
The IOTLB translation for virtqueue itself may make it a little
slower. We might add fast path cache on top of this patch.
Signed-off-by: Jason Wang <jasowang@redhat.com>
[mst: use virtio feature bit: VHOST_F_DEVICE_IOTLB -> VIRTIO_F_IOMMU_PLATFORM ]
[mst: fix build warnings ]
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[ weiyj.lk: missing unlock on error ]
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Current pre-sorted memory region array has some limitations for future
device IOTLB conversion:
1) need extra work for adding and removing a single region, and it's
expected to be slow because of sorting or memory re-allocation.
2) need extra work of removing a large range which may intersect
several regions with different size.
3) need trick for a replacement policy like LRU
To overcome the above shortcomings, this patch convert it to interval
tree which can easily address the above issue with almost no extra
work.
The patch could be used for:
- Extend the current API and only let the userspace to send diffs of
memory table.
- Simplify Device IOTLB implementation.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch introduces vhost memory accessors which were just wrappers
for userspace address access helpers. This is a requirement for vhost
device iotlb implementation which will add iotlb translations in those
accessors.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
VM sockets vhost transport implementation. This driver runs on the
host.
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We use spinlock to synchronize the work list now which may cause
unnecessary contentions. So this patch switch to use llist to remove
this contention. Pktgen tests shows about 5% improvement:
Before:
~1300000 pps
After:
~1370000 pps
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We used to implement the work flushing through tracking queued seq,
done seq, and the number of flushing. This patch simplify this by just
implement work flushing through another kind of vhost work with
completion. This will be used by lockless enqueuing patch.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We used to queue tx packets in sk_receive_queue, this is less
efficient since it requires spinlocks to synchronize between producer
and consumer.
This patch tries to address this by:
- switch from sk_receive_queue to a skb_array, and resize it when
tx_queue_len was changed.
- introduce a new proto_ops peek_len which was used for peeking the
skb length.
- implement a tun version of peek_len for vhost_net to use and convert
vhost_net to use peek_len if possible.
Pktgen test shows about 15.3% improvement on guest receiving pps for small
buffers:
Before: ~1300000pps
After : ~1500000pps
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We don't stop rx polling socket during rx processing, this will lead
unnecessary wakeups from under layer net devices (E.g
sock_def_readable() form tun). Rx will be slowed down in this
way. This patch avoids this by stop polling socket during rx
processing. A small drawback is that this introduces some overheads in
light load case because of the extra start/stop polling, but single
netperf TCP_RR does not notice any change. In a super heavy load case,
e.g using pktgen to inject packet to guest, we get about ~8.8%
improvement on pps:
before: ~1240000 pkt/s
after: ~1350000 pkt/s
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Turns out the template and thus many drivers got the return value wrong:
0 means the fabrics driver needs to put a session reference, which no
driver except for the iSCSI target drivers did. Fortunately none of these
drivers supports explicit Node ACLs, so the bug was harmless.
Even without that only qla2xxx and iscsi every did real work in
shutdown_session, so get rid of the boilerplate code in all other
drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull SCSI target updates from Nicholas Bellinger:
"The highlights this round include:
- Add target_alloc_session() w/ callback helper for doing se_session
allocation + tag + se_node_acl lookup. (HCH + nab)
- Tree-wide fabric driver conversion to use target_alloc_session()
- Convert sbp-target to use percpu_ida tag pre-allocation, and
TARGET_SCF_ACK_KREF I/O krefs (Chris Boot + nab)
- Convert usb-gadget to use percpu_ida tag pre-allocation, and
TARGET_SCF_ACK_KREF I/O krefs (Andrzej Pietrasiewicz + nab)
- Convert xen-scsiback to use percpu_ida tag pre-allocation, and
TARGET_SCF_ACK_KREF I/O krefs (Juergen Gross + nab)
- Convert tcm_fc to use TARGET_SCF_ACK_KREF I/O + TMR krefs
- Convert ib_srpt to use percpu_ida tag pre-allocation
- Add DebugFS node for qla2xxx target sess list (Quinn)
- Rework iser-target connection termination (Jenny + Sagi)
- Convert iser-target to new CQ API (HCH)
- Add pass-through WRITE_SAME support for IBLOCK (Mike Christie)
- Introduce data_bitmap for asynchronous access of data area (Sheng
Yang + Andy)
- Fix target_release_cmd_kref shutdown comp leak (Himanshu Madhani)
Also, there is a separate PULL request coming for cxgb4 NIC driver
prerequisites for supporting hw iscsi segmentation offload (ISO), that
will be the base for a number of v4.7 developments involving
iscsi-target hw offloads"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (36 commits)
target: Fix target_release_cmd_kref shutdown comp leak
target: Avoid DataIN transfers for non-GOOD SAM status
target/user: Report capability of handling out-of-order completions to userspace
target/user: Fix size_t format-spec build warning
target/user: Don't free expired command when time out
target/user: Introduce data_bitmap, replace data_length/data_head/data_tail
target/user: Free data ring in unified function
target/user: Use iovec[] to describe continuous area
target: Remove enum transport_lunflags_table
target/iblock: pass WRITE_SAME to device if possible
iser-target: Kill the ->isert_cmd back pointer in struct iser_tx_desc
iser-target: Kill struct isert_rdma_wr
iser-target: Convert to new CQ API
iser-target: Split and properly type the login buffer
iser-target: Remove ISER_RECV_DATA_SEG_LEN
iser-target: Remove impossible condition from isert_wait_conn
iser-target: Remove redundant wait in release_conn
iser-target: Rework connection termination
iser-target: Separate flows for np listeners and connections cma events
iser-target: Add new state ISER_CONN_BOUND to isert_conn
...
This patch converts vhost/scsi pre-allocation of vhost_scsi_cmd
descriptors to use the new alloc_session callback().
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This patch tries to poll for new added tx buffer or socket receive
queue for a while at the end of tx/rx processing. The maximum time
spent on polling were specified through a new kind of vring ioctl.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch introduces a helper which will return true if we're sure
that the available ring is empty for a specific vq. When we're not
sure, e.g vq access failure, return false instead. This could be used
for busy polling code to exit the busy loop.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This path introduces a helper which can give a hint for whether or not
there's a work queued in the work list. This could be used for busy
polling code to exit the busy loop.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Looking at how callers use this, maybe we should just rename init_used
to vhost_vq_init_access. The _used suffix was a hint that we
access the vq used ring. But maybe what callers care about is
that it must be called after access_ok.
Also, this function manipulates the vq->is_le field which isn't related
to the vq used ring.
This patch simply renames vhost_init_used() to vhost_vq_init_access() as
suggested by Michael.
No behaviour change.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The default use case for vhost is when the host and the vring have the
same endianness (default native endianness). But there are cases where
they differ and vhost should byteswap when accessing the vring.
The first case is when the host is big endian and the vring belongs to
a virtio 1.0 device, which is always little endian.
This is covered by the vq->is_le field. This field is initialized when
userspace calls the VHOST_SET_FEATURES ioctl. It is reset when the device
stops.
We already have a vhost_init_is_le() helper, but the reset operation is
opencoded as follows:
vq->is_le = virtio_legacy_is_little_endian();
It isn't clear that we are resetting vq->is_le here.
This patch moves the code to a helper with a more explicit name.
The other case where we may have to byteswap is when the architecture can
switch endianness at runtime (bi-endian). If endianness differs in the host
and in the guest, then legacy devices need to be used in cross-endian mode.
This mode is available with CONFIG_VHOST_CROSS_ENDIAN_LEGACY=y, which
introduces a vq->user_be field. Userspace may enable cross-endian mode
by calling the SET_VRING_ENDIAN ioctl before the device is started. The
cross-endian mode is disabled when the device is stopped.
The current names of the helpers that manipulate vq->user_be are unclear.
This patch renames those helpers to clearly show that this is cross-endian
stuff and with explicit enable/disable semantics.
No behaviour change.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We don't want side effects. If something fails, we rollback vq->is_le to
its previous value.
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
