This is a PCI device that implements a transport for virtio.  It allows virtio
devices to be used by QEMU based VMMs like KVM or Xen.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Am Freitag, 1. Februar 2008 schrieb Christian Borntraeger:
> Right. I will fix that with an additional patch.

This patch goes on top of the minor number patch. Please let me know if
you want a merged patch:

Currently virtio_blk creates the disk name combinging "vd"  with 'a'++.
This will give strange names after vdz. I have implemented names up to
vdzzz - inspired by the sd.c code. That should be sufficient for now.

There is one driver in the kernel (driver/s390/block/dasd_genhd.c) that
implements names from dasda-dasdzzzz allowing even more disks. Maybe
a janitor can come up with a common implementation usable for all kind
of block device drivers.

I have tested this patch with 100 disks - seems to work.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Rusty,

currently virtio_blk uses one major number per device. While this works
quite well on most systems it is wasteful and will exhaust major numbers
on larger installations.

This patch allocates a major number on init and will use 16 minor numbers
for each disk. That will allow ~64k virtio_blk disks.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Rusty,

I currently try to make my guest boot from an virtio root device
without having an external kernel. Some of the tools that I tried
expect HDIO_GETGEO to work. The most interesting value is likely
the geo.start value to get the offset of a partition. This value
is filled by block/ioctl.c if fops->getgeo is set. This patch also
fills in some standard values for heads, sectors and cylinders.

Makes sense?
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It is done in order to improve performance.
Signed-off-by: NDor Laor <dor.laor@qumranet.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This fixes a potential dangling xmit problem.

We also suppress refill interrupts until we need them.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Fix bug found by Christian Borntraeger: if the other side fills all
the registered network buffers before we enable NAPI, we will never
get an interrupt.  The simplest fix is to process the input queue once
on open.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Hello Rusty,

virtnet_probe already calls alloc_etherdev, which calls ether_setup.
There is no need to do that again.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This is needed for the virtio PCI device to be compiled as a module.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Simple cleanup.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This patch moves virtio under the virtualization menu and changes virtio
devices to not claim to only be for lguest.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Anthony Liguori found double interrupt suppression in the virtio_net
driver, triggered by two skb_recv_done's in a row.  This is because
virtio_ring's interrupt suppression is a best-effort optimization: it
contains no synchronization so the host can miss it and still send
interrupts.

But it's certainly nicer for virtio users if calling disable_cb
actually disables callbacks, so we check for the race in the interrupt
routine.

Note: SMP guests might require syncronization here, but since
disable_cb is actually called from interrupt context, there has to be
some form of synchronization before the next same interrupt handler is
called (Linux guarantees that the same device's irq handler will never
run simultanously on multiple CPUs).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

A reset function solves three problems:

1) It allows us to renegotiate features, eg. if we want to upgrade a
   guest driver without rebooting the guest.

2) It gives us a clean way of shutting down virtqueues: after a reset,
   we know that the buffers won't be used by the host, and

3) It helps the guest recover from messed-up drivers.

So we remove the ->shutdown hook, and the only way we now remove
feature bits is via reset.

We leave it to the driver to do the reset before it deletes queues:
the balloon driver, for example, needs to chat to the host in its
remove function.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Since we want to reset the device to remove them, this is simpler
(device is reset for us on driver remove).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

1) Turn GSO on virtio net into an all-or-nothing (keep checksumming
   separate).  Having multiple bits is a pain: if you can't support something
   you should handle it in software, which is still a performance win.

2) Make VIRTIO_NET_HDR_GSO_ECN a flag in the header, so it can apply to
   IPv6 or v4.

3) Rename VIRTIO_NET_F_NO_CSUM to VIRTIO_NET_F_CSUM (ie. means we do
   checksumming).

4) Add csum and gso params to virtio_net to allow more testing.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It's far easier to deal with packets if we don't have to parse the
packet to figure out the header length to know how much to pull into
the skb data.  Add the field to the virtio_net_hdr struct (and fix the
spaces that somehow crept in there).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This field has been unused since an older version of virtio.  Remove
it now before we freeze the ABI.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au.

The other side (host) can set the NO_NOTIFY flag as an optimization,
to say "no need to kick me when you add things".  Make it clear that
this is advisory only; especially that we should always notify when
the ring is full.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Using unsigned int resulted in silent truncation of the upper 32-bit
on x86_64 resulting in an OOPS since the ring was being initialized
wrong.

Please reconsider my previous patch to just use PAGE_ALIGN().  Open
coding this sort of stuff, no matter how simple it seems, is just
asking for this sort of trouble.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Various drivers want to know when their configuration information
changes: the balloon driver is the immediate user, but the network
driver may one day have a "carrier" status as well.

This introduces that callback (lguest doesn't use it yet).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Previously we used a type/len pair within the config space, but this
seems overkill.  We now simply define a structure which represents the
layout in the config space: the config space can now only be extended
at the end.

The main driver-visible changes:
1) We indicate what fields are present with an explicit feature bit.
2) Virtqueues are explicitly numbered, and not in the config space.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Use it in virtio_net (replacing buggy version there), it's also going
to be used by TAP for partial csum support.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (95 commits)
  ide-tape: remove idetape_config_t typedef
  ide-tape: remove mtio.h related comments
  ide-tape: make function name more accurate
  ide-tape: remove unused sense packet commands.
  ide-tape: use generic byteorder macros
  ide-tape: remove EXPERIMENTAL driver status
  ide-tape: use generic scsi commands
  ide-tape: remove struct idetape_block_size_page_t
  ide-tape: remove structs os_partition_t, os_dat_entry_t, os_dat_t
  ide-tape: remove struct idetape_parameter_block_descriptor_t
  ide-tape: remove struct idetape_medium_partition_page_t
  ide-tape: remove struct idetape_data_compression_page_t
  ide-tape: remove struct idetape_inquiry_result_t
  ide-tape: remove struct idetape_capabilities_page_t
  ide-tape: remove IDETAPE_DEBUG_BUGS
  ide-tape: remove IDETAPE_DEBUG_INFO
  ide-tape: dump gcw fields on error in idetape_identify_device()
  ide-tape: remove struct idetape_mode_parameter_header_t
  ide-tape: remove struct idetape_request_sense_result_t
  ide-tape: remove dead code
  ...

Frederik Himpe reported an unkillable and un-straceable pan process.

Zero length iovecs can go into an infinite loop in writev, because the
iovec iterator does not always advance over them.

The sequence required to trigger this is not trivial. I think it
requires that a zero-length iovec be followed by a non-zero-length iovec
which causes a pagefault in the atomic usercopy. This causes the writev
code to drop back into single-segment copy mode, which then tries to
copy the 0 bytes of the zero-length iovec; a zero length copy looks like
a failure though, so it loops.

Put a test into iov_iter_advance to catch zero-length iovecs. We could
just put the test in the fallback path, but I feel it is more robust to
skip over zero-length iovecs throughout the code (iovec iterator may be
used in filesystems too, so it should be robust).
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: sbp2: fix bogus s/g access change

Since this is used only in idetape_blkdev_ioctl(), remove the typedef and make
the struct function-local.

Bart:
- s/sizeof(struct idetape_config)/sizeof(config)/
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Those are already in mtio.h.

Bart:
- undo 'unsigned int/unsigned long' -> 'uint/ulong' conversion
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

idetape_active_next_stage() was rather ambiguous wrt its purpose. Make that
more explicit and remove superfluous comment.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This is not a network driver.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide-tape has depended on EXPERIMENTAL for ages. Change that since the driver is
being only maintained now.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Also, remove those which weren't used.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

They seem just to sit there completely unused.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Also, shorten function name idetape_get_blocksize_from_block_descriptor() and
move its definition up thereby getting rid of its forward declaration.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes resulting from this patch.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes resulting from this patch.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes resulting from this patch.
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

All those 2-byte values denoting the different capabilities are being written to
the local copy of the caps buffer without being converted to big endian for
simplicity of usage and shorter code later.  Also, we add some comments stating
which are the fields of the caps page in question in order to alleviate the
cryptic pointer casting exercises as in e.g. idetape_get_mode_sense_results().

There should be no functional changes resulting from this patch.

Bart:
- remove two needless "!!"
Signed-off-by: NBorislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>