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: Rusty 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: Rusty 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: Rusty 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: Rusty 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: Rusty 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: Rusty 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: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty 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: Rusty 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: Rusty 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: Rusty 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: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
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: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej 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: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej 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: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
They seem just to sit there completely unused.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej 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: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
There should be no functional changes resulting from this patch.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej 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: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The device capabilities are probed for during device initialization so this
info is available through proc/ioctl() und it is redundant here.
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
No reason to use ide_init_hwif_ports() in ide-cs (as a nice side-effect
this makes ide-cs work on archs that don't define IDE_ARCH_OBSOLETE_INIT).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Move check_dma_crc() to ide-dma.c and add inline version for
CONFIG_BLK_DEV_IDEDMA=n case.
* Rename check_dma_crc() to ide_check_dma_crc().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
SELECT_DRIVE() is called by IDE core code in start_request() before device
driver's ->do_request method. In ide-scsi case ->do_request is implemented
by idescsi_do_request() which is also the only user of idescsi_issue_pc().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Use __ide_set_handler() in ide_execute_command().
While at it:
* Fix whitespace damage in ide_execute_command().
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* siimage.c: use hwif->sata_scr[SATA_{ERROR,STATUS}_OFFSET] instead of
SATA_{ERROR,STATUS}_REG macros.
* Remove no longer needed SATA_*_REG macros.
While at it:
* Remove needless SATA Status register read from sil_sata_reset_poll().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* ->nice0 and ->nice2 ide_drive_t fields are always zero so remove them.
* IDE_NICE_0 and IDE_NICE_2 defines from <linux/hdreg.h> are no longer
used by any kernel code so cover them with #ifndef/#endif __KERNEL__.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Cache value read from the Status register in 'stat' variable in do_probe()
and enable_nest(), then remove remove needless Status register reads.
While at it:
* Add proper KERN_* levels to printk() calls.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
