When opening an image it is useful to know whether the caller
intends to perform I/O on the image or not. In the case of
encrypted images this will allow the block driver to avoid
having to prompt for decryption keys when we merely want to
query header metadata about the image. eg qemu-img info

This flag is enforced at the top level only, since even if
we don't want todo I/O on the 'qcow2' file payload, the
underlying 'file' driver will still need todo I/O to read
the qcow2 header, for example.
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_query_blk_stats() does not need access to all of BlockStats,
BlockDeviceStats is enough and is what this function is actually
supposed to fill.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This is the only instance of bdrv_query_blk_stats() accessing anything
in the BlockStats structure other than s->stats, so let us move it to
its caller (where it makes just as much sense) allowing us to make
bdrv_query_blk_stats() take a pointer to the BlockDeviceStats instead of
BlockStats.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Using heap instead of stack for better safety.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Fix two places to use literal printf format when possible.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The function is unused since commit f21d96d0 ('block: Use BdrvChild in
BlockBackend').
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Mac OS X can be picky when it comes to allowing the user
to use physical devices in QEMU. Most mounted volumes
appear to be off limits to QEMU. If an issue is detected,
a message is displayed showing the user how to unmount a
volume. Now QEMU uses both CD and DVD media.
Signed-off-by: NJohn Arbuckle <programmingkidx@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Writethrough mode is going to become a BlockBackend feature rather than
a BDS one, so forbid it in places where we won't be able to support it
when the code finally matches the envisioned design.

We only allowed setting the cache mode of non-root nodes after the 2.5
release, so we're still free to make this change.

The target of block jobs is now always opened in a writeback mode
because it doesn't have a BlockBackend attached. This makes more sense
anyway because block jobs know when to flush. If the graph is modified
on job completion, the original cache mode moves to the new root, so
for the guest device writethough always stays enabled if it was
configured this way.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

First of all, we're generally not writing to backing files, but when we
do, it's in the context of block jobs which know very well when to flush
the image.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The WCE bit is a frontend property and should not be part of the backend
configuration. This is especially important because the same BDS can be
used by different users with different WCE requirements.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch changes dirty bitmaps from following a BlockBackend in graph
changes to sticking with the node they were created at. For the full
discussion, read the following mailing list thread:

  [Qemu-block] block: Dirty bitmaps and COR in bdrv_move_feature_fields()
  https://lists.nongnu.org/archive/html/qemu-block/2016-02/msg00745.html

In summary, the justification for this change is:

* When moving the dirty bitmap to the top of the tree was introduced in
  bdrv_append() in commit a9fc4408, it didn't actually have any effect
  because there could never be a bitmap in use when bdrv_append() was
  called (op blockers would prevent this). This is still true today for
  all internal uses of dirty bitmaps.

* Support for user-defined dirty bitmaps was introduced in 2.4, but we
  discouraged users from using it because we didn't consider it ready
  yet.

  Moreover, in 2.5, the bdrv_swap() removal introduced a bug that left
  dangling pointers if a dirty bitmap was present (the anchors of the
  dirty bitmap were swapped, but the back link in the first element
  wasn't updated), so it didn't even work correctly.

* block-dirty-bitmap-add takes an arbitrary node name, even if no
  BlockBackend is attached. This suggests that it is a node level
  operation and not a BlockBackend one. Consequently, there is no reason
  for dirty bitmaps to stay with a BlockBackend that was attached to the
  node they were created for.

* It was suggested that block-dirty-bitmap-add could track the node if a
  node name was specified, and track the BlockBackend if the device name
  was specified. This would however be inconsistent with other QMP
  commands. Commands that accept both device and node names currently
  interpret the device name just as an alias for the current root node
  of that BlockBackend.

* Dirty bitmaps have a name that is only unique amongst the bitmaps in a
  specific node. Moving bitmaps could lead to name clashes. Automatic
  renaming would involve too much magic.

* Persistent bitmaps are stored in a specific node. Moving them around
  automatically might be at least surprising, but it would probably also
  become a real problem because that would have to happen atomically
  without the management tool knowing of the operation.

At the end of the day it seems to be very clear that it was a mistake to
include dirty bitmaps in bdrv_move_feature_fields(). The functionality
of moving bitmaps and/or attaching them to a BlockBackend instead will
probably be needed, but it should be done with a new explicit QMP
command or option.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Ever since we first introduced bdrv_append() in commit 8802d1fd ('qapi:
Introduce blockdev-group-snapshot-sync command'), the copy-on-read flag
was moved to the new top layer when taking a snapshot. The only problem
is that it doesn't make a whole lot of sense.

The use case for manually enabled CoR is to avoid reading data twice
from a slow remote image, so we want to save it to a local overlay, say
an ISO image accessed via HTTP to a local qcow2 overlay. When taking a
snapshot, we end up with a backing chain like this:

    http <- local.qcow2 <- snap_overlay.qcow2

There is no point in doing CoR from local.qcow2 into snap_overlay.qcow2,
we just want to keep copying data from the remote source into
local.qcow2.

The other use case of CoR is in the context of streaming, which isn't
very interesting for bdrv_move_feature_fields() because op blockers
prevent this combination.

This patch makes the copy-on-read flag stay on the image for which it
was originally set and prevents it from being propagated to the new
overlay. It is no longer intended to move CoR to the BlockBackend level.
In order for this to make sense, we also need to keep the respective
image read-write.

As a side effect of these changes, creating a live snapshot image (as
opposed to using an existing externally created one) on top of a COR
block device works now. It used to fail because it tried to open its
backing file both read-only and with COR.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The call in hmp_drive_del() is dead code because blk_remove_bs() is
called a few lines above. The only other remaining user is
bdrv_delete(), which only abuses bdrv_make_anon() to remove it from the
named nodes list. This path inlines the list entry removal into
bdrv_delete() and removes bdrv_make_anon().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

# gpg: Signature made Tue 29 Mar 2016 01:48:09 BST using RSA key ID C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg:                 aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg:                 aka "Jeffrey Cody <codyprime@gmail.com>"

* remotes/cody/tags/block-pull-request:
  qemu-iotests: add no-op streaming test
  qemu-iotests: fix test_stream_partial()
  block: never cancel a streaming job without running stream_complete()
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

slirp updates

# gpg: Signature made Tue 29 Mar 2016 00:16:05 BST using RSA key ID FB6B2F1D
# gpg: Good signature from "Samuel Thibault <samuel.thibault@gnu.org>"
# gpg:                 aka "Samuel Thibault <sthibault@debian.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@inria.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@labri.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@ens-lyon.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 900C B024 B679 31D4 0F82  304B D017 8C76 7D06 9EE6
#      Subkey fingerprint: F632 74CD C630 0873 CB3D  29D9 E3E5 1CE8 FB6B 2F1D

* remotes/thibault/tags/samuel-thibault:
  Rework ipv6 options
  Use C99 flexible array instead of 1-byte trailing array
  Avoid embedding struct mbuf in other structures
  slirp: send icmp6 errors when UDP send failed
  slirp: Fix memory leak on small incoming ipv4 packet
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

VFIO updates 2016-03-28

 - Use 128bit math to avoid asserts with IOMMU regions (Bandan Das)

# gpg: Signature made Mon 28 Mar 2016 23:16:52 BST using RSA key ID 3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>"
# gpg:                 aka "Alex Williamson <alex@shazbot.org>"
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>"
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>"

* remotes/awilliam/tags/vfio-update-20160328.0:
  vfio: convert to 128 bit arithmetic calculations when adding mem regions
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Rename the recently-added ip6-foo options into ipv6-foo options, to make
them coherent with other ipv6 options.

Also rework the documentation.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>

vfio_listener_region_add for a iommu mr results in
an overflow assert since iommu memory region is initialized
with UINT64_MAX. Convert calculations to 128 bit arithmetic
for iommu memory regions and let int128_get64 assert for non iommu
regions if there's an overflow.
Suggested-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBandan Das <bsd@redhat.com>
[missed (end - 1) on 2nd trace call, move llsize closer to use]
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

This patch tests that in a partial block-stream operation, no data is
ever copied from the base image.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Message-id: 5272a2aa57bc0b3f981f8b3e0c813e58a88c974b.1458566441.git.berto@igalia.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

This test is streaming to the top layer using the intermediate image
as the base. This is a mistake since block-stream never copies data
from the base image and its backing chain, so this is effectively a
no-op.

In addition to fixing the base parameter, this patch also writes some
data to the intermediate image before the test, so there's something
to copy and the test is meaningful.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Message-id: 2efa304da38b32d47c120ce728568a589c5a3afc.1458566441.git.berto@igalia.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

We need to call stream_complete() in order to do all the necessary
clean-ups, even if there's an early failure. At the moment it's only
useful to make sure that s->backing_file_str is not leaked, but it
will become more important if we introduce support for streaming to
any intermediate node.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 2abedf2debc65c250560237f31a8e6756883c8fc.1458566441.git.berto@igalia.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

* Log filtering from Alex and Peter
* Chardev fix from Marc-André
* config.status tweak from David
* Header file tweaks from Markus, myself and Veronia (Outreachy candidate)
* get_ticks_per_sec() removal from Rutuja (Outreachy candidate)
* Coverity fix from myself
* PKE implementation from myself, based on rth's XSAVE support

# gpg: Signature made Thu 24 Mar 2016 20:15:11 GMT using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream: (28 commits)
  target-i386: implement PKE for TCG
  config.status: Pass extra parameters
  char: translate from QIOChannel error to errno
  exec: fix error handling in file_ram_alloc
  cputlb: modernise the debug support
  qemu-log: support simple pid substitution for logs
  target-arm: dfilter support for in_asm
  qemu-log: dfilter-ise exec, out_asm, op and opt_op
  qemu-log: new option -dfilter to limit output
  qemu-log: Improve the "exec" TB execution logging
  qemu-log: Avoid function call for disabled qemu_log_mask logging
  qemu-log: correct help text for -d cpu
  tcg: pass down TranslationBlock to tcg_code_gen
  util: move declarations out of qemu-common.h
  Replaced get_tick_per_sec() by NANOSECONDS_PER_SECOND
  hw: explicitly include qemu-common.h and cpu.h
  include/crypto: Include qapi-types.h or qemu/bswap.h instead of qemu-common.h
  isa: Move DMA_transfer_handler from qemu-common.h to hw/isa/isa.h
  Move ParallelIOArg from qemu-common.h to sysemu/char.h
  Move QEMU_ALIGN_*() from qemu-common.h to qemu/osdep.h
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Conflicts:
	scripts/clean-includes

Support for booting from virtio-scsi devices in the s390-ccw bios.

# gpg: Signature made Thu 24 Mar 2016 08:14:21 GMT using RSA key ID C6F02FAF
# gpg: Good signature from "Cornelia Huck <huckc@linux.vnet.ibm.com>"
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>"

* remotes/cohuck/tags/s390x-20160324:
  s390-ccw.img: rebuild image
  pc-bios/s390-ccw: disambiguation of "No zIPL magic" message
  pc-bios/s390-ccw: enhance bootmap detection
  pc-bios/s390-ccw: enable virtio-scsi
  pc-bios/s390-ccw: add virtio-scsi implementation
  pc-bios/s390-ccw: add scsi definitions
  pc-bios/s390-ccw: add simplified virtio call
  pc-bios/s390-ccw: make provisions for different backends
  pc-bios/s390-ccw: add vdev object to store all device details
  pc-bios/s390-ccw: update virtio implementation to allow up to 3 vrings
  pc-bios/s390-ccw: qemuize types
  pc-bios/s390-ccw: add utility functions and "export" some others
  pc-bios/s390-ccw: virtio_panic -> panic
  pc-bios/s390-ccw: add more disk layout checks
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

input-linux + spice fixes

# gpg: Signature made Thu 24 Mar 2016 07:54:45 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-ui-20160324-1:
  spice: Disallow use of gl + TCP port
  input-linux: fix Coverity warning
  input-linux: switch over to -object
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

ppc patch queue for 2016-03-24

Accumulated patches for target-ppc, pseries machine type and related
devices.

* Preliminary patches from BenH & Cédric Le Goater's powernv code
    * We don't want the full machine type before 2.7
    * Adding some of the SPRs also fixes migration corner cases for
      spapr (when qemu has no knowledge of the registers, they're
      obviously not migrated)
    * We include some patches that aren't strictly fixes, but make
      applying the others easier, and they're low risk
* Fix to buffer management which significantly improves throughput in
  the spapr-llan virtual network device
* Start with 64-bit mode enabled on spapr.  This is the way it's
  supposed to be but we broke it a while back and didn't notice
  because Linux guests cope anyway.
    * Picked up by kvm-unit-tests
    * Still some bugs here that I'm working on

# gpg: Signature made Thu 24 Mar 2016 04:29:42 GMT using RSA key ID 20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.6-20160324:
  ppc: move POWER8 Book4 regs in their own routine
  hw/net/spapr_llan: Enable the RX buffer pools by default for new machines
  hw/net/spapr_llan: Fix receive buffer handling for better performance
  hw/net/spapr_llan: Extract rx buffer code into separate functions
  ppc: A couple more dummy POWER8 Book4 regs
  ppc: Add dummy CIABR SPR
  ppc: Add POWER8 IAMR register
  ppc: Fix writing to AMR/UAMOR
  ppc: Initialize AMOR in PAPR mode
  ppc: Add dummy SPR_IC for POWER8
  ppc: Create cpu_ppc_set_papr() helper
  ppc: Add a bunch of hypervisor SPRs to Book3s
  ppc: Add macros to register hypervisor mode SPRs
  ppc: Update SPR definitions
  spapr/target-ppc/kvm: Only add hcall-instructions if KVM supports it
  ppc64: set MSR_SF bit
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

MIPS patches 2016-03-23

Changes:
* add mips-softmmu-common.mak
* indicate presence of IEEE 754-2008 FPU in MIPS64R6-generic and P5600

# gpg: Signature made Wed 23 Mar 2016 16:38:04 GMT using RSA key ID 0B29DA6B
# gpg: Good signature from "Leon Alrae <leon.alrae@imgtec.com>"

* remotes/lalrae/tags/mips-20160323:
  default-configs: add mips-softmmu-common.mak
  target-mips: indicate presence of IEEE 754-2008 FPU in R6/R5+MSA CPUs
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

cocoa queue:
 * update cocoa UI front end to use QKeyCodes
 * fix the help menu documentation links to actually work
   (with both an installed and an uninstalled QEMU)

# gpg: Signature made Wed 23 Mar 2016 14:31:01 GMT using RSA key ID 14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"

* remotes/pmaydell/tags/pull-cocoa-20160323-1:
  ui/cocoa.m: switch to QKeyCode
  qapi-schema.json: Add power and keypad equal keys
  ui/cocoa.m: fix help menus
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Tested with kvm-unit-tests.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This allows you to do:
  ./config.status --the-option-you-forgot
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1452599928-7471-1-git-send-email-dgilbert@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

TriCore FPU + bugfixes

# gpg: Signature made Wed 23 Mar 2016 08:26:03 GMT using RSA key ID 6B69CA14
# gpg: Good signature from "Bastian Koppelmann <kbastian@mail.uni-paderborn.de>"

* remotes/bkoppelmann/tags/pull-tricore-20160323:
  target-tricore: Add ftoi and itof instructions
  target-tricore: Add cmp.f instruction
  target-tricore: Add div.f instruction
  target-tricore: Add mul.f instruction
  target-tricore: add add.f/sub.f instructions
  target-tricore: Move general CHECK_REG_PAIR of decode_rrr_divide
  target-tricore: Add FPU infrastructure
  target-tricore: Fix psw_read() clearing too many bits
  target-tricore: Fix helper_msub64_q_ssov not reseting OVF bit
  target-tricore: add missing break in insn decode switch stmt
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Currently, virgl support has to go through a local unix socket, trying
to connect to a VM using -spice gl through spice://localhost:5900 will
only result in a black screen.
This commit errors out when the user tries to start a VM with both GL
support and a port/tls-port set.
This would fit better in spice-server, but currently QEMU does not call
into spice-server when parsing 'gl' on its command line, so we have to
do this check in QEMU instead.
Signed-off-by: NChristophe Fergeau <cfergeau@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 1457955672-28758-1-git-send-email-cfergeau@redhat.com

[ applied codestyle fix: break long line ]
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 1458129049-12484-1-git-send-email-kraxel@redhat.com

This patches makes input-linux use -object instead of a new command line
switch.  So, instead of the switch ...

    -input-linux /dev/input/event$nr

... you must create an object this way:

    -object input-linux,id=$name,evdev=/dev/input/event$nr

Bonus is that you can hot-add and hot-remove them via monitor now.
Suggested-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1457681901-30916-1-git-send-email-kraxel@redhat.com

commit fce55481360d "ppc: A couple more dummy POWER8 Book4 regs"
squashed in to rapidly a set of POWER8 Book4 regs in the wrong
routine. This patch introduces the missing gen_spr_power8_book4()
routine to fix their location.
Signed-off-by: NCédric Le Goater <clg@fr.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

RX buffer pools are now enabled by default for new machine types.
For older machine types, they are still disabled to avoid breaking
migration.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

tl;dr:
This patch introduces an alternate way of handling the receive
buffers of the spapr-vlan device, resulting in much better
receive performance for the guest.

Full story:
One of our testers recently discovered that the performance of the
spapr-vlan device is very poor compared to other NICs, and that
a simple "ping -i 0.2 -s 65507 someip" in the guest can result
in more than 50% lost ping packets (especially with older guest
kernels < 3.17).

After doing some analysis, it was clear that there is a problem
with the way we handle the receive buffers in spapr_llan.c: The
ibmveth driver of the guest Linux kernel tries to add a lot of
buffers into several buffer pools (with 512, 2048 and 65536 byte
sizes by default, but it can be changed via the entries in the
/sys/devices/vio/1000/pool* directories of the guest). However,
the spapr-vlan device of QEMU only tries to squeeze all receive
buffer descriptors into one single page which has been supplied
by the guest during the H_REGISTER_LOGICAL_LAN call, without
taking care of different buffer sizes. This has two bad effects:
First, only a very limited number of buffer descriptors is accepted
at all. Second, we also hand 64k buffers to the guest even if
the 2k buffers would fit better - and this results in dropped packets
in the IP layer of the guest since too much skbuf memory is used.

Though it seems at a first glance like PAPR says that we should store
the receive buffer descriptors in the page that is supplied during
the H_REGISTER_LOGICAL_LAN call, chapter 16.4.1.2 in the LoPAPR spec
declares that "the contents of these descriptors are architecturally
opaque, none of these descriptors are manipulated by code above
the architected interfaces". That means we don't have to store
the RX buffer descriptors in this page, but can also manage the
receive buffers at the hypervisor level only. This is now what we
are doing here: Introducing proper RX buffer pools which are also
sorted by size of the buffers, so we can hand out a buffer with
the best fitting size when a packet has been received.

To avoid problems with migration from/to older version of QEMU,
the old behavior is also retained and enabled by default. The new
buffer management has to be enabled via a new "use-rx-buffer-pools"
property.

Now with the new buffer pool management enabled, the problem with
"ping -s 65507" is fixed for me, and the throughput of a simple
test with wget increases from creeping 3MB/s up to 20MB/s!
Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Refactor the code a little bit by extracting the code that reads
and writes the receive buffer list page into separate functions.
There should be no functional change in this patch, this is just
a preparation for the upcoming extensions that introduce receive
buffer pools.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: squashed in patch 'ppc: Add dummy ACOP SPR' ]
Signed-off-by: NCédric Le Goater <clg@fr.ibm.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We should implement HW breakpoint/watchpoint, qemu supports them...
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>