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  1. 28 9月, 2012 1 次提交
    • A
      virtio: Introduce virtqueue_get_avail_bytes() · 0d8d7690
      由 Amit Shah 提交于 
      The current virtqueue_avail_bytes() is oddly named, and checks if a
particular number of bytes are available in a vq.  A better API is to
fetch the number of bytes available in the vq, and let the caller do
what's interesting with the numbers.

Introduce virtqueue_get_avail_bytes(), which returns the number of bytes
for buffers marked for both, in as well as out.  virtqueue_avail_bytes()
is made a wrapper over this new function.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      0d8d7690
  3. 07 8月, 2012 1 次提交
  5. 17 7月, 2012 1 次提交
  7. 12 7月, 2012 2 次提交
  9. 22 5月, 2012 1 次提交
  11. 19 4月, 2012 1 次提交
  13. 22 2月, 2012 1 次提交
  15. 29 11月, 2011 1 次提交
  17. 17 9月, 2011 1 次提交
  19. 12 9月, 2011 1 次提交
  21. 05 8月, 2011 1 次提交
  23. 05 7月, 2011 1 次提交
  25. 12 6月, 2011 1 次提交
  27. 29 3月, 2011 1 次提交
    • M
      virtio-pci: fix bus master work around on load · 89c473fd
      由 Michael S. Tsirkin 提交于 
      Commit c81131db
detects old guests by comparing virtio and
PCI status. It attempts to do this on load,
as well, but load_config callback in a binding
is invoked too early and so the virtio status
isn't set yet.

We could add yet another callback to the
binding, to invoke after load, but it
seems easier to reuse the existing vmstate
callback.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
      89c473fd
  29. 21 3月, 2011 1 次提交
  31. 02 2月, 2011 1 次提交
  33. 10 1月, 2011 2 次提交
    • S
      virtio-pci: Use ioeventfd for virtqueue notify · 25db9ebe
      由 Stefan Hajnoczi 提交于 
      Virtqueue notify is currently handled synchronously in userspace virtio.  This
prevents the vcpu from executing guest code while hardware emulation code
handles the notify.

On systems that support KVM, the ioeventfd mechanism can be used to make
virtqueue notify a lightweight exit by deferring hardware emulation to the
iothread and allowing the VM to continue execution.  This model is similar to
how vhost receives virtqueue notifies.

The result of this change is improved performance for userspace virtio devices.
Virtio-blk throughput increases especially for multithreaded scenarios and
virtio-net transmit throughput increases substantially.

Some virtio devices are known to have guest drivers which expect a notify to be
processed synchronously and spin waiting for completion.
For virtio-net, this also seems to interact with the guest stack in strange
ways so that TCP throughput for small message sizes (~200bytes)
is harmed. Only enable ioeventfd for virtio-blk for now.

Care must be taken not to interfere with vhost-net, which uses host
notifiers.  If the set_host_notifier() API is used by a device
virtio-pci will disable virtio-ioeventfd and let the device deal with
host notifiers as it wishes.

Finally, there used to be a limit of 6 KVM io bus devices inside the
kernel.  On such a kernel, don't use ioeventfd for virtqueue host
notification since the limit is reached too easily.  This ensures that
existing vhost-net setups (which always use ioeventfd) have ioeventfds
available so they can continue to work.

After migration and on VM change state (running/paused) virtio-ioeventfd
will enable/disable itself.

 * VIRTIO_CONFIG_S_DRIVER_OK -> enable virtio-ioeventfd
 * !VIRTIO_CONFIG_S_DRIVER_OK -> disable virtio-ioeventfd
 * virtio_pci_set_host_notifier() -> disable virtio-ioeventfd
 * vm_change_state(running=0) -> disable virtio-ioeventfd
 * vm_change_state(running=1) -> enable virtio-ioeventfd
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      25db9ebe
    • M
      virtio: move vmstate change tracking to core · 85cf2a8d
      由 Michael S. Tsirkin 提交于 
      Move tracking vmstate change from virtio-net to virtio.c
as it is going to be used by virito-blk and virtio-pci
for the ioeventfd support.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      85cf2a8d
  35. 07 10月, 2010 1 次提交
  37. 08 9月, 2010 1 次提交
  39. 31 8月, 2010 1 次提交
  41. 23 8月, 2010 1 次提交
  43. 26 7月, 2010 1 次提交
  45. 04 5月, 2010 1 次提交
  47. 02 4月, 2010 3 次提交
  49. 11 2月, 2010 1 次提交
    • C
      block: add topology qdev properties · 428c149b
      由 Christoph Hellwig 提交于 
      Add three new qdev properties to export block topology information to
the guest.  This is needed to get optimal I/O alignment for RAID arrays
or SSDs.

The options are:

 - physical_block_size to specify the physical block size of the device,
   this is going to increase from 512 bytes to 4096 kilobytes for many
   modern storage devices
 - min_io_size to specify the minimal I/O size without performance impact,
   this is typically set to the RAID chunk size for arrays.
 - opt_io_size to specify the optimal sustained I/O size, this is
   typically the RAID stripe width for arrays.

I decided to not auto-probe these values from blkid which might easily
be possible as I don't know how to deal with these issues on migration.

Note that we specificly only set the physical_block_size, and not the
logial one which is the unit all I/O is described in.  The reason for
that is that IDE does not support increasing the logical block size and
at last for now I want to stick to one meachnisms in queue and allow
for easy switching of transports for a given backing image which would
not be possible if scsi and virtio use real 4k sectors, while ide only
uses the physical block exponent.

To make this more common for the different block drivers introduce a
new BlockConf structure holding all common block properties and a
DEFINE_BLOCK_PROPERTIES macro to add them all together, mirroring
what is done for network drivers.  Also switch over all block drivers
to use it, except for the floppy driver which has weird driveA/driveB
properties and probably won't require any advanced block options ever.

Example usage for a virtio device with 4k physical block size and
8k optimal I/O size:

  -drive file=scratch.img,media=disk,cache=none,id=scratch \
  -device virtio-blk-pci,drive=scratch,physical_block_size=4096,opt_io_size=8192

aliguori: updated patch to take into account BLOCK events
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
      428c149b
  51. 20 1月, 2010 2 次提交
    • A
      virtio-console: qdev conversion, new virtio-serial-bus · 98b19252
      由 Amit Shah 提交于 
      This commit converts the virtio-console device to create a new
virtio-serial bus that can host console and generic serial ports. The
file hosting this code is now called virtio-serial-bus.c.

The virtio console is now a very simple qdev device that sits on the
virtio-serial-bus and communicates between the bus and qemu's chardevs.

This commit also includes a few changes to the virtio backing code for
pci and s390 to spawn the virtio-serial bus.

As a result of the qdev conversion, we get rid of a lot of legacy code.
The old-style way of instantiating a virtio console using

    -virtioconsole ...

is maintained, but the new, preferred way is to use

    -device virtio-serial -device virtconsole,chardev=...

With this commit, multiple devices as well as multiple ports with a
single device can be supported.

For multiple ports support, each port gets an IO vq pair. Since the
guest needs to know in advance how many vqs a particular device will
need, we have to set this number as a property of the virtio-serial
device and also as a config option.

In addition, we also spawn a pair of control IO vqs. This is an internal
channel meant for guest-host communication for things like port
open/close, sending port properties over to the guest, etc.

This commit is a part of a series of other commits to get the full
implementation of multiport support. Future commits will add other
support as well as ride on the savevm version that we bump up here.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
      98b19252
    • A
      virtio: Remove duplicate macro definition for max. virtqueues, bump up the max · bb61564c
      由 Amit Shah 提交于 
      VIRTIO_PCI_QUEUE_MAX is redefined in hw/virtio.c. Let's just keep it in
hw/virtio.h.

Also, bump up the value of the maximum allowed virtqueues to 64. This is
in preparation to allow multiple ports per virtio-console device.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
      bb61564c
  53. 12 1月, 2010 2 次提交
  55. 12 12月, 2009 1 次提交
  57. 28 10月, 2009 1 次提交
  59. 02 10月, 2009 2 次提交
  61. 25 9月, 2009 1 次提交
  63. 11 8月, 2009 1 次提交
    • G
      qdev-ify virtio-blk. · d176c495
      由 Gerd Hoffmann 提交于 
      First user of the new drive property.  With this patch applied host
and guest config can be specified separately, like this:

  -drive if=none,id=disk1,file=/path/to/disk.img
  -device virtio-blk-pci,drive=disk1

You can set any property for virtio-blk-pci now.  You can set the pci
address via addr=.  You can switch the device into 0.10 compat mode
using class=0x0180.  As this is per device you can have one 0.10 and one
0.11 virtio block device in a single virtual machine.

Old syntax continues to work.  Internally it does the same as the two
lines above though.  One side effect this has is a different
initialization order, which might result in a different pci address
being assigned by default.

Long term plan here is to have this working for all block devices, i.e.
once all scsi is properly qdev-ified you will be able to do something
like this:

  -drive if=none,id=sda,file=/path/to/disk.img
  -device lsi,id=lsi,addr=<pciaddr>
  -device scsi-disk,drive=sda,bus=lsi.0,lun=<n>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Message-Id:
      d176c495
  65. 24 6月, 2009 1 次提交