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  1. 12 6月, 2011 2 次提交
  3. 02 6月, 2011 1 次提交
  5. 19 4月, 2011 1 次提交
  7. 04 4月, 2011 1 次提交
  9. 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
  11. 21 3月, 2011 2 次提交
  13. 02 2月, 2011 1 次提交
  15. 11 1月, 2011 1 次提交
  17. 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
    • S
      virtio-pci: Rename bugs field to flags · 3dbca8e6
      由 Stefan Hajnoczi 提交于 
      The VirtIOPCIProxy bugs field is currently used to enable workarounds
for older guests.  Rename it to flags so that other per-device behavior
can be tracked.

A later patch uses the flags field to remember whether ioeventfd should
be used for virtqueue host notification.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      3dbca8e6
  19. 12 12月, 2010 1 次提交
  21. 21 11月, 2010 2 次提交
  23. 07 10月, 2010 1 次提交
  25. 08 9月, 2010 3 次提交
    • A
      virtio-net: Introduce a new bottom half packet TX · a697a334
      由 Alex Williamson 提交于 
      Based on a patch from Mark McLoughlin, this patch introduces a new
bottom half packet transmitter that avoids the latency imposed by
the tx_timer approach.  Rather than scheduling a timer when a TX
packet comes in, schedule a bottom half to be run from the iothread.
The bottom half handler first attempts to flush the queue with
notification disabled (this is where we could race with a guest
without txburst).  If we flush a full burst, reschedule immediately.
If we send short of a full burst, try to re-enable notification.
To avoid a race with TXs that may have occurred, we must then
flush again.  If we find some packets to send, the guest it probably
active, so we can reschedule again.

tx_timer and tx_bh are mutually exclusive, so we can re-use the
tx_waiting flag to indicate one or the other needs to be setup.
This allows us to seamlessly migrate between timer and bh TX
handling.

The bottom half handler becomes the new default and we add a new
tx= option to virtio-net-pci.  Usage:

-device virtio-net-pci,tx=timer # select timer mitigation vs "bh"
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      a697a334
    • A
      virtio-net: Limit number of packets sent per TX flush · e3f30488
      由 Alex Williamson 提交于 
      If virtio_net_flush_tx() is called with notification disabled, we can
race with the guest, processing packets at the same rate as they
get produced.  The trouble is that this means we have no guaranteed
exit condition from the function and can spend minutes in there.
Currently flush_tx is only called with notification on, which seems
to limit us to one pass through the queue per call.  An upcoming
patch changes this.

Also add an option to set this value on the command line as different
workloads may wish to use different values.  We can't necessarily
support any random value, so this is a developer option: x-txburst=
Usage:

-device virtio-net-pci,x-txburst=64 # 64 packets per tx flush

One pass through the queue (256) seems to be a good default value
for this, balancing latency with throughput.  We use a signed int
for x-txburst because 2^31 packets in a burst would take many, many
minutes to process and it allows us to easily return a negative
value value from virtio_net_flush_tx() to indicate a back-off
or error condition.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      e3f30488
    • A
      virtio-net: Make tx_timer timeout configurable · f0c07c7c
      由 Alex Williamson 提交于 
      Add an option to make the TX mitigation timer adjustable as a device
option.  The 150us hard coded default used currently is reasonable,
but may not be suitable for all workloads, this gives us a way to
adjust it using a single binary.  We can't support any random option
though, so use the "x-" prefix to indicate this is a developer
option.  Usage:

-device virtio-net-pci,x-txtimer=500000,... # .5ms timeout
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      f0c07c7c
  27. 24 8月, 2010 1 次提交
    • B
      Rearrange block headers · 2446333c
      由 Blue Swirl 提交于 
      Changing block.h or blockdev.h resulted in recompiling most objects.

Move DriveInfo typedef and BlockInterfaceType enum definitions
to qemu-common.h and rearrange blockdev.h use to decrease churn.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>
      2446333c
  29. 23 8月, 2010 1 次提交
  31. 26 7月, 2010 1 次提交
  33. 13 7月, 2010 2 次提交
  35. 12 7月, 2010 1 次提交
    • I
      pci: don't overwrite multi functio bit in pci header type. · b80d4a98
      由 Isaku Yamahata 提交于 
      Don't overwrite pci header type.
Otherwise, multi function bit which pci_init_header_type() sets
appropriately is lost.
Anyway PCI_HEADER_TYPE_NORMAL is zero, so it is unnecessary to zero
which is already zero cleared.

how to test:
run qemu and issue info pci to see whether a device in question is
normal device, not pci-to-pci bridge.
This is handy because guest os isn't required.

tested changes:
The following files are covered by using following commands.
sparc64-softmmu
  apb_pci.c, vga-pci.c, cmd646.c, ne2k_pci.c, sun4u.c
ppc-softmmu
  grackle_pci.c, cmd646.c, ne2k_pci.c, vga-pci.c, macio.c
ppc-softmmu -M mac99
  unin_pci.c(uni-north, uni-north-agp)
ppc64-softmmu
  pci-ohci, ne2k_pci, vga-pci, unin_pci.c(u3-agp)
x86_64-softmmu
  acpi_piix4.c, ide/piix.c, piix_pci.c
  -vga vmware vmware_vga.c
  -watchdog i6300esb wdt_i6300esb.c
  -usb usb-uhci.c
  -sound ac97 ac97.c
  -nic model=rtl8139 rtl8139.c
  -nic model=pcnet pcnet.c
  -balloon virtio virtio-pci.c:

untested changes:
The following changes aren't tested.
prep_pci.c: ppc-softmmu -M prep should cover, but core dumped.
unin_pci.c(uni-north-pci): the caller is commented out.
openpic.c: the caller is commented out in ppc_prep.c
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>
      b80d4a98
  37. 02 7月, 2010 2 次提交
    • M
      qdev: Decouple qdev_prop_drive from DriveInfo · f8b6cc00
      由 Markus Armbruster 提交于 
      Make the property point to BlockDriverState, cutting out the DriveInfo
middleman.  This prepares the ground for block devices that don't have
a DriveInfo.

Currently all user-defined ones have a DriveInfo, because the only way
to define one is -drive & friends (they go through drive_init()).
DriveInfo is closely tied to -drive, and like -drive, it mixes
information about host and guest part of the block device.  I'm
working towards a new way to define block devices, with clean
host/guest separation, and I need to get DriveInfo out of the way for
that.

Fortunately, the device models are perfectly happy with
BlockDriverState, except for two places: ide_drive_initfn() and
scsi_disk_initfn() need to check the DriveInfo for a serial number set
with legacy -drive serial=...  Use drive_get_by_blockdev() there.

Device model code should now use DriveInfo only when explicitly
dealing with drives defined the old way, i.e. without -device.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      f8b6cc00
    • M
      blockdev: Clean up automatic drive deletion · 14bafc54
      由 Markus Armbruster 提交于 
      We automatically delete blockdev host parts on unplug of the guest
device.  Too much magic, but we can't change that now.

The delete happens early in the guest device teardown, before the
connection to the host part is severed.  Thus, the guest part's
pointer to the host part dangles for a brief time.  No actual harm
comes from this, but we'll catch such dangling pointers a few commits
down the road.  Clean up the dangling pointers by delaying the
automatic deletion until the guest part's pointer is gone.

Device usb-storage deliberately makes two qdev properties refer to the
same drive, because it automatically creates a second device.  Again,
too much magic we can't change now.  Multiple references worked okay
before, but now free_drive() dies for the second one.  Zap the extra
reference.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      14bafc54
  39. 23 6月, 2010 2 次提交
  41. 04 6月, 2010 1 次提交
  43. 04 5月, 2010 1 次提交
  45. 02 4月, 2010 2 次提交
  47. 01 4月, 2010 1 次提交
    • A
      Don't check for bus master for old guests · c81131db
      由 Alexander Graf 提交于 
      Older Linux guests don't activate the bus master enable bit. So for those we
can just try to be clever and track if they set the DEVICE_OK bit even though
bus mastering is still disabled.

Under that condition we can disable the windows safety check. With that logic
in place both guests should work just fine. Without PCI hotplug breaks
virtio-net in Linux < 2.6.34 guests.
Signed-off-by: NAlexander Graf <agraf@suse.de>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
      c81131db
  49. 16 3月, 2010 2 次提交
  51. 09 3月, 2010 1 次提交
  53. 20 2月, 2010 1 次提交
  55. 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
  57. 20 1月, 2010 1 次提交