Skip to content

Q
qemu

openeuler / qemu

通知 10
Star 0
Fork 0
Q
qemu

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 02 8月, 2011 3 次提交
  3. 01 8月, 2011 1 次提交
    • K
      coroutine: introduce coroutines · 00dccaf1
      由 Kevin Wolf 提交于 
      Asynchronous code is becoming very complex.  At the same time
synchronous code is growing because it is convenient to write.
Sometimes duplicate code paths are even added, one synchronous and the
other asynchronous.  This patch introduces coroutines which allow code
that looks synchronous but is asynchronous under the covers.

A coroutine has its own stack and is therefore able to preserve state
across blocking operations, which traditionally require callback
functions and manual marshalling of parameters.

Creating and starting a coroutine is easy:

  coroutine = qemu_coroutine_create(my_coroutine);
  qemu_coroutine_enter(coroutine, my_data);

The coroutine then executes until it returns or yields:

  void coroutine_fn my_coroutine(void *opaque) {
      MyData *my_data = opaque;

      /* do some work */

      qemu_coroutine_yield();

      /* do some more work */
  }

Yielding switches control back to the caller of qemu_coroutine_enter().
This is typically used to switch back to the main thread's event loop
after issuing an asynchronous I/O request.  The request callback will
then invoke qemu_coroutine_enter() once more to switch back to the
coroutine.

Note that if coroutines are used only from threads which hold the global
mutex they will never execute concurrently.  This makes programming with
coroutines easier than with threads.  Race conditions cannot occur since
only one coroutine may be active at any time.  Other coroutines can only
run across yield.

This coroutines implementation is based on the gtk-vnc implementation
written by Anthony Liguori <anthony@codemonkey.ws> but it has been
significantly rewritten by Kevin Wolf <kwolf@redhat.com> to use
setjmp()/longjmp() instead of the more expensive swapcontext() and by
Paolo Bonzini <pbonzini@redhat.com> for Windows Fibers support.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
      00dccaf1
  5. 22 7月, 2011 1 次提交
  7. 21 7月, 2011 1 次提交
  9. 18 7月, 2011 2 次提交
  11. 17 7月, 2011 1 次提交
  13. 19 6月, 2011 2 次提交
  15. 14 6月, 2011 8 次提交
    • G
      usb-ehci: split trace calls to handle arg count limits · 025b168c
      由 Gerd Hoffmann 提交于 
      Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      025b168c
    • G
      usb-ehci: itd handling fixes. · e654887f
      由 Gerd Hoffmann 提交于 
      This patch fixes a bunch of issues in the itd descriptor handling.
Most important fix is to handle transfers which cross page borders
correctly by looking up the address of the next page.  Luckily the
linux uses physically contigous memory so the data used to hits the
correct location even with this bug instead of corrupting guest
memory.  Also the transfer length updates for outgoing transfers wasn't
correct.

While being at it DPRINTFs have been replaced by tracepoints.

The isoch_pause logic has been disabled.  Not clear to me which propose
this serves and I think it is incorrect too as we just skip processing
itds.  Even when no xfer happens we have to clear the active bit.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      e654887f
    • G
      usb-ehci: multiqueue support · 8ac6d699
      由 Gerd Hoffmann 提交于 
      This patch adds support for keeping multiple queues going at the same
time.  One slow device will not affect other devices any more.

The patch adds code to manage EHCIQueue structs.  It also does a number
of changes to the state machine:

 * The state machine will never ever stop in EXECUTING any more.
   Instead it will continue with the next queue (aka HORIZONTALQH) when
   the usb device returns USB_RET_ASYNC.
 * The state machine will stop processing when it figures it walks in
   circles (easy to figure now that we have a EHCIQueue struct for each
   QH we've processed).  The bailout logic should not be needed any
   more.  For now it is still in, but will assert() in case it triggers.
 * The state machine will just skip queues with a async USBPacket in
   flight.
 * The state machine will resume processing as soon as the async
   USBPacket is finished.

The patch also takes care to flush the QH struct back to guest memory
when needed, so we don't get stale data when (re-)loading it from guest
memory in FETCHQH state.

It also makes the writeback code to not touch the first three dwords of
the QH struct as the EHCI must not write them.  This actually fixes a
bug where QH chaining changes (next ptr) by the linux ehci driver where
overwritten by the emulated EHCI.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      8ac6d699
    • G
      usb-ehci: trace buffer copy · f2c88dc1
      由 Gerd Hoffmann 提交于 
      Add a trace point for buffer copies and drop the DPRINTF's.

No change in behavior.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      f2c88dc1
    • G
      usb-ehci: improve mmio tracing · c4f8e211
      由 Gerd Hoffmann 提交于 
      Add a separate tracepoint to log how register values change in response
to a mmio write.  Especially useful for registers which have read-only
or clear-on-write bits in them.

No change in behavior.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      c4f8e211
    • G
      usb-ehci: trace port state · dcbd0b5c
      由 Gerd Hoffmann 提交于 
      Trace usb port operations (attach, detach, reset),
drop a few obsolete DPRINTF's.

No change in behavior.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      dcbd0b5c
    • G
      usb-ehci: trace state machine changes · 26d53979
      由 Gerd Hoffmann 提交于 
      Add functions to get and set the current state of the state machine,
add tracepoints there to trace state transitions.  Add support for
traceing the queue heads and transfer descriptors as we look at them.

Drop a few DPRINTFs and all DPRINTF_ST lines, they are obsolete now.

No change in behavior.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      26d53979
    • G
      usb-ehci: trace mmio and usbsts · 439a97cc
      由 Gerd Hoffmann 提交于 
      This patch starts adding trace support to ehci.  It traces
updates of the status register (USBSTS), mmio access and
controller reset.

It also adds functions to set and clear status register bits
and puts them in use everywhere.

Some DPRINTF's are dropped in favor of the new tracepoints.

No change in behavior.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      439a97cc
  17. 05 6月, 2011 1 次提交
  19. 26 5月, 2011 3 次提交
  21. 18 5月, 2011 1 次提交
    • S
      qed: Periodically flush and clear need check bit · 6f321e93
      由 Stefan Hajnoczi 提交于 
      One strategy to limit the startup delay of consistency check when
opening image files is to ensure that the file is marked dirty for as
little time as possible.

QED currently marks the image dirty when the first allocating write
request is issued and clears the dirty bit again when the image is
cleanly closed.  In practice that means the image is marked dirty for
most of a guest's lifetime and prone to being in a dirty state upon
crash or power failure.

It is safe to clear the dirty bit after all allocating write requests
have completed and a flush has been performed.  This patch adds a timer
after the last allocating write request completes.  When the timer fires
it will flush and then clear the dirty bit.  The timer is set to 5
seconds and is cancelled upon arrival of a new allocating write request.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      6f321e93
  23. 08 5月, 2011 2 次提交
  25. 03 5月, 2011 1 次提交
  27. 26 4月, 2011 2 次提交
  29. 07 4月, 2011 1 次提交
  31. 04 4月, 2011 10 次提交