With the conversion of the block layer to coroutines, bdrv_read/write
have changed to run a nested event loop that calls qemu_bh_poll.
Consequently a scheduled BH can be called while a DMA transfer handler
runs and this means that DMA_run becomes reentrant.
Devices haven't been designed to cope with that, so instead of running a
nested transfer handler just wait for the next invocation of the BH from the
main loop.
This fixes some problems with the floppy device.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When available, we'd like to be able to access the DeviceState
when registering a savevm. For buses with a get_dev_path()
function, this will allow us to create more unique savevm
id strings.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In the very least, a change like this requires discussion on the list.
The naming convention is goofy and it causes a massive merge problem. Something
like this _must_ be presented on the list first so people can provide input
and cope with it.
This reverts commit 99a0949b72.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This reverts commit 8217606e6e (and
updates later added users of qemu_register_reset), we solved the
problem it originally addressed less invasively.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add the parameter 'order' to qemu_register_reset and sort callbacks on
registration. On system reset, callbacks with lower order will be
invoked before those with higher order. Update all existing users to the
standard order 0.
Note: At least for x86, the existing users seem to assume that handlers
are called in their registration order. Therefore, the patch preserves
this property. If someone feels bored, (s)he could try to identify this
dependency and express it properly on callback registration.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Change from v1:
Avoid changing the existing coding style in certain files.
Signed-off-by: Stuart Brady <stuart.brady@gmail.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6120 c046a42c-6fe2-441c-8c8c-71466251a162
The current DMA routines are driven by a call in main_loop_wait() after every
select.
This patch converts the DMA code to be driven by a constantly rescheduled
bottom half. The advantage of using a scheduled bottom half is that we can
stop scheduling the bottom half when there no DMA channels are runnable. This
means we can potentially detect this case and sleep longer in the main loop.
The only two architectures implementing DMA_run() are cris and i386. For cris,
I converted it to a simple repeating bottom half. I've only compile tested
this as cris does not seem to work on a 64-bit host. It should be functionally
identical to the previous implementation so I expect it to work.
For x86, I've made sure to only fire the DMA bottom half if there is a DMA
channel that is runnable. The effect of this is that unless you're using sb16
or a floppy disk, the DMA bottom half never fires.
You probably should test this malc. My own benchmarks actually show slight
improvement by it's possible the change in timing could affect your demos.
Since v1, I've changed the code to use a BH instead of a timer. cris at least
seems to depend on faster than 10ms polling.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5573 c046a42c-6fe2-441c-8c8c-71466251a162
