• This patch enhances QEMU's built-in debugger for SMP guest debugging.
    Using the thread support of the gdb remote protocol, each VCPU is mapped
    on a pseudo thread and exposed to the gdb frontend. This way you can
    easy switch the focus of gdb between the VCPUs and observe their states.
    On breakpoint hit, the focus is automatically adjusted just as for
    normal multi-threaded application under gdb control.
    
    Furthermore, the patch propagates breakpoint and watchpoint insertions
    or removals to all CPUs, not just the current one as it was the case so
    far. Without this, SMP guest debugging was practically unfeasible.
    
    Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5743 c046a42c-6fe2-441c-8c8c-71466251a162
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  • It is safe not to set dpy_refresh and that's used to indicate that the display
    doesn't need updates.  This saves us two wakeups per second.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5583 c046a42c-6fe2-441c-8c8c-71466251a162
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  • Mostly code motion.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5581 c046a42c-6fe2-441c-8c8c-71466251a162
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  • The motivating goal behind this is to allow other tools to use the CharDriver
    code.  This patch is pure code motion except for the Makefile changes and the
    copyright/header in qemu-char.c.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5580 c046a42c-6fe2-441c-8c8c-71466251a162
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  • The goal of this series is to move the CharDriverState code out of vl.c and
    into its own file, qemu-char.c.  This patch moves around some declarations so
    the next patch can be pure code motion.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5579 c046a42c-6fe2-441c-8c8c-71466251a162
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  • With the recent changes to the main loop, we no longer have unconditional
    polling.  This means we can now sleep in select() for much longer than we
    previously did.  This patch increases our select() sleep time from 10ms to 5s
    which is effectively unlimited since we're going to wake up sooner than that
    in almost all circumstances.
    
    With this patch, I see the number of wake-ups with an idle dynamic ticks guest
    drop from 80 per second to about 15 times per second.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5578 c046a42c-6fe2-441c-8c8c-71466251a162
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  • Tidy up win32 main loop bits, allow timeout >= 1s, and force timeout to 0 if
    there is a pending bottom half.
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5577 c046a42c-6fe2-441c-8c8c-71466251a162
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  • This patch makes qemu keep track of the character devices in use and
    implements a "info chardev" monitor command to print a list.
    
    qemu_chr_open() sticks the devices into a linked list now.  It got a new
    argument (label), so there is a name for each device.  It also assigns a
    filename to each character device.  By default it just copyes the
    filename passed in.  Individual drivers can fill in something else
    though.  qemu_chr_open_pty() sets the filename to name of the pseudo tty
    allocated.
    
    Output looks like this:
    
      (qemu) info chardev
      monitor: filename=unix:/tmp/run.sh-26827/monitor,server,nowait
      serial0: filename=unix:/tmp/run.sh-26827/console,server
      serial1: filename=pty:/dev/pts/5
      parallel0: filename=vc:640x480
    
    Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5575 c046a42c-6fe2-441c-8c8c-71466251a162
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  • 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
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  • Bottom halves are supposed to not complete until the next iteration of the main
    loop.  This is very important to ensure that guests can not cause stack
    overflows in the block driver code.  Right now, if you attempt to schedule a
    bottom half within a bottom half callback, you will enter an infinite loop.
    
    This patch uses the same logic that we use for the IOHandler loop to make the
    bottom half processing robust in list manipulation while in a callback.
    
    This patch also introduces idle scheduling for bottom halves.  qemu_bh_poll()
    returns an indication of whether any bottom halves were successfully executed.
    qemu_aio_wait() uses this to immediately return if a bottom half was executed
    instead of waiting for a completion notification.
    
    qemu_bh_schedule_idle() works around this by not reporting the callback has
    run in the qemu_bh_poll loop.  qemu_aio_wait() probably needs some refactoring
    but that would require a larger code audit.  idle scheduling seems like a good
    compromise.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5572 c046a42c-6fe2-441c-8c8c-71466251a162
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  • This patch changes the cache= option to accept none, writeback, or writethough
    to control the host page cache behavior.  By default, writethrough caching is
    now used which internally is implemented by using O_DSYNC to open the disk
    images.  When using -snapshot, writeback is used by default since data integrity
    it not at all an issue.
    
    cache=none has the same behavior as cache=off previously.  The later syntax is
    still supported by now deprecated.  I also cleaned up the O_DIRECT
    implementation to avoid many of the #ifdefs.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5485 c046a42c-6fe2-441c-8c8c-71466251a162
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  • Replace signalfd with signal handler/pipe.  There is no way to interrupt
    the CPU execution loop when a file descriptor becomes readable.  This
    results in a large performance regression in sparc emulation during
    bootup.
       
    This patch switches us to signal handler/pipe which was originally
    suggested by Ian Jackson.  The signal handler lets us interrupt the
    CPU emulation loop while the write to a pipe lets us avoid the
    select/signal race condition.
        
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5451 c046a42c-6fe2-441c-8c8c-71466251a162
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  • This patch replaces the static memory savevm/loadvm handler with a "live" one.
    This handler is used even if performing a non-live migration.
    
    The key difference between this handler and the previous is that each page is
    prefixed with the address of the page.  The QEMUFile rate limiting code, in
    combination with the live migration dirty tracking bits, is used to determine
    which pages should be sent and how many should be sent.
    
    The live save code "converges" when the number of dirty pages reaches a fixed
    amount.  Currently, this is 10 pages.  This is something that should eventually
    be derived from whatever the bandwidth limitation is.
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5437 c046a42c-6fe2-441c-8c8c-71466251a162
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  • The current savevm/loadvm protocol has some draw backs.  It does not support
    the ability to do progressive saving which means it cannot be used for live
    checkpointing or migration.  The sections sizes are 32-bit integers which
    means that it will not function when using more than 4GB of memory for a guest.
    It attempts to seek within the output file which means it cannot be streamed.
    The current protocol also is pretty lax about how it supports forward
    compatibility.  If a saved section version is greater than what the restore
    code support, the restore code generally treats the saved data as being in
    whatever version it supports.  This means that restoring a saved VM on an older
    version of QEMU will likely result in silent guest failure.
    
    This patch introduces a new version of the savevm protocol.  It has the
    following features:
    
     * Support for progressive save of sections (for live checkpoint/migration)
     * An asynchronous API for doing save
     * Support for interleaving multiple progressive save sections
       (for future support of memory hot-add/storage migration)
     * Fully streaming format
     * Strong section version checking
    
    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
    
    
    
    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5434 c046a42c-6fe2-441c-8c8c-71466251a162
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