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Date: Thu, 4 Oct 2007 20:05:03 +0300
From: "Blue Swirl" <blauwirbel@gmail.com>
Subject: Re: [Qemu-devel] Pending Disk I/O requests during live VM migration
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To: qemu-devel@nongnu.org

On 10/4/07, Kaushik Bhandankar <kaushikb@cc.gatech.edu> wrote:
> 1) I guess the IDE disk code is in ioemu/hw/ide.c. But where is the IDE
> disk controller code located ??

Same file, see ide_ioport_write().

> 2) I do not really understand BMDMA in ioemu/hw/ide.c. google doesnt
> seem to be helping much here. Any documentation about the QEMU IDE disks
> would be greatly appreciated.

No idea.

> 3) vl.c:5522 seems to be not the correct code (I guess our vl.c codes
> are different).. Could you point me to the routine in vl.c where the
> pending disk IO requests are flushed before VM save (I guess the VM save
> happens in qemu_savevm_state() in vl.c wherein it invokes all the
> registered save handlers)?

It's in:
void do_savevm(const char *name)

> 4) Somebody told me that the pending disk IO requests are stored
> somewhere in quemu's I/O disk model but I am not sure exactly
> where....Can somebody help me with this ?

Qemu uses asynchronous IO, grepping aio or AIO should find something.