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Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus
From: |
Markus Armbruster |
Subject: |
Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus |
Date: |
Mon, 25 Oct 2010 18:22:12 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) |
Gleb Natapov <address@hidden> writes:
> On Mon, Oct 25, 2010 at 04:29:35PM +0200, Markus Armbruster wrote:
>> Gleb Natapov <address@hidden> writes:
>>
>> > Without this patch both buses on PIIX3_IDE device have the same unit id.
>>
>> Are you sure that's wrong?
>>
> So how do I know which bus is it on PIIX3_IDE?
[...]
Let me try to explain the IDE pointer thicket.
piix3-ide provides two IDE buses. pci_piix_ide_initfn() stores them in
PCIIDEState member IDEBus bus[2]. Technically redundant, because qdev
stores child buses in dev.qdev.child_bus.
IDEBus points back: qbus.parent.
Up to two IDE devices can sit on each IDE bus. The first one uses
IDEBus members master and ifs[0], the second one uses slave and ifs[1].
ifs[i].bus points back to the IDE bus.
{master,slave}.qdev.parent_bus point back to the IDE bus.
Say you got an IDEDevice and want to know which to which of the two
buses it's connected. Let's call it d.
d->qdev.parent_bus is the BusState.
Upcast to IDEBus: b = DO_UPCAST(IDEBus, qbus, d->qdev.parent_bus).
b->qbus.parent is the IDE controller.
Upcast to PCIIDEState: c = DO_UPCAST(PCIIDEState, dev, n->qbus.parent);
If c->bus[0] == b, it's on the first bus.
Else it must be on the second bus, i.e. c->bus[1] == b.
Hope I didn't screw this up too badly.
- [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/24
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Markus Armbruster, 2010/10/25
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/25
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus,
Markus Armbruster <=
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/25
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Markus Armbruster, 2010/10/25
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/25
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Markus Armbruster, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Markus Armbruster, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Markus Armbruster, 2010/10/26
- Re: [Qemu-devel] [PATCH] initialize unit id of IDE bus, Gleb Natapov, 2010/10/26