[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH RFC] qdev: add init order filter
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH RFC] qdev: add init order filter |
Date: |
Thu, 9 Mar 2017 12:13:45 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 |
On 09/03/2017 00:59, Michael S. Tsirkin wrote:
> Allow forcing a specific order of initialization on
> devices created with -device.
> Helpful e.g. for built-in devices such as IOMMUs which must
> exist before all other devices.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>
> Looks like we have a ton of problems because devices
> are initialized in a random order, while we
> really want e.g. iommu to be initialized
> earlier than devices.
>
> This will be helpful for other things, e.g.
> real hardware often is initialized in a specific order,
> creating built-in devices for the board often
> has to happen in a specific order, etc.
In the specific case of PCI bus_master_as there is a simple workaround
by placing a dummy container (which lets us build the AddressSpace) and
then adding the alias region at machine_done time.
This is exactly how MemoryListener is supposed to work, so I would start
from there.
Paolo