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Date: Sun, 21 Jun 2015 11:16:50 +0300
From: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH v1] pci: Don't register a specialized
 'config_write' if default behavior is intended
Reply-To: marcel@redhat.com
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To: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Cc: Leonid Shatz <leonid.shatz@ravellosystems.com>, Hannes Reinecke <hare@suse.de>, Idan Brown <idan.brown@ravellosystems.com>, qemu-devel@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>

On 06/17/2015 09:46 PM, Shmulik Ladkani wrote:
> Hi,
>
> On Wed, 17 Jun 2015 12:36:14 +0300, marcel.apfelbaum@gmail.com wrote:
>>> NOTE:
>>> Not sure if my statement regarding ommitting 'config_write' holds
>>> for the megasas case:
>>> It's parent is TYPE_MEGASAS_BASE whose parent is TYPE_PCI_DEVICE.
>>> Can we assume 'config_write' will be set to
>>> 'pci_default_write_config' in this case?
>> No need to assume here, you can simply add a trace and check.
>> However, the do_pci_register_device method assigns config_write method
>> to PCIDevice *instances* using the class method or the default
>> pci_default_write_config.
>>
>> Since TYPE_MEGASAS_BASE does not define a config_write method, the
>> field will remain NULL. Anyway, you are welcomed to run it and
>> double-check.
>
> Verified; do_pci_register_device indeed sets it to pci_default_write_config.
>
> Thanks,
> Shmulik
>
Cool!

Thanks,
Marcel