From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1LUnDp-0006Zc-3h
	for qemu-devel@nongnu.org; Wed, 04 Feb 2009 14:15:41 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1LUnDn-0006ZQ-NX
	for qemu-devel@nongnu.org; Wed, 04 Feb 2009 14:15:39 -0500
Received: from [199.232.76.173] (port=51882 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1LUnDn-0006ZN-Hm
	for qemu-devel@nongnu.org; Wed, 04 Feb 2009 14:15:39 -0500
Received: from mail-qy0-f20.google.com ([209.85.221.20]:39215)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <anthony@codemonkey.ws>) id 1LUnDn-0004PG-8c
	for qemu-devel@nongnu.org; Wed, 04 Feb 2009 14:15:39 -0500
Received: by qyk13 with SMTP id 13so5115131qyk.10
	for <qemu-devel@nongnu.org>; Wed, 04 Feb 2009 11:15:38 -0800 (PST)
Message-ID: <4989E947.9020201@codemonkey.ws>
Date: Wed, 04 Feb 2009 13:15:19 -0600
From: Anthony Liguori <anthony@codemonkey.ws>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [patch 01/18] qemu: add pci helper functions
References: <20090204133303.113145633@localhost.localdomain>	<20090204133923.175155873@localhost.localdomain>
	<200902041456.20944.paul@codesourcery.com>
In-Reply-To: <200902041456.20944.paul@codesourcery.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org
Cc: Marcelo Tosatti <mtosatti@redhat.com>

Paul Brook wrote:
> On Wednesday 04 February 2009, Marcelo Tosatti wrote:
>   
>> +PCIDevice *pci_find_device(int bus_num, int slot)
>> +{
>> +    int devfn;
>> +    PCIDevice *d;
>> +    PCIBus *bus = pci_find_bus(bus_num);
>> +
>> +    if (!bus)
>> +        return NULL;
>> +
>> +    for(devfn = 0; devfn < 256; devfn++) {
>> +        d = bus->devices[devfn];
>> +            if (d && PCI_SLOT(devfn) == slot)
>> +                return d;
>> +    }
>> +    return NULL;
>> +}
>>     
>
> This loop is bogus. You already know the devfn from the slot.
> It's also completely busted if you have multifunction devices.
>   

It should probably try a bit harder to handle the multifunction case.  
You know your device is bus->devices[slot * 8] but you should also check 
slot * 8 + 1..slot * 8 + 7 to see if there are any sub functions and 
return NULL or something.

Regards,

Anthony Liguori

> Paul
>
>
>