Michael S. Tsirkin wrote:
> On Thu, Oct 29, 2009 at 12:30:02PM +0100, Màrius Montón wrote:
>
>> Lennart Sorensen wrote:
>>
>> On Tue, Oct 27, 2009 at 04:05:25PM +0100, Màrius Montón wrote:
>>
>>
>> Màrius Montón wrote:
>>
>>
>> Hello,
>>
>> For my PCI device to QEMU, I need the real address the PCI bus
>> is using
>> to access my device. For a IO BAR (PCI_ADDRESS_SPACE_IO), I
>> receive the
>> real address (like 0xc200 or similar), but when registering a
>> PCI_ADDRESS_SPACE_MEM I only receive the offset to the BAR.
>>
>> How I can receive or obtaint the real address on each access to
>> my device?
>>
>> Cjeers,
>>
>> Màrius
>>
>>
>>
>> nobody can tell me anything? :(
>>
>>
>> Add the offset to the address in the bar?
>>
>> The problem is how to know what bar is accessing in case I have only one
>> function for all BARs.
>>
>
> I expect that's unusual: different BARs usually have different
> functionality. Just implement different functions and pass
> calls on to a shared helper?
>
>
It is because I'm trying to add PCI devices from a configuration file
(no hot-plug), and this way was the easies way I found... any idea?
>> After all the OS is allowed to change your BAR if it wants to.
>> So internally the only thing that makes sense to a PCI device is the
>> offset from it's base address.
>>
>> You listen to addresses at your IO range, and at your memory BAR range.
>> What you do when you see a request for your range then depends on the
>> offset that address had from the current base. This would also be true
>> for the IO.
>>
>> I know all PCI internals, but I don't understand why for IO I receive all
>> address and only the offset for MEM BARs (or I'm wrong?)
>>
>> Màrius
>>
>
> PCI only calls a map method. I think this gets a 32 bit address, not BAR
> offset:
>
> r->addr = new_addr;
> if (r->addr != -1) {
> r->map_func(d, i, r->addr, r->size, r->type);
> }
>
>
>
I may study that functions
Màrius
