Re: [Qemu-devel] [PATCHv2 0/2] pci: allow PCI bus slots to be marked as reserved

[Marcel Apfelbaum <marcel@redhat.com>]

On 14/07/2017 13:37, Mark Cave-Ayland wrote:
> On 14/07/17 11:25, Marcel Apfelbaum wrote:
> 
>> On 14/07/2017 12:59, Mark Cave-Ayland wrote:
>>> On 11/07/17 22:44, Mark Cave-Ayland wrote:
>>>
>>>> For some machines it is impossible to plug devices into a particular
>>>> PCI bus
>>>> slot, e.g. for a real Ultra 5 there are 2 PCI bridges attached to the
>>>> root
>>>> bus behind which all devices must be plugged. Ignoring this rule will
>>>> cause
>>>> problems with interrupt routing since the interrupt numbers are
>>>> calculated
>>>> based upon PCI bridge id and secondary PCI bus slot id.
>>>>
>>>> This patchset adds a new slot_reserved_mask property to PCIBus which
>>>> is a
>>>> bitmask used to indicate whether PCI bus slots are reserved, i.e.
>>>> they cannot
>>>> be used for hot or cold plugging on a particular PCI bus.
>>>>
>>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>>>
>>>> v2:
>>>> - Rename dev_reserved_mask to slot_reserved_mask as suggested by Marcel
>>>> - Squash patches 2 and 3 together
>>>>
>>>>
>>>> Mark Cave-Ayland (2):
>>>>     pci: move check for existing devfn into new pci_bus_devfn_available()
>>>>       helper
>>>>     pci: add reserved slot check to do_pci_register_device()
>>>>
>>>>    hw/pci/pci.c             |   34 ++++++++++++++++++++++++++++++----
>>>>    include/hw/pci/pci_bus.h |    1 +
>>>>    2 files changed, 31 insertions(+), 4 deletions(-)
>>>
>>> Ping? Any further feedback on the v2 version? My latest set of sun4u
>>> patches is dependent upon this patchset and it's freeze coming up next
>>> week!
>>>
>>

Hi Mark,

>> Hi,
>>
>> As in prev version, other than the minor comment
>> on replacing "if (...) return true; else return false"
>> with the actual value, I am OK with it.
> 
> Okay great! So change pci_bus_devfn_available() to something like this?
> 
> static bool pci_bus_devfn_available(PCIBus *bus, int devfn)
> {
>      return !(bus->devices[devfn]);
> }
> 

Yes, thanks.

>> I believe Michael asked to see the series using this feature,
>> can you add a link to it, or post it with the dependency on this one?
> 
> Sure, I posted the link earlier in the week:
> https://lists.nongnu.org/archive/html/qemu-devel/2017-07/msg03045.html.
> Or more specifically:
> 
> https://lists.nongnu.org/archive/html/qemu-devel/2017-07/msg03041.html
> 

Hi Michael,
Can you please have a look to the above patch using
the 'reserved slots' patch?

Thanks,
Marcel

> 
> ATB,
> 
> Mark.
>