Re: [dpdk-dev] [PATCH v2 5/7] eal/linux: mmap ioports on ppc64

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-05-30 10:45, Olivier Matz:
> On 05/24/2016 07:15 AM, Yuanhan Liu wrote:
> > On Mon, May 23, 2016 at 03:40:58PM +0200, Olivier Matz wrote:
> >> For reference, here is the report of the ABI checker for EAL:
> >>
> >> [−] struct rte_pci_ioport (2)
> >>
> >>  1 Field len has been added to this type.
> >>    1) This field will not be initialized by old clients.
> >>    2) Size of the inclusive type has been changed.
> >>       NOTE: this field should be accessed only from the new library
> >>       functions, otherwise it may result in crash or incorrect behavior
> >>       of applications.
> >>  2 Size of this type has been changed from 16 bytes to 24 bytes. 	
> >>    The fields or parameters of such data type may be incorrectly
> >>    initialized or accessed by old client applications.
> >>
> >> [−] affected symbols (4)
> >>  rte_eal_pci_ioport_map ( struct rte_pci_device* dev, int bar,
> >>     struct rte_pci_ioport* p ) @@ DPDK_16.04
> >>  3rd parameter 'p' (pointer) has base type 'struct rte_pci_ioport'.
> >>  rte_eal_pci_ioport_read ( struct rte_pci_ioport* p, void* data,
> >>     size_t len, off_t offset ) @@ DPDK_16.04
> >>  1st parameter 'p' (pointer) has base type 'struct rte_pci_ioport'.
> >>  rte_eal_pci_ioport_unmap ( struct rte_pci_ioport* p ) @@ DPDK_16.04
> >>  1st parameter 'p' (pointer) has base type 'struct rte_pci_ioport'.
> >>  rte_eal_pci_ioport_write ( struct rte_pci_ioport* p, void const* data,
> >>     size_t len, off_t offset ) @@ DPDK_16.04
> >>  1st parameter 'p' (pointer) has base type 'struct rte_pci_ioport'.
> >>
> >>
> >> My understanding of the comment for this structure is that it's
> >> internal to EAL:
> > 
> > I'm not quite sure that is enough. Cc'ed Panu, the guru on ABI stuff,
> > hopefully he could shed some light on it.
> > 
> >> /**
> >>  * A structure used to access io resources for a pci device.
> >>  * rte_pci_ioport is arch, os, driver specific, and should not be used
> >> outside
> >>  * of pci ioport api.
> >>  */
> >> struct rte_pci_ioport {
> >>  ...
> >> }
> >>
> >> So I'd say it's ok to have it integrated for 16.07.
> > 
> > I'll let Thomas to decide it :)
> 
> Panu or Thomas, do you have any comment on this?

The user of this struct is virtio.
The ABI policy does not apply to drivers:
	- A means Application
	- external drivers must be rebuilt for each new release

Thus no problem here.