On 7/1/2016 4:52 PM, De Lara Guarch, Pablo wrote:
> Hi Ferruh,
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Ferruh Yigit
>> Sent: Friday, July 01, 2016 4:08 PM
>> To: dev at dpdk.org
>> Cc: Stephen Hemminger
>> Subject: [dpdk-dev] [PATCH v2] igb_uio: fix possible mmap failure for Linux >
>> v4.3
>>
>> mmap the iomem range of the PCI device fails for kernels that
>> enabled CONFIG_IO_STRICT_DEVMEM option:
>>
>> EAL: pci_map_resource():
>> cannot mmap(39, 0x7f1c51800000, 0x100000, 0x0):
>> Invalid argument (0xffffffffffffffff)
>>
>> CONFIG_IO_STRICT_DEVMEM is introduced in Linux v4.4 and not enabled
>> by default:
>
> This was introduced in kernel 4.5 (change the title as well ;))
"git describe" mislead me but you are right, I will update
$ git describe 90a545e
v4.4-rc5-2-g90a545e
Thanks
>
>> Linux commit: 90a545e restrict /dev/mem to idle io memory ranges
>>
>> As a workaround igb_uio can stop reserving PCI memory resources, from
>> kernel point of view iomem region looks like idle and mmap works
>> again. This matches uio_pci_generic usage.
>>
>> With this update device iomem range is not protected against any
>> other kernel drivers or userspace access. But this shouldn't
>> be a problem for dpdk usage module since purpose of the igb_uio
>> module is to provide userspace access.
>>
>> Fixes: af75078fece3 ("first public release")
>> Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
>
