[dpdk-dev] [dpdk-stable] [PATCH v3 1/6] mem: add function for checking memsegs IOVAs addresses
Eelco Chaudron
echaudro at redhat.com
Tue Jul 10 13:14:57 CEST 2018
On 10 Jul 2018, at 12:52, Alejandro Lucero wrote:
> On Tue, Jul 10, 2018 at 11:06 AM, Eelco Chaudron <echaudro at redhat.com>
> wrote:
>
>>
>>
>> On 10 Jul 2018, at 11:34, Alejandro Lucero wrote:
>>
>> On Tue, Jul 10, 2018 at 9:56 AM, Eelco Chaudron <echaudro at redhat.com>
>>> wrote:
>>>
>>>
>>>>
>>>> On 4 Jul 2018, at 14:53, Alejandro Lucero wrote:
>>>>
>>>> A device can suffer addressing limitations. This functions checks
>>>>
>>>>> memsegs have iovas within the supported range based on dma mask.
>>>>>
>>>>> PMD should use this during initialization if supported devices
>>>>> suffer addressing limitations, returning an error if this function
>>>>> returns memsegs out of range.
>>>>>
>>>>> Another potential usage is for emulated IOMMU hardware with
>>>>> addressing
>>>>> limitations.
>>>>>
>>>>> Signed-off-by: Alejandro Lucero <alejandro.lucero at netronome.com>
>>>>> Acked-by: Anatoly Burakov <anatoly.burakov at intel.com>
>>>>> ---
>>>>> lib/librte_eal/common/eal_common_memory.c | 33
>>>>> ++++++++++++++++++++++++++++++
>>>>> lib/librte_eal/common/include/rte_memory.h | 3 +++
>>>>> lib/librte_eal/rte_eal_version.map | 1 +
>>>>> 3 files changed, 37 insertions(+)
>>>>>
>>>>> diff --git a/lib/librte_eal/common/eal_common_memory.c
>>>>> b/lib/librte_eal/common/eal_common_memory.c
>>>>> index fc6c44d..f5efebe 100644
>>>>> --- a/lib/librte_eal/common/eal_common_memory.c
>>>>> +++ b/lib/librte_eal/common/eal_common_memory.c
>>>>> @@ -109,6 +109,39 @@
>>>>> }
>>>>> }
>>>>>
>>>>> +/* check memseg iovas are within the required range based on dma
>>>>> mask
>>>>> */
>>>>> +int
>>>>> +rte_eal_check_dma_mask(uint8_t maskbits)
>>>>> +{
>>>>> +
>>>>> + const struct rte_mem_config *mcfg;
>>>>> + uint64_t mask;
>>>>> + int i;
>>>>> +
>>>>>
>>>>>
>>>> I think we should add some sanity check to the input maskbits, i.e.
>>>> [64,0)
>>>> or [64, 32]? What would be a reasonable lower bound.
>>>>
>>>>
>>>> This is not a user's API, so any invocation will be reviewed, but I
>>>> guess
>>> adding a sanity check here does not harm.
>>>
>>> Not sure about lower bound but upper should 64, although it does not
>>> make
>>> sense but it is safe. Lower bound is not so problematic.
>>>
>>>
>>>
>>>> + /* create dma mask */
>>>>
>>>>> + mask = ~((1ULL << maskbits) - 1);
>>>>> +
>>>>> + /* get pointer to global configuration */
>>>>> + mcfg = rte_eal_get_configuration()->mem_config;
>>>>> +
>>>>> + for (i = 0; i < RTE_MAX_MEMSEG; i++) {
>>>>> + if (mcfg->memseg[i].addr == NULL)
>>>>> + break;
>>>>>
>>>>
>> Looking at some other code, it looks like NULL entries might exists.
>> So
>> should a continue; rather than a break; be used here?
>>
>>
> I do not think so. memsegs are allocated sequentially, so first with
> addr
> as NULL implies no more memsegs.
I was referring to the mem walk functions, rte_memseg_list_walk(). Maybe
some having more experience with this area can review/comment.
>
>
>>
>> +
>>>>> + if (mcfg->memseg[i].iova & mask) {
>>>>> + RTE_LOG(INFO, EAL,
>>>>> + "memseg[%d] iova %"PRIx64" out of
>>>>> range:\n",
>>>>> + i, mcfg->memseg[i].iova);
>>>>> +
>>>>> + RTE_LOG(INFO, EAL, "\tusing dma mask
>>>>> %"PRIx64"\n",
>>>>> + mask);
>>>>> + return -1;
>>>>> + }
>>>>> + }
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +
>>>>> /* return the number of memory channels */
>>>>> unsigned rte_memory_get_nchannel(void)
>>>>> {
>>>>> diff --git a/lib/librte_eal/common/include/rte_memory.h
>>>>> b/lib/librte_eal/common/include/rte_memory.h
>>>>> index 80a8fc0..b2a0168 100644
>>>>> --- a/lib/librte_eal/common/include/rte_memory.h
>>>>> +++ b/lib/librte_eal/common/include/rte_memory.h
>>>>> @@ -209,6 +209,9 @@ struct rte_memseg {
>>>>> */
>>>>> unsigned rte_memory_get_nrank(void);
>>>>>
>>>>> +/* check memsegs iovas are within a range based on dma mask */
>>>>> +int rte_eal_check_dma_mask(uint8_t maskbits);
>>>>> +
>>>>> /**
>>>>> * Drivers based on uio will not load unless physical
>>>>> * addresses are obtainable. It is only possible to get
>>>>> diff --git a/lib/librte_eal/rte_eal_version.map
>>>>> b/lib/librte_eal/rte_eal_version.map
>>>>> index f4f46c1..aa6cf87 100644
>>>>> --- a/lib/librte_eal/rte_eal_version.map
>>>>> +++ b/lib/librte_eal/rte_eal_version.map
>>>>> @@ -184,6 +184,7 @@ DPDK_17.11 {
>>>>>
>>>>> rte_eal_create_uio_dev;
>>>>> rte_bus_get_iommu_class;
>>>>> + rte_eal_check_dma_mask;
>>>>> rte_eal_has_pci;
>>>>> rte_eal_iova_mode;
>>>>> rte_eal_mbuf_default_mempool_ops;
>>>>> --
>>>>> 1.9.1
>>>>>
>>>>>
>>>>
>>
>>
More information about the dev
mailing list