From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alejandro Lucero Subject: Re: [dpdk-stable] [PATCH v3 1/6] mem: add function for checking memsegs IOVAs addresses Date: Tue, 10 Jul 2018 11:52:01 +0100 Message-ID: References: <1530708838-2682-1-git-send-email-alejandro.lucero@netronome.com> <1530708838-2682-2-git-send-email-alejandro.lucero@netronome.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: dev , stable@dpdk.org, "Burakov, Anatoly" , Maxime Coquelin , Ferruh Yigit To: Eelco Chaudron Return-path: Received: from mail-ed1-f65.google.com (mail-ed1-f65.google.com [209.85.208.65]) by dpdk.org (Postfix) with ESMTP id E189A1B1ED for ; Tue, 10 Jul 2018 12:52:01 +0200 (CEST) Received: by mail-ed1-f65.google.com with SMTP id t3-v6so16227147eds.3 for ; Tue, 10 Jul 2018 03:52:01 -0700 (PDT) In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, Jul 10, 2018 at 11:06 AM, Eelco Chaudron wrote: > > > On 10 Jul 2018, at 11:34, Alejandro Lucero wrote: > > On Tue, Jul 10, 2018 at 9:56 AM, Eelco Chaudron >> 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 >>>> Acked-by: Anatoly Burakov >>>> --- >>>> 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. > > + >>>> + 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 >>>> >>>> >>> > >