Re: [dpdk-dev] [PATCH] kni: fix bug 389 - Crash in librte_kni driver due to noncontiguous pages

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 11-Feb-20 9:28 AM, Ferruh Yigit wrote:
> On 2/10/2020 7:47 PM, Scott Wasson wrote:
>> Fixes: edd2fafbc0b8 ("kni: allocate memory dynamically for each device")
>> Cc: iryzhov@nfware.com
>> Cc: stable@dpdk.org
> 
> I suggest following patch subject:
> "kni: fix not contiguous FIFO"
> 
> And I little detail in the comment log can be good:
> "
> KNI requires FIFO to be physically contiguous, with existing
> 'rte_memzone_reserve()' API this is not guaranteed by default and as a result
> KNI rings and packet delivery is broken.
> 
> Fixing it by providing 'RTE_MEMZONE_IOVA_CONTIG' flag to ask physically
> contiguous memory.
> "
> 
> And the Fixes tag should show the commit that updates the
> 'rte_memzone_reserve()' API to not provide physically contiguous memory.
> @Anatoly, can you help finding that commit?

The commit that added the ability to reserve contiguous memory was added 
before the memory subsystem itself started allocating non-contiguous 
memory, but all other drivers/libraries had added support for 
IOVA-contiguous memory as separate commits (see 74dbbcd6f8 for example).

So, technically, the "offending commit" is the *omission* of KNI from 
these changes. But, the API itself was added in 23fa86e529e, so that's 
what we should use for Fixes: tag IMO.

> 
> 
>>
>> Signed-off-by: Scott Wasson <scott_wasson@affirmednetworks.com>
>> ---
>>   lib/librte_kni/rte_kni.c |   14 +++++++-------
>>   1 files changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
>> index e388751..df4a021 100644
>> --- a/lib/librte_kni/rte_kni.c
>> +++ b/lib/librte_kni/rte_kni.c
>> @@ -145,31 +145,31 @@ enum kni_ops_status {
>>   	char mz_name[RTE_MEMZONE_NAMESIZE];
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_TX_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_tx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_tx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
> 
> Can you please break the line, so it doesn't go beyond 80 chars?
> 
>>   	KNI_MEM_CHECK(kni->m_tx_q == NULL, tx_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_RX_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_rx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_rx_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_rx_q == NULL, rx_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_ALLOC_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_alloc_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_alloc_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_alloc_q == NULL, alloc_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_FREE_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_free_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_free_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_free_q == NULL, free_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_REQ_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_req_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_req_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_req_q == NULL, req_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_RESP_Q_MZ_NAME_FMT, kni->name);
>> -	kni->m_resp_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_resp_q = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_resp_q == NULL, resp_q_fail);
>>   
>>   	snprintf(mz_name, RTE_MEMZONE_NAMESIZE, KNI_SYNC_ADDR_MZ_NAME_FMT, kni->name);
>> -	kni->m_sync_addr = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, 0);
>> +	kni->m_sync_addr = rte_memzone_reserve(mz_name, KNI_FIFO_SIZE, SOCKET_ID_ANY, RTE_MEMZONE_IOVA_CONTIG);
>>   	KNI_MEM_CHECK(kni->m_sync_addr == NULL, sync_addr_fail);
>>   
>>   	return 0;
>>
> 


-- 
Thanks,
Anatoly