RE: [dpdk-dev] Issue with VFIO/IOMMU Hi Burakov,
-----Original Message----- From: Burakov, Anatoly [mailto:anatoly.bura...@intel.com <anatoly.bura...@intel.com>] Sent: Friday, September 04, 2020 7:20 PM To: Vikas Gupta <vikas.gu...@broadcom.com>; dev@dpdk.org Cc: Ajit Kumar Khaparde <ajit.khapa...@broadcom.com>; Vikram Prakash < vikram.prak...@broadcom.com> Subject: Re: [dpdk-dev] Issue with VFIO/IOMMU On 03-Sep-20 12:09 PM, Vikas Gupta wrote: > Hi, > > I observe an issue with IOVA address returned by api > rte_memzone_reserve_aligned (flags= RTE_MEMZONE_IOVA_CONTIG) used for > queue memory allocation. With high level debugging, I notice that IOVA > address returned in mz->iova is not mapped by VFIO_IOMMU_MAP_DMA so in > turn SMMU exception is seen. I'm not sure i follow. How did you determine that to be the case, given that, by your own admission below, `vfio_type1_dma_mem_map` function is executed several times? [Vikas]: I`ll mention map and unmap as below in explaining through one of the example map = function vfio_type1_dma_mem_map called with argument do_map = 1 unamp = function type1_dma_mem_map called with argument do_map = 0 What I notice that for some particular address received in mz->iova, after rte_memzone_reserve_aligned is successfully returned, the map function (vfio_type1_dma_mem_map do_map =1) was not called prior to return of function rte_memzone_reserve_aligned. Below is one of the sequence to understand. Let’s say there is an address ‘*iova_fail’*, for which exception is raised by SMMU while dpdk-test runs with Crypto PMD. When dpdk-test is run with Crypto test suit I see that for an address* iova_fail* several times vfio_type1_dma_mem_map is called with (do_map = 0/1 with length = 2MB). I believe this happens due to call for memory allocation/free for buffers/queues. The test runs fine as long as the map is called before rte_memzone_reserve_aligned returns and similarly for unmap when same memory is freed. But after several times with map/unmap for* iova_fail*, map is NOT called before rte_memzone_reserve_aligned is retuned though iova_fail was previously unmapped. Since it’s not mapped, SMMU raises an exception. Please note issue is not frequently visible and might reproduce after pmd_crypto_autotest is run multiple times over dpdk-test. If you are not able to follow I`ll try to send the debug printfs for test. Thanks, Vikas > > > > *Details for the setup* > > Platform: Armv8 (Broadcom Stingray) > > DPDK release: DPDK 20.08 <http://fast.dpdk.org/rel/dpdk-20.08.tar.xz> > > PMD patch: > > https://patches.dpdk.org/project/dpdk/list/?series=&submitter=1907&sta > te=&q=&archive=&delegate= > > dpdk-test is launched using below command > > *dpdk-test --vdev <cryptopmd_name> -w 0000:00:00.0 --iova-mode pa * > > > > The test suite is launched over dpdk-test application command prompt > using command ‘cryptodev_<cryptopmd_name>_autotest’ > > The issue is seen when several iterations of above test_suite is > executed which in turn do multiple calls to > rte_memzone_reserve_aligned, rte_mempool_create and rte_memzone_free, rte_mempool_free. > > Function *vfio_type1_dma_mem_map* with map/unmap event is executed > several times during test_suite run. > > > > Any inputs would be helpful. > > > > Thanks, > > Vikas > -- Thanks, Anatoly
