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From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Nithin Dabilpuram <ndabilpuram@marvell.com>,
	David Christensen <drc@linux.vnet.ibm.com>,
	david.marchand@redhat.com
Cc: jerinj@marvell.com, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v8 0/3] fix issue with partial DMA unmap
Date: Tue, 16 Feb 2021 13:14:37 +0000
Message-ID: <9fa8f512-c00d-f8bc-5c5e-36581846bc78@intel.com> (raw)
In-Reply-To: <20210115073243.7025-1-ndabilpuram@marvell.com>

On 15-Jan-21 7:32 AM, Nithin Dabilpuram wrote:
> Partial DMA unmap is not supported by VFIO type1 IOMMU
> in Linux. Though the return value is zero, the returned
> DMA unmap size is not same as expected size.
> So add test case and fix to both heap triggered DMA
> mapping and user triggered DMA mapping/unmapping.
> 
> Refer vfio_dma_do_unmap() in drivers/vfio/vfio_iommu_type1.c
> Snippet of comment is below.
> 
>          /*
>           * vfio-iommu-type1 (v1) - User mappings were coalesced together to
>           * avoid tracking individual mappings.  This means that the granularity
>           * of the original mapping was lost and the user was allowed to attempt
>           * to unmap any range.  Depending on the contiguousness of physical
>           * memory and page sizes supported by the IOMMU, arbitrary unmaps may
>           * or may not have worked.  We only guaranteed unmap granularity
>           * matching the original mapping; even though it was untracked here,
>           * the original mappings are reflected in IOMMU mappings.  This
>           * resulted in a couple unusual behaviors.  First, if a range is not
>           * able to be unmapped, ex. a set of 4k pages that was mapped as a
>           * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
>           * a zero sized unmap.  Also, if an unmap request overlaps the first
>           * address of a hugepage, the IOMMU will unmap the entire hugepage.
>           * This also returns success and the returned unmap size reflects the
>           * actual size unmapped.
> 
>           * We attempt to maintain compatibility with this "v1" interface, but
>           * we take control out of the hands of the IOMMU.  Therefore, an unmap
>           * request offset from the beginning of the original mapping will
>           * return success with zero sized unmap.  And an unmap request covering
>           * the first iova of mapping will unmap the entire range.
> 
> This behavior can be verified by using first patch and add return check for
> dma_unmap.size != len in vfio_type1_dma_mem_map()
> 
> v8:
> - Add cc stable to patch 3/3
> 
> v7:
> - Dropped vfio test case of patch 3/4 i.e
>    "test: add test case to validate VFIO DMA map/unmap"
>    as it couldn't be supported in POWER9 system.
> 
> v6:
> - Fixed issue with x86-32 build introduced by v5.
> 
> v5:
> - Changed vfio test in test_vfio.c to use system pages allocated from
>    heap instead of mmap() so that it comes in range of initially configured
>    window for POWER9 System.
> - Added acked-by from David for 1/4, 2/4.
> 
> v4:
> - Fixed issue with patch 4/4 on x86 builds.
> 
> v3:
> - Fixed external memory test case(4/4) to use system page size
>    instead of 4K.
> - Fixed check-git-log.sh issue and rebased.
> - Added acked-by from anatoly.burakov@intel.com to first 3 patches.
> 
> v2:
> - Reverted earlier commit that enables mergin contiguous mapping for
>    IOVA as PA. (see 1/3)
> - Updated documentation about kernel dma mapping limits and vfio
>    module parameter.
> - Moved vfio test to test_vfio.c and handled comments from
>    Anatoly.
> 
> Nithin Dabilpuram (3):
>    vfio: revert changes for map contiguous areas in one go
>    vfio: fix DMA mapping granularity for type1 IOVA as VA
>    test: change external memory test to use system page sz
> 

Is there anything preventing this from getting merged? Let's try for 
21.05 :)

-- 
Thanks,
Anatoly

  parent reply	other threads:[~2021-02-16 13:14 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-12  8:11 [dpdk-dev] [PATCH 0/2] " Nithin Dabilpuram
2020-10-12  8:11 ` [dpdk-dev] [PATCH 1/2] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-10-14 14:39   ` Burakov, Anatoly
2020-10-15  9:54     ` [dpdk-dev] [EXT] " Nithin Dabilpuram
2020-10-12  8:11 ` [dpdk-dev] [PATCH 2/2] vfio: fix partial DMA unmapping for VFIO type1 Nithin Dabilpuram
2020-10-14 15:07   ` Burakov, Anatoly
2020-10-15  6:09     ` [dpdk-dev] [EXT] " Nithin Dabilpuram
2020-10-15 10:00       ` Burakov, Anatoly
2020-10-15 11:38         ` Nithin Dabilpuram
2020-10-15 11:50         ` Nithin Dabilpuram
2020-10-15 11:57         ` Nithin Dabilpuram
2020-10-15 15:10           ` Burakov, Anatoly
2020-10-16  7:10             ` Nithin Dabilpuram
2020-10-17 16:14               ` Burakov, Anatoly
2020-10-19  9:43                 ` Nithin Dabilpuram
2020-10-22 12:13                   ` Nithin Dabilpuram
2020-10-28 13:04                     ` Burakov, Anatoly
2020-10-28 14:17                       ` Nithin Dabilpuram
2020-10-28 16:07                         ` Burakov, Anatoly
2020-10-28 16:31                           ` Nithin Dabilpuram
2020-11-05  9:04 ` [dpdk-dev] [PATCH v2 0/3] fix issue with partial DMA unmap Nithin Dabilpuram
2020-11-05  9:04   ` [dpdk-dev] [PATCH v2 1/3] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2020-11-05  9:04   ` [dpdk-dev] [PATCH v2 2/3] vfio: fix DMA mapping granularity for type1 iova as va Nithin Dabilpuram
2020-11-10 14:04     ` Burakov, Anatoly
2020-11-10 14:22       ` Burakov, Anatoly
2020-11-10 14:17     ` Burakov, Anatoly
2020-11-11  5:08       ` Nithin Dabilpuram
2020-11-11 10:00         ` Burakov, Anatoly
2020-11-05  9:04   ` [dpdk-dev] [PATCH v2 3/3] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-12-01 19:32 ` [dpdk-dev] [PATCH v3 0/4] fix issue with partial DMA unmap Nithin Dabilpuram
2020-12-01 19:32   ` [dpdk-dev] [PATCH v3 1/4] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2020-12-01 19:33   ` [dpdk-dev] [PATCH v3 2/4] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2020-12-01 19:33   ` [dpdk-dev] [PATCH v3 3/4] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-12-01 19:33   ` [dpdk-dev] [PATCH v3 4/4] test: change external memory test to use system page sz Nithin Dabilpuram
2020-12-01 23:23     ` David Christensen
2020-12-02  5:40       ` Nithin Dabilpuram
2020-12-02  5:46 ` [dpdk-dev] [PATCH v4 0/4] fix issue with partial DMA unmap Nithin Dabilpuram
2020-12-02  5:46   ` [dpdk-dev] [PATCH v4 1/4] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2020-12-02 18:36     ` David Christensen
2020-12-02  5:46   ` [dpdk-dev] [PATCH v4 2/4] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2020-12-02 18:38     ` David Christensen
2020-12-02  5:46   ` [dpdk-dev] [PATCH v4 3/4] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-12-02 19:23     ` David Christensen
2020-12-03  7:14       ` Nithin Dabilpuram
2020-12-14  8:24         ` Nithin Dabilpuram
2020-12-02  5:46   ` [dpdk-dev] [PATCH v4 4/4] test: change external memory test to use system page sz Nithin Dabilpuram
2020-12-14  8:19 ` [dpdk-dev] [PATCH v5 0/4] fix issue with partial DMA unmap Nithin Dabilpuram
2020-12-14  8:19   ` [dpdk-dev] [PATCH v5 1/4] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2020-12-14  8:19   ` [dpdk-dev] [PATCH v5 2/4] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2020-12-14  8:19   ` [dpdk-dev] [PATCH v5 3/4] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-12-14  8:19   ` [dpdk-dev] [PATCH v5 4/4] test: change external memory test to use system page sz Nithin Dabilpuram
2020-12-17 19:06 ` [dpdk-dev] [PATCH v6 0/4] fix issue with partial DMA unmap Nithin Dabilpuram
2020-12-17 19:06   ` [dpdk-dev] [PATCH v6 1/4] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2020-12-17 19:06   ` [dpdk-dev] [PATCH v6 2/4] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2020-12-17 19:06   ` [dpdk-dev] [PATCH v6 3/4] test: add test case to validate VFIO DMA map/unmap Nithin Dabilpuram
2020-12-17 19:10     ` Nithin Dabilpuram
2021-01-05 19:33       ` David Christensen
2021-01-06  8:40         ` Nithin Dabilpuram
2021-01-06 21:20           ` David Christensen
2020-12-17 19:06   ` [dpdk-dev] [PATCH v6 4/4] test: change external memory test to use system page sz Nithin Dabilpuram
2020-12-23  5:13   ` [dpdk-dev] [PATCH v6 0/4] fix issue with partial DMA unmap Nithin Dabilpuram
2021-01-04 22:29     ` David Christensen
2021-01-12 17:39 ` [dpdk-dev] [PATCH v7 0/3] " Nithin Dabilpuram
2021-01-12 17:39   ` [dpdk-dev] [PATCH v7 1/3] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2021-01-12 17:39   ` [dpdk-dev] [PATCH v7 2/3] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2021-01-12 17:39   ` [dpdk-dev] [PATCH v7 3/3] test: change external memory test to use system page sz Nithin Dabilpuram
2021-01-14 16:30     ` David Marchand
2021-01-15  6:57       ` Nithin Dabilpuram
2021-01-15  7:32 ` [dpdk-dev] [PATCH v8 0/3] fix issue with partial DMA unmap Nithin Dabilpuram
2021-01-15  7:32   ` [dpdk-dev] [PATCH v8 1/3] vfio: revert changes for map contiguous areas in one go Nithin Dabilpuram
2021-03-05  7:50     ` David Marchand
2021-03-05 13:54       ` Burakov, Anatoly
2021-03-05 15:50         ` Nithin Dabilpuram
2021-04-01 11:27           ` Burakov, Anatoly
2021-01-15  7:32   ` [dpdk-dev] [PATCH v8 2/3] vfio: fix DMA mapping granularity for type1 IOVA as VA Nithin Dabilpuram
2021-01-15  7:32   ` [dpdk-dev] [PATCH v8 3/3] test: change external memory test to use system page sz Nithin Dabilpuram
2021-02-11 11:21     ` Burakov, Anatoly
2021-02-16 13:14   ` Burakov, Anatoly [this message]
2021-02-22  9:41     ` [dpdk-dev] [PATCH v8 0/3] fix issue with partial DMA unmap Nithin Dabilpuram
2021-02-22 10:06       ` David Marchand
2021-03-01 12:13   ` David Marchand

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