From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Nithin Dabilpuram <ndabilpuram@marvell.com>
Cc: jerinj@marvell.com, dev@dpdk.org, stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 2/2] vfio: fix partial DMA unmapping for VFIO type1
Date: Wed, 14 Oct 2020 16:07:10 +0100 [thread overview]
Message-ID: <05afb7f5-96bf-dffd-15dd-2024586f7290@intel.com> (raw)
In-Reply-To: <20201012081106.10610-3-ndabilpuram@marvell.com>
On 12-Oct-20 9:11 AM, Nithin Dabilpuram wrote:
> Partial unmapping is not supported for VFIO IOMMU type1
> by kernel. Though kernel gives return as zero, the unmapped size
> returned will not be same as expected. So check for
> returned unmap size and return error.
>
> For case of DMA map/unmap triggered by heap allocations,
> maintain granularity of memseg page size so that heap
> expansion and contraction does not have this issue.
This is quite unfortunate, because there was a different bug that had to
do with kernel having a very limited number of mappings available [1],
as a result of which the page concatenation code was added.
It should therefore be documented that the dma_entry_limit parameter
should be adjusted should the user run out of the DMA entries.
[1]
https://lore.kernel.org/lkml/155414977872.12780.13728555131525362206.stgit@gimli.home/T/
>
> For user requested DMA map/unmap disallow partial unmapping
> for VFIO type1.
>
> Fixes: 73a639085938 ("vfio: allow to map other memory regions")
> Cc: anatoly.burakov@intel.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> ---
> lib/librte_eal/linux/eal_vfio.c | 34 ++++++++++++++++++++++++++++------
> lib/librte_eal/linux/eal_vfio.h | 1 +
> 2 files changed, 29 insertions(+), 6 deletions(-)
>
> diff --git a/lib/librte_eal/linux/eal_vfio.c b/lib/librte_eal/linux/eal_vfio.c
> index d26e164..ef95259 100644
> --- a/lib/librte_eal/linux/eal_vfio.c
> +++ b/lib/librte_eal/linux/eal_vfio.c
> @@ -69,6 +69,7 @@ static const struct vfio_iommu_type iommu_types[] = {
> {
> .type_id = RTE_VFIO_TYPE1,
> .name = "Type 1",
> + .partial_unmap = false,
> .dma_map_func = &vfio_type1_dma_map,
> .dma_user_map_func = &vfio_type1_dma_mem_map
> },
> @@ -76,6 +77,7 @@ static const struct vfio_iommu_type iommu_types[] = {
> {
> .type_id = RTE_VFIO_SPAPR,
> .name = "sPAPR",
> + .partial_unmap = true,
> .dma_map_func = &vfio_spapr_dma_map,
> .dma_user_map_func = &vfio_spapr_dma_mem_map
> },
> @@ -83,6 +85,7 @@ static const struct vfio_iommu_type iommu_types[] = {
> {
> .type_id = RTE_VFIO_NOIOMMU,
> .name = "No-IOMMU",
> + .partial_unmap = true,
> .dma_map_func = &vfio_noiommu_dma_map,
> .dma_user_map_func = &vfio_noiommu_dma_mem_map
> },
> @@ -525,12 +528,19 @@ vfio_mem_event_callback(enum rte_mem_event type, const void *addr, size_t len,
> /* for IOVA as VA mode, no need to care for IOVA addresses */
> if (rte_eal_iova_mode() == RTE_IOVA_VA && msl->external == 0) {
> uint64_t vfio_va = (uint64_t)(uintptr_t)addr;
> - if (type == RTE_MEM_EVENT_ALLOC)
> - vfio_dma_mem_map(default_vfio_cfg, vfio_va, vfio_va,
> - len, 1);
> - else
> - vfio_dma_mem_map(default_vfio_cfg, vfio_va, vfio_va,
> - len, 0);
> + uint64_t page_sz = msl->page_sz;
> +
> + /* Maintain granularity of DMA map/unmap to memseg size */
> + for (; cur_len < len; cur_len += page_sz) {
> + if (type == RTE_MEM_EVENT_ALLOC)
> + vfio_dma_mem_map(default_vfio_cfg, vfio_va,
> + vfio_va, page_sz, 1);
> + else
> + vfio_dma_mem_map(default_vfio_cfg, vfio_va,
> + vfio_va, page_sz, 0);
> + vfio_va += page_sz;
> + }
> +
You'd also have to revert d1c7c0cdf7bac5eb40d3a2a690453aefeee5887b
because currently the PA path will opportunistically concantenate
contiguous segments into single mapping too.
> return;
> }
>
> @@ -1383,6 +1393,12 @@ vfio_type1_dma_mem_map(int vfio_container_fd, uint64_t vaddr, uint64_t iova,
> RTE_LOG(ERR, EAL, " cannot clear DMA remapping, error %i (%s)\n",
> errno, strerror(errno));
> return -1;
> + } else if (dma_unmap.size != len) {
> + RTE_LOG(ERR, EAL, " unexpected size %"PRIu64" of DMA "
> + "remapping cleared instead of %"PRIu64"\n",
> + (uint64_t)dma_unmap.size, len);
> + rte_errno = EIO;
> + return -1;
> }
> }
>
> @@ -1853,6 +1869,12 @@ container_dma_unmap(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
> /* we're partially unmapping a previously mapped region, so we
> * need to split entry into two.
> */
> + if (!vfio_cfg->vfio_iommu_type->partial_unmap) {
> + RTE_LOG(DEBUG, EAL, "DMA partial unmap unsupported\n");
> + rte_errno = ENOTSUP;
> + ret = -1;
> + goto out;
> + }
How would we ever arrive here if we never do more than 1 page worth of
memory anyway? I don't think this is needed.
> if (user_mem_maps->n_maps == VFIO_MAX_USER_MEM_MAPS) {
> RTE_LOG(ERR, EAL, "Not enough space to store partial mapping\n");
> rte_errno = ENOMEM;
> diff --git a/lib/librte_eal/linux/eal_vfio.h b/lib/librte_eal/linux/eal_vfio.h
> index cb2d35f..6ebaca6 100644
> --- a/lib/librte_eal/linux/eal_vfio.h
> +++ b/lib/librte_eal/linux/eal_vfio.h
> @@ -113,6 +113,7 @@ typedef int (*vfio_dma_user_func_t)(int fd, uint64_t vaddr, uint64_t iova,
> struct vfio_iommu_type {
> int type_id;
> const char *name;
> + bool partial_unmap;
> vfio_dma_user_func_t dma_user_map_func;
> vfio_dma_func_t dma_map_func;
> };
>
--
Thanks,
Anatoly
next prev parent reply other threads:[~2020-10-14 15:07 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 8:11 [dpdk-dev] [PATCH 0/2] fix issue with partial DMA unmap 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 [this message]
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 ` [dpdk-dev] [PATCH v8 0/3] fix issue with partial DMA unmap Burakov, Anatoly
2021-02-22 9:41 ` Nithin Dabilpuram
2021-02-22 10:06 ` David Marchand
2021-03-01 12:13 ` David Marchand
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