[dpdk-dev] [PATCH v3 1/6] mem: add function for checking memsegs IOVAs addresses
Alejandro Lucero
alejandro.lucero at netronome.com
Thu Oct 11 11:26:00 CEST 2018
On Wed, Oct 10, 2018 at 10:00 AM Tu, Lijuan <lijuan.tu at intel.com> wrote:
> Hi
>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Alejandro Lucero
> > Sent: Friday, October 5, 2018 8:45 PM
> > To: dev at dpdk.org
> > Subject: [dpdk-dev] [PATCH v3 1/6] mem: add function for checking
> > memsegs IOVAs addresses
> >
> > A device can suffer addressing limitations. This function checks memsegs
> > have iovas within the supported range based on dma mask.
> >
> > PMDs should use this function during initialization if device suffers
> > addressing limitations, returning an error if this function returns
> memsegs
> > out of range.
> >
> > Another usage is for emulated IOMMU hardware with addressing limitations.
> >
> > It is necessary to save the most restricted dma mask for checking out
> > memory allocated dynamically after initialization.
> >
> > Signed-off-by: Alejandro Lucero <alejandro.lucero at netronome.com>
> > Reviewed-by: Anatoly Burakov <anatoly.burakov at intel.com>
> > ---
> > doc/guides/rel_notes/release_18_11.rst | 10 ++++
> > lib/librte_eal/common/eal_common_memory.c | 60
> > +++++++++++++++++++++++
> > lib/librte_eal/common/include/rte_eal_memconfig.h | 3 ++
> > lib/librte_eal/common/include/rte_memory.h | 3 ++
> > lib/librte_eal/common/malloc_heap.c | 12 +++++
> > lib/librte_eal/linuxapp/eal/eal.c | 2 +
> > lib/librte_eal/rte_eal_version.map | 1 +
> > 7 files changed, 91 insertions(+)
> >
> > diff --git a/doc/guides/rel_notes/release_18_11.rst
> > b/doc/guides/rel_notes/release_18_11.rst
> > index 2133a5b..c806dc6 100644
> > --- a/doc/guides/rel_notes/release_18_11.rst
> > +++ b/doc/guides/rel_notes/release_18_11.rst
> > @@ -104,6 +104,14 @@ New Features
> > the specified port. The port must be stopped before the command call
> in
> > order
> > to reconfigure queues.
> >
> > +* **Added check for ensuring allocated memory addressable by devices.**
> > +
> > + Some devices can have addressing limitations so a new function,
> > + ``rte_eal_check_dma_mask``, has been added for checking allocated
> > + memory is not out of the device range. Because now memory can be
> > + dynamically allocated after initialization, a dma mask is kept and
> > + any new allocated memory will be checked out against that dma mask
> > + and rejected if out of range. If more than one device has addressing
> > limitations, the dma mask is the more restricted one.
> >
> > API Changes
> > -----------
> > @@ -156,6 +164,8 @@ ABI Changes
> > ``rte_config`` structure on account of improving DPDK usability
> > when
> > using either ``--legacy-mem`` or ``--single-file-segments``
> flags.
> >
> > +* eal: added ``dma_maskbits`` to ``rte_mem_config`` for keeping more
> > restricted
> > + dma mask based on devices addressing limitations.
> >
> > Removed Items
> > -------------
> > diff --git a/lib/librte_eal/common/eal_common_memory.c
> > b/lib/librte_eal/common/eal_common_memory.c
> > index 0b69804..c482f0d 100644
> > --- a/lib/librte_eal/common/eal_common_memory.c
> > +++ b/lib/librte_eal/common/eal_common_memory.c
> > @@ -385,6 +385,66 @@ struct virtiova {
> > rte_memseg_walk(dump_memseg, f);
> > }
> >
> > +static int
> > +check_iova(const struct rte_memseg_list *msl __rte_unused,
> > + const struct rte_memseg *ms, void *arg) {
> > + uint64_t *mask = arg;
> > + rte_iova_t iova;
> > +
> > + /* higher address within segment */
> > + iova = (ms->iova + ms->len) - 1;
> > + if (!(iova & *mask))
> > + return 0;
> > +
> > + RTE_LOG(DEBUG, EAL, "memseg iova %"PRIx64", len %zx, out of
> > range\n",
> > + ms->iova, ms->len);
> > +
> > + RTE_LOG(DEBUG, EAL, "\tusing dma mask %"PRIx64"\n", *mask);
> > + return 1;
> > +}
> > +
> > +#if defined(RTE_ARCH_64)
> > +#define MAX_DMA_MASK_BITS 63
> > +#else
> > +#define MAX_DMA_MASK_BITS 31
> > +#endif
> > +
> > +/* check memseg iovas are within the required range based on dma mask
> > +*/ int __rte_experimental rte_eal_check_dma_mask(uint8_t maskbits) {
> > + struct rte_mem_config *mcfg =
> > rte_eal_get_configuration()->mem_config;
> > + uint64_t mask;
> > +
> > + /* sanity check */
> > + if (maskbits > MAX_DMA_MASK_BITS) {
> > + RTE_LOG(ERR, EAL, "wrong dma mask size %u (Max: %u)\n",
> > + maskbits, MAX_DMA_MASK_BITS);
> > + return -1;
> > + }
> > +
> > + /* create dma mask */
> > + mask = ~((1ULL << maskbits) - 1);
> > +
> > + if (rte_memseg_walk(check_iova, &mask))
>
> [Lijuan]In my environment, testpmd halts at rte_memseg_walk() when
> maskbits is 0.
>
>
Can you explain this further?
Who is calling rte_eal_check_dma_mask with mask 0? is this a X86_64 system?
The only explanation I can find is the IOMMU hardware reporting mgaw=0 what
I would say is something completely wrong.
> > + /*
> > + * Dma mask precludes hugepage usage.
> > + * This device can not be used and we do not need to keep
> > + * the dma mask.
> > + */
> > + return 1;
> > +
> > + /*
> > + * we need to keep the more restricted maskbit for checking
> > + * potential dynamic memory allocation in the future.
> > + */
> > + mcfg->dma_maskbits = mcfg->dma_maskbits == 0 ? maskbits :
> > + RTE_MIN(mcfg->dma_maskbits, maskbits);
> > +
> > + return 0;
> > +}
> > +
> > /* return the number of memory channels */ unsigned
> > rte_memory_get_nchannel(void) { diff --git
> > a/lib/librte_eal/common/include/rte_eal_memconfig.h
> > b/lib/librte_eal/common/include/rte_eal_memconfig.h
> > index 62a21c2..b5dff70 100644
> > --- a/lib/librte_eal/common/include/rte_eal_memconfig.h
> > +++ b/lib/librte_eal/common/include/rte_eal_memconfig.h
> > @@ -81,6 +81,9 @@ struct rte_mem_config {
> > /* legacy mem and single file segments options are shared */
> > uint32_t legacy_mem;
> > uint32_t single_file_segments;
> > +
> > + /* keeps the more restricted dma mask */
> > + uint8_t dma_maskbits;
> > } __attribute__((__packed__));
> >
> >
> > diff --git a/lib/librte_eal/common/include/rte_memory.h
> > b/lib/librte_eal/common/include/rte_memory.h
> > index 14bd277..c349d6c 100644
> > --- a/lib/librte_eal/common/include/rte_memory.h
> > +++ b/lib/librte_eal/common/include/rte_memory.h
> > @@ -454,6 +454,9 @@ typedef int (*rte_memseg_list_walk_t)(const struct
> > rte_memseg_list *msl,
> > */
> > 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/common/malloc_heap.c
> > b/lib/librte_eal/common/malloc_heap.c
> > index ac7bbb3..3b5b2b6 100644
> > --- a/lib/librte_eal/common/malloc_heap.c
> > +++ b/lib/librte_eal/common/malloc_heap.c
> > @@ -259,11 +259,13 @@ struct malloc_elem *
> > int socket, unsigned int flags, size_t align, size_t bound,
> > bool contig, struct rte_memseg **ms, int n_segs) {
> > + struct rte_mem_config *mcfg =
> > rte_eal_get_configuration()->mem_config;
> > struct rte_memseg_list *msl;
> > struct malloc_elem *elem = NULL;
> > size_t alloc_sz;
> > int allocd_pages;
> > void *ret, *map_addr;
> > + uint64_t mask;
> >
> > alloc_sz = (size_t)pg_sz * n_segs;
> >
> > @@ -291,6 +293,16 @@ struct malloc_elem *
> > goto fail;
> > }
> >
> > + if (mcfg->dma_maskbits) {
> > + mask = ~((1ULL << mcfg->dma_maskbits) - 1);
> > + if (rte_eal_check_dma_mask(mask)) {
> > + RTE_LOG(ERR, EAL,
> > + "%s(): couldn't allocate memory due to DMA
> mask\n",
> > + __func__);
> > + goto fail;
> > + }
> > + }
> > +
> > /* add newly minted memsegs to malloc heap */
> > elem = malloc_heap_add_memory(heap, msl, map_addr, alloc_sz);
> >
> > diff --git a/lib/librte_eal/linuxapp/eal/eal.c
> > b/lib/librte_eal/linuxapp/eal/eal.c
> > index 4a55d3b..dfe1b8c 100644
> > --- a/lib/librte_eal/linuxapp/eal/eal.c
> > +++ b/lib/librte_eal/linuxapp/eal/eal.c
> > @@ -263,6 +263,8 @@ enum rte_iova_mode
> > * processes could later map the config into this exact location */
> > rte_config.mem_config->mem_cfg_addr = (uintptr_t)
> > rte_mem_cfg_addr;
> >
> > + rte_config.mem_config->dma_maskbits = 0;
> > +
> > }
> >
> > /* attach to an existing shared memory config */ diff --git
> > a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
> > index 73282bb..2baefce 100644
> > --- a/lib/librte_eal/rte_eal_version.map
> > +++ b/lib/librte_eal/rte_eal_version.map
> > @@ -291,6 +291,7 @@ EXPERIMENTAL {
> > rte_devargs_parsef;
> > rte_devargs_remove;
> > rte_devargs_type_count;
> > + rte_eal_check_dma_mask;
> > rte_eal_cleanup;
> > rte_eal_hotplug_add;
> > rte_eal_hotplug_remove;
> > --
> > 1.9.1
>
>
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