From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: <dev@dpdk.org>, Bruce Richardson <bruce.richardson@intel.com>,
"Ray Kinsella" <mdr@ashroe.eu>,
Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>,
Narcisa Ana Maria Vasile <navasile@linux.microsoft.com>,
Dmitry Malloy <dmitrym@microsoft.com>,
Pallavi Kadam <pallavi.kadam@intel.com>
Cc: <xuan.ding@intel.com>, <ferruh.yigit@intel.com>
Subject: Re: [dpdk-dev] [PATCH v1 1/1] vfio: add page-by-page mapping API
Date: Wed, 29 Sep 2021 11:18:49 +0100 [thread overview]
Message-ID: <9972054c-c68f-5b8c-d8cd-2330fce82369@intel.com> (raw)
In-Reply-To: <043fc2d53770da8248b9cd0214775f9d41f2e0fb.1631273229.git.anatoly.burakov@intel.com>
On 10-Sep-21 12:27 PM, Anatoly Burakov wrote:
> Currently, there is no way to map memory for DMA in a way that allows
> unmapping it partially later, because some IOMMU's do not support
> partial unmapping. There is a workaround of mapping all of these
> segments separately, but this is inconvenient and silly, so this
> commit adds a proper API that does it.
>
> This commit relies on earlier infrastructure that was built out to
> support "chunking", as the concept of "chunks" is essentially the same
> as page size.
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
> lib/eal/freebsd/eal.c | 10 ++++
> lib/eal/include/rte_vfio.h | 33 ++++++++++++++
> lib/eal/linux/eal_vfio.c | 93 +++++++++++++++++++++++++++++++-------
> lib/eal/version.map | 3 ++
> lib/eal/windows/eal.c | 10 ++++
> 5 files changed, 133 insertions(+), 16 deletions(-)
>
> diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c
> index 6cee5ae369..78e18f9765 100644
> --- a/lib/eal/freebsd/eal.c
> +++ b/lib/eal/freebsd/eal.c
> @@ -1085,6 +1085,16 @@ rte_vfio_container_dma_map(__rte_unused int container_fd,
> return -1;
> }
>
> +int
> +rte_vfio_container_dma_map_paged(__rte_unused int container_fd,
> + __rte_unused uint64_t vaddr,
> + __rte_unused uint64_t iova,
> + __rte_unused uint64_t len,
> + __rte_unused uint64_t pagesz)
> +{
> + return -1;
> +}
> +
> int
> rte_vfio_container_dma_unmap(__rte_unused int container_fd,
> __rte_unused uint64_t vaddr,
> diff --git a/lib/eal/include/rte_vfio.h b/lib/eal/include/rte_vfio.h
> index 2d90b36480..6afae2ccce 100644
> --- a/lib/eal/include/rte_vfio.h
> +++ b/lib/eal/include/rte_vfio.h
> @@ -17,6 +17,8 @@ extern "C" {
> #include <stdbool.h>
> #include <stdint.h>
>
> +#include <rte_compat.h>
> +
> /*
> * determine if VFIO is present on the system
> */
> @@ -331,6 +333,37 @@ int
> rte_vfio_container_dma_map(int container_fd, uint64_t vaddr,
> uint64_t iova, uint64_t len);
>
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
> + *
> + * Perform DMA mapping for devices in a container, mapping memory page-by-page.
> + *
> + * @param container_fd
> + * the specified container fd. Use RTE_VFIO_DEFAULT_CONTAINER_FD to
> + * use the default container.
> + *
> + * @param vaddr
> + * Starting virtual address of memory to be mapped.
> + *
> + * @param iova
> + * Starting IOVA address of memory to be mapped.
> + *
> + * @param len
> + * Length of memory segment being mapped.
> + *
> + * @param pagesz
> + * Page size of the underlying memory.
> + *
> + * @return
> + * 0 if successful
> + * <0 if failed
> + */
> +__rte_experimental
> +int
> +rte_vfio_container_dma_map_paged(int container_fd, uint64_t vaddr,
> + uint64_t iova, uint64_t len, uint64_t pagesz);
> +
> /**
> * Perform DMA unmapping for devices in a container.
> *
> diff --git a/lib/eal/linux/eal_vfio.c b/lib/eal/linux/eal_vfio.c
> index 657c89ca58..c791730251 100644
> --- a/lib/eal/linux/eal_vfio.c
> +++ b/lib/eal/linux/eal_vfio.c
> @@ -1872,11 +1872,12 @@ vfio_dma_mem_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
>
> static int
> container_dma_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
> - uint64_t len)
> + uint64_t len, uint64_t pagesz)
> {
> struct user_mem_map *new_map;
> struct user_mem_maps *user_mem_maps;
> bool has_partial_unmap;
> + uint64_t chunk_size;
> int ret = 0;
>
> user_mem_maps = &vfio_cfg->mem_maps;
> @@ -1887,19 +1888,37 @@ container_dma_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
> ret = -1;
> goto out;
> }
> - /* map the entry */
> - if (vfio_dma_mem_map(vfio_cfg, vaddr, iova, len, 1)) {
> - /* technically, this will fail if there are currently no devices
> - * plugged in, even if a device were added later, this mapping
> - * might have succeeded. however, since we cannot verify if this
> - * is a valid mapping without having a device attached, consider
> - * this to be unsupported, because we can't just store any old
> - * mapping and pollute list of active mappings willy-nilly.
> - */
> - RTE_LOG(ERR, EAL, "Couldn't map new region for DMA\n");
> - ret = -1;
> - goto out;
> +
> + /* technically, mapping will fail if there are currently no devices
> + * plugged in, even if a device were added later, this mapping might
> + * have succeeded. however, since we cannot verify if this is a valid
> + * mapping without having a device attached, consider this to be
> + * unsupported, because we can't just store any old mapping and pollute
> + * list of active mappings willy-nilly.
> + */
> +
> + /* if page size was not specified, map the entire segment in one go */
> + if (pagesz == 0) {
> + if (vfio_dma_mem_map(vfio_cfg, vaddr, iova, len, 1)) {
> + RTE_LOG(ERR, EAL, "Couldn't map new region for DMA\n");
> + ret = -1;
> + goto out;
> + }
> + } else {
> + /* otherwise, do mappings page-by-page */
> + uint64_t offset;
> +
> + for (offset = 0; offset < len; offset += pagesz) {
> + uint64_t va = vaddr + offset;
> + uint64_t io = iova + offset;
> + if (vfio_dma_mem_map(vfio_cfg, va, io, pagesz, 1)) {
> + RTE_LOG(ERR, EAL, "Couldn't map new region for DMA\n");
> + ret = -1;
> + goto out;
> + }
> + }
> }
> +
> /* do we have partial unmap support? */
> has_partial_unmap = vfio_cfg->vfio_iommu_type->partial_unmap;
>
> @@ -1908,8 +1927,18 @@ container_dma_map(struct vfio_config *vfio_cfg, uint64_t vaddr, uint64_t iova,
> new_map->addr = vaddr;
> new_map->iova = iova;
> new_map->len = len;
> - /* for IOMMU types supporting partial unmap, we don't need chunking */
> - new_map->chunk = has_partial_unmap ? 0 : len;
> +
> + /*
> + * Chunking essentially serves largely the same purpose as page sizes,
> + * so for the purposes of this calculation, we treat them as the same.
> + * The reason we have page sizes is because we want to map things in a
> + * way that allows us to partially unmap later. Therefore, when IOMMU
> + * supports partial unmap, page size is irrelevant and can be ignored.
> + * For IOMMU that don't support partial unmap, page size is equivalent
> + * to chunk size.
> + */
> + chunk_size = pagesz == 0 ? len : pagesz;
> + new_map->chunk = has_partial_unmap ? 0 : chunk_size;
>
> compact_user_maps(user_mem_maps);
> out:
> @@ -2179,7 +2208,29 @@ rte_vfio_container_dma_map(int container_fd, uint64_t vaddr, uint64_t iova,
> return -1;
> }
>
> - return container_dma_map(vfio_cfg, vaddr, iova, len);
> + /* not having page size means we map entire segment */
> + return container_dma_map(vfio_cfg, vaddr, iova, len, 0);
> +}
> +
> +int
> +rte_vfio_container_dma_map_paged(int container_fd, uint64_t vaddr,
> + uint64_t iova, uint64_t len, uint64_t pagesz)
> +{
> + struct vfio_config *vfio_cfg;
> +
> + if (len == 0 || pagesz == 0 || !rte_is_power_of_2(pagesz) ||
> + (len % pagesz) != 0) {
This should also check if VA/IOVA is page-aligned. Will fix in v2.
> + rte_errno = EINVAL;
> + return -1;
> + }
> +
> + vfio_cfg = get_vfio_cfg_by_container_fd(container_fd);
> + if (vfio_cfg == NULL) {
> + RTE_LOG(ERR, EAL, "Invalid VFIO container fd\n");
> + return -1;
> + }
> +
> + return container_dma_map(vfio_cfg, vaddr, iova, len, pagesz);
> }
>
> int
> @@ -2299,6 +2350,16 @@ rte_vfio_container_dma_map(__rte_unused int container_fd,
> return -1;
> }
>
> +int
> +rte_vfio_container_dma_map_paged(__rte_unused int container_fd,
> + __rte_unused uint64_t vaddr,
> + __rte_unused uint64_t iova,
> + __rte_unused uint64_t len,
> + __rte_unused uint64_t pagesz)
> +{
> + return -1;
> +}
> +
> int
> rte_vfio_container_dma_unmap(__rte_unused int container_fd,
> __rte_unused uint64_t vaddr,
> diff --git a/lib/eal/version.map b/lib/eal/version.map
> index beeb986adc..eaa6b0bedf 100644
> --- a/lib/eal/version.map
> +++ b/lib/eal/version.map
> @@ -426,6 +426,9 @@ EXPERIMENTAL {
>
> # added in 21.08
> rte_power_monitor_multi; # WINDOWS_NO_EXPORT
> +
> + # added in 21.11
> + rte_vfio_container_dma_map_paged;
> };
>
> INTERNAL {
> diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c
> index 3d8c520412..fcd6bc1894 100644
> --- a/lib/eal/windows/eal.c
> +++ b/lib/eal/windows/eal.c
> @@ -459,6 +459,16 @@ rte_vfio_container_dma_map(__rte_unused int container_fd,
> return -1;
> }
>
> +int
> +rte_vfio_container_dma_map_paged(__rte_unused int container_fd,
> + __rte_unused uint64_t vaddr,
> + __rte_unused uint64_t iova,
> + __rte_unused uint64_t len,
> + __rte_unused uint64_t pagesz)
> +{
> + return -1;
> +}
> +
> int
> rte_vfio_container_dma_unmap(__rte_unused int container_fd,
> __rte_unused uint64_t vaddr,
>
--
Thanks,
Anatoly
next prev parent reply other threads:[~2021-09-29 10:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-10 11:27 Anatoly Burakov
2021-09-10 12:31 ` Burakov, Anatoly
2021-09-29 10:18 ` Burakov, Anatoly [this message]
2021-10-28 8:18 ` David Marchand
2021-10-28 13:00 ` Burakov, Anatoly
2021-10-28 14:09 ` [dpdk-dev] [PATCH v2 " Anatoly Burakov
2021-11-02 15:16 ` Burakov, Anatoly
2022-06-02 8:23 ` David Marchand
2023-07-03 23:48 ` Stephen Hemminger
2023-07-04 12:51 ` Burakov, Anatoly
2022-06-02 9:14 ` Ray Kinsella
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