Anatoly Burakov <anatoly.bura...@intel.com> writes:
> 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.bura...@intel.com> > --- > > Notes: > v2: > - Added checks for page alignment of supplied values > - Added rte_errno values (similar to patch 103165 [1]) > > [1] > http://patches.dpdk.org/project/dpdk/patch/e8c5e7ba089e2283c3cd67e4529e52fe49390eb9.1635428963.git.anatoly.bura...@intel.com/ > > lib/eal/freebsd/eal.c | 11 ++++ > lib/eal/include/rte_vfio.h | 33 ++++++++++++ > lib/eal/linux/eal_vfio.c | 108 +++++++++++++++++++++++++++++++------ > lib/eal/version.map | 1 + > lib/eal/windows/eal.c | 11 ++++ > 5 files changed, 148 insertions(+), 16 deletions(-) > > diff --git a/lib/eal/freebsd/eal.c b/lib/eal/freebsd/eal.c > index 9935356ed4..5ca5fa8e11 100644 > --- a/lib/eal/freebsd/eal.c > +++ b/lib/eal/freebsd/eal.c > @@ -1090,6 +1090,17 @@ 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) > +{ > + rte_errno = ENOTSUP; > + 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 aa2087a2da..0f5b6c14af 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 +2208,44 @@ 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; > + bool va_aligned, iova_aligned, len_aligned, pagesz_aligned; > + > + /* avoid divide by zero first */ > + if (len == 0 || pagesz == 0) { > + rte_errno = EINVAL; > + return -1; > + } > + /* > + * for direct maps, we leave it up to the kernel to decide whether the > + * parameters are valid, but since we are going to map page-by-page and > + * are expecting certain guarantees from the parameters we receive, we > + * are going to check those here. > + */ > + pagesz_aligned = rte_align64pow2(pagesz) == pagesz; > + len_aligned = (len % pagesz) == 0; > + va_aligned = RTE_ALIGN(vaddr, pagesz) == pagesz; > + iova_aligned = RTE_ALIGN(iova, pagesz) == pagesz; > + if (!pagesz_aligned || !len_aligned || !va_aligned || !iova_aligned) { > + 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 +2365,16 @@ 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 9d43655b66..82a34c2014 100644 > --- a/lib/eal/version.map > +++ b/lib/eal/version.map > @@ -420,6 +420,7 @@ EXPERIMENTAL { > rte_intr_instance_free; > rte_intr_type_get; > rte_intr_type_set; Pls anontate with the target release in a comment. > + rte_vfio_container_dma_map_paged; > }; > > INTERNAL { > diff --git a/lib/eal/windows/eal.c b/lib/eal/windows/eal.c > index f7ce1b6671..93771cb230 100644 > --- a/lib/eal/windows/eal.c > +++ b/lib/eal/windows/eal.c > @@ -484,6 +484,17 @@ 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) > +{ > + rte_errno = ENOTSUP; > + return -1; > +} > + > int > rte_vfio_container_dma_unmap(__rte_unused int container_fd, > __rte_unused uint64_t vaddr, -- Regards, Ray K
