From 94abbccdf2916cb03f9626f2d36c6e9971490c12 Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Tue, 4 Aug 2020 19:20:47 +0300 Subject: [PATCH] vdpa/mlx5: Add shared memory registration code Add code to support registering address space region for the device. The virtio driver can run as either: 1. Guest virtio driver 2. Userspace virtio driver on the host 3. Kernel virtio driver on the host In any case a memory key object is required to provide access to memory for the device. This code will be shared by network or block driver implementations. Reviewed-by: Parav Pandit Signed-off-by: Eli Cohen Link: https://lore.kernel.org/r/20200804162048.22587-12-eli@mellanox.com Signed-off-by: Michael S. Tsirkin --- drivers/vdpa/mlx5/Makefile | 2 +- drivers/vdpa/mlx5/core/Makefile | 1 - drivers/vdpa/mlx5/core/mlx5_vdpa.h | 34 +++ drivers/vdpa/mlx5/core/mr.c | 484 +++++++++++++++++++++++++++++++++++++ drivers/vdpa/mlx5/core/resources.c | 3 + 5 files changed, 522 insertions(+), 2 deletions(-) delete mode 100644 drivers/vdpa/mlx5/core/Makefile create mode 100644 drivers/vdpa/mlx5/core/mr.c diff --git a/drivers/vdpa/mlx5/Makefile b/drivers/vdpa/mlx5/Makefile index d552abb..b347c62 100644 --- a/drivers/vdpa/mlx5/Makefile +++ b/drivers/vdpa/mlx5/Makefile @@ -1 +1 @@ -obj-$(CONFIG_MLX5_VDPA) += core/resources.o +obj-$(CONFIG_MLX5_VDPA) += core/resources.o core/mr.o diff --git a/drivers/vdpa/mlx5/core/Makefile b/drivers/vdpa/mlx5/core/Makefile deleted file mode 100644 index 7070f8c..0000000 --- a/drivers/vdpa/mlx5/core/Makefile +++ /dev/null @@ -1 +0,0 @@ -obj-y += resources.o diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h index f3571c8..5c92a57 100644 --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h @@ -7,6 +7,31 @@ #include #include +struct mlx5_vdpa_direct_mr { + u64 start; + u64 end; + u32 perm; + struct mlx5_core_mkey mr; + struct sg_table sg_head; + int log_size; + int nsg; + struct list_head list; + u64 offset; +}; + +struct mlx5_vdpa_mr { + struct mlx5_core_mkey mkey; + + /* list of direct MRs descendants of this indirect mr */ + struct list_head head; + unsigned long num_directs; + unsigned long num_klms; + bool initialized; + + /* serialize mkey creation and destruction */ + struct mutex mkey_mtx; +}; + struct mlx5_vdpa_resources { u32 pdn; struct mlx5_uars_page *uar; @@ -26,6 +51,8 @@ struct mlx5_vdpa_dev { u8 status; u32 max_vqs; u32 generation; + + struct mlx5_vdpa_mr mr; }; int mlx5_vdpa_alloc_pd(struct mlx5_vdpa_dev *dev, u32 *pdn, u16 uid); @@ -41,6 +68,13 @@ int mlx5_vdpa_alloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 *tdn); void mlx5_vdpa_dealloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 tdn); int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev); void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev); +int mlx5_vdpa_create_mkey(struct mlx5_vdpa_dev *mvdev, struct mlx5_core_mkey *mkey, u32 *in, + int inlen); +int mlx5_vdpa_destroy_mkey(struct mlx5_vdpa_dev *mvdev, struct mlx5_core_mkey *mkey); +int mlx5_vdpa_handle_set_map(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb, + bool *change_map); +int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb); +void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev); #define mlx5_vdpa_warn(__dev, format, ...) \ dev_warn((__dev)->mdev->device, "%s:%d:(pid %d) warning: " format, __func__, __LINE__, \ diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c new file mode 100644 index 0000000..0846989 --- /dev/null +++ b/drivers/vdpa/mlx5/core/mr.c @@ -0,0 +1,484 @@ +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB +/* Copyright (c) 2020 Mellanox Technologies Ltd. */ + +#include +#include +#include +#include +#include "mlx5_vdpa.h" + +/* DIV_ROUND_UP where the divider is a power of 2 give by its log base 2 value */ +#define MLX5_DIV_ROUND_UP_POW2(_n, _s) \ +({ \ + u64 __s = _s; \ + u64 _res; \ + _res = (((_n) + (1 << (__s)) - 1) >> (__s)); \ + _res; \ +}) + +static int get_octo_len(u64 len, int page_shift) +{ + u64 page_size = 1ULL << page_shift; + int npages; + + npages = ALIGN(len, page_size) >> page_shift; + return (npages + 1) / 2; +} + +static void fill_sg(struct mlx5_vdpa_direct_mr *mr, void *in) +{ + struct scatterlist *sg; + __be64 *pas; + int i; + + pas = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt); + for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i) + (*pas) = cpu_to_be64(sg_dma_address(sg)); +} + +static void mlx5_set_access_mode(void *mkc, int mode) +{ + MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3); + MLX5_SET(mkc, mkc, access_mode_4_2, mode >> 2); +} + +static void populate_mtts(struct mlx5_vdpa_direct_mr *mr, __be64 *mtt) +{ + struct scatterlist *sg; + int i; + + for_each_sg(mr->sg_head.sgl, sg, mr->nsg, i) + mtt[i] = cpu_to_be64(sg_dma_address(sg)); +} + +static int create_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr) +{ + int inlen; + void *mkc; + void *in; + int err; + + inlen = MLX5_ST_SZ_BYTES(create_mkey_in) + roundup(MLX5_ST_SZ_BYTES(mtt) * mr->nsg, 16); + in = kvzalloc(inlen, GFP_KERNEL); + if (!in) + return -ENOMEM; + + MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid); + fill_sg(mr, in); + mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry); + MLX5_SET(mkc, mkc, lw, !!(mr->perm & VHOST_MAP_WO)); + MLX5_SET(mkc, mkc, lr, !!(mr->perm & VHOST_MAP_RO)); + mlx5_set_access_mode(mkc, MLX5_MKC_ACCESS_MODE_MTT); + MLX5_SET(mkc, mkc, qpn, 0xffffff); + MLX5_SET(mkc, mkc, pd, mvdev->res.pdn); + MLX5_SET64(mkc, mkc, start_addr, mr->offset); + MLX5_SET64(mkc, mkc, len, mr->end - mr->start); + MLX5_SET(mkc, mkc, log_page_size, mr->log_size); + MLX5_SET(mkc, mkc, translations_octword_size, + get_octo_len(mr->end - mr->start, mr->log_size)); + MLX5_SET(create_mkey_in, in, translations_octword_actual_size, + get_octo_len(mr->end - mr->start, mr->log_size)); + populate_mtts(mr, MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt)); + err = mlx5_vdpa_create_mkey(mvdev, &mr->mr, in, inlen); + kvfree(in); + if (err) { + mlx5_vdpa_warn(mvdev, "Failed to create direct MR\n"); + return err; + } + + return 0; +} + +static void destroy_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr) +{ + mlx5_vdpa_destroy_mkey(mvdev, &mr->mr); +} + +static u64 map_start(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr) +{ + return max_t(u64, map->start, mr->start); +} + +static u64 map_end(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr) +{ + return min_t(u64, map->last + 1, mr->end); +} + +static u64 maplen(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr) +{ + return map_end(map, mr) - map_start(map, mr); +} + +#define MLX5_VDPA_INVALID_START_ADDR ((u64)-1) +#define MLX5_VDPA_INVALID_LEN ((u64)-1) + +static u64 indir_start_addr(struct mlx5_vdpa_mr *mkey) +{ + struct mlx5_vdpa_direct_mr *s; + + s = list_first_entry_or_null(&mkey->head, struct mlx5_vdpa_direct_mr, list); + if (!s) + return MLX5_VDPA_INVALID_START_ADDR; + + return s->start; +} + +static u64 indir_len(struct mlx5_vdpa_mr *mkey) +{ + struct mlx5_vdpa_direct_mr *s; + struct mlx5_vdpa_direct_mr *e; + + s = list_first_entry_or_null(&mkey->head, struct mlx5_vdpa_direct_mr, list); + if (!s) + return MLX5_VDPA_INVALID_LEN; + + e = list_last_entry(&mkey->head, struct mlx5_vdpa_direct_mr, list); + + return e->end - s->start; +} + +#define LOG_MAX_KLM_SIZE 30 +#define MAX_KLM_SIZE BIT(LOG_MAX_KLM_SIZE) + +static u32 klm_bcount(u64 size) +{ + return (u32)size; +} + +static void fill_indir(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mkey, void *in) +{ + struct mlx5_vdpa_direct_mr *dmr; + struct mlx5_klm *klmarr; + struct mlx5_klm *klm; + bool first = true; + u64 preve; + int i; + + klmarr = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt); + i = 0; + list_for_each_entry(dmr, &mkey->head, list) { +again: + klm = &klmarr[i++]; + if (first) { + preve = dmr->start; + first = false; + } + + if (preve == dmr->start) { + klm->key = cpu_to_be32(dmr->mr.key); + klm->bcount = cpu_to_be32(klm_bcount(dmr->end - dmr->start)); + preve = dmr->end; + } else { + klm->key = cpu_to_be32(mvdev->res.null_mkey); + klm->bcount = cpu_to_be32(klm_bcount(dmr->start - preve)); + preve = dmr->start; + goto again; + } + } +} + +static int klm_byte_size(int nklms) +{ + return 16 * ALIGN(nklms, 4); +} + +static int create_indirect_key(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr) +{ + int inlen; + void *mkc; + void *in; + int err; + u64 start; + u64 len; + + start = indir_start_addr(mr); + len = indir_len(mr); + if (start == MLX5_VDPA_INVALID_START_ADDR || len == MLX5_VDPA_INVALID_LEN) + return -EINVAL; + + inlen = MLX5_ST_SZ_BYTES(create_mkey_in) + klm_byte_size(mr->num_klms); + in = kzalloc(inlen, GFP_KERNEL); + if (!in) + return -ENOMEM; + + MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid); + mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry); + MLX5_SET(mkc, mkc, lw, 1); + MLX5_SET(mkc, mkc, lr, 1); + mlx5_set_access_mode(mkc, MLX5_MKC_ACCESS_MODE_KLMS); + MLX5_SET(mkc, mkc, qpn, 0xffffff); + MLX5_SET(mkc, mkc, pd, mvdev->res.pdn); + MLX5_SET64(mkc, mkc, start_addr, start); + MLX5_SET64(mkc, mkc, len, len); + MLX5_SET(mkc, mkc, translations_octword_size, klm_byte_size(mr->num_klms) / 16); + MLX5_SET(create_mkey_in, in, translations_octword_actual_size, mr->num_klms); + fill_indir(mvdev, mr, in); + err = mlx5_vdpa_create_mkey(mvdev, &mr->mkey, in, inlen); + kfree(in); + return err; +} + +static void destroy_indirect_key(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mkey) +{ + mlx5_vdpa_destroy_mkey(mvdev, &mkey->mkey); +} + +static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr, + struct vhost_iotlb *iotlb) +{ + struct vhost_iotlb_map *map; + unsigned long lgcd = 0; + int log_entity_size; + unsigned long size; + u64 start = 0; + int err; + struct page *pg; + unsigned int nsg; + int sglen; + u64 pa; + u64 paend; + struct scatterlist *sg; + struct device *dma = mvdev->mdev->device; + int ret; + + for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1); + map; map = vhost_iotlb_itree_next(map, start, mr->end - 1)) { + size = maplen(map, mr); + lgcd = gcd(lgcd, size); + start += size; + } + log_entity_size = ilog2(lgcd); + + sglen = 1 << log_entity_size; + nsg = MLX5_DIV_ROUND_UP_POW2(mr->end - mr->start, log_entity_size); + + err = sg_alloc_table(&mr->sg_head, nsg, GFP_KERNEL); + if (err) + return err; + + sg = mr->sg_head.sgl; + for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1); + map; map = vhost_iotlb_itree_next(map, mr->start, mr->end - 1)) { + paend = map->addr + maplen(map, mr); + for (pa = map->addr; pa < paend; pa += sglen) { + pg = pfn_to_page(__phys_to_pfn(pa)); + if (!sg) { + mlx5_vdpa_warn(mvdev, "sg null. start 0x%llx, end 0x%llx\n", + map->start, map->last + 1); + err = -ENOMEM; + goto err_map; + } + sg_set_page(sg, pg, sglen, 0); + sg = sg_next(sg); + if (!sg) + goto done; + } + } +done: + mr->log_size = log_entity_size; + mr->nsg = nsg; + ret = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0); + if (!ret) + goto err_map; + + err = create_direct_mr(mvdev, mr); + if (err) + goto err_direct; + + return 0; + +err_direct: + dma_unmap_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0); +err_map: + sg_free_table(&mr->sg_head); + return err; +} + +static void unmap_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr) +{ + struct device *dma = mvdev->mdev->device; + + destroy_direct_mr(mvdev, mr); + dma_unmap_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0); + sg_free_table(&mr->sg_head); +} + +static int add_direct_chain(struct mlx5_vdpa_dev *mvdev, u64 start, u64 size, u8 perm, + struct vhost_iotlb *iotlb) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + struct mlx5_vdpa_direct_mr *dmr; + struct mlx5_vdpa_direct_mr *n; + LIST_HEAD(tmp); + u64 st; + u64 sz; + int err; + int i = 0; + + st = start; + while (size) { + sz = (u32)min_t(u64, MAX_KLM_SIZE, size); + dmr = kzalloc(sizeof(*dmr), GFP_KERNEL); + if (!dmr) + goto err_alloc; + + dmr->start = st; + dmr->end = st + sz; + dmr->perm = perm; + err = map_direct_mr(mvdev, dmr, iotlb); + if (err) { + kfree(dmr); + goto err_alloc; + } + + list_add_tail(&dmr->list, &tmp); + size -= sz; + mr->num_directs++; + mr->num_klms++; + st += sz; + i++; + } + list_splice_tail(&tmp, &mr->head); + return 0; + +err_alloc: + list_for_each_entry_safe(dmr, n, &mr->head, list) { + list_del_init(&dmr->list); + unmap_direct_mr(mvdev, dmr); + kfree(dmr); + } + return err; +} + +/* The iotlb pointer contains a list of maps. Go over the maps, possibly + * merging mergeable maps, and create direct memory keys that provide the + * device access to memory. The direct mkeys are then referred to by the + * indirect memory key that provides access to the enitre address space given + * by iotlb. + */ +static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + struct mlx5_vdpa_direct_mr *dmr; + struct mlx5_vdpa_direct_mr *n; + struct vhost_iotlb_map *map; + u32 pperm = U16_MAX; + u64 last = U64_MAX; + u64 ps = U64_MAX; + u64 pe = U64_MAX; + u64 start = 0; + int err = 0; + int nnuls; + + if (mr->initialized) + return 0; + + INIT_LIST_HEAD(&mr->head); + for (map = vhost_iotlb_itree_first(iotlb, start, last); map; + map = vhost_iotlb_itree_next(map, start, last)) { + start = map->start; + if (pe == map->start && pperm == map->perm) { + pe = map->last + 1; + } else { + if (ps != U64_MAX) { + if (pe < map->start) { + /* We have a hole in the map. Check how + * many null keys are required to fill it. + */ + nnuls = MLX5_DIV_ROUND_UP_POW2(map->start - pe, + LOG_MAX_KLM_SIZE); + mr->num_klms += nnuls; + } + err = add_direct_chain(mvdev, ps, pe - ps, pperm, iotlb); + if (err) + goto err_chain; + } + ps = map->start; + pe = map->last + 1; + pperm = map->perm; + } + } + err = add_direct_chain(mvdev, ps, pe - ps, pperm, iotlb); + if (err) + goto err_chain; + + /* Create the memory key that defines the guests's address space. This + * memory key refers to the direct keys that contain the MTT + * translations + */ + err = create_indirect_key(mvdev, mr); + if (err) + goto err_chain; + + mr->initialized = true; + return 0; + +err_chain: + list_for_each_entry_safe_reverse(dmr, n, &mr->head, list) { + list_del_init(&dmr->list); + unmap_direct_mr(mvdev, dmr); + kfree(dmr); + } + return err; +} + +int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + int err; + + mutex_lock(&mr->mkey_mtx); + err = _mlx5_vdpa_create_mr(mvdev, iotlb); + mutex_unlock(&mr->mkey_mtx); + return err; +} + +void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + struct mlx5_vdpa_direct_mr *dmr; + struct mlx5_vdpa_direct_mr *n; + + mutex_lock(&mr->mkey_mtx); + if (!mr->initialized) + goto out; + + destroy_indirect_key(mvdev, mr); + list_for_each_entry_safe_reverse(dmr, n, &mr->head, list) { + list_del_init(&dmr->list); + unmap_direct_mr(mvdev, dmr); + kfree(dmr); + } + memset(mr, 0, sizeof(*mr)); + mr->initialized = false; +out: + mutex_unlock(&mr->mkey_mtx); +} + +static bool map_empty(struct vhost_iotlb *iotlb) +{ + return !vhost_iotlb_itree_first(iotlb, 0, U64_MAX); +} + +int mlx5_vdpa_handle_set_map(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb, + bool *change_map) +{ + struct mlx5_vdpa_mr *mr = &mvdev->mr; + int err; + + *change_map = false; + if (map_empty(iotlb)) { + mlx5_vdpa_destroy_mr(mvdev); + return 0; + } + mutex_lock(&mr->mkey_mtx); + if (mr->initialized) { + mlx5_vdpa_info(mvdev, "memory map update\n"); + *change_map = true; + } + if (!*change_map) + err = _mlx5_vdpa_create_mr(mvdev, iotlb); + mutex_unlock(&mr->mkey_mtx); + + return err; +} diff --git a/drivers/vdpa/mlx5/core/resources.c b/drivers/vdpa/mlx5/core/resources.c index 6c6552b..96e6421 100644 --- a/drivers/vdpa/mlx5/core/resources.c +++ b/drivers/vdpa/mlx5/core/resources.c @@ -227,6 +227,7 @@ int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev) mlx5_vdpa_warn(mvdev, "resources already allocated\n"); return -EINVAL; } + mutex_init(&mvdev->mr.mkey_mtx); res->uar = mlx5_get_uars_page(mdev); if (IS_ERR(res->uar)) { err = PTR_ERR(res->uar); @@ -262,6 +263,7 @@ err_pd: err_uctx: mlx5_put_uars_page(mdev, res->uar); err_uars: + mutex_destroy(&mvdev->mr.mkey_mtx); return err; } @@ -277,5 +279,6 @@ void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev) dealloc_pd(mvdev, res->pdn, res->uid); destroy_uctx(mvdev, res->uid); mlx5_put_uars_page(mvdev->mdev, res->uar); + mutex_destroy(&mvdev->mr.mkey_mtx); res->valid = false; } -- 2.7.4