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 <parav@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Link: https://lore.kernel.org/r/20200804162048.22587-12-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Eli Cohen 2020-08-04 19:20:47 +03:00 committed by Michael S. Tsirkin
parent 29064bfdab
commit 94abbccdf2
5 changed files with 522 additions and 2 deletions

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@ -1 +1 @@
obj-$(CONFIG_MLX5_VDPA) += core/resources.o
obj-$(CONFIG_MLX5_VDPA) += core/resources.o core/mr.o

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@ -1 +0,0 @@
obj-y += resources.o

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@ -7,6 +7,31 @@
#include <linux/vdpa.h>
#include <linux/mlx5/driver.h>
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__, \

484
drivers/vdpa/mlx5/core/mr.c Normal file
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@ -0,0 +1,484 @@
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2020 Mellanox Technologies Ltd. */
#include <linux/vdpa.h>
#include <linux/gcd.h>
#include <linux/string.h>
#include <linux/mlx5/qp.h>
#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;
}

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@ -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;
}