vfio/mlx5: Implement vfio_pci driver for mlx5 devices

This patch adds support for vfio_pci driver for mlx5 devices.

It uses vfio_pci_core to register to the VFIO subsystem and then
implements the mlx5 specific logic in the migration area.

The migration implementation follows the definition from uapi/vfio.h and
uses the mlx5 VF->PF command channel to achieve it.

This patch implements the suspend/resume flows.

Link: https://lore.kernel.org/all/20220224142024.147653-14-yishaih@nvidia.com
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
This commit is contained in:
Yishai Hadas 2022-02-24 16:20:22 +02:00 committed by Leon Romanovsky
parent f1d98f346e
commit 6fadb02126
7 changed files with 649 additions and 0 deletions

View file

@ -20320,6 +20320,12 @@ L: kvm@vger.kernel.org
S: Maintained
F: drivers/vfio/platform/
VFIO MLX5 PCI DRIVER
M: Yishai Hadas <yishaih@nvidia.com>
L: kvm@vger.kernel.org
S: Maintained
F: drivers/vfio/pci/mlx5/
VGA_SWITCHEROO
R: Lukas Wunner <lukas@wunner.de>
S: Maintained

View file

@ -43,4 +43,7 @@ config VFIO_PCI_IGD
To enable Intel IGD assignment through vfio-pci, say Y.
endif
source "drivers/vfio/pci/mlx5/Kconfig"
endif

View file

@ -7,3 +7,5 @@ obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
vfio-pci-y := vfio_pci.o
vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5/

View file

@ -0,0 +1,10 @@
# SPDX-License-Identifier: GPL-2.0-only
config MLX5_VFIO_PCI
tristate "VFIO support for MLX5 PCI devices"
depends on MLX5_CORE
depends on VFIO_PCI_CORE
help
This provides migration support for MLX5 devices using the VFIO
framework.
If you don't know what to do here, say N.

View file

@ -0,0 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5-vfio-pci.o
mlx5-vfio-pci-y := main.o cmd.o

View file

@ -12,6 +12,7 @@
struct mlx5_vf_migration_file {
struct file *filp;
struct mutex lock;
bool disabled;
struct sg_append_table table;
size_t total_length;

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@ -0,0 +1,623 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved
*/
#include <linux/device.h>
#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/interrupt.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/sched/mm.h>
#include <linux/vfio_pci_core.h>
#include <linux/anon_inodes.h>
#include "cmd.h"
/* Arbitrary to prevent userspace from consuming endless memory */
#define MAX_MIGRATION_SIZE (512*1024*1024)
struct mlx5vf_pci_core_device {
struct vfio_pci_core_device core_device;
u16 vhca_id;
u8 migrate_cap:1;
/* protect migration state */
struct mutex state_mutex;
enum vfio_device_mig_state mig_state;
struct mlx5_vf_migration_file *resuming_migf;
struct mlx5_vf_migration_file *saving_migf;
};
static struct page *
mlx5vf_get_migration_page(struct mlx5_vf_migration_file *migf,
unsigned long offset)
{
unsigned long cur_offset = 0;
struct scatterlist *sg;
unsigned int i;
/* All accesses are sequential */
if (offset < migf->last_offset || !migf->last_offset_sg) {
migf->last_offset = 0;
migf->last_offset_sg = migf->table.sgt.sgl;
migf->sg_last_entry = 0;
}
cur_offset = migf->last_offset;
for_each_sg(migf->last_offset_sg, sg,
migf->table.sgt.orig_nents - migf->sg_last_entry, i) {
if (offset < sg->length + cur_offset) {
migf->last_offset_sg = sg;
migf->sg_last_entry += i;
migf->last_offset = cur_offset;
return nth_page(sg_page(sg),
(offset - cur_offset) / PAGE_SIZE);
}
cur_offset += sg->length;
}
return NULL;
}
static int mlx5vf_add_migration_pages(struct mlx5_vf_migration_file *migf,
unsigned int npages)
{
unsigned int to_alloc = npages;
struct page **page_list;
unsigned long filled;
unsigned int to_fill;
int ret;
to_fill = min_t(unsigned int, npages, PAGE_SIZE / sizeof(*page_list));
page_list = kvzalloc(to_fill * sizeof(*page_list), GFP_KERNEL);
if (!page_list)
return -ENOMEM;
do {
filled = alloc_pages_bulk_array(GFP_KERNEL, to_fill, page_list);
if (!filled) {
ret = -ENOMEM;
goto err;
}
to_alloc -= filled;
ret = sg_alloc_append_table_from_pages(
&migf->table, page_list, filled, 0,
filled << PAGE_SHIFT, UINT_MAX, SG_MAX_SINGLE_ALLOC,
GFP_KERNEL);
if (ret)
goto err;
migf->allocated_length += filled * PAGE_SIZE;
/* clean input for another bulk allocation */
memset(page_list, 0, filled * sizeof(*page_list));
to_fill = min_t(unsigned int, to_alloc,
PAGE_SIZE / sizeof(*page_list));
} while (to_alloc > 0);
kvfree(page_list);
return 0;
err:
kvfree(page_list);
return ret;
}
static void mlx5vf_disable_fd(struct mlx5_vf_migration_file *migf)
{
struct sg_page_iter sg_iter;
mutex_lock(&migf->lock);
/* Undo alloc_pages_bulk_array() */
for_each_sgtable_page(&migf->table.sgt, &sg_iter, 0)
__free_page(sg_page_iter_page(&sg_iter));
sg_free_append_table(&migf->table);
migf->disabled = true;
migf->total_length = 0;
migf->allocated_length = 0;
migf->filp->f_pos = 0;
mutex_unlock(&migf->lock);
}
static int mlx5vf_release_file(struct inode *inode, struct file *filp)
{
struct mlx5_vf_migration_file *migf = filp->private_data;
mlx5vf_disable_fd(migf);
mutex_destroy(&migf->lock);
kfree(migf);
return 0;
}
static ssize_t mlx5vf_save_read(struct file *filp, char __user *buf, size_t len,
loff_t *pos)
{
struct mlx5_vf_migration_file *migf = filp->private_data;
ssize_t done = 0;
if (pos)
return -ESPIPE;
pos = &filp->f_pos;
mutex_lock(&migf->lock);
if (*pos > migf->total_length) {
done = -EINVAL;
goto out_unlock;
}
if (migf->disabled) {
done = -ENODEV;
goto out_unlock;
}
len = min_t(size_t, migf->total_length - *pos, len);
while (len) {
size_t page_offset;
struct page *page;
size_t page_len;
u8 *from_buff;
int ret;
page_offset = (*pos) % PAGE_SIZE;
page = mlx5vf_get_migration_page(migf, *pos - page_offset);
if (!page) {
if (done == 0)
done = -EINVAL;
goto out_unlock;
}
page_len = min_t(size_t, len, PAGE_SIZE - page_offset);
from_buff = kmap_local_page(page);
ret = copy_to_user(buf, from_buff + page_offset, page_len);
kunmap_local(from_buff);
if (ret) {
done = -EFAULT;
goto out_unlock;
}
*pos += page_len;
len -= page_len;
done += page_len;
buf += page_len;
}
out_unlock:
mutex_unlock(&migf->lock);
return done;
}
static const struct file_operations mlx5vf_save_fops = {
.owner = THIS_MODULE,
.read = mlx5vf_save_read,
.release = mlx5vf_release_file,
.llseek = no_llseek,
};
static struct mlx5_vf_migration_file *
mlx5vf_pci_save_device_data(struct mlx5vf_pci_core_device *mvdev)
{
struct mlx5_vf_migration_file *migf;
int ret;
migf = kzalloc(sizeof(*migf), GFP_KERNEL);
if (!migf)
return ERR_PTR(-ENOMEM);
migf->filp = anon_inode_getfile("mlx5vf_mig", &mlx5vf_save_fops, migf,
O_RDONLY);
if (IS_ERR(migf->filp)) {
int err = PTR_ERR(migf->filp);
kfree(migf);
return ERR_PTR(err);
}
stream_open(migf->filp->f_inode, migf->filp);
mutex_init(&migf->lock);
ret = mlx5vf_cmd_query_vhca_migration_state(
mvdev->core_device.pdev, mvdev->vhca_id, &migf->total_length);
if (ret)
goto out_free;
ret = mlx5vf_add_migration_pages(
migf, DIV_ROUND_UP_ULL(migf->total_length, PAGE_SIZE));
if (ret)
goto out_free;
ret = mlx5vf_cmd_save_vhca_state(mvdev->core_device.pdev,
mvdev->vhca_id, migf);
if (ret)
goto out_free;
return migf;
out_free:
fput(migf->filp);
return ERR_PTR(ret);
}
static ssize_t mlx5vf_resume_write(struct file *filp, const char __user *buf,
size_t len, loff_t *pos)
{
struct mlx5_vf_migration_file *migf = filp->private_data;
loff_t requested_length;
ssize_t done = 0;
if (pos)
return -ESPIPE;
pos = &filp->f_pos;
if (*pos < 0 ||
check_add_overflow((loff_t)len, *pos, &requested_length))
return -EINVAL;
if (requested_length > MAX_MIGRATION_SIZE)
return -ENOMEM;
mutex_lock(&migf->lock);
if (migf->disabled) {
done = -ENODEV;
goto out_unlock;
}
if (migf->allocated_length < requested_length) {
done = mlx5vf_add_migration_pages(
migf,
DIV_ROUND_UP(requested_length - migf->allocated_length,
PAGE_SIZE));
if (done)
goto out_unlock;
}
while (len) {
size_t page_offset;
struct page *page;
size_t page_len;
u8 *to_buff;
int ret;
page_offset = (*pos) % PAGE_SIZE;
page = mlx5vf_get_migration_page(migf, *pos - page_offset);
if (!page) {
if (done == 0)
done = -EINVAL;
goto out_unlock;
}
page_len = min_t(size_t, len, PAGE_SIZE - page_offset);
to_buff = kmap_local_page(page);
ret = copy_from_user(to_buff + page_offset, buf, page_len);
kunmap_local(to_buff);
if (ret) {
done = -EFAULT;
goto out_unlock;
}
*pos += page_len;
len -= page_len;
done += page_len;
buf += page_len;
migf->total_length += page_len;
}
out_unlock:
mutex_unlock(&migf->lock);
return done;
}
static const struct file_operations mlx5vf_resume_fops = {
.owner = THIS_MODULE,
.write = mlx5vf_resume_write,
.release = mlx5vf_release_file,
.llseek = no_llseek,
};
static struct mlx5_vf_migration_file *
mlx5vf_pci_resume_device_data(struct mlx5vf_pci_core_device *mvdev)
{
struct mlx5_vf_migration_file *migf;
migf = kzalloc(sizeof(*migf), GFP_KERNEL);
if (!migf)
return ERR_PTR(-ENOMEM);
migf->filp = anon_inode_getfile("mlx5vf_mig", &mlx5vf_resume_fops, migf,
O_WRONLY);
if (IS_ERR(migf->filp)) {
int err = PTR_ERR(migf->filp);
kfree(migf);
return ERR_PTR(err);
}
stream_open(migf->filp->f_inode, migf->filp);
mutex_init(&migf->lock);
return migf;
}
static void mlx5vf_disable_fds(struct mlx5vf_pci_core_device *mvdev)
{
if (mvdev->resuming_migf) {
mlx5vf_disable_fd(mvdev->resuming_migf);
fput(mvdev->resuming_migf->filp);
mvdev->resuming_migf = NULL;
}
if (mvdev->saving_migf) {
mlx5vf_disable_fd(mvdev->saving_migf);
fput(mvdev->saving_migf->filp);
mvdev->saving_migf = NULL;
}
}
static struct file *
mlx5vf_pci_step_device_state_locked(struct mlx5vf_pci_core_device *mvdev,
u32 new)
{
u32 cur = mvdev->mig_state;
int ret;
if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_STOP) {
ret = mlx5vf_cmd_suspend_vhca(
mvdev->core_device.pdev, mvdev->vhca_id,
MLX5_SUSPEND_VHCA_IN_OP_MOD_SUSPEND_RESPONDER);
if (ret)
return ERR_PTR(ret);
return NULL;
}
if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RUNNING_P2P) {
ret = mlx5vf_cmd_resume_vhca(
mvdev->core_device.pdev, mvdev->vhca_id,
MLX5_RESUME_VHCA_IN_OP_MOD_RESUME_RESPONDER);
if (ret)
return ERR_PTR(ret);
return NULL;
}
if (cur == VFIO_DEVICE_STATE_RUNNING && new == VFIO_DEVICE_STATE_RUNNING_P2P) {
ret = mlx5vf_cmd_suspend_vhca(
mvdev->core_device.pdev, mvdev->vhca_id,
MLX5_SUSPEND_VHCA_IN_OP_MOD_SUSPEND_INITIATOR);
if (ret)
return ERR_PTR(ret);
return NULL;
}
if (cur == VFIO_DEVICE_STATE_RUNNING_P2P && new == VFIO_DEVICE_STATE_RUNNING) {
ret = mlx5vf_cmd_resume_vhca(
mvdev->core_device.pdev, mvdev->vhca_id,
MLX5_RESUME_VHCA_IN_OP_MOD_RESUME_INITIATOR);
if (ret)
return ERR_PTR(ret);
return NULL;
}
if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_STOP_COPY) {
struct mlx5_vf_migration_file *migf;
migf = mlx5vf_pci_save_device_data(mvdev);
if (IS_ERR(migf))
return ERR_CAST(migf);
get_file(migf->filp);
mvdev->saving_migf = migf;
return migf->filp;
}
if ((cur == VFIO_DEVICE_STATE_STOP_COPY && new == VFIO_DEVICE_STATE_STOP)) {
mlx5vf_disable_fds(mvdev);
return 0;
}
if (cur == VFIO_DEVICE_STATE_STOP && new == VFIO_DEVICE_STATE_RESUMING) {
struct mlx5_vf_migration_file *migf;
migf = mlx5vf_pci_resume_device_data(mvdev);
if (IS_ERR(migf))
return ERR_CAST(migf);
get_file(migf->filp);
mvdev->resuming_migf = migf;
return migf->filp;
}
if (cur == VFIO_DEVICE_STATE_RESUMING && new == VFIO_DEVICE_STATE_STOP) {
ret = mlx5vf_cmd_load_vhca_state(mvdev->core_device.pdev,
mvdev->vhca_id,
mvdev->resuming_migf);
if (ret)
return ERR_PTR(ret);
mlx5vf_disable_fds(mvdev);
return 0;
}
/*
* vfio_mig_get_next_state() does not use arcs other than the above
*/
WARN_ON(true);
return ERR_PTR(-EINVAL);
}
static struct file *
mlx5vf_pci_set_device_state(struct vfio_device *vdev,
enum vfio_device_mig_state new_state)
{
struct mlx5vf_pci_core_device *mvdev = container_of(
vdev, struct mlx5vf_pci_core_device, core_device.vdev);
enum vfio_device_mig_state next_state;
struct file *res = NULL;
int ret;
mutex_lock(&mvdev->state_mutex);
while (new_state != mvdev->mig_state) {
ret = vfio_mig_get_next_state(vdev, mvdev->mig_state,
new_state, &next_state);
if (ret) {
res = ERR_PTR(ret);
break;
}
res = mlx5vf_pci_step_device_state_locked(mvdev, next_state);
if (IS_ERR(res))
break;
mvdev->mig_state = next_state;
if (WARN_ON(res && new_state != mvdev->mig_state)) {
fput(res);
res = ERR_PTR(-EINVAL);
break;
}
}
mutex_unlock(&mvdev->state_mutex);
return res;
}
static int mlx5vf_pci_get_device_state(struct vfio_device *vdev,
enum vfio_device_mig_state *curr_state)
{
struct mlx5vf_pci_core_device *mvdev = container_of(
vdev, struct mlx5vf_pci_core_device, core_device.vdev);
mutex_lock(&mvdev->state_mutex);
*curr_state = mvdev->mig_state;
mutex_unlock(&mvdev->state_mutex);
return 0;
}
static int mlx5vf_pci_open_device(struct vfio_device *core_vdev)
{
struct mlx5vf_pci_core_device *mvdev = container_of(
core_vdev, struct mlx5vf_pci_core_device, core_device.vdev);
struct vfio_pci_core_device *vdev = &mvdev->core_device;
int vf_id;
int ret;
ret = vfio_pci_core_enable(vdev);
if (ret)
return ret;
if (!mvdev->migrate_cap) {
vfio_pci_core_finish_enable(vdev);
return 0;
}
vf_id = pci_iov_vf_id(vdev->pdev);
if (vf_id < 0) {
ret = vf_id;
goto out_disable;
}
ret = mlx5vf_cmd_get_vhca_id(vdev->pdev, vf_id + 1, &mvdev->vhca_id);
if (ret)
goto out_disable;
mvdev->mig_state = VFIO_DEVICE_STATE_RUNNING;
vfio_pci_core_finish_enable(vdev);
return 0;
out_disable:
vfio_pci_core_disable(vdev);
return ret;
}
static void mlx5vf_pci_close_device(struct vfio_device *core_vdev)
{
struct mlx5vf_pci_core_device *mvdev = container_of(
core_vdev, struct mlx5vf_pci_core_device, core_device.vdev);
mlx5vf_disable_fds(mvdev);
vfio_pci_core_close_device(core_vdev);
}
static const struct vfio_device_ops mlx5vf_pci_ops = {
.name = "mlx5-vfio-pci",
.open_device = mlx5vf_pci_open_device,
.close_device = mlx5vf_pci_close_device,
.ioctl = vfio_pci_core_ioctl,
.device_feature = vfio_pci_core_ioctl_feature,
.read = vfio_pci_core_read,
.write = vfio_pci_core_write,
.mmap = vfio_pci_core_mmap,
.request = vfio_pci_core_request,
.match = vfio_pci_core_match,
.migration_set_state = mlx5vf_pci_set_device_state,
.migration_get_state = mlx5vf_pci_get_device_state,
};
static int mlx5vf_pci_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
struct mlx5vf_pci_core_device *mvdev;
int ret;
mvdev = kzalloc(sizeof(*mvdev), GFP_KERNEL);
if (!mvdev)
return -ENOMEM;
vfio_pci_core_init_device(&mvdev->core_device, pdev, &mlx5vf_pci_ops);
if (pdev->is_virtfn) {
struct mlx5_core_dev *mdev =
mlx5_vf_get_core_dev(pdev);
if (mdev) {
if (MLX5_CAP_GEN(mdev, migration)) {
mvdev->migrate_cap = 1;
mvdev->core_device.vdev.migration_flags =
VFIO_MIGRATION_STOP_COPY |
VFIO_MIGRATION_P2P;
mutex_init(&mvdev->state_mutex);
}
mlx5_vf_put_core_dev(mdev);
}
}
ret = vfio_pci_core_register_device(&mvdev->core_device);
if (ret)
goto out_free;
dev_set_drvdata(&pdev->dev, mvdev);
return 0;
out_free:
vfio_pci_core_uninit_device(&mvdev->core_device);
kfree(mvdev);
return ret;
}
static void mlx5vf_pci_remove(struct pci_dev *pdev)
{
struct mlx5vf_pci_core_device *mvdev = dev_get_drvdata(&pdev->dev);
vfio_pci_core_unregister_device(&mvdev->core_device);
vfio_pci_core_uninit_device(&mvdev->core_device);
kfree(mvdev);
}
static const struct pci_device_id mlx5vf_pci_table[] = {
{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_MELLANOX, 0x101e) }, /* ConnectX Family mlx5Gen Virtual Function */
{}
};
MODULE_DEVICE_TABLE(pci, mlx5vf_pci_table);
static struct pci_driver mlx5vf_pci_driver = {
.name = KBUILD_MODNAME,
.id_table = mlx5vf_pci_table,
.probe = mlx5vf_pci_probe,
.remove = mlx5vf_pci_remove,
};
static void __exit mlx5vf_pci_cleanup(void)
{
pci_unregister_driver(&mlx5vf_pci_driver);
}
static int __init mlx5vf_pci_init(void)
{
return pci_register_driver(&mlx5vf_pci_driver);
}
module_init(mlx5vf_pci_init);
module_exit(mlx5vf_pci_cleanup);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Max Gurtovoy <mgurtovoy@nvidia.com>");
MODULE_AUTHOR("Yishai Hadas <yishaih@nvidia.com>");
MODULE_DESCRIPTION(
"MLX5 VFIO PCI - User Level meta-driver for MLX5 device family");