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Message-ID: <e7b22356-0ce8-1c14-e693-6803a9b77485@nvidia.com>
Date: Thu, 19 Jan 2023 12:21:01 +0200
From: Max Gurtovoy <mgurtovoy@...dia.com>
To: Lei Rao <lei.rao@...el.com>, kbusch@...nel.org, axboe@...com,
kch@...dia.com, hch@....de, sagi@...mberg.me,
alex.williamson@...hat.com, cohuck@...hat.com, jgg@...pe.ca,
yishaih@...dia.com, shameerali.kolothum.thodi@...wei.com,
kevin.tian@...el.com, mjrosato@...ux.ibm.com,
linux-kernel@...r.kernel.org, linux-nvme@...ts.infradead.org,
kvm@...r.kernel.org
Cc: eddie.dong@...el.com, yadong.li@...el.com, yi.l.liu@...el.com,
Konrad.wilk@...cle.com, stephen@...eticom.com, hang.yuan@...el.com
Subject: Re: [RFC PATCH 3/5] nvme-vfio: enable the function of VFIO live
migration.
Hi Leo,
On 06/12/2022 7:58, Lei Rao wrote:
> Implement specific VFIO live migration operations for NVMe devices.
>
> Signed-off-by: Lei Rao <lei.rao@...el.com>
> Signed-off-by: Yadong Li <yadong.li@...el.com>
> Signed-off-by: Chaitanya Kulkarni <kch@...dia.com>
> Reviewed-by: Eddie Dong <eddie.dong@...el.com>
> Reviewed-by: Hang Yuan <hang.yuan@...el.com>
> ---
> drivers/vfio/pci/nvme/Kconfig | 5 +-
> drivers/vfio/pci/nvme/nvme.c | 543 ++++++++++++++++++++++++++++++++--
> drivers/vfio/pci/nvme/nvme.h | 111 +++++++
> 3 files changed, 637 insertions(+), 22 deletions(-)
> create mode 100644 drivers/vfio/pci/nvme/nvme.h
>
> diff --git a/drivers/vfio/pci/nvme/Kconfig
> b/drivers/vfio/pci/nvme/Kconfig
> index c281fe154007..12e0eaba0de1 100644
> --- a/drivers/vfio/pci/nvme/Kconfig
> +++ b/drivers/vfio/pci/nvme/Kconfig
> @@ -1,9 +1,10 @@
> # SPDX-License-Identifier: GPL-2.0-only
> config NVME_VFIO_PCI
> tristate "VFIO support for NVMe PCI devices"
> + depends on NVME_CORE
> depends on VFIO_PCI_CORE
> help
> - This provides generic VFIO PCI support for NVMe device
> - using the VFIO framework.
> + This provides migration support for NVMe devices using the
> + VFIO framework.
>
> If you don't know what to do here, say N.
> diff --git a/drivers/vfio/pci/nvme/nvme.c b/drivers/vfio/pci/nvme/nvme.c
> index f1386d8a9287..698e470a4e53 100644
> --- a/drivers/vfio/pci/nvme/nvme.c
> +++ b/drivers/vfio/pci/nvme/nvme.c
> @@ -13,29 +13,503 @@
> #include <linux/types.h>
> #include <linux/vfio.h>
> #include <linux/anon_inodes.h>
> -#include <linux/kernel.h>
> -#include <linux/vfio_pci_core.h>
> +
> +#include "nvme.h"
> +
> +#define MAX_MIGRATION_SIZE (256 * 1024)
> +
> +static int nvmevf_cmd_suspend_device(struct nvmevf_pci_core_device
> *nvmevf_dev)
> +{
> + struct pci_dev *dev = nvmevf_dev->core_device.pdev;
> + struct nvme_live_mig_command c = { };
> + int ret;
> +
> + c.suspend.opcode = nvme_admin_live_mig_suspend;
> + c.suspend.vf_index = nvmevf_dev->vf_id;
> +
> + ret = nvme_submit_vf_cmd(dev, (struct nvme_command *)&c, NULL,
> NULL, 0);
> + if (ret) {
> + dev_warn(&dev->dev, "Suspend virtual function failed
> (ret=0x%x)\n", ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int nvmevf_cmd_resume_device(struct nvmevf_pci_core_device
> *nvmevf_dev)
> +{
> + struct pci_dev *dev = nvmevf_dev->core_device.pdev;
> + struct nvme_live_mig_command c = { };
> + int ret;
> +
> + c.resume.opcode = nvme_admin_live_mig_resume;
> + c.resume.vf_index = nvmevf_dev->vf_id;
> +
> + ret = nvme_submit_vf_cmd(dev, (struct nvme_command *)&c, NULL,
> NULL, 0);
> + if (ret) {
> + dev_warn(&dev->dev, "Resume virtual function failed
> (ret=0x%x)\n", ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int nvmevf_cmd_query_data_size(struct nvmevf_pci_core_device
> *nvmevf_dev,
> + size_t *state_size)
> +{
> + struct pci_dev *dev = nvmevf_dev->core_device.pdev;
> + struct nvme_live_mig_command c = { };
> + size_t result;
> + int ret;
> +
> + c.query.opcode = nvme_admin_live_mig_query_data_size;
> + c.query.vf_index = nvmevf_dev->vf_id;
> +
> + ret = nvme_submit_vf_cmd(dev, (struct nvme_command *)&c, &result,
> NULL, 0);
> + if (ret) {
> + dev_warn(&dev->dev, "Query the states size failed
> (ret=0x%x)\n", ret);
> + *state_size = 0;
> + return ret;
> + }
> + *state_size = result;
> + return 0;
> +}
> +
> +static int nvmevf_cmd_save_data(struct nvmevf_pci_core_device
> *nvmevf_dev,
> + void *buffer, size_t buffer_len)
> +{
> + struct pci_dev *dev = nvmevf_dev->core_device.pdev;
> + struct nvme_live_mig_command c = { };
> + int ret;
> +
> + c.save.opcode = nvme_admin_live_mig_save_data;
> + c.save.vf_index = nvmevf_dev->vf_id;
> +
> + ret = nvme_submit_vf_cmd(dev, (struct nvme_command *)&c, NULL,
> buffer, buffer_len);
> + if (ret) {
> + dev_warn(&dev->dev, "Save the device states failed
> (ret=0x%x)\n", ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static int nvmevf_cmd_load_data(struct nvmevf_pci_core_device
> *nvmevf_dev,
> + struct nvmevf_migration_file *migf)
> +{
> + struct pci_dev *dev = nvmevf_dev->core_device.pdev;
> + struct nvme_live_mig_command c = { };
> + int ret;
> +
> + c.load.opcode = nvme_admin_live_mig_load_data;
> + c.load.vf_index = nvmevf_dev->vf_id;
> + c.load.size = migf->total_length;
> +
> + ret = nvme_submit_vf_cmd(dev, (struct nvme_command *)&c, NULL,
> + migf->vf_data, migf->total_length);
> + if (ret) {
> + dev_warn(&dev->dev, "Load the device states failed
> (ret=0x%x)\n", ret);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static struct nvmevf_pci_core_device *nvmevf_drvdata(struct pci_dev
> *pdev)
> +{
> + struct vfio_pci_core_device *core_device =
> dev_get_drvdata(&pdev->dev);
> +
> + return container_of(core_device, struct nvmevf_pci_core_device,
> core_device);
> +}
> +
> +static void nvmevf_disable_fd(struct nvmevf_migration_file *migf)
> +{
> + mutex_lock(&migf->lock);
> +
> + /* release the device states buffer */
> + kvfree(migf->vf_data);
> + migf->vf_data = NULL;
> + migf->disabled = true;
> + migf->total_length = 0;
> + migf->filp->f_pos = 0;
> + mutex_unlock(&migf->lock);
> +}
> +
> +static int nvmevf_release_file(struct inode *inode, struct file *filp)
> +{
> + struct nvmevf_migration_file *migf = filp->private_data;
> +
> + nvmevf_disable_fd(migf);
> + mutex_destroy(&migf->lock);
> + kfree(migf);
> + return 0;
> +}
> +
> +static ssize_t nvmevf_save_read(struct file *filp, char __user *buf,
> size_t len, loff_t *pos)
> +{
> + struct nvmevf_migration_file *migf = filp->private_data;
> + ssize_t done = 0;
> + int ret;
> +
> + 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 = -EINVAL;
> + goto out_unlock;
> + }
> +
> + len = min_t(size_t, migf->total_length - *pos, len);
> + if (len) {
> + ret = copy_to_user(buf, migf->vf_data + *pos, len);
> + if (ret) {
> + done = -EFAULT;
> + goto out_unlock;
> + }
> + *pos += len;
> + done = len;
> + }
> +
> +out_unlock:
> + mutex_unlock(&migf->lock);
> + return done;
> +}
> +
> +static const struct file_operations nvmevf_save_fops = {
> + .owner = THIS_MODULE,
> + .read = nvmevf_save_read,
> + .release = nvmevf_release_file,
> + .llseek = no_llseek,
> +};
> +
> +static ssize_t nvmevf_resume_write(struct file *filp, const char
> __user *buf,
> + size_t len, loff_t *pos)
> +{
> + struct nvmevf_migration_file *migf = filp->private_data;
> + loff_t requested_length;
> + ssize_t done = 0;
> + int ret;
> +
> + 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;
> + }
> +
> + ret = copy_from_user(migf->vf_data + *pos, buf, len);
> + if (ret) {
> + done = -EFAULT;
> + goto out_unlock;
> + }
> + *pos += len;
> + done = len;
> + migf->total_length += len;
> +
> +out_unlock:
> + mutex_unlock(&migf->lock);
> + return done;
> +}
> +
> +static const struct file_operations nvmevf_resume_fops = {
> + .owner = THIS_MODULE,
> + .write = nvmevf_resume_write,
> + .release = nvmevf_release_file,
> + .llseek = no_llseek,
> +};
> +
> +static void nvmevf_disable_fds(struct nvmevf_pci_core_device
> *nvmevf_dev)
> +{
> + if (nvmevf_dev->resuming_migf) {
> + nvmevf_disable_fd(nvmevf_dev->resuming_migf);
> + fput(nvmevf_dev->resuming_migf->filp);
> + nvmevf_dev->resuming_migf = NULL;
> + }
> +
> + if (nvmevf_dev->saving_migf) {
> + nvmevf_disable_fd(nvmevf_dev->saving_migf);
> + fput(nvmevf_dev->saving_migf->filp);
> + nvmevf_dev->saving_migf = NULL;
> + }
> +}
> +
> +static struct nvmevf_migration_file *
> +nvmevf_pci_resume_device_data(struct nvmevf_pci_core_device *nvmevf_dev)
> +{
> + struct nvmevf_migration_file *migf;
> + int ret;
> +
> + migf = kzalloc(sizeof(*migf), GFP_KERNEL);
> + if (!migf)
> + return ERR_PTR(-ENOMEM);
> +
> + migf->filp = anon_inode_getfile("nvmevf_mig",
> &nvmevf_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);
> +
> + /* Allocate buffer to load the device states and the max states
> is 256K */
> + migf->vf_data = kvzalloc(MAX_MIGRATION_SIZE, GFP_KERNEL);
> + if (!migf->vf_data) {
> + ret = -ENOMEM;
> + goto out_free;
> + }
> +
> + return migf;
> +
> +out_free:
> + fput(migf->filp);
> + return ERR_PTR(ret);
> +}
> +
> +static struct nvmevf_migration_file *
> +nvmevf_pci_save_device_data(struct nvmevf_pci_core_device *nvmevf_dev)
> +{
> + struct nvmevf_migration_file *migf;
> + int ret;
> +
> + migf = kzalloc(sizeof(*migf), GFP_KERNEL);
> + if (!migf)
> + return ERR_PTR(-ENOMEM);
> +
> + migf->filp = anon_inode_getfile("nvmevf_mig", &nvmevf_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 = nvmevf_cmd_query_data_size(nvmevf_dev, &migf->total_length);
> + if (ret)
> + goto out_free;
> + /* Allocate buffer and save the device states*/
> + migf->vf_data = kvzalloc(migf->total_length, GFP_KERNEL);
> + if (!migf->vf_data) {
> + ret = -ENOMEM;
> + goto out_free;
> + }
> +
> + ret = nvmevf_cmd_save_data(nvmevf_dev, migf->vf_data,
> migf->total_length);
> + if (ret)
> + goto out_free;
> +
> + return migf;
> +out_free:
> + fput(migf->filp);
> + return ERR_PTR(ret);
> +}
> +
> +static struct file *
> +nvmevf_pci_step_device_state_locked(struct nvmevf_pci_core_device
> *nvmevf_dev, u32 new)
> +{
> + u32 cur = nvmevf_dev->mig_state;
> + int ret;
> +
> + if (cur == VFIO_DEVICE_STATE_RUNNING && new ==
> VFIO_DEVICE_STATE_STOP) {
> + ret = nvmevf_cmd_suspend_device(nvmevf_dev);
> + if (ret)
> + return ERR_PTR(ret);
> + return NULL;
> + }
> +
> + if (cur == VFIO_DEVICE_STATE_STOP && new ==
> VFIO_DEVICE_STATE_STOP_COPY) {
> + struct nvmevf_migration_file *migf;
> +
> + migf = nvmevf_pci_save_device_data(nvmevf_dev);
> + if (IS_ERR(migf))
> + return ERR_CAST(migf);
> + get_file(migf->filp);
> + nvmevf_dev->saving_migf = migf;
> + return migf->filp;
> + }
> +
> + if (cur == VFIO_DEVICE_STATE_STOP_COPY && new ==
> VFIO_DEVICE_STATE_STOP) {
> + nvmevf_disable_fds(nvmevf_dev);
> + return NULL;
> + }
> +
> + if (cur == VFIO_DEVICE_STATE_STOP && new ==
> VFIO_DEVICE_STATE_RESUMING) {
> + struct nvmevf_migration_file *migf;
> +
> + migf = nvmevf_pci_resume_device_data(nvmevf_dev);
> + if (IS_ERR(migf))
> + return ERR_CAST(migf);
> + get_file(migf->filp);
> + nvmevf_dev->resuming_migf = migf;
> + return migf->filp;
> + }
> +
> + if (cur == VFIO_DEVICE_STATE_RESUMING && new ==
> VFIO_DEVICE_STATE_STOP) {
> + ret = nvmevf_cmd_load_data(nvmevf_dev,
> nvmevf_dev->resuming_migf);
> + if (ret)
> + return ERR_PTR(ret);
> + nvmevf_disable_fds(nvmevf_dev);
> + return NULL;
> + }
> +
> + if (cur == VFIO_DEVICE_STATE_STOP && new ==
> VFIO_DEVICE_STATE_RUNNING) {
> + nvmevf_cmd_resume_device(nvmevf_dev);
> + return NULL;
> + }
> +
> + /* vfio_mig_get_next_state() does not use arcs other than the
> above */
> + WARN_ON(true);
> + return ERR_PTR(-EINVAL);
> +}
> +
> +static void nvmevf_state_mutex_unlock(struct nvmevf_pci_core_device
> *nvmevf_dev)
> +{
> +again:
> + spin_lock(&nvmevf_dev->reset_lock);
> + if (nvmevf_dev->deferred_reset) {
> + nvmevf_dev->deferred_reset = false;
> + spin_unlock(&nvmevf_dev->reset_lock);
> + nvmevf_dev->mig_state = VFIO_DEVICE_STATE_RUNNING;
> + nvmevf_disable_fds(nvmevf_dev);
> + goto again;
> + }
> + mutex_unlock(&nvmevf_dev->state_mutex);
> + spin_unlock(&nvmevf_dev->reset_lock);
> +}
> +
> +static struct file *
> +nvmevf_pci_set_device_state(struct vfio_device *vdev, enum
> vfio_device_mig_state new_state)
> +{
> + struct nvmevf_pci_core_device *nvmevf_dev = container_of(vdev,
> + struct nvmevf_pci_core_device, core_device.vdev);
> + enum vfio_device_mig_state next_state;
> + struct file *res = NULL;
> + int ret;
> +
> + mutex_lock(&nvmevf_dev->state_mutex);
> + while (new_state != nvmevf_dev->mig_state) {
> + ret = vfio_mig_get_next_state(vdev, nvmevf_dev->mig_state,
> new_state, &next_state);
> + if (ret) {
> + res = ERR_PTR(-EINVAL);
> + break;
> + }
> +
> + res = nvmevf_pci_step_device_state_locked(nvmevf_dev,
> next_state);
> + if (IS_ERR(res))
> + break;
> + nvmevf_dev->mig_state = next_state;
> + if (WARN_ON(res && new_state != nvmevf_dev->mig_state)) {
> + fput(res);
> + res = ERR_PTR(-EINVAL);
> + break;
> + }
> + }
> + nvmevf_state_mutex_unlock(nvmevf_dev);
> + return res;
> +}
> +
> +static int nvmevf_pci_get_device_state(struct vfio_device *vdev,
> + enum vfio_device_mig_state *curr_state)
> +{
> + struct nvmevf_pci_core_device *nvmevf_dev = container_of(
> + vdev, struct nvmevf_pci_core_device, core_device.vdev);
> +
> + mutex_lock(&nvmevf_dev->state_mutex);
> + *curr_state = nvmevf_dev->mig_state;
> + nvmevf_state_mutex_unlock(nvmevf_dev);
> + return 0;
> +}
>
> static int nvmevf_pci_open_device(struct vfio_device *core_vdev)
> {
> - struct vfio_pci_core_device *vdev =
> - container_of(core_vdev, struct vfio_pci_core_device, vdev);
> + struct nvmevf_pci_core_device *nvmevf_dev = container_of(
> + core_vdev, struct nvmevf_pci_core_device, core_device.vdev);
> + struct vfio_pci_core_device *vdev = &nvmevf_dev->core_device;
> int ret;
>
> ret = vfio_pci_core_enable(vdev);
> if (ret)
> return ret;
>
> + if (nvmevf_dev->migrate_cap)
> + nvmevf_dev->mig_state = VFIO_DEVICE_STATE_RUNNING;
> vfio_pci_core_finish_enable(vdev);
> return 0;
> }
>
> +static void nvmevf_cmd_close_migratable(struct nvmevf_pci_core_device
> *nvmevf_dev)
> +{
> + if (!nvmevf_dev->migrate_cap)
> + return;
> +
> + mutex_lock(&nvmevf_dev->state_mutex);
> + nvmevf_disable_fds(nvmevf_dev);
> + nvmevf_state_mutex_unlock(nvmevf_dev);
> +}
> +
> +static void nvmevf_pci_close_device(struct vfio_device *core_vdev)
> +{
> + struct nvmevf_pci_core_device *nvmevf_dev = container_of(
> + core_vdev, struct nvmevf_pci_core_device, core_device.vdev);
> +
> + nvmevf_cmd_close_migratable(nvmevf_dev);
> + vfio_pci_core_close_device(core_vdev);
> +}
> +
> +static const struct vfio_migration_ops nvmevf_pci_mig_ops = {
> + .migration_set_state = nvmevf_pci_set_device_state,
> + .migration_get_state = nvmevf_pci_get_device_state,
> +};
> +
> +static int nvmevf_migration_init_dev(struct vfio_device *core_vdev)
> +{
> + struct nvmevf_pci_core_device *nvmevf_dev = container_of(core_vdev,
> + struct nvmevf_pci_core_device, core_device.vdev);
> + struct pci_dev *pdev = to_pci_dev(core_vdev->dev);
> + int vf_id;
> + int ret = -1;
> +
> + if (!pdev->is_virtfn)
> + return ret;
> +
> + nvmevf_dev->migrate_cap = 1;
> +
> + vf_id = pci_iov_vf_id(pdev);
> + if (vf_id < 0)
> + return ret;
> + nvmevf_dev->vf_id = vf_id + 1;
> + core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY;
> +
> + mutex_init(&nvmevf_dev->state_mutex);
> + spin_lock_init(&nvmevf_dev->reset_lock);
> + core_vdev->mig_ops = &nvmevf_pci_mig_ops;
> +
> + return vfio_pci_core_init_dev(core_vdev);
> +}
> +
> static const struct vfio_device_ops nvmevf_pci_ops = {
> .name = "nvme-vfio-pci",
> - .init = vfio_pci_core_init_dev,
> + .init = nvmevf_migration_init_dev,
> .release = vfio_pci_core_release_dev,
> .open_device = nvmevf_pci_open_device,
> - .close_device = vfio_pci_core_close_device,
> + .close_device = nvmevf_pci_close_device,
> .ioctl = vfio_pci_core_ioctl,
> .device_feature = vfio_pci_core_ioctl_feature,
> .read = vfio_pci_core_read,
> @@ -47,32 +521,56 @@ static const struct vfio_device_ops
> nvmevf_pci_ops = {
>
> static int nvmevf_pci_probe(struct pci_dev *pdev, const struct
> pci_device_id *id)
> {
> - struct vfio_pci_core_device *vdev;
> + struct nvmevf_pci_core_device *nvmevf_dev;
> int ret;
>
> - vdev = vfio_alloc_device(vfio_pci_core_device, vdev, &pdev->dev,
> - &nvmevf_pci_ops);
> - if (IS_ERR(vdev))
> - return PTR_ERR(vdev);
> + nvmevf_dev = vfio_alloc_device(nvmevf_pci_core_device,
> core_device.vdev,
> + &pdev->dev, &nvmevf_pci_ops);
> + if (IS_ERR(nvmevf_dev))
> + return PTR_ERR(nvmevf_dev);
>
> - dev_set_drvdata(&pdev->dev, vdev);
> - ret = vfio_pci_core_register_device(vdev);
> + dev_set_drvdata(&pdev->dev, &nvmevf_dev->core_device);
> + ret = vfio_pci_core_register_device(&nvmevf_dev->core_device);
> if (ret)
> goto out_put_dev;
> -
> return 0;
>
> out_put_dev:
> - vfio_put_device(&vdev->vdev);
> + vfio_put_device(&nvmevf_dev->core_device.vdev);
> return ret;
> +
> }
>
> static void nvmevf_pci_remove(struct pci_dev *pdev)
> {
> - struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
> + struct nvmevf_pci_core_device *nvmevf_dev = nvmevf_drvdata(pdev);
> +
> + vfio_pci_core_unregister_device(&nvmevf_dev->core_device);
> + vfio_put_device(&nvmevf_dev->core_device.vdev);
> +}
> +
> +static void nvmevf_pci_aer_reset_done(struct pci_dev *pdev)
> +{
> + struct nvmevf_pci_core_device *nvmevf_dev = nvmevf_drvdata(pdev);
> +
> + if (!nvmevf_dev->migrate_cap)
> + return;
>
> - vfio_pci_core_unregister_device(vdev);
> - vfio_put_device(&vdev->vdev);
> + /*
> + * As the higher VFIO layers are holding locks across reset and
> using
> + * those same locks with the mm_lock we need to prevent ABBA
> deadlock
> + * with the state_mutex and mm_lock.
> + * In case the state_mutex was taken already we defer the cleanup
> work
> + * to the unlock flow of the other running context.
> + */
> + spin_lock(&nvmevf_dev->reset_lock);
> + nvmevf_dev->deferred_reset = true;
> + if (!mutex_trylock(&nvmevf_dev->state_mutex)) {
> + spin_unlock(&nvmevf_dev->reset_lock);
> + return;
> + }
> + spin_unlock(&nvmevf_dev->reset_lock);
> + nvmevf_state_mutex_unlock(nvmevf_dev);
> }
>
> static const struct pci_device_id nvmevf_pci_table[] = {
> @@ -83,12 +581,17 @@ static const struct pci_device_id
> nvmevf_pci_table[] = {
>
> MODULE_DEVICE_TABLE(pci, nvmevf_pci_table);
>
> +static const struct pci_error_handlers nvmevf_err_handlers = {
> + .reset_done = nvmevf_pci_aer_reset_done,
> + .error_detected = vfio_pci_core_aer_err_detected,
> +};
> +
> static struct pci_driver nvmevf_pci_driver = {
> .name = KBUILD_MODNAME,
> .id_table = nvmevf_pci_table,
> .probe = nvmevf_pci_probe,
> .remove = nvmevf_pci_remove,
> - .err_handler = &vfio_pci_core_err_handlers,
> + .err_handler = &nvmevf_err_handlers,
> .driver_managed_dma = true,
> };
>
> @@ -96,4 +599,4 @@ module_pci_driver(nvmevf_pci_driver);
>
> MODULE_LICENSE("GPL");
> MODULE_AUTHOR("Lei Rao <lei.rao@...el.com>");
> -MODULE_DESCRIPTION("NVMe VFIO PCI - Generic VFIO PCI driver for NVMe");
> +MODULE_DESCRIPTION("NVMe VFIO PCI - VFIO PCI driver with live
> migration support for NVMe");
> diff --git a/drivers/vfio/pci/nvme/nvme.h b/drivers/vfio/pci/nvme/nvme.h
> new file mode 100644
> index 000000000000..c8464554ef53
> --- /dev/null
> +++ b/drivers/vfio/pci/nvme/nvme.h
> @@ -0,0 +1,111 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022, INTEL CORPORATION. All rights reserved
> + */
> +
> +#ifndef NVME_VFIO_PCI_H
> +#define NVME_VFIO_PCI_H
> +
> +#include <linux/kernel.h>
> +#include <linux/vfio_pci_core.h>
> +#include <linux/nvme.h>
> +
> +struct nvme_live_mig_query_size {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __u32 rsvd1[9];
> + __u16 vf_index;
> + __u16 rsvd2;
> + __u32 rsvd3[5];
> +};
> +
> +struct nvme_live_mig_suspend {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __u32 rsvd1[9];
> + __u16 vf_index;
> + __u16 rsvd2;
> + __u32 rsvd3[5];
> +};
> +
> +struct nvme_live_mig_resume {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __u32 rsvd1[9];
> + __u16 vf_index;
> + __u16 rsvd2;
> + __u32 rsvd3[5];
> +};
> +
> +struct nvme_live_mig_save_data {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __u32 rsvd1[5];
> + __le64 prp1;
> + __le64 prp2;
> + __u16 vf_index;
> + __u16 rsvd2;
> + __u32 rsvd3[5];
> +};
Just noticed that the save_data (similar to READ operation) doesn't have
size/length member.
How does it work for you ?
BTW,
Are you doing iterative reads from the device to get the state ?
> +
> +struct nvme_live_mig_load_data {
> + __u8 opcode;
> + __u8 flags;
> + __u16 command_id;
> + __u32 rsvd1[5];
> + __le64 prp1;
> + __le64 prp2;
> + __u16 vf_index;
> + __u16 rsvd2;
> + __u32 size;
> + __u32 rsvd3[4];
> +};
> +
> +enum nvme_live_mig_admin_opcode {
> + nvme_admin_live_mig_query_data_size = 0xC4,
> + nvme_admin_live_mig_suspend = 0xC8,
> + nvme_admin_live_mig_resume = 0xCC,
> + nvme_admin_live_mig_save_data = 0xD2,
> + nvme_admin_live_mig_load_data = 0xD5,
> +};
> +
> +struct nvme_live_mig_command {
> + union {
> + struct nvme_live_mig_query_size query;
> + struct nvme_live_mig_suspend suspend;
> + struct nvme_live_mig_resume resume;
> + struct nvme_live_mig_save_data save;
> + struct nvme_live_mig_load_data load;
> + };
> +};
> +
> +struct nvmevf_migration_file {
> + struct file *filp;
> + struct mutex lock;
> + bool disabled;
> + u8 *vf_data;
> + size_t total_length;
> +};
> +
> +struct nvmevf_pci_core_device {
> + struct vfio_pci_core_device core_device;
> + int vf_id;
> + u8 migrate_cap:1;
> + u8 deferred_reset:1;
> + /* protect migration state */
> + struct mutex state_mutex;
> + enum vfio_device_mig_state mig_state;
> + /* protect the reset_done flow */
> + spinlock_t reset_lock;
> + struct nvmevf_migration_file *resuming_migf;
> + struct nvmevf_migration_file *saving_migf;
> +};
> +
> +extern int nvme_submit_vf_cmd(struct pci_dev *dev, struct
> nvme_command *cmd,
> + size_t *result, void *buffer, unsigned int bufflen);
> +
> +#endif /* NVME_VFIO_PCI_H */
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