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SubjectRe: [PATCH v2 1/2] hisi_acc_vfio_pci: Add debugfs to migration driver
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kindly ping!
On 2022/10/19 16:10, Longfang Liu wrote:
> There are multiple devices, software and operational steps involved
> in the process of live migration. An error occurred on any node may
> cause the live migration operation to fail.
> This complex process makes it very difficult to locate and analyze
> the cause when the function fails.
>
> In order to quickly locate the cause of the problem when the
> live migration fails, I added a set of debugfs to the accelerator
> live migration driver.
>
> +-----------------------------------+
> | |
> | QEMU |
> | |
> +---+--^--------------------+--^----+
> | | | |
> | | | |
> +---v--+----+ +---v--+----+
> | | | |
> | src VF | | dest VF |
> | | | |
> +---+--^----+ +---+--^----+
> | | | |
> | | | |
> +---v--+----+ +---v--+----+
> | Debugfs | | Debugfs |
> +-----+-----+ +-----+-----+
> |state|debug| |state|debug|
> +-----+-----+ +-----+-----+
>
> This set of debugfs will create two files for each VF device:
> a state file and a debug file.
>
> The migration status of the current VF device can be obtained by
> reading the status file.
>
> The live migration function of the current device can be tested by
> operating the debug file, and the functional status of the equipment
> and software at each stage can be tested step by step without
> performing the complete live migration function. And after the live
> migration is performed, the migration device data of the live migration
> can be obtained through the debug file.
>
> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> ---
> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 314 +++++++++++++++++-
> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 14 +
> 2 files changed, 326 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> index 39eeca18a0f7..eedf8fdf4403 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> @@ -3,6 +3,7 @@
> * Copyright (c) 2021, HiSilicon Ltd.
> */
>
> +#include <linux/anon_inodes.h>
> #include <linux/device.h>
> #include <linux/eventfd.h>
> #include <linux/file.h>
> @@ -16,6 +17,9 @@
>
> #include "hisi_acc_vfio_pci.h"
>
> +static struct dentry *hisi_acc_debugfs_root;
> +static atomic_t hisi_acc_root_ref;
> +
> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
> {
> @@ -609,6 +613,18 @@ hisi_acc_check_int_state(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> }
> }
>
> +static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file *src_migf,
> + struct hisi_acc_vf_migration_file *dst_migf)
> +{
> + if (!dst_migf)
> + return;
> +
> + dst_migf->disabled = false;
> + dst_migf->total_length = src_migf->total_length;
> + memcpy(&dst_migf->vf_data, &src_migf->vf_data,
> + sizeof(struct acc_vf_data));
> +}
> +
> static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
> {
> mutex_lock(&migf->lock);
> @@ -621,12 +637,16 @@ static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
> static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> {
> if (hisi_acc_vdev->resuming_migf) {
> + hisi_acc_vf_migf_save(hisi_acc_vdev->resuming_migf,
> + hisi_acc_vdev->debug_migf);
> hisi_acc_vf_disable_fd(hisi_acc_vdev->resuming_migf);
> fput(hisi_acc_vdev->resuming_migf->filp);
> hisi_acc_vdev->resuming_migf = NULL;
> }
>
> if (hisi_acc_vdev->saving_migf) {
> + hisi_acc_vf_migf_save(hisi_acc_vdev->saving_migf,
> + hisi_acc_vdev->debug_migf);
> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
> fput(hisi_acc_vdev->saving_migf->filp);
> hisi_acc_vdev->saving_migf = NULL;
> @@ -1176,6 +1196,269 @@ static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int
> return vfio_pci_core_ioctl(core_vdev, cmd, arg);
> }
>
> +static int hisi_acc_vf_debug_create(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct hisi_acc_vf_migration_file *migf;
> +
> + migf = kzalloc(sizeof(*migf), GFP_KERNEL);
> + if (!migf)
> + return -ENOMEM;
> +
> + migf->disabled = false;
> + hisi_acc_vdev->debug_migf = migf;
> + mutex_init(&migf->lock);
> +
> + return 0;
> +}
> +
> +static void hisi_acc_vf_debug_release(struct hisi_acc_vf_migration_file *migf)
> +{
> + migf->disabled = true;
> + migf->total_length = 0;
> + mutex_destroy(&migf->lock);
> + kfree(migf);
> +}
> +
> +static int hisi_acc_vf_debug_test(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct device *dev = &hisi_acc_vdev->vf_dev->dev;
> + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
> + u64 data;
> + int ret;
> +
> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
> +
> + ret = qm_wait_dev_not_ready(vf_qm);
> + if (ret)
> + dev_err(dev, "VF device not ready!\n");
> +
> + return ret;
> +}
> +
> +static ssize_t hisi_acc_vf_debug_read(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + char buf[VFIO_DEV_DBG_LEN];
> + int len;
> +
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "echo 0: test vf state save\n"
> + "echo 1: test vf state resume\n"
> + "echo 2: test vf send mailbox\n"
> + "echo 3: dump vf config data\n"
> + "echo 4: dump vf migration state\n");
> +
> + return simple_read_from_buffer(buffer, count, pos, buf, len);
> +}
> +
> +static void hisi_acc_vf_dev_data_dump(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
> + struct device *dev = &hisi_acc_vdev->vf_dev->dev;
> +
> + if (hisi_acc_vdev->debug_migf &&
> + hisi_acc_vdev->debug_migf->total_length) {
> + print_hex_dump(KERN_INFO, "dev mig data:",
> + DUMP_PREFIX_OFFSET, 16, 1,
> + (u8 *)&hisi_acc_vdev->debug_migf->vf_data,
> + vf_data_sz, false);
> + } else {
> + dev_info(dev, "device not migrated!\n");
> + }
> +}
> +
> +static void hisi_acc_vf_dev_attr_show(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct device *dev = &hisi_acc_vdev->vf_dev->dev;
> +
> + if (hisi_acc_vdev->debug_migf &&
> + hisi_acc_vdev->debug_migf->total_length) {
> + dev_info(dev, "acc device:\n"
> + "device state: %d\n"
> + "device ready: %u\n"
> + "data valid: %d\n"
> + "data size: %lu\n",
> + hisi_acc_vdev->mig_state,
> + hisi_acc_vdev->vf_qm_state,
> + hisi_acc_vdev->debug_migf->disabled,
> + hisi_acc_vdev->debug_migf->total_length);
> + } else {
> + dev_info(dev, "device not migrated!\n");
> + }
> +}
> +
> +static int hisi_acc_vf_debug_resume(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> + struct device *dev = &hisi_acc_vdev->vf_dev->dev;
> + int ret;
> +
> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to save device data!\n");
> + return -EINVAL;
> + }
> +
> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to match the VF!\n");
> + return -EINVAL;
> + }
> +
> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to recover the VF!\n");
> + return -EINVAL;
> + }
> +
> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
> + dev_info(dev, "successful to resume device data!\n");
> +
> + return 0;
> +}
> +
> +static int hisi_acc_vf_debug_save(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
> + struct device *dev = &hisi_acc_vdev->vf_dev->dev;
> + int ret;
> +
> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
> + if (ret) {
> + dev_err(dev, "failed to save device data!\n");
> + return -EINVAL;
> + }
> + dev_info(dev, "successful to save device data!\n");
> +
> + return 0;
> +}
> +
> +static ssize_t hisi_acc_vf_debug_write(struct file *filp, const char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + struct hisi_acc_vf_core_device *hisi_acc_vdev = filp->private_data;
> + char tbuf[VFIO_DEV_DBG_LEN];
> + unsigned long val;
> + int len, ret;
> +
> + if (*pos)
> + return 0;
> +
> + if (count >= VFIO_DEV_DBG_LEN)
> + return -ENOSPC;
> +
> + len = simple_write_to_buffer(tbuf, VFIO_DEV_DBG_LEN - 1,
> + pos, buffer, count);
> + if (len < 0 || len > VFIO_DEV_DBG_LEN - 1)
> + return -EINVAL;
> + tbuf[len] = '\0';
> + if (kstrtoul(tbuf, 0, &val))
> + return -EFAULT;
> +
> + switch (val) {
> + case STATE_SAVE:
> + ret = hisi_acc_vf_debug_save(hisi_acc_vdev);
> + if (ret)
> + return ret;
> + break;
> + case STATE_RESUME:
> + ret = hisi_acc_vf_debug_resume(hisi_acc_vdev);
> + if (ret)
> + return ret;
> + break;
> + case MB_TEST:
> + ret = hisi_acc_vf_debug_test(hisi_acc_vdev);
> + if (ret)
> + return -EINVAL;
> + break;
> + case MIG_DATA_DUMP:
> + hisi_acc_vf_dev_data_dump(hisi_acc_vdev);
> + break;
> + case MIG_DEV_SHOW:
> + hisi_acc_vf_dev_attr_show(hisi_acc_vdev);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return count;
> +}
> +
> +static const struct file_operations hisi_acc_vf_debug_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = hisi_acc_vf_debug_read,
> + .write = hisi_acc_vf_debug_write,
> +};
> +
> +static ssize_t hisi_acc_vf_state_read(struct file *filp, char __user *buffer,
> + size_t count, loff_t *pos)
> +{
> + struct hisi_acc_vf_core_device *hisi_acc_vdev = filp->private_data;
> + char buf[VFIO_DEV_DBG_LEN];
> + u32 state;
> + int len;
> +
> + state = hisi_acc_vdev->mig_state;
> + switch (state) {
> + case VFIO_DEVICE_STATE_RUNNING:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "RUNNING\n");
> + break;
> + case VFIO_DEVICE_STATE_STOP_COPY:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "STOP and COPYING\n");
> + break;
> + case VFIO_DEVICE_STATE_STOP:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "STOP\n");
> + break;
> + case VFIO_DEVICE_STATE_RESUMING:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "RESUMING\n");
> + break;
> + default:
> + len = scnprintf(buf, VFIO_DEV_DBG_LEN, "%s\n",
> + "Error\n");
> + }
> +
> + return simple_read_from_buffer(buffer, count, pos, buf, len);
> +}
> +
> +static const struct file_operations hisi_acc_vf_state_fops = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = hisi_acc_vf_state_read,
> +};
> +
> +static void hisi_acc_vf_debugfs_init(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + struct pci_dev *vf_pdev = hisi_acc_vdev->vf_dev;
> + struct device *dev = &vf_pdev->dev;
> + int ret;
> +
> + hisi_acc_vdev->debug_root = debugfs_create_dir(dev_name(dev), hisi_acc_debugfs_root);
> + debugfs_create_file("state", 0444, hisi_acc_vdev->debug_root,
> + hisi_acc_vdev, &hisi_acc_vf_state_fops);
> +
> + ret = hisi_acc_vf_debug_create(hisi_acc_vdev);
> + if (ret) {
> + dev_err(dev, "failed to alloc migration debug node\n");
> + return;
> + }
> + debugfs_create_file("debug", 0644, hisi_acc_vdev->debug_root,
> + hisi_acc_vdev, &hisi_acc_vf_debug_fops);
> +}
> +
> +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device *hisi_acc_vdev)
> +{
> + if (hisi_acc_vdev->debug_migf)
> + hisi_acc_vf_debug_release(hisi_acc_vdev->debug_migf);
> +
> + debugfs_remove_recursive(hisi_acc_vdev->debug_root);
> +}
> +
> static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
> {
> struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
> @@ -1268,7 +1551,7 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
> struct hisi_acc_vf_core_device *hisi_acc_vdev;
> const struct vfio_device_ops *ops = &hisi_acc_vfio_pci_ops;
> struct hisi_qm *pf_qm;
> - int vf_id;
> + int vf_id = -1;
> int ret;
>
> pf_qm = hisi_acc_get_pf_qm(pdev);
> @@ -1285,6 +1568,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
> if (IS_ERR(hisi_acc_vdev))
> return PTR_ERR(hisi_acc_vdev);
>
> + if (vf_id >= 0)
> + hisi_acc_vf_debugfs_init(hisi_acc_vdev);
> +
> dev_set_drvdata(&pdev->dev, &hisi_acc_vdev->core_device);
> ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
> if (ret)
> @@ -1300,6 +1586,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
> {
> struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_drvdata(pdev);
>
> + hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
> vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
> vfio_put_device(&hisi_acc_vdev->core_device.vdev);
> }
> @@ -1327,7 +1614,30 @@ static struct pci_driver hisi_acc_vfio_pci_driver = {
> .driver_managed_dma = true,
> };
>
> -module_pci_driver(hisi_acc_vfio_pci_driver);
> +static int __init hisi_acc_vfio_pci_init(void)
> +{
> + int ret;
> +
> + hisi_acc_debugfs_root = debugfs_create_dir("hisi_vfio_acc", NULL);
> +
> + ret = pci_register_driver(&hisi_acc_vfio_pci_driver);
> + if (ret < 0) {
> + debugfs_remove_recursive(hisi_acc_debugfs_root);
> + pr_err("failed to register pci driver.\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void __exit hisi_acc_vfio_pci_exit(void)
> +{
> + pci_unregister_driver(&hisi_acc_vfio_pci_driver);
> + debugfs_remove_recursive(hisi_acc_debugfs_root);
> +}
> +
> +module_init(hisi_acc_vfio_pci_init);
> +module_exit(hisi_acc_vfio_pci_exit);
>
> MODULE_LICENSE("GPL v2");
> MODULE_AUTHOR("Liu Longfang <liulongfang@huawei.com>");
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> index 67343325b320..ae2a686c2e4d 100644
> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
> @@ -4,8 +4,11 @@
> #ifndef HISI_ACC_VFIO_PCI_H
> #define HISI_ACC_VFIO_PCI_H
>
> +#include <linux/debugfs.h>
> #include <linux/hisi_acc_qm.h>
>
> +#define VFIO_DEV_DBG_LEN 256
> +
> #define MB_POLL_PERIOD_US 10
> #define MB_POLL_TIMEOUT_US 1000
> #define QM_CACHE_WB_START 0x204
> @@ -49,6 +52,14 @@
> #define QM_EQC_DW0 0X8000
> #define QM_AEQC_DW0 0X8020
>
> +enum mig_debug_cmd {
> + STATE_SAVE,
> + STATE_RESUME,
> + MB_TEST,
> + MIG_DATA_DUMP,
> + MIG_DEV_SHOW,
> +};
> +
> struct acc_vf_data {
> #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
> /* QM match information */
> @@ -111,5 +122,8 @@ struct hisi_acc_vf_core_device {
> spinlock_t reset_lock;
> struct hisi_acc_vf_migration_file *resuming_migf;
> struct hisi_acc_vf_migration_file *saving_migf;
> + /* For debugfs */
> + struct dentry *debug_root;
> + struct hisi_acc_vf_migration_file *debug_migf;
> };
> #endif /* HISI_ACC_VFIO_PCI_H */
>

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