[PATCH v8 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

[Longfang Liu]

On the debugfs framework of VFIO, if the CONFIG_DEBUG_FS macro is
enabled, the debug function is registered for the live migration driver
of the HiSilicon accelerator device.

On the basis of the original public debug function, a private debug
function is added:

mig_data file: used to get the migration data of the live migration device
mig_attr file: used to get device attributes of the live migration device
debug file: used to test for acquiring and writing device state data
for VF device.

Signed-off-by: Longfang Liu <liulongfang@xxxxxxxxxx>
---
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 282 ++++++++++++++++++
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h    |  11 +
 2 files changed, 293 insertions(+)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index a1589947e721..a0ecb1cd5707 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -15,6 +15,7 @@
 #include <linux/anon_inodes.h>
 
 #include "hisi_acc_vfio_pci.h"
+#include "../../vfio.h"
 
 /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
 static int qm_wait_dev_not_ready(struct hisi_qm *qm)
@@ -606,6 +607,18 @@ 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);
@@ -618,12 +631,16 @@ 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;
@@ -1303,6 +1320,265 @@ 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_io(struct vfio_device *vdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
+	struct device *dev = vdev->dev;
+	u64 data;
+	int ret;
+
+	ret = qm_wait_dev_not_ready(vf_qm);
+	if (ret)
+		dev_err(dev, "VF device not ready!\n");
+
+	data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
+	dev_info(dev, "debug mailbox val: 0x%llx\n", data);
+
+	return ret;
+}
+
+static int hisi_acc_vf_debug_resume(struct vfio_device *vdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
+	struct device *dev = vdev->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 vfio_device *vdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
+	struct device *dev = vdev->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 int
+hisi_acc_vf_debug_operate(struct vfio_device *vdev, unsigned int cmd)
+{
+	int ret;
+
+	switch (cmd) {
+	case STATE_SAVE:
+		ret = hisi_acc_vf_debug_save(vdev);
+		if (ret)
+			return ret;
+		break;
+	case STATE_RESUME:
+		ret = hisi_acc_vf_debug_resume(vdev);
+		if (ret)
+			return ret;
+		break;
+	case RW_IO_TEST:
+		ret = hisi_acc_vf_debug_io(vdev);
+		if (ret)
+			return ret;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int hisi_acc_vf_debug_check(struct vfio_device *vdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
+	enum vfio_device_mig_state state;
+
+	if (!vdev->mig_ops || !migf) {
+		dev_err(vdev->dev, "device not support debugfs!\n");
+		return -EINVAL;
+	}
+
+	/* If device not opened, the debugfs operation will trigger calltrace */
+	(void)vdev->mig_ops->migration_get_state(vdev, &state);
+	if (state == VFIO_DEVICE_STATE_ERROR ||
+	    state == VFIO_DEVICE_STATE_STOP) {
+		dev_err(vdev->dev, "device not opened!\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static ssize_t hisi_acc_vf_debug_write(struct file *filp, const char __user *buffer,
+			    size_t count, loff_t *pos)
+{
+	struct vfio_device	*vdev = filp->private_data;
+	char tbuf[VFIO_DEV_DBG_LEN];
+	unsigned long cmd;
+	int len, ret;
+
+	if (*pos)
+		return 0;
+
+	if (count >= VFIO_DEV_DBG_LEN)
+		return -ENOSPC;
+
+	ret = hisi_acc_vf_debug_check(vdev);
+	if (ret)
+		return -EINVAL;
+
+	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, &cmd))
+		return -EFAULT;
+
+	ret = hisi_acc_vf_debug_operate(vdev, cmd);
+	if (ret) {
+		dev_err(vdev->dev, "device debug test failed!\n");
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static const struct file_operations hisi_acc_vf_debug_fops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.write = hisi_acc_vf_debug_write,
+};
+
+static void seq_print_hex_data(struct seq_file *seq, const void *buf, size_t len)
+{
+#define HEX_LINE_SIZE		131
+#define HEX_ROW_SIZE		16
+	unsigned char linebuf[HEX_LINE_SIZE];
+	int i, linelen, remaining = len;
+	const u8 *ptr = buf;
+
+	for (i = 0; i < len; i += HEX_ROW_SIZE) {
+		linelen = min(remaining, HEX_ROW_SIZE);
+		remaining -= HEX_ROW_SIZE;
+
+		hex_dump_to_buffer(ptr + i, linelen, HEX_ROW_SIZE, 1,
+					linebuf, sizeof(linebuf), false);
+
+		seq_printf(seq, "%s%.8x: %s\n", "Mig Data:", i, linebuf);
+	}
+}
+
+static int hisi_acc_vf_data_read(struct seq_file *seq, void *data)
+{
+	struct device *vf_dev = seq->private;
+	struct vfio_pci_core_device *core_device = dev_get_drvdata(vf_dev);
+	struct vfio_device	*vdev = &core_device->vdev;
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev->debug_migf;
+	size_t vf_data_sz = offsetofend(struct acc_vf_data, padding);
+
+	if (debug_migf && debug_migf->total_length)
+		seq_print_hex_data(seq, (unsigned char *)&debug_migf->vf_data,
+				vf_data_sz);
+	else
+		seq_printf(seq, "%s\n", "device not migrated!");
+
+	return 0;
+}
+
+static int hisi_acc_vf_attr_read(struct seq_file *seq, void *data)
+{
+	struct device *vf_dev = seq->private;
+	struct vfio_pci_core_device *core_device = dev_get_drvdata(vf_dev);
+	struct vfio_device	*vdev = &core_device->vdev;
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
+	struct hisi_acc_vf_migration_file *debug_migf = hisi_acc_vdev->debug_migf;
+
+	if (debug_migf && debug_migf->total_length) {
+		seq_printf(seq,
+			 "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,
+			 debug_migf->disabled,
+			 debug_migf->total_length);
+	} else {
+		seq_printf(seq, "%s\n", "device not migrated!");
+	}
+
+	return 0;
+}
+
+static int hisi_acc_vfio_debug_init(struct hisi_acc_vf_core_device *hisi_acc_vdev)
+{
+	struct vfio_device *vdev = &hisi_acc_vdev->core_device.vdev;
+	struct device *dev = vdev->dev;
+	void *migf = NULL;
+
+	if (!debugfs_initialized())
+		return 0;
+
+	vfio_vf_debugfs_init(vdev);
+
+	migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), GFP_KERNEL);
+	if (!migf)
+		return -ENOMEM;
+
+	hisi_acc_vdev->debug_migf = migf;
+
+	debugfs_create_devm_seqfile(dev, "migration_data", vdev->debug_root,
+				  hisi_acc_vf_data_read);
+	debugfs_create_devm_seqfile(dev, "migration_attr", vdev->debug_root,
+				  hisi_acc_vf_attr_read);
+
+	debugfs_create_file("migration_debug", 0200, vdev->debug_root,
+				  vdev, &hisi_acc_vf_debug_fops);
+
+	return 0;
+}
+
+static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device *hisi_acc_vdev)
+{
+	struct vfio_device *vdev = &hisi_acc_vdev->core_device.vdev;
+
+	if (!debugfs_initialized())
+		return;
+
+	vfio_vf_debugfs_exit(vdev);
+	kfree(hisi_acc_vdev->debug_migf);
+}
+
 static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev)
 {
 	struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(core_vdev);
@@ -1416,6 +1692,9 @@ 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 (ops == &hisi_acc_vfio_pci_migrn_ops)
+		hisi_acc_vfio_debug_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)
@@ -1423,6 +1702,8 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device
 	return 0;
 
 out_put_vdev:
+	if (ops == &hisi_acc_vfio_pci_migrn_ops)
+		hisi_acc_vf_debugfs_exit(hisi_acc_vdev);
 	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
 	return ret;
 }
@@ -1431,6 +1712,7 @@ 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);
 }
diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
index dcabfeec6ca1..ef50b12f018d 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.h
@@ -49,6 +49,14 @@
 #define QM_EQC_DW0		0X8000
 #define QM_AEQC_DW0		0X8020
 
+#define VFIO_DEV_DBG_LEN		256
+
+enum mig_debug_cmd {
+	STATE_SAVE,
+	STATE_RESUME,
+	RW_IO_TEST,
+};
+
 struct acc_vf_data {
 #define QM_MATCH_SIZE offsetofend(struct acc_vf_data, qm_rsv_state)
 	/* QM match information */
@@ -113,5 +121,8 @@ 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 hisi_acc_vf_migration_file *debug_migf;
 };
 #endif /* HISI_ACC_VFIO_PCI_H */
-- 
2.24.0