summaryrefslogtreecommitdiff
path: root/drivers/vfio/pci/pds/pci_drv.c
blob: 16e93b11ab1b0ef9a3b8e07ac4e838397b26e5ea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2023 Advanced Micro Devices, Inc. */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <linux/vfio.h>

#include <linux/pds/pds_common.h>
#include <linux/pds/pds_core_if.h>
#include <linux/pds/pds_adminq.h>

#include "vfio_dev.h"
#include "pci_drv.h"
#include "cmds.h"

#define PDS_VFIO_DRV_DESCRIPTION	"AMD/Pensando VFIO Device Driver"
#define PCI_VENDOR_ID_PENSANDO		0x1dd8

static void pds_vfio_recovery(struct pds_vfio_pci_device *pds_vfio)
{
	/*
	 * Documentation states that the kernel migration driver must not
	 * generate asynchronous device state transitions outside of
	 * manipulation by the user or the VFIO_DEVICE_RESET ioctl.
	 *
	 * Since recovery is an asynchronous event received from the device,
	 * initiate a reset in the following situations:
	 *   1. Migration is in progress, which will cause the next step of
	 *	the migration to fail.
	 *   2. If the device is in a state that will be set to
	 *	VFIO_DEVICE_STATE_RUNNING on the next action (i.e. VM is
	 *	shutdown and device is in VFIO_DEVICE_STATE_STOP).
	 */
	mutex_lock(&pds_vfio->state_mutex);
	if ((pds_vfio->state != VFIO_DEVICE_STATE_RUNNING &&
	     pds_vfio->state != VFIO_DEVICE_STATE_ERROR) ||
	    (pds_vfio->state == VFIO_DEVICE_STATE_RUNNING &&
	     pds_vfio_dirty_is_enabled(pds_vfio)))
		pds_vfio_reset(pds_vfio, VFIO_DEVICE_STATE_ERROR);
	mutex_unlock(&pds_vfio->state_mutex);
}

static int pds_vfio_pci_notify_handler(struct notifier_block *nb,
				       unsigned long ecode, void *data)
{
	struct pds_vfio_pci_device *pds_vfio =
		container_of(nb, struct pds_vfio_pci_device, nb);
	struct device *dev = pds_vfio_to_dev(pds_vfio);
	union pds_core_notifyq_comp *event = data;

	dev_dbg(dev, "%s: event code %lu\n", __func__, ecode);

	/*
	 * We don't need to do anything for RESET state==0 as there is no notify
	 * or feedback mechanism available, and it is possible that we won't
	 * even see a state==0 event since the pds_core recovery is pending.
	 *
	 * Any requests from VFIO while state==0 will fail, which will return
	 * error and may cause migration to fail.
	 */
	if (ecode == PDS_EVENT_RESET) {
		dev_info(dev, "%s: PDS_EVENT_RESET event received, state==%d\n",
			 __func__, event->reset.state);
		/*
		 * pds_core device finished recovery and sent us the
		 * notification (state == 1) to allow us to recover
		 */
		if (event->reset.state == 1)
			pds_vfio_recovery(pds_vfio);
	}

	return 0;
}

static int
pds_vfio_pci_register_event_handler(struct pds_vfio_pci_device *pds_vfio)
{
	struct device *dev = pds_vfio_to_dev(pds_vfio);
	struct notifier_block *nb = &pds_vfio->nb;
	int err;

	if (!nb->notifier_call) {
		nb->notifier_call = pds_vfio_pci_notify_handler;
		err = pdsc_register_notify(nb);
		if (err) {
			nb->notifier_call = NULL;
			dev_err(dev,
				"failed to register pds event handler: %pe\n",
				ERR_PTR(err));
			return -EINVAL;
		}
		dev_dbg(dev, "pds event handler registered\n");
	}

	return 0;
}

static void
pds_vfio_pci_unregister_event_handler(struct pds_vfio_pci_device *pds_vfio)
{
	if (pds_vfio->nb.notifier_call) {
		pdsc_unregister_notify(&pds_vfio->nb);
		pds_vfio->nb.notifier_call = NULL;
	}
}

static int pds_vfio_pci_probe(struct pci_dev *pdev,
			      const struct pci_device_id *id)
{
	struct pds_vfio_pci_device *pds_vfio;
	int err;

	pds_vfio = vfio_alloc_device(pds_vfio_pci_device, vfio_coredev.vdev,
				     &pdev->dev, pds_vfio_ops_info());
	if (IS_ERR(pds_vfio))
		return PTR_ERR(pds_vfio);

	dev_set_drvdata(&pdev->dev, &pds_vfio->vfio_coredev);

	err = vfio_pci_core_register_device(&pds_vfio->vfio_coredev);
	if (err)
		goto out_put_vdev;

	err = pds_vfio_register_client_cmd(pds_vfio);
	if (err) {
		dev_err(&pdev->dev, "failed to register as client: %pe\n",
			ERR_PTR(err));
		goto out_unregister_coredev;
	}

	err = pds_vfio_pci_register_event_handler(pds_vfio);
	if (err)
		goto out_unregister_client;

	return 0;

out_unregister_client:
	pds_vfio_unregister_client_cmd(pds_vfio);
out_unregister_coredev:
	vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev);
out_put_vdev:
	vfio_put_device(&pds_vfio->vfio_coredev.vdev);
	return err;
}

static void pds_vfio_pci_remove(struct pci_dev *pdev)
{
	struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev);

	pds_vfio_pci_unregister_event_handler(pds_vfio);
	pds_vfio_unregister_client_cmd(pds_vfio);
	vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev);
	vfio_put_device(&pds_vfio->vfio_coredev.vdev);
}

static const struct pci_device_id pds_vfio_pci_table[] = {
	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_PENSANDO, 0x1003) }, /* Ethernet VF */
	{ 0, }
};
MODULE_DEVICE_TABLE(pci, pds_vfio_pci_table);

static void pds_vfio_pci_aer_reset_done(struct pci_dev *pdev)
{
	struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev);

	mutex_lock(&pds_vfio->state_mutex);
	pds_vfio_reset(pds_vfio, VFIO_DEVICE_STATE_RUNNING);
	mutex_unlock(&pds_vfio->state_mutex);
}

static const struct pci_error_handlers pds_vfio_pci_err_handlers = {
	.reset_done = pds_vfio_pci_aer_reset_done,
	.error_detected = vfio_pci_core_aer_err_detected,
};

static struct pci_driver pds_vfio_pci_driver = {
	.name = KBUILD_MODNAME,
	.id_table = pds_vfio_pci_table,
	.probe = pds_vfio_pci_probe,
	.remove = pds_vfio_pci_remove,
	.err_handler = &pds_vfio_pci_err_handlers,
	.driver_managed_dma = true,
};

module_pci_driver(pds_vfio_pci_driver);

MODULE_IMPORT_NS(IOMMUFD);
MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION);
MODULE_AUTHOR("Brett Creeley <brett.creeley@amd.com>");
MODULE_LICENSE("GPL");