2 * Virtio PCI driver - common functionality for all device versions
4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
7 * Copyright IBM Corp. 2007
8 * Copyright Red Hat, Inc. 2014
11 * Anthony Liguori <aliguori@us.ibm.com>
12 * Rusty Russell <rusty@rustcorp.com.au>
13 * Michael S. Tsirkin <mst@redhat.com>
15 * This work is licensed under the terms of the GNU GPL, version 2 or later.
16 * See the COPYING file in the top-level directory.
20 #include "virtio_pci_common.h"
22 static bool force_legacy
= false;
24 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
25 module_param(force_legacy
, bool, 0444);
26 MODULE_PARM_DESC(force_legacy
,
27 "Force legacy mode for transitional virtio 1 devices");
30 /* wait for pending irq handlers */
31 void vp_synchronize_vectors(struct virtio_device
*vdev
)
33 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
36 if (vp_dev
->intx_enabled
)
37 synchronize_irq(vp_dev
->pci_dev
->irq
);
39 for (i
= 0; i
< vp_dev
->msix_vectors
; ++i
)
40 synchronize_irq(pci_irq_vector(vp_dev
->pci_dev
, i
));
43 /* the notify function used when creating a virt queue */
44 bool vp_notify(struct virtqueue
*vq
)
46 /* we write the queue's selector into the notification register to
47 * signal the other end */
48 iowrite16(vq
->index
, (void __iomem
*)vq
->priv
);
52 /* Handle a configuration change: Tell driver if it wants to know. */
53 static irqreturn_t
vp_config_changed(int irq
, void *opaque
)
55 struct virtio_pci_device
*vp_dev
= opaque
;
57 virtio_config_changed(&vp_dev
->vdev
);
61 /* Notify all virtqueues on an interrupt. */
62 static irqreturn_t
vp_vring_interrupt(int irq
, void *opaque
)
64 struct virtio_pci_device
*vp_dev
= opaque
;
65 struct virtio_pci_vq_info
*info
;
66 irqreturn_t ret
= IRQ_NONE
;
69 spin_lock_irqsave(&vp_dev
->lock
, flags
);
70 list_for_each_entry(info
, &vp_dev
->virtqueues
, node
) {
71 if (vring_interrupt(irq
, info
->vq
) == IRQ_HANDLED
)
74 spin_unlock_irqrestore(&vp_dev
->lock
, flags
);
79 /* A small wrapper to also acknowledge the interrupt when it's handled.
80 * I really need an EIO hook for the vring so I can ack the interrupt once we
81 * know that we'll be handling the IRQ but before we invoke the callback since
82 * the callback may notify the host which results in the host attempting to
83 * raise an interrupt that we would then mask once we acknowledged the
85 static irqreturn_t
vp_interrupt(int irq
, void *opaque
)
87 struct virtio_pci_device
*vp_dev
= opaque
;
90 /* reading the ISR has the effect of also clearing it so it's very
91 * important to save off the value. */
92 isr
= ioread8(vp_dev
->isr
);
94 /* It's definitely not us if the ISR was not high */
98 /* Configuration change? Tell driver if it wants to know. */
99 if (isr
& VIRTIO_PCI_ISR_CONFIG
)
100 vp_config_changed(irq
, opaque
);
102 return vp_vring_interrupt(irq
, opaque
);
105 static int vp_request_msix_vectors(struct virtio_device
*vdev
, int nvectors
,
106 bool per_vq_vectors
, struct irq_affinity
*desc
)
108 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
109 const char *name
= dev_name(&vp_dev
->vdev
.dev
);
113 vp_dev
->msix_vectors
= nvectors
;
115 vp_dev
->msix_names
= kmalloc(nvectors
* sizeof *vp_dev
->msix_names
,
117 if (!vp_dev
->msix_names
)
119 vp_dev
->msix_affinity_masks
120 = kzalloc(nvectors
* sizeof *vp_dev
->msix_affinity_masks
,
122 if (!vp_dev
->msix_affinity_masks
)
124 for (i
= 0; i
< nvectors
; ++i
)
125 if (!alloc_cpumask_var(&vp_dev
->msix_affinity_masks
[i
],
129 err
= pci_alloc_irq_vectors_affinity(vp_dev
->pci_dev
, nvectors
,
130 nvectors
, PCI_IRQ_MSIX
|
131 (desc
? PCI_IRQ_AFFINITY
: 0),
135 vp_dev
->msix_enabled
= 1;
137 /* Set the vector used for configuration */
138 v
= vp_dev
->msix_used_vectors
;
139 snprintf(vp_dev
->msix_names
[v
], sizeof *vp_dev
->msix_names
,
141 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, v
),
142 vp_config_changed
, 0, vp_dev
->msix_names
[v
],
146 ++vp_dev
->msix_used_vectors
;
148 v
= vp_dev
->config_vector(vp_dev
, v
);
149 /* Verify we had enough resources to assign the vector */
150 if (v
== VIRTIO_MSI_NO_VECTOR
) {
155 if (!per_vq_vectors
) {
156 /* Shared vector for all VQs */
157 v
= vp_dev
->msix_used_vectors
;
158 snprintf(vp_dev
->msix_names
[v
], sizeof *vp_dev
->msix_names
,
159 "%s-virtqueues", name
);
160 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, v
),
161 vp_vring_interrupt
, 0, vp_dev
->msix_names
[v
],
165 ++vp_dev
->msix_used_vectors
;
172 static struct virtqueue
*vp_setup_vq(struct virtio_device
*vdev
, unsigned index
,
173 void (*callback
)(struct virtqueue
*vq
),
177 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
178 struct virtio_pci_vq_info
*info
= kmalloc(sizeof *info
, GFP_KERNEL
);
179 struct virtqueue
*vq
;
182 /* fill out our structure that represents an active queue */
184 return ERR_PTR(-ENOMEM
);
186 vq
= vp_dev
->setup_vq(vp_dev
, info
, index
, callback
, name
,
193 spin_lock_irqsave(&vp_dev
->lock
, flags
);
194 list_add(&info
->node
, &vp_dev
->virtqueues
);
195 spin_unlock_irqrestore(&vp_dev
->lock
, flags
);
197 INIT_LIST_HEAD(&info
->node
);
200 vp_dev
->vqs
[index
] = info
;
208 static void vp_del_vq(struct virtqueue
*vq
)
210 struct virtio_pci_device
*vp_dev
= to_vp_device(vq
->vdev
);
211 struct virtio_pci_vq_info
*info
= vp_dev
->vqs
[vq
->index
];
214 spin_lock_irqsave(&vp_dev
->lock
, flags
);
215 list_del(&info
->node
);
216 spin_unlock_irqrestore(&vp_dev
->lock
, flags
);
218 vp_dev
->del_vq(info
);
222 /* the config->del_vqs() implementation */
223 void vp_del_vqs(struct virtio_device
*vdev
)
225 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
226 struct virtqueue
*vq
, *n
;
229 list_for_each_entry_safe(vq
, n
, &vdev
->vqs
, list
) {
230 if (vp_dev
->per_vq_vectors
) {
231 int v
= vp_dev
->vqs
[vq
->index
]->msix_vector
;
233 if (v
!= VIRTIO_MSI_NO_VECTOR
) {
234 int irq
= pci_irq_vector(vp_dev
->pci_dev
, v
);
236 irq_set_affinity_hint(irq
, NULL
);
242 vp_dev
->per_vq_vectors
= false;
244 if (vp_dev
->intx_enabled
) {
245 free_irq(vp_dev
->pci_dev
->irq
, vp_dev
);
246 vp_dev
->intx_enabled
= 0;
249 for (i
= 0; i
< vp_dev
->msix_used_vectors
; ++i
)
250 free_irq(pci_irq_vector(vp_dev
->pci_dev
, i
), vp_dev
);
252 for (i
= 0; i
< vp_dev
->msix_vectors
; i
++)
253 if (vp_dev
->msix_affinity_masks
[i
])
254 free_cpumask_var(vp_dev
->msix_affinity_masks
[i
]);
256 if (vp_dev
->msix_enabled
) {
257 /* Disable the vector used for configuration */
258 vp_dev
->config_vector(vp_dev
, VIRTIO_MSI_NO_VECTOR
);
260 pci_free_irq_vectors(vp_dev
->pci_dev
);
261 vp_dev
->msix_enabled
= 0;
264 vp_dev
->msix_vectors
= 0;
265 vp_dev
->msix_used_vectors
= 0;
266 kfree(vp_dev
->msix_names
);
267 vp_dev
->msix_names
= NULL
;
268 kfree(vp_dev
->msix_affinity_masks
);
269 vp_dev
->msix_affinity_masks
= NULL
;
274 static int vp_find_vqs_msix(struct virtio_device
*vdev
, unsigned nvqs
,
275 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
276 const char * const names
[], bool per_vq_vectors
,
277 struct irq_affinity
*desc
)
279 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
281 int i
, err
, nvectors
, allocated_vectors
;
283 vp_dev
->vqs
= kcalloc(nvqs
, sizeof(*vp_dev
->vqs
), GFP_KERNEL
);
287 if (per_vq_vectors
) {
288 /* Best option: one for change interrupt, one per vq. */
290 for (i
= 0; i
< nvqs
; ++i
)
294 /* Second best: one for change, shared for all vqs. */
298 err
= vp_request_msix_vectors(vdev
, nvectors
, per_vq_vectors
,
299 per_vq_vectors
? desc
: NULL
);
303 vp_dev
->per_vq_vectors
= per_vq_vectors
;
304 allocated_vectors
= vp_dev
->msix_used_vectors
;
305 for (i
= 0; i
< nvqs
; ++i
) {
312 msix_vec
= VIRTIO_MSI_NO_VECTOR
;
313 else if (vp_dev
->per_vq_vectors
)
314 msix_vec
= allocated_vectors
++;
316 msix_vec
= VP_MSIX_VQ_VECTOR
;
317 vqs
[i
] = vp_setup_vq(vdev
, i
, callbacks
[i
], names
[i
],
319 if (IS_ERR(vqs
[i
])) {
320 err
= PTR_ERR(vqs
[i
]);
324 if (!vp_dev
->per_vq_vectors
|| msix_vec
== VIRTIO_MSI_NO_VECTOR
)
327 /* allocate per-vq irq if available and necessary */
328 snprintf(vp_dev
->msix_names
[msix_vec
],
329 sizeof *vp_dev
->msix_names
,
331 dev_name(&vp_dev
->vdev
.dev
), names
[i
]);
332 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, msix_vec
),
334 vp_dev
->msix_names
[msix_vec
],
346 static int vp_find_vqs_intx(struct virtio_device
*vdev
, unsigned nvqs
,
347 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
348 const char * const names
[])
350 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
353 vp_dev
->vqs
= kcalloc(nvqs
, sizeof(*vp_dev
->vqs
), GFP_KERNEL
);
357 err
= request_irq(vp_dev
->pci_dev
->irq
, vp_interrupt
, IRQF_SHARED
,
358 dev_name(&vdev
->dev
), vp_dev
);
362 vp_dev
->intx_enabled
= 1;
363 vp_dev
->per_vq_vectors
= false;
364 for (i
= 0; i
< nvqs
; ++i
) {
369 vqs
[i
] = vp_setup_vq(vdev
, i
, callbacks
[i
], names
[i
],
370 VIRTIO_MSI_NO_VECTOR
);
371 if (IS_ERR(vqs
[i
])) {
372 err
= PTR_ERR(vqs
[i
]);
383 /* the config->find_vqs() implementation */
384 int vp_find_vqs(struct virtio_device
*vdev
, unsigned nvqs
,
385 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
386 const char * const names
[], struct irq_affinity
*desc
)
390 /* Try MSI-X with one vector per queue. */
391 err
= vp_find_vqs_msix(vdev
, nvqs
, vqs
, callbacks
, names
, true, desc
);
394 /* Fallback: MSI-X with one vector for config, one shared for queues. */
395 err
= vp_find_vqs_msix(vdev
, nvqs
, vqs
, callbacks
, names
, false, desc
);
398 /* Finally fall back to regular interrupts. */
399 return vp_find_vqs_intx(vdev
, nvqs
, vqs
, callbacks
, names
);
402 const char *vp_bus_name(struct virtio_device
*vdev
)
404 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
406 return pci_name(vp_dev
->pci_dev
);
409 /* Setup the affinity for a virtqueue:
410 * - force the affinity for per vq vector
411 * - OR over all affinities for shared MSI
412 * - ignore the affinity request if we're using INTX
414 int vp_set_vq_affinity(struct virtqueue
*vq
, int cpu
)
416 struct virtio_device
*vdev
= vq
->vdev
;
417 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
418 struct virtio_pci_vq_info
*info
= vp_dev
->vqs
[vq
->index
];
419 struct cpumask
*mask
;
425 if (vp_dev
->msix_enabled
) {
426 mask
= vp_dev
->msix_affinity_masks
[info
->msix_vector
];
427 irq
= pci_irq_vector(vp_dev
->pci_dev
, info
->msix_vector
);
429 irq_set_affinity_hint(irq
, NULL
);
432 cpumask_set_cpu(cpu
, mask
);
433 irq_set_affinity_hint(irq
, mask
);
439 const struct cpumask
*vp_get_vq_affinity(struct virtio_device
*vdev
, int index
)
441 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
443 if (!vp_dev
->per_vq_vectors
||
444 vp_dev
->vqs
[index
]->msix_vector
== VIRTIO_MSI_NO_VECTOR
)
447 return pci_irq_get_affinity(vp_dev
->pci_dev
,
448 vp_dev
->vqs
[index
]->msix_vector
);
451 #ifdef CONFIG_PM_SLEEP
452 static int virtio_pci_freeze(struct device
*dev
)
454 struct pci_dev
*pci_dev
= to_pci_dev(dev
);
455 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
458 ret
= virtio_device_freeze(&vp_dev
->vdev
);
461 pci_disable_device(pci_dev
);
465 static int virtio_pci_restore(struct device
*dev
)
467 struct pci_dev
*pci_dev
= to_pci_dev(dev
);
468 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
471 ret
= pci_enable_device(pci_dev
);
475 pci_set_master(pci_dev
);
476 return virtio_device_restore(&vp_dev
->vdev
);
479 static const struct dev_pm_ops virtio_pci_pm_ops
= {
480 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze
, virtio_pci_restore
)
485 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
486 static const struct pci_device_id virtio_pci_id_table
[] = {
487 { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET
, PCI_ANY_ID
) },
491 MODULE_DEVICE_TABLE(pci
, virtio_pci_id_table
);
493 static void virtio_pci_release_dev(struct device
*_d
)
495 struct virtio_device
*vdev
= dev_to_virtio(_d
);
496 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
498 /* As struct device is a kobject, it's not safe to
499 * free the memory (including the reference counter itself)
500 * until it's release callback. */
504 static int virtio_pci_probe(struct pci_dev
*pci_dev
,
505 const struct pci_device_id
*id
)
507 struct virtio_pci_device
*vp_dev
;
510 /* allocate our structure and fill it out */
511 vp_dev
= kzalloc(sizeof(struct virtio_pci_device
), GFP_KERNEL
);
515 pci_set_drvdata(pci_dev
, vp_dev
);
516 vp_dev
->vdev
.dev
.parent
= &pci_dev
->dev
;
517 vp_dev
->vdev
.dev
.release
= virtio_pci_release_dev
;
518 vp_dev
->pci_dev
= pci_dev
;
519 INIT_LIST_HEAD(&vp_dev
->virtqueues
);
520 spin_lock_init(&vp_dev
->lock
);
522 /* enable the device */
523 rc
= pci_enable_device(pci_dev
);
525 goto err_enable_device
;
528 rc
= virtio_pci_legacy_probe(vp_dev
);
529 /* Also try modern mode if we can't map BAR0 (no IO space). */
530 if (rc
== -ENODEV
|| rc
== -ENOMEM
)
531 rc
= virtio_pci_modern_probe(vp_dev
);
535 rc
= virtio_pci_modern_probe(vp_dev
);
537 rc
= virtio_pci_legacy_probe(vp_dev
);
542 pci_set_master(pci_dev
);
544 rc
= register_virtio_device(&vp_dev
->vdev
);
552 virtio_pci_legacy_remove(vp_dev
);
554 virtio_pci_modern_remove(vp_dev
);
556 pci_disable_device(pci_dev
);
562 static void virtio_pci_remove(struct pci_dev
*pci_dev
)
564 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
565 struct device
*dev
= get_device(&vp_dev
->vdev
.dev
);
567 unregister_virtio_device(&vp_dev
->vdev
);
570 virtio_pci_legacy_remove(vp_dev
);
572 virtio_pci_modern_remove(vp_dev
);
574 pci_disable_device(pci_dev
);
578 static struct pci_driver virtio_pci_driver
= {
579 .name
= "virtio-pci",
580 .id_table
= virtio_pci_id_table
,
581 .probe
= virtio_pci_probe
,
582 .remove
= virtio_pci_remove
,
583 #ifdef CONFIG_PM_SLEEP
584 .driver
.pm
= &virtio_pci_pm_ops
,
588 module_pci_driver(virtio_pci_driver
);
590 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
591 MODULE_DESCRIPTION("virtio-pci");
592 MODULE_LICENSE("GPL");