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
);
110 unsigned flags
= PCI_IRQ_MSIX
;
114 vp_dev
->msix_vectors
= nvectors
;
116 vp_dev
->msix_names
= kmalloc_array(nvectors
,
117 sizeof(*vp_dev
->msix_names
),
119 if (!vp_dev
->msix_names
)
121 vp_dev
->msix_affinity_masks
122 = kcalloc(nvectors
, sizeof(*vp_dev
->msix_affinity_masks
),
124 if (!vp_dev
->msix_affinity_masks
)
126 for (i
= 0; i
< nvectors
; ++i
)
127 if (!alloc_cpumask_var(&vp_dev
->msix_affinity_masks
[i
],
132 flags
|= PCI_IRQ_AFFINITY
;
133 desc
->pre_vectors
++; /* virtio config vector */
136 err
= pci_alloc_irq_vectors_affinity(vp_dev
->pci_dev
, nvectors
,
137 nvectors
, flags
, desc
);
140 vp_dev
->msix_enabled
= 1;
142 /* Set the vector used for configuration */
143 v
= vp_dev
->msix_used_vectors
;
144 snprintf(vp_dev
->msix_names
[v
], sizeof *vp_dev
->msix_names
,
146 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, v
),
147 vp_config_changed
, 0, vp_dev
->msix_names
[v
],
151 ++vp_dev
->msix_used_vectors
;
153 v
= vp_dev
->config_vector(vp_dev
, v
);
154 /* Verify we had enough resources to assign the vector */
155 if (v
== VIRTIO_MSI_NO_VECTOR
) {
160 if (!per_vq_vectors
) {
161 /* Shared vector for all VQs */
162 v
= vp_dev
->msix_used_vectors
;
163 snprintf(vp_dev
->msix_names
[v
], sizeof *vp_dev
->msix_names
,
164 "%s-virtqueues", name
);
165 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, v
),
166 vp_vring_interrupt
, 0, vp_dev
->msix_names
[v
],
170 ++vp_dev
->msix_used_vectors
;
177 static struct virtqueue
*vp_setup_vq(struct virtio_device
*vdev
, unsigned index
,
178 void (*callback
)(struct virtqueue
*vq
),
183 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
184 struct virtio_pci_vq_info
*info
= kmalloc(sizeof *info
, GFP_KERNEL
);
185 struct virtqueue
*vq
;
188 /* fill out our structure that represents an active queue */
190 return ERR_PTR(-ENOMEM
);
192 vq
= vp_dev
->setup_vq(vp_dev
, info
, index
, callback
, name
, ctx
,
199 spin_lock_irqsave(&vp_dev
->lock
, flags
);
200 list_add(&info
->node
, &vp_dev
->virtqueues
);
201 spin_unlock_irqrestore(&vp_dev
->lock
, flags
);
203 INIT_LIST_HEAD(&info
->node
);
206 vp_dev
->vqs
[index
] = info
;
214 static void vp_del_vq(struct virtqueue
*vq
)
216 struct virtio_pci_device
*vp_dev
= to_vp_device(vq
->vdev
);
217 struct virtio_pci_vq_info
*info
= vp_dev
->vqs
[vq
->index
];
220 spin_lock_irqsave(&vp_dev
->lock
, flags
);
221 list_del(&info
->node
);
222 spin_unlock_irqrestore(&vp_dev
->lock
, flags
);
224 vp_dev
->del_vq(info
);
228 /* the config->del_vqs() implementation */
229 void vp_del_vqs(struct virtio_device
*vdev
)
231 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
232 struct virtqueue
*vq
, *n
;
235 list_for_each_entry_safe(vq
, n
, &vdev
->vqs
, list
) {
236 if (vp_dev
->per_vq_vectors
) {
237 int v
= vp_dev
->vqs
[vq
->index
]->msix_vector
;
239 if (v
!= VIRTIO_MSI_NO_VECTOR
) {
240 int irq
= pci_irq_vector(vp_dev
->pci_dev
, v
);
242 irq_set_affinity_hint(irq
, NULL
);
248 vp_dev
->per_vq_vectors
= false;
250 if (vp_dev
->intx_enabled
) {
251 free_irq(vp_dev
->pci_dev
->irq
, vp_dev
);
252 vp_dev
->intx_enabled
= 0;
255 for (i
= 0; i
< vp_dev
->msix_used_vectors
; ++i
)
256 free_irq(pci_irq_vector(vp_dev
->pci_dev
, i
), vp_dev
);
258 for (i
= 0; i
< vp_dev
->msix_vectors
; i
++)
259 if (vp_dev
->msix_affinity_masks
[i
])
260 free_cpumask_var(vp_dev
->msix_affinity_masks
[i
]);
262 if (vp_dev
->msix_enabled
) {
263 /* Disable the vector used for configuration */
264 vp_dev
->config_vector(vp_dev
, VIRTIO_MSI_NO_VECTOR
);
266 pci_free_irq_vectors(vp_dev
->pci_dev
);
267 vp_dev
->msix_enabled
= 0;
270 vp_dev
->msix_vectors
= 0;
271 vp_dev
->msix_used_vectors
= 0;
272 kfree(vp_dev
->msix_names
);
273 vp_dev
->msix_names
= NULL
;
274 kfree(vp_dev
->msix_affinity_masks
);
275 vp_dev
->msix_affinity_masks
= NULL
;
280 static int vp_find_vqs_msix(struct virtio_device
*vdev
, unsigned nvqs
,
281 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
282 const char * const names
[], bool per_vq_vectors
,
284 struct irq_affinity
*desc
)
286 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
288 int i
, err
, nvectors
, allocated_vectors
;
290 vp_dev
->vqs
= kcalloc(nvqs
, sizeof(*vp_dev
->vqs
), GFP_KERNEL
);
294 if (per_vq_vectors
) {
295 /* Best option: one for change interrupt, one per vq. */
297 for (i
= 0; i
< nvqs
; ++i
)
301 /* Second best: one for change, shared for all vqs. */
305 err
= vp_request_msix_vectors(vdev
, nvectors
, per_vq_vectors
,
306 per_vq_vectors
? desc
: NULL
);
310 vp_dev
->per_vq_vectors
= per_vq_vectors
;
311 allocated_vectors
= vp_dev
->msix_used_vectors
;
312 for (i
= 0; i
< nvqs
; ++i
) {
319 msix_vec
= VIRTIO_MSI_NO_VECTOR
;
320 else if (vp_dev
->per_vq_vectors
)
321 msix_vec
= allocated_vectors
++;
323 msix_vec
= VP_MSIX_VQ_VECTOR
;
324 vqs
[i
] = vp_setup_vq(vdev
, i
, callbacks
[i
], names
[i
],
325 ctx
? ctx
[i
] : false,
327 if (IS_ERR(vqs
[i
])) {
328 err
= PTR_ERR(vqs
[i
]);
332 if (!vp_dev
->per_vq_vectors
|| msix_vec
== VIRTIO_MSI_NO_VECTOR
)
335 /* allocate per-vq irq if available and necessary */
336 snprintf(vp_dev
->msix_names
[msix_vec
],
337 sizeof *vp_dev
->msix_names
,
339 dev_name(&vp_dev
->vdev
.dev
), names
[i
]);
340 err
= request_irq(pci_irq_vector(vp_dev
->pci_dev
, msix_vec
),
342 vp_dev
->msix_names
[msix_vec
],
354 static int vp_find_vqs_intx(struct virtio_device
*vdev
, unsigned nvqs
,
355 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
356 const char * const names
[], const bool *ctx
)
358 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
361 vp_dev
->vqs
= kcalloc(nvqs
, sizeof(*vp_dev
->vqs
), GFP_KERNEL
);
365 err
= request_irq(vp_dev
->pci_dev
->irq
, vp_interrupt
, IRQF_SHARED
,
366 dev_name(&vdev
->dev
), vp_dev
);
370 vp_dev
->intx_enabled
= 1;
371 vp_dev
->per_vq_vectors
= false;
372 for (i
= 0; i
< nvqs
; ++i
) {
377 vqs
[i
] = vp_setup_vq(vdev
, i
, callbacks
[i
], names
[i
],
378 ctx
? ctx
[i
] : false,
379 VIRTIO_MSI_NO_VECTOR
);
380 if (IS_ERR(vqs
[i
])) {
381 err
= PTR_ERR(vqs
[i
]);
392 /* the config->find_vqs() implementation */
393 int vp_find_vqs(struct virtio_device
*vdev
, unsigned nvqs
,
394 struct virtqueue
*vqs
[], vq_callback_t
*callbacks
[],
395 const char * const names
[], const bool *ctx
,
396 struct irq_affinity
*desc
)
400 /* Try MSI-X with one vector per queue. */
401 err
= vp_find_vqs_msix(vdev
, nvqs
, vqs
, callbacks
, names
, true, ctx
, desc
);
404 /* Fallback: MSI-X with one vector for config, one shared for queues. */
405 err
= vp_find_vqs_msix(vdev
, nvqs
, vqs
, callbacks
, names
, false, ctx
, desc
);
408 /* Finally fall back to regular interrupts. */
409 return vp_find_vqs_intx(vdev
, nvqs
, vqs
, callbacks
, names
, ctx
);
412 const char *vp_bus_name(struct virtio_device
*vdev
)
414 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
416 return pci_name(vp_dev
->pci_dev
);
419 /* Setup the affinity for a virtqueue:
420 * - force the affinity for per vq vector
421 * - OR over all affinities for shared MSI
422 * - ignore the affinity request if we're using INTX
424 int vp_set_vq_affinity(struct virtqueue
*vq
, int cpu
)
426 struct virtio_device
*vdev
= vq
->vdev
;
427 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
428 struct virtio_pci_vq_info
*info
= vp_dev
->vqs
[vq
->index
];
429 struct cpumask
*mask
;
435 if (vp_dev
->msix_enabled
) {
436 mask
= vp_dev
->msix_affinity_masks
[info
->msix_vector
];
437 irq
= pci_irq_vector(vp_dev
->pci_dev
, info
->msix_vector
);
439 irq_set_affinity_hint(irq
, NULL
);
442 cpumask_set_cpu(cpu
, mask
);
443 irq_set_affinity_hint(irq
, mask
);
449 const struct cpumask
*vp_get_vq_affinity(struct virtio_device
*vdev
, int index
)
451 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
453 if (!vp_dev
->per_vq_vectors
||
454 vp_dev
->vqs
[index
]->msix_vector
== VIRTIO_MSI_NO_VECTOR
)
457 return pci_irq_get_affinity(vp_dev
->pci_dev
,
458 vp_dev
->vqs
[index
]->msix_vector
);
461 #ifdef CONFIG_PM_SLEEP
462 static int virtio_pci_freeze(struct device
*dev
)
464 struct pci_dev
*pci_dev
= to_pci_dev(dev
);
465 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
468 ret
= virtio_device_freeze(&vp_dev
->vdev
);
471 pci_disable_device(pci_dev
);
475 static int virtio_pci_restore(struct device
*dev
)
477 struct pci_dev
*pci_dev
= to_pci_dev(dev
);
478 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
481 ret
= pci_enable_device(pci_dev
);
485 pci_set_master(pci_dev
);
486 return virtio_device_restore(&vp_dev
->vdev
);
489 static const struct dev_pm_ops virtio_pci_pm_ops
= {
490 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze
, virtio_pci_restore
)
495 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
496 static const struct pci_device_id virtio_pci_id_table
[] = {
497 { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET
, PCI_ANY_ID
) },
501 MODULE_DEVICE_TABLE(pci
, virtio_pci_id_table
);
503 static void virtio_pci_release_dev(struct device
*_d
)
505 struct virtio_device
*vdev
= dev_to_virtio(_d
);
506 struct virtio_pci_device
*vp_dev
= to_vp_device(vdev
);
508 /* As struct device is a kobject, it's not safe to
509 * free the memory (including the reference counter itself)
510 * until it's release callback. */
514 static int virtio_pci_probe(struct pci_dev
*pci_dev
,
515 const struct pci_device_id
*id
)
517 struct virtio_pci_device
*vp_dev
, *reg_dev
= NULL
;
520 /* allocate our structure and fill it out */
521 vp_dev
= kzalloc(sizeof(struct virtio_pci_device
), GFP_KERNEL
);
525 pci_set_drvdata(pci_dev
, vp_dev
);
526 vp_dev
->vdev
.dev
.parent
= &pci_dev
->dev
;
527 vp_dev
->vdev
.dev
.release
= virtio_pci_release_dev
;
528 vp_dev
->pci_dev
= pci_dev
;
529 INIT_LIST_HEAD(&vp_dev
->virtqueues
);
530 spin_lock_init(&vp_dev
->lock
);
532 /* enable the device */
533 rc
= pci_enable_device(pci_dev
);
535 goto err_enable_device
;
538 rc
= virtio_pci_legacy_probe(vp_dev
);
539 /* Also try modern mode if we can't map BAR0 (no IO space). */
540 if (rc
== -ENODEV
|| rc
== -ENOMEM
)
541 rc
= virtio_pci_modern_probe(vp_dev
);
545 rc
= virtio_pci_modern_probe(vp_dev
);
547 rc
= virtio_pci_legacy_probe(vp_dev
);
552 pci_set_master(pci_dev
);
554 rc
= register_virtio_device(&vp_dev
->vdev
);
563 virtio_pci_legacy_remove(vp_dev
);
565 virtio_pci_modern_remove(vp_dev
);
567 pci_disable_device(pci_dev
);
570 put_device(&vp_dev
->vdev
.dev
);
576 static void virtio_pci_remove(struct pci_dev
*pci_dev
)
578 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
579 struct device
*dev
= get_device(&vp_dev
->vdev
.dev
);
581 pci_disable_sriov(pci_dev
);
583 unregister_virtio_device(&vp_dev
->vdev
);
586 virtio_pci_legacy_remove(vp_dev
);
588 virtio_pci_modern_remove(vp_dev
);
590 pci_disable_device(pci_dev
);
594 static int virtio_pci_sriov_configure(struct pci_dev
*pci_dev
, int num_vfs
)
596 struct virtio_pci_device
*vp_dev
= pci_get_drvdata(pci_dev
);
597 struct virtio_device
*vdev
= &vp_dev
->vdev
;
600 if (!(vdev
->config
->get_status(vdev
) & VIRTIO_CONFIG_S_DRIVER_OK
))
603 if (!__virtio_test_bit(vdev
, VIRTIO_F_SR_IOV
))
606 if (pci_vfs_assigned(pci_dev
))
610 pci_disable_sriov(pci_dev
);
614 ret
= pci_enable_sriov(pci_dev
, num_vfs
);
621 static struct pci_driver virtio_pci_driver
= {
622 .name
= "virtio-pci",
623 .id_table
= virtio_pci_id_table
,
624 .probe
= virtio_pci_probe
,
625 .remove
= virtio_pci_remove
,
626 #ifdef CONFIG_PM_SLEEP
627 .driver
.pm
= &virtio_pci_pm_ops
,
629 .sriov_configure
= virtio_pci_sriov_configure
,
632 module_pci_driver(virtio_pci_driver
);
634 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
635 MODULE_DESCRIPTION("virtio-pci");
636 MODULE_LICENSE("GPL");