diff options
Diffstat (limited to 'drivers/virtio/virtio_pci_common.c')
| -rw-r--r-- | drivers/virtio/virtio_pci_common.c | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c new file mode 100644 index 000000000..c2524a720 --- /dev/null +++ b/drivers/virtio/virtio_pci_common.c @@ -0,0 +1,650 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Virtio PCI driver - common functionality for all device versions + * + * This module allows virtio devices to be used over a virtual PCI device. + * This can be used with QEMU based VMMs like KVM or Xen. + * + * Copyright IBM Corp. 2007 + * Copyright Red Hat, Inc. 2014 + * + * Authors: + * Anthony Liguori <aliguori@us.ibm.com> + * Rusty Russell <rusty@rustcorp.com.au> + * Michael S. Tsirkin <mst@redhat.com> + */ + +#include "virtio_pci_common.h" + +static bool force_legacy = false; + +#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) +module_param(force_legacy, bool, 0444); +MODULE_PARM_DESC(force_legacy, + "Force legacy mode for transitional virtio 1 devices"); +#endif + +/* wait for pending irq handlers */ +void vp_synchronize_vectors(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + int i; + + if (vp_dev->intx_enabled) + synchronize_irq(vp_dev->pci_dev->irq); + + for (i = 0; i < vp_dev->msix_vectors; ++i) + synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i)); +} + +/* the notify function used when creating a virt queue */ +bool vp_notify(struct virtqueue *vq) +{ + /* we write the queue's selector into the notification register to + * signal the other end */ + iowrite16(vq->index, (void __iomem *)vq->priv); + return true; +} + +/* Handle a configuration change: Tell driver if it wants to know. */ +static irqreturn_t vp_config_changed(int irq, void *opaque) +{ + struct virtio_pci_device *vp_dev = opaque; + + virtio_config_changed(&vp_dev->vdev); + return IRQ_HANDLED; +} + +/* Notify all virtqueues on an interrupt. */ +static irqreturn_t vp_vring_interrupt(int irq, void *opaque) +{ + struct virtio_pci_device *vp_dev = opaque; + struct virtio_pci_vq_info *info; + irqreturn_t ret = IRQ_NONE; + unsigned long flags; + + spin_lock_irqsave(&vp_dev->lock, flags); + list_for_each_entry(info, &vp_dev->virtqueues, node) { + if (vring_interrupt(irq, info->vq) == IRQ_HANDLED) + ret = IRQ_HANDLED; + } + spin_unlock_irqrestore(&vp_dev->lock, flags); + + return ret; +} + +/* A small wrapper to also acknowledge the interrupt when it's handled. + * I really need an EIO hook for the vring so I can ack the interrupt once we + * know that we'll be handling the IRQ but before we invoke the callback since + * the callback may notify the host which results in the host attempting to + * raise an interrupt that we would then mask once we acknowledged the + * interrupt. */ +static irqreturn_t vp_interrupt(int irq, void *opaque) +{ + struct virtio_pci_device *vp_dev = opaque; + u8 isr; + + /* reading the ISR has the effect of also clearing it so it's very + * important to save off the value. */ + isr = ioread8(vp_dev->isr); + + /* It's definitely not us if the ISR was not high */ + if (!isr) + return IRQ_NONE; + + /* Configuration change? Tell driver if it wants to know. */ + if (isr & VIRTIO_PCI_ISR_CONFIG) + vp_config_changed(irq, opaque); + + return vp_vring_interrupt(irq, opaque); +} + +static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, + bool per_vq_vectors, struct irq_affinity *desc) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + const char *name = dev_name(&vp_dev->vdev.dev); + unsigned int flags = PCI_IRQ_MSIX; + unsigned int i, v; + int err = -ENOMEM; + + vp_dev->msix_vectors = nvectors; + + vp_dev->msix_names = kmalloc_array(nvectors, + sizeof(*vp_dev->msix_names), + GFP_KERNEL); + if (!vp_dev->msix_names) + goto error; + vp_dev->msix_affinity_masks + = kcalloc(nvectors, sizeof(*vp_dev->msix_affinity_masks), + GFP_KERNEL); + if (!vp_dev->msix_affinity_masks) + goto error; + for (i = 0; i < nvectors; ++i) + if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i], + GFP_KERNEL)) + goto error; + + if (desc) { + flags |= PCI_IRQ_AFFINITY; + desc->pre_vectors++; /* virtio config vector */ + } + + err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors, + nvectors, flags, desc); + if (err < 0) + goto error; + vp_dev->msix_enabled = 1; + + /* Set the vector used for configuration */ + v = vp_dev->msix_used_vectors; + snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names, + "%s-config", name); + err = request_irq(pci_irq_vector(vp_dev->pci_dev, v), + vp_config_changed, 0, vp_dev->msix_names[v], + vp_dev); + if (err) + goto error; + ++vp_dev->msix_used_vectors; + + v = vp_dev->config_vector(vp_dev, v); + /* Verify we had enough resources to assign the vector */ + if (v == VIRTIO_MSI_NO_VECTOR) { + err = -EBUSY; + goto error; + } + + if (!per_vq_vectors) { + /* Shared vector for all VQs */ + v = vp_dev->msix_used_vectors; + snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names, + "%s-virtqueues", name); + err = request_irq(pci_irq_vector(vp_dev->pci_dev, v), + vp_vring_interrupt, 0, vp_dev->msix_names[v], + vp_dev); + if (err) + goto error; + ++vp_dev->msix_used_vectors; + } + return 0; +error: + return err; +} + +static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned int index, + void (*callback)(struct virtqueue *vq), + const char *name, + bool ctx, + u16 msix_vec) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL); + struct virtqueue *vq; + unsigned long flags; + + /* fill out our structure that represents an active queue */ + if (!info) + return ERR_PTR(-ENOMEM); + + vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx, + msix_vec); + if (IS_ERR(vq)) + goto out_info; + + info->vq = vq; + if (callback) { + spin_lock_irqsave(&vp_dev->lock, flags); + list_add(&info->node, &vp_dev->virtqueues); + spin_unlock_irqrestore(&vp_dev->lock, flags); + } else { + INIT_LIST_HEAD(&info->node); + } + + vp_dev->vqs[index] = info; + return vq; + +out_info: + kfree(info); + return vq; +} + +static void vp_del_vq(struct virtqueue *vq) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); + struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index]; + unsigned long flags; + + /* + * If it fails during re-enable reset vq. This way we won't rejoin + * info->node to the queue. Prevent unexpected irqs. + */ + if (!vq->reset) { + spin_lock_irqsave(&vp_dev->lock, flags); + list_del(&info->node); + spin_unlock_irqrestore(&vp_dev->lock, flags); + } + + vp_dev->del_vq(info); + kfree(info); +} + +/* the config->del_vqs() implementation */ +void vp_del_vqs(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtqueue *vq, *n; + int i; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) { + if (vp_dev->per_vq_vectors) { + int v = vp_dev->vqs[vq->index]->msix_vector; + + if (v != VIRTIO_MSI_NO_VECTOR) { + int irq = pci_irq_vector(vp_dev->pci_dev, v); + + irq_set_affinity_hint(irq, NULL); + free_irq(irq, vq); + } + } + vp_del_vq(vq); + } + vp_dev->per_vq_vectors = false; + + if (vp_dev->intx_enabled) { + free_irq(vp_dev->pci_dev->irq, vp_dev); + vp_dev->intx_enabled = 0; + } + + for (i = 0; i < vp_dev->msix_used_vectors; ++i) + free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev); + + if (vp_dev->msix_affinity_masks) { + for (i = 0; i < vp_dev->msix_vectors; i++) + free_cpumask_var(vp_dev->msix_affinity_masks[i]); + } + + if (vp_dev->msix_enabled) { + /* Disable the vector used for configuration */ + vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR); + + pci_free_irq_vectors(vp_dev->pci_dev); + vp_dev->msix_enabled = 0; + } + + vp_dev->msix_vectors = 0; + vp_dev->msix_used_vectors = 0; + kfree(vp_dev->msix_names); + vp_dev->msix_names = NULL; + kfree(vp_dev->msix_affinity_masks); + vp_dev->msix_affinity_masks = NULL; + kfree(vp_dev->vqs); + vp_dev->vqs = NULL; +} + +static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, + struct virtqueue *vqs[], vq_callback_t *callbacks[], + const char * const names[], bool per_vq_vectors, + const bool *ctx, + struct irq_affinity *desc) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + u16 msix_vec; + int i, err, nvectors, allocated_vectors, queue_idx = 0; + + vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL); + if (!vp_dev->vqs) + return -ENOMEM; + + if (per_vq_vectors) { + /* Best option: one for change interrupt, one per vq. */ + nvectors = 1; + for (i = 0; i < nvqs; ++i) + if (names[i] && callbacks[i]) + ++nvectors; + } else { + /* Second best: one for change, shared for all vqs. */ + nvectors = 2; + } + + err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors, + per_vq_vectors ? desc : NULL); + if (err) + goto error_find; + + vp_dev->per_vq_vectors = per_vq_vectors; + allocated_vectors = vp_dev->msix_used_vectors; + for (i = 0; i < nvqs; ++i) { + if (!names[i]) { + vqs[i] = NULL; + continue; + } + + if (!callbacks[i]) + msix_vec = VIRTIO_MSI_NO_VECTOR; + else if (vp_dev->per_vq_vectors) + msix_vec = allocated_vectors++; + else + msix_vec = VP_MSIX_VQ_VECTOR; + vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i], + ctx ? ctx[i] : false, + msix_vec); + if (IS_ERR(vqs[i])) { + err = PTR_ERR(vqs[i]); + goto error_find; + } + + if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR) + continue; + + /* allocate per-vq irq if available and necessary */ + snprintf(vp_dev->msix_names[msix_vec], + sizeof *vp_dev->msix_names, + "%s-%s", + dev_name(&vp_dev->vdev.dev), names[i]); + err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec), + vring_interrupt, 0, + vp_dev->msix_names[msix_vec], + vqs[i]); + if (err) + goto error_find; + } + return 0; + +error_find: + vp_del_vqs(vdev); + return err; +} + +static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, + struct virtqueue *vqs[], vq_callback_t *callbacks[], + const char * const names[], const bool *ctx) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + int i, err, queue_idx = 0; + + vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL); + if (!vp_dev->vqs) + return -ENOMEM; + + err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED, + dev_name(&vdev->dev), vp_dev); + if (err) + goto out_del_vqs; + + vp_dev->intx_enabled = 1; + vp_dev->per_vq_vectors = false; + for (i = 0; i < nvqs; ++i) { + if (!names[i]) { + vqs[i] = NULL; + continue; + } + vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i], + ctx ? ctx[i] : false, + VIRTIO_MSI_NO_VECTOR); + if (IS_ERR(vqs[i])) { + err = PTR_ERR(vqs[i]); + goto out_del_vqs; + } + } + + return 0; +out_del_vqs: + vp_del_vqs(vdev); + return err; +} + +/* the config->find_vqs() implementation */ +int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs, + struct virtqueue *vqs[], vq_callback_t *callbacks[], + const char * const names[], const bool *ctx, + struct irq_affinity *desc) +{ + int err; + + /* Try MSI-X with one vector per queue. */ + err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc); + if (!err) + return 0; + /* Fallback: MSI-X with one vector for config, one shared for queues. */ + err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc); + if (!err) + return 0; + /* Is there an interrupt? If not give up. */ + if (!(to_vp_device(vdev)->pci_dev->irq)) + return err; + /* Finally fall back to regular interrupts. */ + return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx); +} + +const char *vp_bus_name(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + return pci_name(vp_dev->pci_dev); +} + +/* Setup the affinity for a virtqueue: + * - force the affinity for per vq vector + * - OR over all affinities for shared MSI + * - ignore the affinity request if we're using INTX + */ +int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask) +{ + struct virtio_device *vdev = vq->vdev; + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index]; + struct cpumask *mask; + unsigned int irq; + + if (!vq->callback) + return -EINVAL; + + if (vp_dev->msix_enabled) { + mask = vp_dev->msix_affinity_masks[info->msix_vector]; + irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector); + if (!cpu_mask) + irq_set_affinity_hint(irq, NULL); + else { + cpumask_copy(mask, cpu_mask); + irq_set_affinity_hint(irq, mask); + } + } + return 0; +} + +const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + if (!vp_dev->per_vq_vectors || + vp_dev->vqs[index]->msix_vector == VIRTIO_MSI_NO_VECTOR) + return NULL; + + return pci_irq_get_affinity(vp_dev->pci_dev, + vp_dev->vqs[index]->msix_vector); +} + +#ifdef CONFIG_PM_SLEEP +static int virtio_pci_freeze(struct device *dev) +{ + struct pci_dev *pci_dev = to_pci_dev(dev); + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + int ret; + + ret = virtio_device_freeze(&vp_dev->vdev); + + if (!ret) + pci_disable_device(pci_dev); + return ret; +} + +static int virtio_pci_restore(struct device *dev) +{ + struct pci_dev *pci_dev = to_pci_dev(dev); + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + int ret; + + ret = pci_enable_device(pci_dev); + if (ret) + return ret; + + pci_set_master(pci_dev); + return virtio_device_restore(&vp_dev->vdev); +} + +static const struct dev_pm_ops virtio_pci_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore) +}; +#endif + + +/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */ +static const struct pci_device_id virtio_pci_id_table[] = { + { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) }, + { 0 } +}; + +MODULE_DEVICE_TABLE(pci, virtio_pci_id_table); + +static void virtio_pci_release_dev(struct device *_d) +{ + struct virtio_device *vdev = dev_to_virtio(_d); + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + + /* As struct device is a kobject, it's not safe to + * free the memory (including the reference counter itself) + * until it's release callback. */ + kfree(vp_dev); +} + +static int virtio_pci_probe(struct pci_dev *pci_dev, + const struct pci_device_id *id) +{ + struct virtio_pci_device *vp_dev, *reg_dev = NULL; + int rc; + + /* allocate our structure and fill it out */ + vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL); + if (!vp_dev) + return -ENOMEM; + + pci_set_drvdata(pci_dev, vp_dev); + vp_dev->vdev.dev.parent = &pci_dev->dev; + vp_dev->vdev.dev.release = virtio_pci_release_dev; + vp_dev->pci_dev = pci_dev; + INIT_LIST_HEAD(&vp_dev->virtqueues); + spin_lock_init(&vp_dev->lock); + + /* enable the device */ + rc = pci_enable_device(pci_dev); + if (rc) + goto err_enable_device; + + if (force_legacy) { + rc = virtio_pci_legacy_probe(vp_dev); + /* Also try modern mode if we can't map BAR0 (no IO space). */ + if (rc == -ENODEV || rc == -ENOMEM) + rc = virtio_pci_modern_probe(vp_dev); + if (rc) + goto err_probe; + } else { + rc = virtio_pci_modern_probe(vp_dev); + if (rc == -ENODEV) + rc = virtio_pci_legacy_probe(vp_dev); + if (rc) + goto err_probe; + } + + pci_set_master(pci_dev); + + rc = register_virtio_device(&vp_dev->vdev); + reg_dev = vp_dev; + if (rc) + goto err_register; + + return 0; + +err_register: + if (vp_dev->is_legacy) + virtio_pci_legacy_remove(vp_dev); + else + virtio_pci_modern_remove(vp_dev); +err_probe: + pci_disable_device(pci_dev); +err_enable_device: + if (reg_dev) + put_device(&vp_dev->vdev.dev); + else + kfree(vp_dev); + return rc; +} + +static void virtio_pci_remove(struct pci_dev *pci_dev) +{ + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + struct device *dev = get_device(&vp_dev->vdev.dev); + + /* + * Device is marked broken on surprise removal so that virtio upper + * layers can abort any ongoing operation. + */ + if (!pci_device_is_present(pci_dev)) + virtio_break_device(&vp_dev->vdev); + + pci_disable_sriov(pci_dev); + + unregister_virtio_device(&vp_dev->vdev); + + if (vp_dev->is_legacy) + virtio_pci_legacy_remove(vp_dev); + else + virtio_pci_modern_remove(vp_dev); + + pci_disable_device(pci_dev); + put_device(dev); +} + +static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int num_vfs) +{ + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + struct virtio_device *vdev = &vp_dev->vdev; + int ret; + + if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK)) + return -EBUSY; + + if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV)) + return -EINVAL; + + if (pci_vfs_assigned(pci_dev)) + return -EPERM; + + if (num_vfs == 0) { + pci_disable_sriov(pci_dev); + return 0; + } + + ret = pci_enable_sriov(pci_dev, num_vfs); + if (ret < 0) + return ret; + + return num_vfs; +} + +static struct pci_driver virtio_pci_driver = { + .name = "virtio-pci", + .id_table = virtio_pci_id_table, + .probe = virtio_pci_probe, + .remove = virtio_pci_remove, +#ifdef CONFIG_PM_SLEEP + .driver.pm = &virtio_pci_pm_ops, +#endif + .sriov_configure = virtio_pci_sriov_configure, +}; + +module_pci_driver(virtio_pci_driver); + +MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>"); +MODULE_DESCRIPTION("virtio-pci"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1"); |