// SPDX-License-Identifier: GPL-2.0-or-later /* * Virtio PCI driver - legacy device support * * 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 * Rusty Russell * Michael S. Tsirkin */ #include "linux/virtio_pci_legacy.h" #include "virtio_pci_common.h" /* virtio config->get_features() implementation */ static u64 vp_get_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* When someone needs more than 32 feature bits, we'll need to * steal a bit to indicate that the rest are somewhere else. */ return vp_legacy_get_features(&vp_dev->ldev); } /* virtio config->finalize_features() implementation */ static int vp_finalize_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* Give virtio_ring a chance to accept features. */ vring_transport_features(vdev); /* Make sure we don't have any features > 32 bits! */ BUG_ON((u32)vdev->features != vdev->features); /* We only support 32 feature bits. */ vp_legacy_set_features(&vp_dev->ldev, vdev->features); return 0; } /* virtio config->get() implementation */ static void vp_get(struct virtio_device *vdev, unsigned int offset, void *buf, unsigned int len) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); void __iomem *ioaddr = vp_dev->ldev.ioaddr + VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) + offset; u8 *ptr = buf; int i; for (i = 0; i < len; i++) ptr[i] = ioread8(ioaddr + i); } /* the config->set() implementation. it's symmetric to the config->get() * implementation */ static void vp_set(struct virtio_device *vdev, unsigned int offset, const void *buf, unsigned int len) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); void __iomem *ioaddr = vp_dev->ldev.ioaddr + VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) + offset; const u8 *ptr = buf; int i; for (i = 0; i < len; i++) iowrite8(ptr[i], ioaddr + i); } /* config->{get,set}_status() implementations */ static u8 vp_get_status(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); return vp_legacy_get_status(&vp_dev->ldev); } static void vp_set_status(struct virtio_device *vdev, u8 status) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* We should never be setting status to 0. */ BUG_ON(status == 0); vp_legacy_set_status(&vp_dev->ldev, status); } static void vp_reset(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* 0 status means a reset. */ vp_legacy_set_status(&vp_dev->ldev, 0); /* Flush out the status write, and flush in device writes, * including MSi-X interrupts, if any. */ vp_legacy_get_status(&vp_dev->ldev); /* Flush pending VQ/configuration callbacks. */ vp_synchronize_vectors(vdev); } static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) { return vp_legacy_config_vector(&vp_dev->ldev, vector); } static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, struct virtio_pci_vq_info *info, unsigned int index, void (*callback)(struct virtqueue *vq), const char *name, bool ctx, u16 msix_vec) { struct virtqueue *vq; u16 num; int err; u64 q_pfn; /* Check if queue is either not available or already active. */ num = vp_legacy_get_queue_size(&vp_dev->ldev, index); if (!num || vp_legacy_get_queue_enable(&vp_dev->ldev, index)) return ERR_PTR(-ENOENT); info->msix_vector = msix_vec; /* create the vring */ vq = vring_create_virtqueue(index, num, VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev, true, false, ctx, vp_notify, callback, name); if (!vq) return ERR_PTR(-ENOMEM); vq->num_max = num; q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT; if (q_pfn >> 32) { dev_err(&vp_dev->pci_dev->dev, "platform bug: legacy virtio-pci must not be used with RAM above 0x%llxGB\n", 0x1ULL << (32 + PAGE_SHIFT - 30)); err = -E2BIG; goto out_del_vq; } /* activate the queue */ vp_legacy_set_queue_address(&vp_dev->ldev, index, q_pfn); vq->priv = (void __force *)vp_dev->ldev.ioaddr + VIRTIO_PCI_QUEUE_NOTIFY; if (msix_vec != VIRTIO_MSI_NO_VECTOR) { msix_vec = vp_legacy_queue_vector(&vp_dev->ldev, index, msix_vec); if (msix_vec == VIRTIO_MSI_NO_VECTOR) { err = -EBUSY; goto out_deactivate; } } return vq; out_deactivate: vp_legacy_set_queue_address(&vp_dev->ldev, index, 0); out_del_vq: vring_del_virtqueue(vq); return ERR_PTR(err); } static void del_vq(struct virtio_pci_vq_info *info) { struct virtqueue *vq = info->vq; struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); if (vp_dev->msix_enabled) { vp_legacy_queue_vector(&vp_dev->ldev, vq->index, VIRTIO_MSI_NO_VECTOR); /* Flush the write out to device */ ioread8(vp_dev->ldev.ioaddr + VIRTIO_PCI_ISR); } /* Select and deactivate the queue */ vp_legacy_set_queue_address(&vp_dev->ldev, vq->index, 0); vring_del_virtqueue(vq); } static const struct virtio_config_ops virtio_pci_config_ops = { .get = vp_get, .set = vp_set, .get_status = vp_get_status, .set_status = vp_set_status, .reset = vp_reset, .find_vqs = vp_find_vqs, .del_vqs = vp_del_vqs, .synchronize_cbs = vp_synchronize_vectors, .get_features = vp_get_features, .finalize_features = vp_finalize_features, .bus_name = vp_bus_name, .set_vq_affinity = vp_set_vq_affinity, .get_vq_affinity = vp_get_vq_affinity, }; /* the PCI probing function */ int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) { struct virtio_pci_legacy_device *ldev = &vp_dev->ldev; struct pci_dev *pci_dev = vp_dev->pci_dev; int rc; ldev->pci_dev = pci_dev; rc = vp_legacy_probe(ldev); if (rc) return rc; vp_dev->isr = ldev->isr; vp_dev->vdev.id = ldev->id; vp_dev->vdev.config = &virtio_pci_config_ops; vp_dev->config_vector = vp_config_vector; vp_dev->setup_vq = setup_vq; vp_dev->del_vq = del_vq; vp_dev->is_legacy = true; return 0; } void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) { struct virtio_pci_legacy_device *ldev = &vp_dev->ldev; vp_legacy_remove(ldev); }