On Thu, Mar 21, 2013 at 06:59:34PM +1030, Rusty Russell wrote:
> Differences:
> 1) Uses 4 pci capabilities to demark common, irq, notify and dev-specific areas.
> 2) Guest sets queue size, using host-provided maximum.
> 3) Guest sets queue alignment, rather than ABI-defined 4096.
> 4) More than 32 feature bits (a lot more!).
>
> Signed-off-by: Rusty Russell <rustcorp.com.au>
> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> ---
> drivers/virtio/Makefile | 1 +
> drivers/virtio/virtio_pci.c | 979 +++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 980 insertions(+)
> create mode 100644 drivers/virtio/virtio_pci.c
>
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> index 23834f5..eec0a42 100644
> --- a/drivers/virtio/Makefile
> +++ b/drivers/virtio/Makefile
> @@ -1,4 +1,5 @@
> obj-$(CONFIG_VIRTIO) += virtio.o virtio_ring.o
> obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
> +obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
> obj-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
> obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
> diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
> new file mode 100644
> index 0000000..b86b99c
> --- /dev/null
> +++ b/drivers/virtio/virtio_pci.c
> @@ -0,0 +1,979 @@
> +/*
> + * Virtio PCI driver
> + *
> + * This module allows virtio devices to be used over a virtual PCI
> + * device. Copyright 2011, Rusty Russell IBM Corporation, but based
> + * on the older virtio_pci_legacy.c, which was Copyright IBM
> + * Corp. 2007.
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +#define VIRTIO_PCI_NO_LEGACY
> +#include <linux/module.h>
> +#include <linux/list.h>
> +#include <linux/pci.h>
> +#include <linux/slab.h>
> +#include <linux/interrupt.h>
> +#include <linux/virtio.h>
> +#include <linux/virtio_config.h>
> +#include <linux/virtio_ring.h>
> +#include <linux/virtio_pci.h>
> +#include <linux/highmem.h>
> +#include <linux/spinlock.h>
> +
> +MODULE_AUTHOR("Rusty Russell <rusty@xxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("virtio-pci");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION("2");
> +
> +/* Our device structure */
> +struct virtio_pci_device {
> + struct virtio_device vdev;
> + struct pci_dev *pci_dev;
> +
> + /* The IO mapping for the PCI config space */
> + struct virtio_pci_common_cfg __iomem *common;
> + /* Where to read and clear interrupt */
> + u8 __iomem *isr;
> + /* Write the virtqueue index here to notify device of activity. */
> + __le16 __iomem *notify;
> + /* Device-specific data. */
> + void __iomem *device;
> +
> + /* a list of queues so we can dispatch IRQs */
> + spinlock_t lock;
> + struct list_head virtqueues;
> +
> + /* MSI-X support */
> + int msix_enabled;
> + int intx_enabled;
> + struct msix_entry *msix_entries;
> + cpumask_var_t *msix_affinity_masks;
> + /* Name strings for interrupts. This size should be enough,
> + * and I'm too lazy to allocate each name separately. */
> + char (*msix_names)[256];
> + /* Number of available vectors */
> + unsigned msix_vectors;
> + /* Vectors allocated, excluding per-vq vectors if any */
> + unsigned msix_used_vectors;
> +
> + /* Status saved during hibernate/restore */
> + u8 saved_status;
> +
> + /* Whether we have vector per vq */
> + bool per_vq_vectors;
> +};
> +
> +/* Constants for MSI-X */
> +/* Use first vector for configuration changes, second and the rest for
> + * virtqueues Thus, we need at least 2 vectors for MSI. */
> +enum {
> + VP_MSIX_CONFIG_VECTOR = 0,
> + VP_MSIX_VQ_VECTOR = 1,
> +};
In the future, I have a plan to allow one vector only. To make this
work without exits for data path VQ, we could make hypervisor set a bit
in guest memory whenever it wants to signal a configuration change.
Guest will execute a config write that will make the hypervisor clear
this register.
I guess this can wait, we are putting too stuff much into this
new layout patchset already.
> +
> +struct virtio_pci_vq_info {
> + /* the actual virtqueue */
> + struct virtqueue *vq;
> +
> + /* the pages used for the queue. */
> + void *queue;
> +
> + /* the list node for the virtqueues list */
> + struct list_head node;
> +
> + /* MSI-X vector (or none) */
> + unsigned msix_vector;
> +};
> +
> +/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
> +static DEFINE_PCI_DEVICE_TABLE(virtio_pci_id_table) = {
> + { PCI_DEVICE(0x1af4, PCI_ANY_ID) },
> + { 0 }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
> +
> +/* Convert a generic virtio device to our structure */
> +static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
> +{
> + return container_of(vdev, struct virtio_pci_device, vdev);
> +}
> +
> +/* There is no iowrite64. We use two 32-bit ops. */
> +static void iowrite64(u64 val, const __le64 *addr)
> +{
> + iowrite32((u32)val, (__le32 *)addr);
> + iowrite32(val >> 32, (__le32 *)addr + 1);
> +}
> +
> +/* There is no ioread64. We use two 32-bit ops. */
> +static u64 ioread64(__le64 *addr)
> +{
> + return ioread32(addr) | ((u64)ioread32((__le32 *)addr + 1) << 32);
> +}
> +
> +static u64 vp_get_features(struct virtio_device *vdev)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + u64 features;
> +
> + iowrite32(0, &vp_dev->common->device_feature_select);
> + features = ioread32(&vp_dev->common->device_feature);
> + iowrite32(1, &vp_dev->common->device_feature_select);
> + features |= ((u64)ioread32(&vp_dev->common->device_feature) << 32);
> + return features;
> +}
> +
> +static void 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);
> +
> + iowrite32(0, &vp_dev->common->guest_feature_select);
> + iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
> + iowrite32(1, &vp_dev->common->guest_feature_select);
> + iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature);
> +}
> +
> +/* virtio config->get() implementation */
> +static void vp_get(struct virtio_device *vdev, unsigned offset,
> + void *buf, unsigned len)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + void __iomem *ioaddr = vp_dev->device + offset;
> + u8 *ptr = buf;
> + int i;
> +
> + for (i = 0; i < len; i++)
> + ptr[i] = ioread8(ioaddr + i);
> +}
> +
> +#define VP_GETx(bits) \
> +static u##bits vp_get##bits(struct virtio_device *vdev, unsigned int offset) \
> +{ \
> + u##bits v; \
> + vp_get(vdev, offset, &v, sizeof(v)); \
> + return v; \
> +}
> +
> +VP_GETx(8)
> +VP_GETx(16)
> +VP_GETx(32)
> +VP_GETx(64)
> +
> +/* the config->set() implementation. it's symmetric to the config->get()
> + * implementation */
> +static void vp_set(struct virtio_device *vdev, unsigned offset,
> + const void *buf, unsigned len)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + void __iomem *ioaddr = vp_dev->device + offset;
> + const u8 *ptr = buf;
> + int i;
> +
> + for (i = 0; i < len; i++)
> + iowrite8(ptr[i], ioaddr + i);
> +}
> +
> +#define VP_SETx(bits) \
> +static void vp_set##bits(struct virtio_device *vdev, unsigned int offset, \
> + u##bits v) \
> +{ \
> + vp_set(vdev, offset, &v, sizeof(v)); \
> +}
> +
> +VP_SETx(8)
> +VP_SETx(16)
> +VP_SETx(32)
> +VP_SETx(64)
> +
> +/* 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 ioread8(&vp_dev->common->device_status);
> +}
> +
> +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);
> + iowrite8(status, &vp_dev->common->device_status);
> +}
> +
> +/* wait for pending irq handlers */
> +static 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(vp_dev->msix_entries[i].vector);
> +}
> +
> +static void vp_reset(struct virtio_device *vdev)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + /* 0 status means a reset. */
> + iowrite8(0, &vp_dev->common->device_status);
> + /* Flush out the status write, and flush in device writes,
> + * including MSi-X interrupts, if any. */
MSI-X ?
> + ioread8(&vp_dev->common->device_status);
> + /* Flush pending VQ/configuration callbacks. */
> + vp_synchronize_vectors(vdev);
> +}
> +
> +/* the notify function used when creating a virt queue */
> +static void vp_notify(struct virtqueue *vq)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
> +
> + /* we write the queue's selector into the notification register to
> + * signal the other end */
> + iowrite16(vq->index, vp_dev->notify);
> +}
> +
> +/* 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;
> + struct virtio_driver *drv;
> + drv = container_of(vp_dev->vdev.dev.driver,
> + struct virtio_driver, driver);
> +
> + if (drv->config_changed)
> + drv->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 void vp_free_vectors(struct virtio_device *vdev)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + int i;
> +
> + 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(vp_dev->msix_entries[i].vector, vp_dev);
> +
> + for (i = 0; i < vp_dev->msix_vectors; i++)
> + if (vp_dev->msix_affinity_masks[i])
> + free_cpumask_var(vp_dev->msix_affinity_masks[i]);
> +
> + if (vp_dev->msix_enabled) {
> + /* Disable the vector used for configuration */
> + iowrite16(VIRTIO_MSI_NO_VECTOR, &vp_dev->common->msix_config);
> + /* Flush the write out to device */
> + ioread16(&vp_dev->common->msix_config);
> +
> + pci_disable_msix(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_entries);
> + vp_dev->msix_entries = NULL;
> + kfree(vp_dev->msix_affinity_masks);
> + vp_dev->msix_affinity_masks = NULL;
> +}
> +
> +static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
> + bool per_vq_vectors)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + const char *name = dev_name(&vp_dev->vdev.dev);
> + unsigned i, v;
> + int err = -ENOMEM;
> +
> + vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
> + GFP_KERNEL);
> + if (!vp_dev->msix_entries)
> + goto error;
> + vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
> + GFP_KERNEL);
> + if (!vp_dev->msix_names)
> + goto error;
> + vp_dev->msix_affinity_masks
> + = kzalloc(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;
> +
> + for (i = 0; i < nvectors; ++i)
> + vp_dev->msix_entries[i].entry = i;
> +
> + /* pci_enable_msix returns positive if we can't get this many. */
> + err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
> + if (err > 0)
> + err = -ENOSPC;
> + if (err)
> + goto error;
> + vp_dev->msix_vectors = nvectors;
> + 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(vp_dev->msix_entries[v].vector,
> + vp_config_changed, 0, vp_dev->msix_names[v],
> + vp_dev);
> + if (err)
> + goto error;
> + ++vp_dev->msix_used_vectors;
> +
> + iowrite16(v, &vp_dev->common->msix_config);
> + /* Verify we had enough resources to assign the vector */
> + v = ioread16(&vp_dev->common->msix_config);
> + 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(vp_dev->msix_entries[v].vector,
> + vp_vring_interrupt, 0, vp_dev->msix_names[v],
> + vp_dev);
> + if (err)
> + goto error;
> + ++vp_dev->msix_used_vectors;
> + }
> + return 0;
> +error:
> + vp_free_vectors(vdev);
> + return err;
> +}
> +
> +static int vp_request_intx(struct virtio_device *vdev)
> +{
> + int err;
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> +
> + err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
> + IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
> + if (!err)
> + vp_dev->intx_enabled = 1;
> + return err;
> +}
> +
> +static size_t vring_pci_size(u16 num)
> +{
> + /* We only need a cacheline separation. */
> + return PAGE_ALIGN(vring_size(num, SMP_CACHE_BYTES));
> +}
> +
> +static void *alloc_virtqueue_pages(u16 *num)
> +{
> + void *pages;
> +
> + /* 1024 entries uses about 32k */
> + if (*num > 1024)
> + *num = 1024;
> +
> + for (; *num; *num /= 2) {
> + pages = alloc_pages_exact(vring_pci_size(*num),
> + GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
> + if (pages)
> + return pages;
> + }
> + return NULL;
> +}
> +
> +static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
> + void (*callback)(struct virtqueue *vq),
> + const char *name,
> + u16 msix_vec)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + struct virtio_pci_vq_info *info;
> + struct virtqueue *vq;
> + u16 num;
> + int err;
> +
> + /* Select the queue we're interested in */
> + iowrite16(index, &vp_dev->common->queue_select);
> +
> + switch (ioread64(&vp_dev->common->queue_address)) {
> + case 0xFFFFFFFFFFFFFFFFULL:
> + return ERR_PTR(-ENOENT);
> + case 0:
> + /* Uninitialized. Excellent. */
> + break;
> + default:
> + /* We've already set this up? */
> + return ERR_PTR(-EBUSY);
> + }
> +
> + /* Maximum size must be a power of 2. */
> + num = ioread16(&vp_dev->common->queue_size);
> + if (num & (num - 1)) {
> + dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + /* allocate and fill out our structure the represents an active
> + * queue */
> + info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
> + if (!info)
> + return ERR_PTR(-ENOMEM);
> +
> + info->msix_vector = msix_vec;
> +
> + info->queue = alloc_virtqueue_pages(&num);
> + if (info->queue == NULL) {
> + err = -ENOMEM;
> + goto out_info;
> + }
> +
> + /* create the vring */
> + vq = vring_new_virtqueue(index, num, SMP_CACHE_BYTES, vdev,
> + true, info->queue, vp_notify, callback, name);
> + if (!vq) {
> + err = -ENOMEM;
> + goto out_alloc_pages;
> + }
> +
> + vq->priv = info;
> + info->vq = vq;
> +
> + if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
> + iowrite16(msix_vec, &vp_dev->common->queue_msix_vector);
> + msix_vec = ioread16(&vp_dev->common->queue_msix_vector);
> + if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
> + err = -EBUSY;
> + goto out_new_virtqueue;
> + }
> + }
> +
> + if (callback) {
> + unsigned long flags;
> + 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);
> + }
> +
> + /* Activate the queue. */
> + iowrite64(virt_to_phys(info->queue), &vp_dev->common->queue_address);
> + iowrite16(SMP_CACHE_BYTES, &vp_dev->common->queue_align);
> + iowrite16(num, &vp_dev->common->queue_size);
> +
> + return vq;
> +
> +out_new_virtqueue:
> + vring_del_virtqueue(vq);
> +out_alloc_pages:
> + free_pages_exact(info->queue, vring_pci_size(num));
> +out_info:
> + kfree(info);
> + return ERR_PTR(err);
> +}
> +
> +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 = vq->priv;
> + unsigned long flags, size = vring_pci_size(vq->vring.num);
> +
> + spin_lock_irqsave(&vp_dev->lock, flags);
> + list_del(&info->node);
> + spin_unlock_irqrestore(&vp_dev->lock, flags);
> +
> + /* Select and deactivate the queue */
> + iowrite16(vq->index, &vp_dev->common->queue_select);
> +
> + if (vp_dev->msix_enabled) {
> + iowrite16(VIRTIO_MSI_NO_VECTOR,
> + &vp_dev->common->queue_msix_vector);
> + /* Flush the write out to device */
> + ioread16(&vp_dev->common->queue_msix_vector);
> + }
> +
> + vring_del_virtqueue(vq);
> +
> + /* This is for our own benefit, not the device's! */
> + iowrite64(0, &vp_dev->common->queue_address);
> + iowrite16(0, &vp_dev->common->queue_size);
> + iowrite16(0, &vp_dev->common->queue_align);
> +
> + free_pages_exact(info->queue, size);
> + kfree(info);
> +}
> +
> +/* the config->del_vqs() implementation */
> +static void vp_del_vqs(struct virtio_device *vdev)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + struct virtqueue *vq, *n;
> + struct virtio_pci_vq_info *info;
> +
> + list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
> + info = vq->priv;
> + if (vp_dev->per_vq_vectors &&
> + info->msix_vector != VIRTIO_MSI_NO_VECTOR)
> + free_irq(vp_dev->msix_entries[info->msix_vector].vector,
> + vq);
> + vp_del_vq(vq);
> + }
> + vp_dev->per_vq_vectors = false;
> +
> + vp_free_vectors(vdev);
> +}
> +
> +static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
> + struct virtqueue *vqs[],
> + vq_callback_t *callbacks[],
> + const char *names[],
> + bool use_msix,
> + bool per_vq_vectors)
> +{
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + u16 msix_vec;
> + int i, err, nvectors, allocated_vectors;
> +
> + if (!use_msix) {
> + /* Old style: one normal interrupt for change and all vqs. */
> + err = vp_request_intx(vdev);
> + if (err)
> + goto error_request;
> + } else {
> + if (per_vq_vectors) {
> + /* Best option: one for change interrupt, one per vq. */
> + nvectors = 1;
> + for (i = 0; i < nvqs; ++i)
> + if (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);
> + if (err)
> + goto error_request;
> + }
> +
> + 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;
> + } else if (!callbacks[i] || !vp_dev->msix_enabled)
> + 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] = setup_vq(vdev, i, callbacks[i], names[i], 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(vp_dev->msix_entries[msix_vec].vector,
> + vring_interrupt, 0,
> + vp_dev->msix_names[msix_vec],
> + vqs[i]);
> + if (err) {
> + vp_del_vq(vqs[i]);
> + goto error_find;
> + }
> + }
> + return 0;
> +
> +error_find:
> + vp_del_vqs(vdev);
> +
> +error_request:
> + return err;
> +}
> +
> +/* the config->find_vqs() implementation */
> +static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
> + struct virtqueue *vqs[],
> + vq_callback_t *callbacks[],
> + const char *names[])
> +{
> + int err;
> +
> + /* Try MSI-X with one vector per queue. */
> + err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
> + if (!err)
> + return 0;
> + /* Fallback: MSI-X with one vector for config, one shared for queues. */
> + err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
> + true, false);
> + if (!err)
> + return 0;
> + /* Finally fall back to regular interrupts. */
> + return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
> + false, false);
> +}
> +
> +static 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
> + */
> +static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
> +{
> + struct virtio_device *vdev = vq->vdev;
> + struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> + struct virtio_pci_vq_info *info = vq->priv;
> + 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 = vp_dev->msix_entries[info->msix_vector].vector;
> + if (cpu == -1)
> + irq_set_affinity_hint(irq, NULL);
> + else {
> + cpumask_set_cpu(cpu, mask);
> + irq_set_affinity_hint(irq, mask);
> + }
> + }
> + return 0;
> +}
> +
> +static const struct virtio_config_ops virtio_pci_config_ops = {
> + .get8 = vp_get8,
> + .set8 = vp_set8,
> + .get16 = vp_get16,
> + .set16 = vp_set16,
> + .get32 = vp_get32,
> + .set32 = vp_set32,
> + .get64 = vp_get64,
> + .set64 = vp_set64,
> + .get_status = vp_get_status,
> + .set_status = vp_set_status,
> + .reset = vp_reset,
> + .find_vqs = vp_find_vqs,
> + .del_vqs = vp_del_vqs,
> + .get_features = vp_get_features,
> + .finalize_features = vp_finalize_features,
> + .bus_name = vp_bus_name,
> + .set_vq_affinity = vp_set_vq_affinity,
> +};
> +
> +static void virtio_pci_release_dev(struct device *_d)
> +{
> + /*
> + * No need for a release method as we allocate/free
> + * all devices together with the pci devices.
> + * Provide an empty one to avoid getting a warning from core.
> + */
> +}
> +
> +static void __iomem *map_capability(struct pci_dev *dev, int off, size_t expect)
> +{
> + u8 bar;
> + u32 offset, length;
> + void __iomem *p;
> +
> + pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, bar),
> + &bar);
> + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, offset),
> + &offset);
> + pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
> + &length);
> +
> + if (length < expect) {
> + dev_err(&dev->dev,
> + "virtio_pci: small capability len %u (%u expected)\n",
> + length, expect);
> + return NULL;
> + }
> +
> + /* We want uncachable mapping, even if bar is cachable. */
> + p = pci_iomap_range(dev, bar, offset, length, PAGE_SIZE, true);
> + if (!p)
> + dev_err(&dev->dev,
> + "virtio_pci: unable to map virtio %u@%u on bar %i\n",
> + length, offset, bar);
> + return p;
> +}
> +
> +
> +/* the PCI probing function */
> +static int virtio_pci_probe(struct pci_dev *pci_dev,
> + const struct pci_device_id *id)
> +{
> + struct virtio_pci_device *vp_dev;
> + int err, common, isr, notify, device;
> +
> + /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
> + if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
> + return -ENODEV;
> +
> + if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
> + printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
> + VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
> + return -ENODEV;
> + }
> +
> + /* check for a common config: if not, use legacy mode (bar 0). */
> + common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG,
> + IORESOURCE_IO|IORESOURCE_MEM);
> + if (!common) {
> + dev_info(&pci_dev->dev,
> + "virtio_pci: leaving for legacy driver\n");
> + return -ENODEV;
> + }
> +
> + /* If common is there, these should be too... */
> + isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG,
> + IORESOURCE_IO|IORESOURCE_MEM);
> + notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG,
> + IORESOURCE_IO|IORESOURCE_MEM);
> + device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG,
> + IORESOURCE_IO|IORESOURCE_MEM);
> + if (!isr || !notify || !device) {
> + dev_err(&pci_dev->dev,
> + "virtio_pci: missing capabilities %i/%i/%i/%i\n",
> + common, isr, notify, device);
> + return -EINVAL;
> + }
> +
> + /* allocate our structure and fill it out */
> + vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
> + if (vp_dev == NULL)
> + return -ENOMEM;
> +
> + vp_dev->vdev.dev.parent = &pci_dev->dev;
> + vp_dev->vdev.dev.release = virtio_pci_release_dev;
> + vp_dev->vdev.config = &virtio_pci_config_ops;
> + vp_dev->pci_dev = pci_dev;
> + INIT_LIST_HEAD(&vp_dev->virtqueues);
> + spin_lock_init(&vp_dev->lock);
> +
> + /* Disable MSI/MSIX to bring device to a known good state. */
> + pci_msi_off(pci_dev);
> +
> + /* enable the device */
> + err = pci_enable_device(pci_dev);
> + if (err)
> + goto out;
> +
> + err = pci_request_regions(pci_dev, "virtio-pci");
> + if (err)
> + goto out_enable_device;
> +
> + err = -EINVAL;
> + vp_dev->common = map_capability(pci_dev, common,
> + sizeof(struct virtio_pci_common_cfg));
> + if (!vp_dev->common)
> + goto out_req_regions;
> + vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8));
> + if (!vp_dev->isr)
> + goto out_map_common;
> + vp_dev->notify = map_capability(pci_dev, notify, sizeof(u16));
> + if (!vp_dev->notify)
> + goto out_map_isr;
> + vp_dev->device = map_capability(pci_dev, device, 0);
> + if (!vp_dev->device)
> + goto out_map_notify;
> +
> + pci_set_drvdata(pci_dev, vp_dev);
> + pci_set_master(pci_dev);
> +
> + /* we use the subsystem vendor/device id as the virtio vendor/device
> + * id. this allows us to use the same PCI vendor/device id for all
> + * virtio devices and to identify the particular virtio driver by
> + * the subsystem ids */
> + vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
> + vp_dev->vdev.id.device = pci_dev->subsystem_device;
> +
> + /* finally register the virtio device */
> + err = register_virtio_device(&vp_dev->vdev);
> + if (err)
> + goto out_set_drvdata;
> +
> + return 0;
> +
> +out_set_drvdata:
> + pci_set_drvdata(pci_dev, NULL);
> + pci_iounmap(pci_dev, vp_dev->device);
> +out_map_notify:
> + pci_iounmap(pci_dev, vp_dev->notify);
> +out_map_isr:
> + pci_iounmap(pci_dev, vp_dev->isr);
> +out_map_common:
> + pci_iounmap(pci_dev, vp_dev->common);
> +out_req_regions:
> + pci_release_regions(pci_dev);
> +out_enable_device:
> + pci_disable_device(pci_dev);
> +out:
> + kfree(vp_dev);
> + return err;
> +}
> +
> +static void virtio_pci_remove(struct pci_dev *pci_dev)
> +{
> + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
> +
> + unregister_virtio_device(&vp_dev->vdev);
> +
> + vp_del_vqs(&vp_dev->vdev);
> + pci_set_drvdata(pci_dev, NULL);
> + pci_iounmap(pci_dev, vp_dev->device);
> + pci_iounmap(pci_dev, vp_dev->notify);
> + pci_iounmap(pci_dev, vp_dev->isr);
> + pci_iounmap(pci_dev, vp_dev->common);
> + pci_release_regions(pci_dev);
> + pci_disable_device(pci_dev);
> + kfree(vp_dev);
> +}
> +
> +#ifdef CONFIG_PM
> +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);
> + struct virtio_driver *drv;
> + int ret;
> +
> + drv = container_of(vp_dev->vdev.dev.driver,
> + struct virtio_driver, driver);
> +
> + ret = 0;
> + vp_dev->saved_status = vp_get_status(&vp_dev->vdev);
> + if (drv && drv->freeze)
> + ret = drv->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);
> + struct virtio_driver *drv;
> + int ret;
> +
> + drv = container_of(vp_dev->vdev.dev.driver,
> + struct virtio_driver, driver);
> +
> + ret = pci_enable_device(pci_dev);
> + if (ret)
> + return ret;
> +
> + pci_set_master(pci_dev);
> + vp_finalize_features(&vp_dev->vdev);
> +
> + if (drv && drv->restore)
> + ret = drv->restore(&vp_dev->vdev);
> +
> + /* Finally, tell the device we're all set */
> + if (!ret)
> + vp_set_status(&vp_dev->vdev, vp_dev->saved_status);
> +
> + return ret;
> +}
> +
> +static const struct dev_pm_ops virtio_pci_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
> +};
> +#endif
> +
> +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
> + .driver.pm = &virtio_pci_pm_ops,
> +#endif
> +};
> +
> +module_pci_driver(virtio_pci_driver);
> --
> 1.7.10.4
>
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