diff options
Diffstat (limited to 'drivers/vfio/pci/virtio/legacy_io.c')
| -rw-r--r-- | drivers/vfio/pci/virtio/legacy_io.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/vfio/pci/virtio/legacy_io.c b/drivers/vfio/pci/virtio/legacy_io.c new file mode 100644 index 000000000000..20382ee15fac --- /dev/null +++ b/drivers/vfio/pci/virtio/legacy_io.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/pm_runtime.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/vfio.h> +#include <linux/vfio_pci_core.h> +#include <linux/virtio_pci.h> +#include <linux/virtio_net.h> +#include <linux/virtio_pci_admin.h> + +#include "common.h" + +static int +virtiovf_issue_legacy_rw_cmd(struct virtiovf_pci_core_device *virtvdev, + loff_t pos, char __user *buf, + size_t count, bool read) +{ + bool msix_enabled = + (virtvdev->core_device.irq_type == VFIO_PCI_MSIX_IRQ_INDEX); + struct pci_dev *pdev = virtvdev->core_device.pdev; + u8 *bar0_buf = virtvdev->bar0_virtual_buf; + bool common; + u8 offset; + int ret; + + common = pos < VIRTIO_PCI_CONFIG_OFF(msix_enabled); + /* offset within the relevant configuration area */ + offset = common ? pos : pos - VIRTIO_PCI_CONFIG_OFF(msix_enabled); + mutex_lock(&virtvdev->bar_mutex); + if (read) { + if (common) + ret = virtio_pci_admin_legacy_common_io_read(pdev, offset, + count, bar0_buf + pos); + else + ret = virtio_pci_admin_legacy_device_io_read(pdev, offset, + count, bar0_buf + pos); + if (ret) + goto out; + if (copy_to_user(buf, bar0_buf + pos, count)) + ret = -EFAULT; + } else { + if (copy_from_user(bar0_buf + pos, buf, count)) { + ret = -EFAULT; + goto out; + } + + if (common) + ret = virtio_pci_admin_legacy_common_io_write(pdev, offset, + count, bar0_buf + pos); + else + ret = virtio_pci_admin_legacy_device_io_write(pdev, offset, + count, bar0_buf + pos); + } +out: + mutex_unlock(&virtvdev->bar_mutex); + return ret; +} + +static int +virtiovf_pci_bar0_rw(struct virtiovf_pci_core_device *virtvdev, + loff_t pos, char __user *buf, + size_t count, bool read) +{ + struct vfio_pci_core_device *core_device = &virtvdev->core_device; + struct pci_dev *pdev = core_device->pdev; + u16 queue_notify; + int ret; + + if (!(le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO)) + return -EIO; + + if (pos + count > virtvdev->bar0_virtual_buf_size) + return -EINVAL; + + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret) { + pci_info_ratelimited(pdev, "runtime resume failed %d\n", ret); + return -EIO; + } + + switch (pos) { + case VIRTIO_PCI_QUEUE_NOTIFY: + if (count != sizeof(queue_notify)) { + ret = -EINVAL; + goto end; + } + if (read) { + ret = vfio_pci_core_ioread16(core_device, true, &queue_notify, + virtvdev->notify_addr); + if (ret) + goto end; + if (copy_to_user(buf, &queue_notify, + sizeof(queue_notify))) { + ret = -EFAULT; + goto end; + } + } else { + if (copy_from_user(&queue_notify, buf, count)) { + ret = -EFAULT; + goto end; + } + ret = vfio_pci_core_iowrite16(core_device, true, queue_notify, + virtvdev->notify_addr); + } + break; + default: + ret = virtiovf_issue_legacy_rw_cmd(virtvdev, pos, buf, count, + read); + } + +end: + pm_runtime_put(&pdev->dev); + return ret ? ret : count; +} + +static ssize_t virtiovf_pci_read_config(struct vfio_device *core_vdev, + char __user *buf, size_t count, + loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + size_t register_offset; + loff_t copy_offset; + size_t copy_count; + __le32 val32; + __le16 val16; + u8 val8; + int ret; + + ret = vfio_pci_core_read(core_vdev, buf, count, ppos); + if (ret < 0) + return ret; + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_DEVICE_ID, + sizeof(val16), ©_offset, + ©_count, ®ister_offset)) { + val16 = cpu_to_le16(VIRTIO_TRANS_ID_NET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, copy_count)) + return -EFAULT; + } + + if ((le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO) && + vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND, + sizeof(val16), ©_offset, + ©_count, ®ister_offset)) { + if (copy_from_user((void *)&val16 + register_offset, buf + copy_offset, + copy_count)) + return -EFAULT; + val16 |= cpu_to_le16(PCI_COMMAND_IO); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_REVISION_ID, + sizeof(val8), ©_offset, + ©_count, ®ister_offset)) { + /* Transional needs to have revision 0 */ + val8 = 0; + if (copy_to_user(buf + copy_offset, &val8, copy_count)) + return -EFAULT; + } + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, + sizeof(val32), ©_offset, + ©_count, ®ister_offset)) { + u32 bar_mask = ~(virtvdev->bar0_virtual_buf_size - 1); + u32 pci_base_addr_0 = le32_to_cpu(virtvdev->pci_base_addr_0); + + val32 = cpu_to_le32((pci_base_addr_0 & bar_mask) | PCI_BASE_ADDRESS_SPACE_IO); + if (copy_to_user(buf + copy_offset, (void *)&val32 + register_offset, copy_count)) + return -EFAULT; + } + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_ID, + sizeof(val16), ©_offset, + ©_count, ®ister_offset)) { + /* + * Transitional devices use the PCI subsystem device id as + * virtio device id, same as legacy driver always did. + */ + val16 = cpu_to_le16(VIRTIO_ID_NET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID, + sizeof(val16), ©_offset, + ©_count, ®ister_offset)) { + val16 = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + return count; +} + +ssize_t virtiovf_pci_core_read(struct vfio_device *core_vdev, char __user *buf, + size_t count, loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + + if (!count) + return 0; + + if (index == VFIO_PCI_CONFIG_REGION_INDEX) + return virtiovf_pci_read_config(core_vdev, buf, count, ppos); + + if (index == VFIO_PCI_BAR0_REGION_INDEX) + return virtiovf_pci_bar0_rw(virtvdev, pos, buf, count, true); + + return vfio_pci_core_read(core_vdev, buf, count, ppos); +} + +static ssize_t virtiovf_pci_write_config(struct vfio_device *core_vdev, + const char __user *buf, size_t count, + loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + size_t register_offset; + loff_t copy_offset; + size_t copy_count; + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND, + sizeof(virtvdev->pci_cmd), + ©_offset, ©_count, + ®ister_offset)) { + if (copy_from_user((void *)&virtvdev->pci_cmd + register_offset, + buf + copy_offset, + copy_count)) + return -EFAULT; + } + + if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, + sizeof(virtvdev->pci_base_addr_0), + ©_offset, ©_count, + ®ister_offset)) { + if (copy_from_user((void *)&virtvdev->pci_base_addr_0 + register_offset, + buf + copy_offset, + copy_count)) + return -EFAULT; + } + + return vfio_pci_core_write(core_vdev, buf, count, ppos); +} + +ssize_t virtiovf_pci_core_write(struct vfio_device *core_vdev, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + + if (!count) + return 0; + + if (index == VFIO_PCI_CONFIG_REGION_INDEX) + return virtiovf_pci_write_config(core_vdev, buf, count, ppos); + + if (index == VFIO_PCI_BAR0_REGION_INDEX) + return virtiovf_pci_bar0_rw(virtvdev, pos, (char __user *)buf, count, false); + + return vfio_pci_core_write(core_vdev, buf, count, ppos); +} + +int virtiovf_pci_ioctl_get_region_info(struct vfio_device *core_vdev, + unsigned int cmd, unsigned long arg) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + unsigned long minsz = offsetofend(struct vfio_region_info, offset); + void __user *uarg = (void __user *)arg; + struct vfio_region_info info = {}; + + if (copy_from_user(&info, uarg, minsz)) + return -EFAULT; + + if (info.argsz < minsz) + return -EINVAL; + + switch (info.index) { + case VFIO_PCI_BAR0_REGION_INDEX: + info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); + info.size = virtvdev->bar0_virtual_buf_size; + info.flags = VFIO_REGION_INFO_FLAG_READ | + VFIO_REGION_INFO_FLAG_WRITE; + return copy_to_user(uarg, &info, minsz) ? -EFAULT : 0; + default: + return vfio_pci_core_ioctl(core_vdev, cmd, arg); + } +} + +long virtiovf_vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd, + unsigned long arg) +{ + switch (cmd) { + case VFIO_DEVICE_GET_REGION_INFO: + return virtiovf_pci_ioctl_get_region_info(core_vdev, cmd, arg); + default: + return vfio_pci_core_ioctl(core_vdev, cmd, arg); + } +} + +static int virtiovf_set_notify_addr(struct virtiovf_pci_core_device *virtvdev) +{ + struct vfio_pci_core_device *core_device = &virtvdev->core_device; + int ret; + + /* + * Setup the BAR where the 'notify' exists to be used by vfio as well + * This will let us mmap it only once and use it when needed. + */ + ret = vfio_pci_core_setup_barmap(core_device, + virtvdev->notify_bar); + if (ret) + return ret; + + virtvdev->notify_addr = core_device->barmap[virtvdev->notify_bar] + + virtvdev->notify_offset; + return 0; +} + +int virtiovf_open_legacy_io(struct virtiovf_pci_core_device *virtvdev) +{ + if (!virtvdev->bar0_virtual_buf) + return 0; + + /* + * Upon close_device() the vfio_pci_core_disable() is called + * and will close all the previous mmaps, so it seems that the + * valid life cycle for the 'notify' addr is per open/close. + */ + return virtiovf_set_notify_addr(virtvdev); +} + +static int virtiovf_get_device_config_size(unsigned short device) +{ + /* Network card */ + return offsetofend(struct virtio_net_config, status); +} + +static int virtiovf_read_notify_info(struct virtiovf_pci_core_device *virtvdev) +{ + u64 offset; + int ret; + u8 bar; + + ret = virtio_pci_admin_legacy_io_notify_info(virtvdev->core_device.pdev, + VIRTIO_ADMIN_CMD_NOTIFY_INFO_FLAGS_OWNER_MEM, + &bar, &offset); + if (ret) + return ret; + + virtvdev->notify_bar = bar; + virtvdev->notify_offset = offset; + return 0; +} + +static bool virtiovf_bar0_exists(struct pci_dev *pdev) +{ + struct resource *res = pdev->resource; + + return res->flags; +} + +bool virtiovf_support_legacy_io(struct pci_dev *pdev) +{ + return virtio_pci_admin_has_legacy_io(pdev) && !virtiovf_bar0_exists(pdev); +} + +int virtiovf_init_legacy_io(struct virtiovf_pci_core_device *virtvdev) +{ + struct pci_dev *pdev = virtvdev->core_device.pdev; + int ret; + + ret = virtiovf_read_notify_info(virtvdev); + if (ret) + return ret; + + virtvdev->bar0_virtual_buf_size = VIRTIO_PCI_CONFIG_OFF(true) + + virtiovf_get_device_config_size(pdev->device); + BUILD_BUG_ON(!is_power_of_2(virtvdev->bar0_virtual_buf_size)); + virtvdev->bar0_virtual_buf = kzalloc(virtvdev->bar0_virtual_buf_size, + GFP_KERNEL); + if (!virtvdev->bar0_virtual_buf) + return -ENOMEM; + mutex_init(&virtvdev->bar_mutex); + return 0; +} + +void virtiovf_release_legacy_io(struct virtiovf_pci_core_device *virtvdev) +{ + kfree(virtvdev->bar0_virtual_buf); +} + +void virtiovf_legacy_io_reset_done(struct pci_dev *pdev) +{ + struct virtiovf_pci_core_device *virtvdev = dev_get_drvdata(&pdev->dev); + + virtvdev->pci_cmd = 0; +} |