[PATCH V4 vfio 9/9] vfio/virtio: Introduce a vfio driver over virtio devices

Yishai Hadas
2023-11-29T14:39:20Z

Introduce a vfio driver over virtio devices to support the legacy
interface functionality for VFs.

Background, from the virtio spec [1].
--------------------------------------------------------------------
In some systems, there is a need to support a virtio legacy driver with
a device that does not directly support the legacy interface. In such
scenarios, a group owner device can provide the legacy interface
functionality for the group member devices. The driver of the owner
device can then access the legacy interface of a member device on behalf
of the legacy member device driver.

For example, with the SR-IOV group type, group members (VFs) can not
present the legacy interface in an I/O BAR in BAR0 as expected by the
legacy pci driver. If the legacy driver is running inside a virtual
machine, the hypervisor executing the virtual machine can present a
virtual device with an I/O BAR in BAR0. The hypervisor intercepts the
legacy driver accesses to this I/O BAR and forwards them to the group
owner device (PF) using group administration commands.
--------------------------------------------------------------------

Specifically, this driver adds support for a virtio-net VF to be exposed
as a transitional device to a guest driver and allows the legacy IO BAR
functionality on top.

This allows a VM which uses a legacy virtio-net driver in the guest to
work transparently over a VF which its driver in the host is that new
driver.

The driver can be extended easily to support some other types of virtio
devices (e.g virtio-blk), by adding in a few places the specific type
properties as was done for virtio-net.

For now, only the virtio-net use case was tested and as such we introduce
the support only for such a device.

Practically,
Upon probing a VF for a virtio-net device, in case its PF supports
legacy access over the virtio admin commands and the VF doesn't have BAR
0, we set some specific 'vfio_device_ops' to be able to simulate in SW a
transitional device with I/O BAR in BAR 0.

The existence of the simulated I/O bar is reported later on by
overwriting the VFIO_DEVICE_GET_REGION_INFO command and the device
exposes itself as a transitional device by overwriting some properties
upon reading its config space.

Once we report the existence of I/O BAR as BAR 0 a legacy driver in the
guest may use it via read/write calls according to the virtio
specification.

Any read/write towards the control parts of the BAR will be captured by
the new driver and will be translated into admin commands towards the
device.

Any data path read/write access (i.e. virtio driver notifications) will
be forwarded to the physical BAR which its properties were supplied by
the admin command VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO upon the
probing/init flow.

With that code in place a legacy driver in the guest has the look and
feel as if having a transitional device with legacy support for both its
control and data path flows.

[1]
https://github.com/oasis-tcs/virtio-spec/commit/03c2d32e5093ca9f2a17797242fbef88efe94b8c

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
---
MAINTAINERS | 7 +
drivers/vfio/pci/Kconfig | 2 +
drivers/vfio/pci/Makefile | 2 +
drivers/vfio/pci/virtio/Kconfig | 16 +
drivers/vfio/pci/virtio/Makefile | 4 +
drivers/vfio/pci/virtio/main.c | 554 +++++++++++++++++++++++++++++++
6 files changed, 585 insertions(+)
create mode 100644 drivers/vfio/pci/virtio/Kconfig
create mode 100644 drivers/vfio/pci/virtio/Makefile
create mode 100644 drivers/vfio/pci/virtio/main.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 012df8ccf34e..b246b769092d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22872,6 +22872,13 @@ L: kvm@vger.kernel.org
S: Maintained
F: drivers/vfio/pci/mlx5/

+VFIO VIRTIO PCI DRIVER
+M: Yishai Hadas <yishaih@nvidia.com>
+L: kvm@vger.kernel.org
+L: virtualization@lists.linux-foundation.org
+S: Maintained
+F: drivers/vfio/pci/virtio
+
VFIO PCI DEVICE SPECIFIC DRIVERS
R: Jason Gunthorpe <jgg@nvidia.com>
R: Yishai Hadas <yishaih@nvidia.com>
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 8125e5f37832..18c397df566d 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -65,4 +65,6 @@ source "drivers/vfio/pci/hisilicon/Kconfig"

source "drivers/vfio/pci/pds/Kconfig"

+source "drivers/vfio/pci/virtio/Kconfig"
+
endmenu
diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 45167be462d8..046139a4eca5 100644
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -13,3 +13,5 @@ obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5/
obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/

obj-$(CONFIG_PDS_VFIO_PCI) += pds/
+
+obj-$(CONFIG_VIRTIO_VFIO_PCI) += virtio/
diff --git a/drivers/vfio/pci/virtio/Kconfig b/drivers/vfio/pci/virtio/Kconfig
new file mode 100644
index 000000000000..3a6707639220
--- /dev/null
+++ b/drivers/vfio/pci/virtio/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config VIRTIO_VFIO_PCI
+ tristate "VFIO support for VIRTIO NET PCI devices"
+ depends on VIRTIO_PCI
+ select VFIO_PCI_CORE
+ help
+ This provides support for exposing VIRTIO NET VF devices which support
+ legacy IO access, using the VFIO framework that can work with a legacy
+ virtio driver in the guest.
+ Based on PCIe spec, VFs do not support I/O Space; thus, VF BARs shall
+ not indicate I/O Space.
+ As of that this driver emulated I/O BAR in software to let a VF be
+ seen as a transitional device in the guest and let it work with
+ a legacy driver.
+
+ If you don't know what to do here, say N.
diff --git a/drivers/vfio/pci/virtio/Makefile b/drivers/vfio/pci/virtio/Makefile
new file mode 100644
index 000000000000..2039b39fb723
--- /dev/null
+++ b/drivers/vfio/pci/virtio/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_VIRTIO_VFIO_PCI) += virtio-vfio-pci.o
+virtio-vfio-pci-y := main.o
+
diff --git a/drivers/vfio/pci/virtio/main.c b/drivers/vfio/pci/virtio/main.c
new file mode 100644
index 000000000000..3ca19c891673
--- /dev/null
+++ b/drivers/vfio/pci/virtio/main.c
@@ -0,0 +1,554 @@
+// 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>
+
+struct virtiovf_pci_core_device {
+ struct vfio_pci_core_device core_device;
+ u8 bar0_virtual_buf_size;
+ u8 *bar0_virtual_buf;
+ /* synchronize access to the virtual buf */
+ struct mutex bar_mutex;
+ void __iomem *notify_addr;
+ u64 notify_offset;
+ __le32 pci_base_addr_0;
+ __le16 pci_cmd;
+ u8 notify_bar;
+};
+
+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
+translate_io_bar_to_mem_bar(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;
+ u16 queue_notify;
+ int ret;
+
+ if (pos + count > virtvdev->bar0_virtual_buf_size)
+ return -EINVAL;
+
+ switch (pos) {
+ case VIRTIO_PCI_QUEUE_NOTIFY:
+ if (count != sizeof(queue_notify))
+ return -EINVAL;
+ if (read) {
+ ret = vfio_pci_ioread16(core_device, true, &queue_notify,
+ virtvdev->notify_addr);
+ if (ret)
+ return ret;
+ if (copy_to_user(buf, &queue_notify,
+ sizeof(queue_notify)))
+ return -EFAULT;
+ } else {
+ if (copy_from_user(&queue_notify, buf, count))
+ return -EFAULT;
+ ret = vfio_pci_iowrite16(core_device, true, queue_notify,
+ virtvdev->notify_addr);
+ }
+ break;
+ default:
+ ret = virtiovf_issue_legacy_rw_cmd(virtvdev, pos, buf, count,
+ read);
+ }
+
+ return ret ? ret : count;
+}
+
+static bool range_intersect_range(loff_t range1_start, size_t count1,
+ loff_t range2_start, size_t count2,
+ loff_t *start_offset,
+ size_t *intersect_count,
+ size_t *register_offset)
+{
+ if (range1_start <= range2_start &&
+ range1_start + count1 > range2_start) {
+ *start_offset = range2_start - range1_start;
+ *intersect_count = min_t(size_t, count2,
+ range1_start + count1 - range2_start);
+ *register_offset = 0;
+ return true;
+ }
+
+ if (range1_start > range2_start &&
+ range1_start < range2_start + count2) {
+ *start_offset = 0;
+ *intersect_count = min_t(size_t, count1,
+ range2_start + count2 - range1_start);
+ *register_offset = range1_start - range2_start;
+ return true;
+ }
+
+ return false;
+}
+
+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 (range_intersect_range(pos, count, PCI_DEVICE_ID, sizeof(val16),
+ &copy_offset, &copy_count, &register_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) &&
+ range_intersect_range(pos, count, PCI_COMMAND, sizeof(val16),
+ &copy_offset, &copy_count, &register_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 (range_intersect_range(pos, count, PCI_REVISION_ID, sizeof(val8),
+ &copy_offset, &copy_count, &register_offset)) {
+ /* Transional needs to have revision 0 */
+ val8 = 0;
+ if (copy_to_user(buf + copy_offset, &val8, copy_count))
+ return -EFAULT;
+ }
+
+ if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, sizeof(val32),
+ &copy_offset, &copy_count, &register_offset)) {
+ u8 log_bar_size = ilog2(roundup_pow_of_two(virtvdev->bar0_virtual_buf_size));
+ u32 mask_size = ~((BIT(log_bar_size) - 1));
+ u32 pci_base_addr_0 = le32_to_cpu(virtvdev->pci_base_addr_0);
+
+ val32 = cpu_to_le32((pci_base_addr_0 & mask_size) | PCI_BASE_ADDRESS_SPACE_IO);
+ if (copy_to_user(buf + copy_offset, (void *)&val32 + register_offset, copy_count))
+ return -EFAULT;
+ }
+
+ if (range_intersect_range(pos, count, PCI_SUBSYSTEM_ID, sizeof(val16),
+ &copy_offset, &copy_count, &register_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 (range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID, sizeof(val16),
+ &copy_offset, &copy_count, &register_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;
+}
+
+static 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);
+ struct pci_dev *pdev = virtvdev->core_device.pdev;
+ unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ int ret;
+
+ 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 vfio_pci_core_read(core_vdev, buf, count, ppos);
+
+ ret = pm_runtime_resume_and_get(&pdev->dev);
+ if (ret) {
+ pci_info_ratelimited(pdev, "runtime resume failed %d\n",
+ ret);
+ return -EIO;
+ }
+
+ ret = translate_io_bar_to_mem_bar(virtvdev, pos, buf, count, true);
+ pm_runtime_put(&pdev->dev);
+ return ret;
+}
+
+static 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);
+ struct pci_dev *pdev = virtvdev->core_device.pdev;
+ unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ int ret;
+
+ if (!count)
+ return 0;
+
+ if (index == VFIO_PCI_CONFIG_REGION_INDEX) {
+ size_t register_offset;
+ loff_t copy_offset;
+ size_t copy_count;
+
+ if (range_intersect_range(pos, count, PCI_COMMAND, sizeof(virtvdev->pci_cmd),
+ &copy_offset, &copy_count,
+ &register_offset)) {
+ if (copy_from_user((void *)&virtvdev->pci_cmd + register_offset,
+ buf + copy_offset,
+ copy_count))
+ return -EFAULT;
+ }
+
+ if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
+ sizeof(virtvdev->pci_base_addr_0),
+ &copy_offset, &copy_count,
+ &register_offset)) {
+ if (copy_from_user((void *)&virtvdev->pci_base_addr_0 + register_offset,
+ buf + copy_offset,
+ copy_count))
+ return -EFAULT;
+ }
+ }
+
+ if (index != VFIO_PCI_BAR0_REGION_INDEX)
+ return vfio_pci_core_write(core_vdev, buf, count, ppos);
+
+ ret = pm_runtime_resume_and_get(&pdev->dev);
+ if (ret) {
+ pci_info_ratelimited(pdev, "runtime resume failed %d\n", ret);
+ return -EIO;
+ }
+
+ ret = translate_io_bar_to_mem_bar(virtvdev, pos, (char __user *)buf, count, false);
+ pm_runtime_put(&pdev->dev);
+ return ret;
+}
+
+static 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);
+ }
+}
+
+static 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;
+}
+
+static int virtiovf_pci_open_device(struct vfio_device *core_vdev)
+{
+ struct virtiovf_pci_core_device *virtvdev = container_of(
+ core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
+ struct vfio_pci_core_device *vdev = &virtvdev->core_device;
+ int ret;
+
+ ret = vfio_pci_core_enable(vdev);
+ if (ret)
+ return ret;
+
+ if (virtvdev->bar0_virtual_buf) {
+ /*
+ * 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.
+ */
+ ret = virtiovf_set_notify_addr(virtvdev);
+ if (ret) {
+ vfio_pci_core_disable(vdev);
+ return ret;
+ }
+ }
+
+ vfio_pci_core_finish_enable(vdev);
+ return 0;
+}
+
+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 int virtiovf_pci_init_device(struct vfio_device *core_vdev)
+{
+ struct virtiovf_pci_core_device *virtvdev = container_of(
+ core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
+ struct pci_dev *pdev;
+ int ret;
+
+ ret = vfio_pci_core_init_dev(core_vdev);
+ if (ret)
+ return ret;
+
+ pdev = virtvdev->core_device.pdev;
+ ret = virtiovf_read_notify_info(virtvdev);
+ if (ret)
+ return ret;
+
+ /* Being ready with a buffer that supports MSIX */
+ virtvdev->bar0_virtual_buf_size = VIRTIO_PCI_CONFIG_OFF(true) +
+ virtiovf_get_device_config_size(pdev->device);
+ 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;
+}
+
+static void virtiovf_pci_core_release_dev(struct vfio_device *core_vdev)
+{
+ struct virtiovf_pci_core_device *virtvdev = container_of(
+ core_vdev, struct virtiovf_pci_core_device, core_device.vdev);
+
+ kfree(virtvdev->bar0_virtual_buf);
+ vfio_pci_core_release_dev(core_vdev);
+}
+
+static const struct vfio_device_ops virtiovf_vfio_pci_tran_ops = {
+ .name = "virtio-vfio-pci-trans",
+ .init = virtiovf_pci_init_device,
+ .release = virtiovf_pci_core_release_dev,
+ .open_device = virtiovf_pci_open_device,
+ .close_device = vfio_pci_core_close_device,
+ .ioctl = virtiovf_vfio_pci_core_ioctl,
+ .read = virtiovf_pci_core_read,
+ .write = virtiovf_pci_core_write,
+ .mmap = vfio_pci_core_mmap,
+ .request = vfio_pci_core_request,
+ .match = vfio_pci_core_match,
+ .bind_iommufd = vfio_iommufd_physical_bind,
+ .unbind_iommufd = vfio_iommufd_physical_unbind,
+ .attach_ioas = vfio_iommufd_physical_attach_ioas,
+};
+
+static const struct vfio_device_ops virtiovf_vfio_pci_ops = {
+ .name = "virtio-vfio-pci",
+ .init = vfio_pci_core_init_dev,
+ .release = vfio_pci_core_release_dev,
+ .open_device = virtiovf_pci_open_device,
+ .close_device = vfio_pci_core_close_device,
+ .ioctl = vfio_pci_core_ioctl,
+ .device_feature = vfio_pci_core_ioctl_feature,
+ .read = vfio_pci_core_read,
+ .write = vfio_pci_core_write,
+ .mmap = vfio_pci_core_mmap,
+ .request = vfio_pci_core_request,
+ .match = vfio_pci_core_match,
+ .bind_iommufd = vfio_iommufd_physical_bind,
+ .unbind_iommufd = vfio_iommufd_physical_unbind,
+ .attach_ioas = vfio_iommufd_physical_attach_ioas,
+};
+
+static bool virtiovf_bar0_exists(struct pci_dev *pdev)
+{
+ struct resource *res = pdev->resource;
+
+ return res->flags ? true : false;
+}
+
+static int virtiovf_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *id)
+{
+ const struct vfio_device_ops *ops = &virtiovf_vfio_pci_ops;
+ struct virtiovf_pci_core_device *virtvdev;
+ int ret;
+
+ if (pdev->is_virtfn && virtio_pci_admin_has_legacy_io(pdev) &&
+ !virtiovf_bar0_exists(pdev))
+ ops = &virtiovf_vfio_pci_tran_ops;
+
+ virtvdev = vfio_alloc_device(virtiovf_pci_core_device, core_device.vdev,
+ &pdev->dev, ops);
+ if (IS_ERR(virtvdev))
+ return PTR_ERR(virtvdev);
+
+ dev_set_drvdata(&pdev->dev, &virtvdev->core_device);
+ ret = vfio_pci_core_register_device(&virtvdev->core_device);
+ if (ret)
+ goto out;
+ return 0;
+out:
+ vfio_put_device(&virtvdev->core_device.vdev);
+ return ret;
+}
+
+static void virtiovf_pci_remove(struct pci_dev *pdev)
+{
+ struct virtiovf_pci_core_device *virtvdev = dev_get_drvdata(&pdev->dev);
+
+ vfio_pci_core_unregister_device(&virtvdev->core_device);
+ vfio_put_device(&virtvdev->core_device.vdev);
+}
+
+static const struct pci_device_id virtiovf_pci_table[] = {
+ /* Only virtio-net is supported/tested so far */
+ { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_REDHAT_QUMRANET, 0x1041) },
+ {}
+};
+
+MODULE_DEVICE_TABLE(pci, virtiovf_pci_table);
+
+static struct pci_driver virtiovf_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = virtiovf_pci_table,
+ .probe = virtiovf_pci_probe,
+ .remove = virtiovf_pci_remove,
+ .err_handler = &vfio_pci_core_err_handlers,
+ .driver_managed_dma = true,
+};
+
+module_pci_driver(virtiovf_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yishai Hadas <yishaih@nvidia.com>");
+MODULE_DESCRIPTION(
+ "VIRTIO VFIO PCI - User Level meta-driver for VIRTIO NET devices");
--
2.27.0