On Thu, Sep 21, 2023 at 03:40:40PM +0300, Yishai Hadas wrote: > 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 command VIRTIO_PCI_QUEUE_NOTIFY 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@xxxxxxxxxx> > --- > MAINTAINERS | 6 + > drivers/vfio/pci/Kconfig | 2 + > drivers/vfio/pci/Makefile | 2 + > drivers/vfio/pci/virtio/Kconfig | 15 + > drivers/vfio/pci/virtio/Makefile | 4 + > drivers/vfio/pci/virtio/cmd.c | 4 +- > drivers/vfio/pci/virtio/cmd.h | 8 + > drivers/vfio/pci/virtio/main.c | 546 +++++++++++++++++++++++++++++++ > 8 files changed, 585 insertions(+), 2 deletions(-) > 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 bf0f54c24f81..5098418c8389 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -22624,6 +22624,12 @@ L: kvm@xxxxxxxxxxxxxxx > S: Maintained > F: drivers/vfio/pci/mlx5/ > > +VFIO VIRTIO PCI DRIVER > +M: Yishai Hadas <yishaih@xxxxxxxxxx> > +L: kvm@xxxxxxxxxxxxxxx > +S: Maintained > +F: drivers/vfio/pci/virtio > + > VFIO PCI DEVICE SPECIFIC DRIVERS > R: Jason Gunthorpe <jgg@xxxxxxxxxx> > R: Yishai Hadas <yishaih@xxxxxxxxxx> > 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..89eddce8b1bd > --- /dev/null > +++ b/drivers/vfio/pci/virtio/Kconfig > @@ -0,0 +1,15 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +config VIRTIO_VFIO_PCI > + tristate "VFIO support for VIRTIO PCI devices" > + depends on VIRTIO_PCI > + select VFIO_PCI_CORE > + help > + This provides support for exposing VIRTIO VF devices 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..584372648a03 > --- /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 cmd.o > + > diff --git a/drivers/vfio/pci/virtio/cmd.c b/drivers/vfio/pci/virtio/cmd.c > index f068239cdbb0..aea9d25fbf1d 100644 > --- a/drivers/vfio/pci/virtio/cmd.c > +++ b/drivers/vfio/pci/virtio/cmd.c > @@ -44,7 +44,7 @@ int virtiovf_cmd_lr_write(struct virtiovf_pci_core_device *virtvdev, u16 opcode, > { > struct virtio_device *virtio_dev = > virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev); > - struct virtio_admin_cmd_data_lr_write *in; > + struct virtio_admin_cmd_legacy_wr_data *in; > struct scatterlist in_sg; > struct virtio_admin_cmd cmd = {}; > int ret; > @@ -74,7 +74,7 @@ int virtiovf_cmd_lr_read(struct virtiovf_pci_core_device *virtvdev, u16 opcode, > { > struct virtio_device *virtio_dev = > virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev); > - struct virtio_admin_cmd_data_lr_read *in; > + struct virtio_admin_cmd_legacy_rd_data *in; > struct scatterlist in_sg, out_sg; > struct virtio_admin_cmd cmd = {}; > int ret; > diff --git a/drivers/vfio/pci/virtio/cmd.h b/drivers/vfio/pci/virtio/cmd.h > index c2a3645f4b90..347b1dc85570 100644 > --- a/drivers/vfio/pci/virtio/cmd.h > +++ b/drivers/vfio/pci/virtio/cmd.h > @@ -13,7 +13,15 @@ > > 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; > int vf_id; > + void __iomem *notify_addr; > + u32 notify_offset; > + u8 notify_bar; > + u8 pci_cmd_io :1; > }; > > int virtiovf_cmd_list_query(struct pci_dev *pdev, u8 *buf, int buf_size); > diff --git a/drivers/vfio/pci/virtio/main.c b/drivers/vfio/pci/virtio/main.c > new file mode 100644 > index 000000000000..2486991c49f3 > --- /dev/null > +++ b/drivers/vfio/pci/virtio/main.c > @@ -0,0 +1,546 @@ > +// 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_modern.h> > + > +#include "cmd.h" > + > +#define VIRTIO_LEGACY_IO_BAR_HEADER_LEN 20 > +#define VIRTIO_LEGACY_IO_BAR_MSIX_HEADER_LEN 4 > + > +static int virtiovf_issue_lr_cmd(struct virtiovf_pci_core_device *virtvdev, > + loff_t pos, char __user *buf, > + size_t count, bool read) > +{ > + u8 *bar0_buf = virtvdev->bar0_virtual_buf; > + u16 opcode; > + int ret; > + > + mutex_lock(&virtvdev->bar_mutex); > + if (read) { > + opcode = (pos < VIRTIO_PCI_CONFIG_OFF(true)) ? > + VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ : > + VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ; > + ret = virtiovf_cmd_lr_read(virtvdev, opcode, pos, > + count, bar0_buf + pos); > + if (ret) > + goto out; > + if (copy_to_user(buf, bar0_buf + pos, count)) > + ret = -EFAULT; > + goto out; > + } > + > + if (copy_from_user(bar0_buf + pos, buf, count)) { > + ret = -EFAULT; > + goto out; > + } > + > + opcode = (pos < VIRTIO_PCI_CONFIG_OFF(true)) ? > + VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE : > + VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE; > + ret = virtiovf_cmd_lr_write(virtvdev, opcode, pos, 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; > + break; > + } > + > + 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_lr_cmd(virtvdev, pos, buf, count, read); > + } > + > + return ret ? ret : count; > +} > + > +static bool range_contains_range(loff_t range1_start, size_t count1, > + loff_t range2_start, size_t count2, > + loff_t *start_offset) > +{ > + if (range1_start <= range2_start && > + range1_start + count1 >= range2_start + count2) { > + *start_offset = range2_start - range1_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; > + loff_t copy_offset; > + __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_contains_range(pos, count, PCI_DEVICE_ID, sizeof(val16), > + ©_offset)) { > + val16 = cpu_to_le16(0x1000); > + if (copy_to_user(buf + copy_offset, &val16, sizeof(val16))) > + return -EFAULT; > + } > + > + if (virtvdev->pci_cmd_io && > + range_contains_range(pos, count, PCI_COMMAND, sizeof(val16), > + ©_offset)) { > + if (copy_from_user(&val16, buf, sizeof(val16))) > + return -EFAULT; > + val16 |= cpu_to_le16(PCI_COMMAND_IO); > + if (copy_to_user(buf + copy_offset, &val16, sizeof(val16))) > + return -EFAULT; > + } > + > + if (range_contains_range(pos, count, PCI_REVISION_ID, sizeof(val8), > + ©_offset)) { > + /* Transional needs to have revision 0 */ > + val8 = 0; > + if (copy_to_user(buf + copy_offset, &val8, sizeof(val8))) > + return -EFAULT; > + } > + > + if (range_contains_range(pos, count, PCI_BASE_ADDRESS_0, sizeof(val32), > + ©_offset)) { > + val32 = cpu_to_le32(PCI_BASE_ADDRESS_SPACE_IO); > + if (copy_to_user(buf + copy_offset, &val32, sizeof(val32))) > + return -EFAULT; > + } > + > + if (range_contains_range(pos, count, PCI_SUBSYSTEM_ID, sizeof(val16), > + ©_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, &val16, sizeof(val16))) > + 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) { > + loff_t copy_offset; > + u16 cmd; > + > + if (range_contains_range(pos, count, PCI_COMMAND, sizeof(cmd), > + ©_offset)) { > + if (copy_from_user(&cmd, buf + copy_offset, sizeof(cmd))) > + return -EFAULT; > + virtvdev->pci_cmd_io = (cmd & PCI_COMMAND_IO); > + } > + } > + > + 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 void virtiovf_pci_close_device(struct vfio_device *core_vdev) > +{ > + vfio_pci_core_close_device(core_vdev); > +} > + > +static int virtiovf_get_device_config_size(unsigned short device) > +{ > + switch (device) { > + case 0x1041: > + /* network card */ > + return offsetofend(struct virtio_net_config, status); > + default: > + return 0; > + } > +} > + > +static int virtiovf_read_notify_info(struct virtiovf_pci_core_device *virtvdev) > +{ > + u64 offset; > + int ret; > + u8 bar; > + > + ret = virtiovf_cmd_lq_read_notify(virtvdev, > + 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; > + virtvdev->vf_id = pci_iov_vf_id(pdev); > + if (virtvdev->vf_id < 0) > + return -EINVAL; > + > + ret = virtiovf_read_notify_info(virtvdev); > + if (ret) > + return ret; > + > + virtvdev->bar0_virtual_buf_size = VIRTIO_LEGACY_IO_BAR_HEADER_LEN + > + VIRTIO_LEGACY_IO_BAR_MSIX_HEADER_LEN + > + 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_acc_vfio_pci_tran_ops = { > + .name = "virtio-transitional-vfio-pci", > + .init = virtiovf_pci_init_device, > + .release = virtiovf_pci_core_release_dev, > + .open_device = virtiovf_pci_open_device, > + .close_device = virtiovf_pci_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_acc_vfio_pci_ops = { > + .name = "virtio-acc-vfio-pci", > + .init = vfio_pci_core_init_dev, > + .release = vfio_pci_core_release_dev, > + .open_device = virtiovf_pci_open_device, > + .close_device = virtiovf_pci_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; > +} > + > +#define VIRTIOVF_USE_ADMIN_CMD_BITMAP \ > + (BIT_ULL(VIRTIO_ADMIN_CMD_LIST_QUERY) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LIST_USE) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \ > + BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO)) > + > +static bool virtiovf_support_legacy_access(struct pci_dev *pdev) > +{ > + int buf_size = DIV_ROUND_UP(VIRTIO_ADMIN_MAX_CMD_OPCODE, 64) * 8; > + u8 *buf; > + int ret; > + > + /* Only virtio-net is supported/tested so far */ > + if (pdev->device != 0x1041) > + return false; > + > + buf = kzalloc(buf_size, GFP_KERNEL); > + if (!buf) > + return false; > + > + ret = virtiovf_cmd_list_query(pdev, buf, buf_size); > + if (ret) > + goto end; > + > + if ((le64_to_cpup((__le64 *)buf) & VIRTIOVF_USE_ADMIN_CMD_BITMAP) != > + VIRTIOVF_USE_ADMIN_CMD_BITMAP) { > + ret = -EOPNOTSUPP; > + goto end; > + } > + > + /* confirm the used commands */ > + memset(buf, 0, buf_size); > + *(__le64 *)buf = cpu_to_le64(VIRTIOVF_USE_ADMIN_CMD_BITMAP); > + ret = virtiovf_cmd_list_use(pdev, buf, buf_size); > + > +end: > + kfree(buf); > + return ret ? false : true; > +} > + > +static int virtiovf_pci_probe(struct pci_dev *pdev, > + const struct pci_device_id *id) > +{ > + const struct vfio_device_ops *ops = &virtiovf_acc_vfio_pci_ops; > + struct virtiovf_pci_core_device *virtvdev; > + int ret; > + > + if (pdev->is_virtfn && virtiovf_support_legacy_access(pdev) && > + !virtiovf_bar0_exists(pdev) && pdev->msix_cap) I see this is the reason you set MSIX to true. But I think it's a misunderstanding - that true means MSIX is enabled by guest, not that it exists. > + ops = &virtiovf_acc_vfio_pci_tran_ops; Actually, I remember there's a problem with just always doing transitional and that is VIRTIO_F_ACCESS_PLATFORM - some configs just break in weird ways as device will go through an iommu. It would be nicer I think if userspace had the last word on whether it wants to enable legacy or not, even if hardware supports that. > + > + 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[] = { > + { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) }, > + {} > +}; > + > +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@xxxxxxxxxx>"); > +MODULE_DESCRIPTION( > + "VIRTIO VFIO PCI - User Level meta-driver for VIRTIO device family"); > -- > 2.27.0
