Re: [RFC PATCH v2 vfio 1/7] vfio/pds: Initial support for pds_vfio VFIO driver

Shannon Nelson
2023-01-03T18:38:13Z

On 1/3/23 4:12 AM, liulongfang wrote:
> On 2022/12/15 7:21, Brett Creeley wrote:
>> This is the initial framework for the new pds_vfio device driver. This
>> does the very basics of registering the PCI device 1dd8:1006 and
>> configuring as a VFIO PCI device.
>>
>> With this change, the VF device can be bound to the pds_vfio driver on
>> the host and presented to the VM as an NVMe VF.
>>
>> Signed-off-by: Brett Creeley <brett.creeley@amd.com>
>> Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
>> ---
>> drivers/vfio/pci/pds/Makefile | 6 ++
>> drivers/vfio/pci/pds/pci_drv.c | 102 ++++++++++++++++++++++++++++++++
>> drivers/vfio/pci/pds/vfio_dev.c | 74 +++++++++++++++++++++++
>> drivers/vfio/pci/pds/vfio_dev.h | 23 +++++++
>> include/linux/pds/pds_core_if.h | 1 +
>> 5 files changed, 206 insertions(+)
>> create mode 100644 drivers/vfio/pci/pds/Makefile
>> create mode 100644 drivers/vfio/pci/pds/pci_drv.c
>> create mode 100644 drivers/vfio/pci/pds/vfio_dev.c
>> create mode 100644 drivers/vfio/pci/pds/vfio_dev.h
>>
>> diff --git a/drivers/vfio/pci/pds/Makefile b/drivers/vfio/pci/pds/Makefile
>> new file mode 100644
>> index 000000000000..dcc8f6beffe2
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/Makefile
>> @@ -0,0 +1,6 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +obj-$(CONFIG_PDS_VFIO_PCI) += pds_vfio.o
>> +
>> +pds_vfio-y := \
>> + pci_drv.o \
>> + vfio_dev.o
>> diff --git a/drivers/vfio/pci/pds/pci_drv.c b/drivers/vfio/pci/pds/pci_drv.c
>> new file mode 100644
>> index 000000000000..09cab0dbb0e9
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/pci_drv.c
>> @@ -0,0 +1,102 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright(c) 2022 Pensando Systems, Inc */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/module.h>
>> +#include <linux/pci.h>
>> +#include <linux/types.h>
>> +#include <linux/vfio.h>
>> +
>> +#include <linux/pds/pds_core_if.h>
>> +
>> +#include "vfio_dev.h"
>> +
>> +#define PDS_VFIO_DRV_NAME "pds_vfio"
>> +#define PDS_VFIO_DRV_DESCRIPTION "Pensando VFIO Device Driver"
>> +#define PCI_VENDOR_ID_PENSANDO 0x1dd8
>> +
>> +static int
>> +pds_vfio_pci_probe(struct pci_dev *pdev,
>> + const struct pci_device_id *id)
>> +{
>> + struct pds_vfio_pci_device *pds_vfio;
>> + int err;
>> +
>> + pds_vfio = vfio_alloc_device(pds_vfio_pci_device, vfio_coredev.vdev,
>> + &pdev->dev, pds_vfio_ops_info());
>> + if (IS_ERR(pds_vfio))
>> + return PTR_ERR(pds_vfio);
>> +
>> + dev_set_drvdata(&pdev->dev, &pds_vfio->vfio_coredev);
>> + pds_vfio->pdev = pdev;
>> +
>> + err = vfio_pci_core_register_device(&pds_vfio->vfio_coredev);
>> + if (err)
>> + goto out_put_vdev;
>> +
>> + return 0;
>> +
>> +out_put_vdev:
>> + vfio_put_device(&pds_vfio->vfio_coredev.vdev);
>> + return err;
>> +}
>> +
>> +static void
>> +pds_vfio_pci_remove(struct pci_dev *pdev)
>> +{
>> + struct pds_vfio_pci_device *pds_vfio = pds_vfio_pci_drvdata(pdev);
>> +
>> + vfio_pci_core_unregister_device(&pds_vfio->vfio_coredev);
>> + vfio_put_device(&pds_vfio->vfio_coredev.vdev);
>> +}
>> +
>> +static const struct pci_device_id
>> +pds_vfio_pci_table[] = {
>> + {
>> + .class = PCI_CLASS_STORAGE_EXPRESS,
>> + .class_mask = 0xffffff,
>> + .vendor = PCI_VENDOR_ID_PENSANDO,
>> + .device = PCI_DEVICE_ID_PENSANDO_NVME_VF,
>> + .subvendor = PCI_ANY_ID,
>> + .subdevice = PCI_ANY_ID,
>> + .override_only = PCI_ID_F_VFIO_DRIVER_OVERRIDE,
>> + },
>> + { 0, }
>> +};
>> +MODULE_DEVICE_TABLE(pci, pds_vfio_pci_table);
>> +
>> +static struct pci_driver
>> +pds_vfio_pci_driver = {
>> + .name = PDS_VFIO_DRV_NAME,
>> + .id_table = pds_vfio_pci_table,
>> + .probe = pds_vfio_pci_probe,
>> + .remove = pds_vfio_pci_remove,
>> + .driver_managed_dma = true,
>> +};
>> +
>> +static void __exit
>> +pds_vfio_pci_cleanup(void)
>> +{
>> + pci_unregister_driver(&pds_vfio_pci_driver);
>> +}
>> +module_exit(pds_vfio_pci_cleanup);
>> +
>> +static int __init
>> +pds_vfio_pci_init(void)
>> +{
>> + int err;
>> +
>> + err = pci_register_driver(&pds_vfio_pci_driver);
>> + if (err) {
>> + pr_err("pci driver register failed: %pe\n", ERR_PTR(err));
>> + return err;
>> + }
>> +
>> + return 0;
>> +}
>> +module_init(pds_vfio_pci_init);
>
> It would be better to use module_pci_driver(pds_vfio_pci_driver) instead

Generally you are correct, but note that the next patch adds the
auxiliary_driver registration so that it is no longer a simple PCI init.

sln

>
> Thanks,
> Longfang.
>
>> +
>> +MODULE_DESCRIPTION(PDS_VFIO_DRV_DESCRIPTION);
>> +MODULE_AUTHOR("Pensando Systems, Inc");
>> +MODULE_LICENSE("GPL");
>> diff --git a/drivers/vfio/pci/pds/vfio_dev.c b/drivers/vfio/pci/pds/vfio_dev.c
>> new file mode 100644
>> index 000000000000..f8f4006c0915
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/vfio_dev.c
>> @@ -0,0 +1,74 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright(c) 2022 Pensando Systems, Inc */
>> +
>> +#include <linux/vfio.h>
>> +#include <linux/vfio_pci_core.h>
>> +
>> +#include "vfio_dev.h"
>> +
>> +struct pds_vfio_pci_device *
>> +pds_vfio_pci_drvdata(struct pci_dev *pdev)
>> +{
>> + struct vfio_pci_core_device *core_device = dev_get_drvdata(&pdev->dev);
>> +
>> + return container_of(core_device, struct pds_vfio_pci_device,
>> + vfio_coredev);
>> +}
>> +
>> +static int
>> +pds_vfio_init_device(struct vfio_device *vdev)
>> +{
>> + struct pds_vfio_pci_device *pds_vfio =
>> + container_of(vdev, struct pds_vfio_pci_device,
>> + vfio_coredev.vdev);
>> + struct pci_dev *pdev = to_pci_dev(vdev->dev);
>> + int err;
>> +
>> + err = vfio_pci_core_init_dev(vdev);
>> + if (err)
>> + return err;
>> +
>> + pds_vfio->vf_id = pci_iov_vf_id(pdev);
>> + pds_vfio->pci_id = PCI_DEVID(pdev->bus->number, pdev->devfn);
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +pds_vfio_open_device(struct vfio_device *vdev)
>> +{
>> + struct pds_vfio_pci_device *pds_vfio =
>> + container_of(vdev, struct pds_vfio_pci_device,
>> + vfio_coredev.vdev);
>> + int err;
>> +
>> + err = vfio_pci_core_enable(&pds_vfio->vfio_coredev);
>> + if (err)
>> + return err;
>> +
>> + vfio_pci_core_finish_enable(&pds_vfio->vfio_coredev);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct vfio_device_ops
>> +pds_vfio_ops = {
>> + .name = "pds-vfio",
>> + .init = pds_vfio_init_device,
>> + .release = vfio_pci_core_release_dev,
>> + .open_device = pds_vfio_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,
>> +};
>> +
>> +const struct vfio_device_ops *
>> +pds_vfio_ops_info(void)
>> +{
>> + return &pds_vfio_ops;
>> +}
>> diff --git a/drivers/vfio/pci/pds/vfio_dev.h b/drivers/vfio/pci/pds/vfio_dev.h
>> new file mode 100644
>> index 000000000000..289479a08dce
>> --- /dev/null
>> +++ b/drivers/vfio/pci/pds/vfio_dev.h
>> @@ -0,0 +1,23 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright(c) 2022 Pensando Systems, Inc */
>> +
>> +#ifndef _VFIO_DEV_H_
>> +#define _VFIO_DEV_H_
>> +
>> +#include <linux/pci.h>
>> +#include <linux/vfio_pci_core.h>
>> +
>> +struct pds_vfio_pci_device {
>> + struct vfio_pci_core_device vfio_coredev;
>> + struct pci_dev *pdev;
>> +
>> + int vf_id;
>> + int pci_id;
>> +};
>> +
>> +const struct vfio_device_ops *
>> +pds_vfio_ops_info(void);
>> +struct pds_vfio_pci_device *
>> +pds_vfio_pci_drvdata(struct pci_dev *pdev);
>> +
>> +#endif /* _VFIO_DEV_H_ */
>> diff --git a/include/linux/pds/pds_core_if.h b/include/linux/pds/pds_core_if.h
>> index 6e92697657e4..4362b94a7666 100644
>> --- a/include/linux/pds/pds_core_if.h
>> +++ b/include/linux/pds/pds_core_if.h
>> @@ -9,6 +9,7 @@
>> #define PCI_VENDOR_ID_PENSANDO 0x1dd8
>> #define PCI_DEVICE_ID_PENSANDO_CORE_PF 0x100c
>> #define PCI_DEVICE_ID_PENSANDO_VDPA_VF 0x100b
>> +#define PCI_DEVICE_ID_PENSANDO_NVME_VF 0x1006
>>
>> #define PDS_CORE_BARS_MAX 4
>> #define PDS_CORE_PCI_BAR_DBELL 1
>>