Re: [RFC v2 1/4] hisi-acc-vfio-pci: add new vfio_pci driver for HiSilicon ACC devices

[Alex Williamson <alex.williamson@redhat.com>]

On Fri, 2 Jul 2021 10:58:46 +0100
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:

> Add a vendor-specific vfio_pci driver for HiSilicon ACC devices.
> This will be extended in follow-up patches to add support for
> vfio live migration feature.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  drivers/vfio/pci/Kconfig             |   9 +++
>  drivers/vfio/pci/Makefile            |   2 +
>  drivers/vfio/pci/hisi_acc_vfio_pci.c | 100 +++++++++++++++++++++++++++
>  3 files changed, 111 insertions(+)
>  create mode 100644 drivers/vfio/pci/hisi_acc_vfio_pci.c
> 
> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
> index 9cdef46dd299..709807c28153 100644
> --- a/drivers/vfio/pci/Kconfig
> +++ b/drivers/vfio/pci/Kconfig
> @@ -57,3 +57,12 @@ config MLX5_VFIO_PCI
>  	  framework.
>  
>  	  If you don't know what to do here, say N.
> +
> +config HISI_ACC_VFIO_PCI
> +	tristate "VFIO support for HiSilicon ACC devices"
> +	depends on ARM64 && VFIO_PCI_CORE
> +	help
> +	  This provides generic PCI support for HiSilicon devices using the VFIO
> +	  framework.
> +
> +	  If you don't know what to do here, say N.
> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
> index a0df9c2a4bd9..d1de3e81921f 100644
> --- a/drivers/vfio/pci/Makefile
> +++ b/drivers/vfio/pci/Makefile
> @@ -3,6 +3,7 @@
>  obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o
>  obj-$(CONFIG_VFIO_PCI) += vfio-pci.o
>  obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5-vfio-pci.o
> +obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisi-acc-vfio-pci.o
>  
>  vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
>  vfio-pci-core-$(CONFIG_S390) += vfio_pci_zdev.o
> @@ -11,3 +12,4 @@ vfio-pci-y := vfio_pci.o
>  vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
>  
>  mlx5-vfio-pci-y := mlx5_vfio_pci.o
> +hisi-acc-vfio-pci-y := hisi_acc_vfio_pci.o
> diff --git a/drivers/vfio/pci/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisi_acc_vfio_pci.c
> new file mode 100644
> index 000000000000..a9e173098ab5
> --- /dev/null
> +++ b/drivers/vfio/pci/hisi_acc_vfio_pci.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021, HiSilicon Ltd.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/eventfd.h>
> +#include <linux/file.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/vfio.h>
> +#include <linux/vfio_pci_core.h>
> +
> +static int hisi_acc_vfio_pci_open(struct vfio_device *core_vdev)
> +{
> +	struct vfio_pci_core_device *vdev =
> +		container_of(core_vdev, struct vfio_pci_core_device, vdev);
> +	int ret;
> +
> +	lockdep_assert_held(&core_vdev->reflck->lock);
> +
> +	ret = vfio_pci_core_enable(vdev);
> +	if (ret)
> +		return ret;
> +
> +	vfio_pci_core_finish_enable(vdev);
> +
> +	return 0;
> +}
> +
> +static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
> +	.name		= "hisi-acc-vfio-pci",
> +	.open		= hisi_acc_vfio_pci_open,
> +	.release	= vfio_pci_core_release,
> +	.ioctl		= vfio_pci_core_ioctl,
> +	.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,
> +	.reflck_attach	= vfio_pci_core_reflck_attach,
> +};
> +
> +static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> +{
> +	struct vfio_pci_core_device *vdev;
> +	int ret;
> +
> +	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> +	if (!vdev)
> +		return -ENOMEM;
> +
> +	ret = vfio_pci_core_register_device(vdev, pdev, &hisi_acc_vfio_pci_ops);
> +	if (ret)
> +		goto out_free;
> +
> +	dev_set_drvdata(&pdev->dev, vdev);
> +
> +	return 0;
> +
> +out_free:
> +	kfree(vdev);
> +	return ret;
> +}
> +
> +static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
> +{
> +	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
> +
> +	vfio_pci_core_unregister_device(vdev);
> +	kfree(vdev);
> +}
> +
> +static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
> +	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, 0xa256) }, /* SEC VF */
> +	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, 0xa259) }, /* HPRE VF */
> +	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_HUAWEI, 0xa251) }, /* ZIP VF */
> +	{ 0, }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, hisi_acc_vfio_pci_table);
> +
> +static struct pci_driver hisi_acc_vfio_pci_driver = {
> +	.name			= "hisi-acc-vfio-pci",
> +	.id_table		= hisi_acc_vfio_pci_table,
> +	.probe			= hisi_acc_vfio_pci_probe,
> +	.remove			= hisi_acc_vfio_pci_remove,
> +#ifdef CONFIG_PCI_IOV
> +	.sriov_configure	= vfio_pci_core_sriov_configure,
> +#endif

The device table suggests only VFs are supported by this driver, so it
really shouldn't need sriov_configure support, right?  Thanks,

Alex

> +	.err_handler		= &vfio_pci_core_err_handlers,
> +};
> +
> +module_pci_driver(hisi_acc_vfio_pci_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Liu Longfang <liulongfang@huawei.com>");
> +MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>");
> +MODULE_DESCRIPTION("HiSilicon VFIO PCI - Generic VFIO PCI driver for HiSilicon ACC device family");