Re: [PATCH v7 04/10] hisi_acc_vfio_pci: add new vfio_pci driver for HiSilicon ACC devices

[John Garry]

On 02/03/2022 17:28, Shameer Kolothum wrote:
> +config HISI_ACC_VFIO_PCI
> +	tristate "VFIO PCI support for HiSilicon ACC devices"
> +	depends on (ARM64 && VFIO_PCI_CORE) || (COMPILE_TEST && 64BIT)

This means that we will have HISI_ACC_VFIO_PCI=y for COMPILE_TEST=y and 
64BIT=y and VFIO_PCI_CORE=n, but ...

> +	help
> +	  This provides generic PCI support for HiSilicon ACC devices
> +	  using the VFIO framework.
> +
> +	  If you don't know what to do here, say N.
> diff --git a/drivers/vfio/pci/hisilicon/Makefile b/drivers/vfio/pci/hisilicon/Makefile
> new file mode 100644
> index 000000000000..c66b3783f2f9
> --- /dev/null
> +++ b/drivers/vfio/pci/hisilicon/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisi-acc-vfio-pci.o
> +hisi-acc-vfio-pci-y := hisi_acc_vfio_pci.o
> +
> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
> new file mode 100644
> index 000000000000..8129c3457b3b
> --- /dev/null
> +++ b/drivers/vfio/pci/hisilicon/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/hisi_acc_qm.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_device(struct vfio_device *core_vdev)
> +{
> +	struct vfio_pci_core_device *vdev =
> +		container_of(core_vdev, struct vfio_pci_core_device, vdev);
> +	int ret;
> +
> +	ret = vfio_pci_core_enable(vdev);
> +	if (ret)
> +		return ret;
> +
> +	vfio_pci_core_finish_enable(vdev);

... there does not seem to be a stub for vfio_pci_core_finish_enable(), 
so I don't think that we compile under the conditions described. I think 
that HISI_ACC_VFIO_PCI should always depends on HISI_ACC_VFIO_PCI

> +
> +	return 0;
> +}