Re: [PATCH v4 07/10] vfio/fsl-mc: Add irq infrastructure for fsl-mc devices

[Auger Eric <eric.auger@redhat.com>]

Hi Diana,

On 8/26/20 11:33 AM, Diana Craciun wrote:
> This patch adds the skeleton for interrupt support
> for fsl-mc devices. The interrupts are not yet functional,
> the functionality will be added by subsequent patches.
> 
> Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
> Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
> ---
>  drivers/vfio/fsl-mc/Makefile              |  2 +-
>  drivers/vfio/fsl-mc/vfio_fsl_mc.c         | 75 ++++++++++++++++++++++-
>  drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c    | 63 +++++++++++++++++++
>  drivers/vfio/fsl-mc/vfio_fsl_mc_private.h |  7 ++-
>  4 files changed, 143 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> 
> diff --git a/drivers/vfio/fsl-mc/Makefile b/drivers/vfio/fsl-mc/Makefile
> index 0c6e5d2ddaae..cad6dbf0b735 100644
> --- a/drivers/vfio/fsl-mc/Makefile
> +++ b/drivers/vfio/fsl-mc/Makefile
> @@ -1,4 +1,4 @@
>  # SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
>  
> -vfio-fsl-mc-y := vfio_fsl_mc.o
> +vfio-fsl-mc-y := vfio_fsl_mc.o vfio_fsl_mc_intr.o
>  obj-$(CONFIG_VFIO_FSL_MC) += vfio-fsl-mc.o
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> index bbd3365e877e..42014297b484 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -209,11 +209,79 @@ static long vfio_fsl_mc_ioctl(void *device_data, unsigned int cmd,
>  	}
>  	case VFIO_DEVICE_GET_IRQ_INFO:
>  	{
> -		return -ENOTTY;
> +		struct vfio_irq_info info;
> +
> +		minsz = offsetofend(struct vfio_irq_info, count);
> +		if (copy_from_user(&info, (void __user *)arg, minsz))
> +			return -EFAULT;
> +
> +		if (info.argsz < minsz)
> +			return -EINVAL;
> +
> +		if (info.index >= mc_dev->obj_desc.irq_count)
> +			return -EINVAL;
> +
> +		info.flags = VFIO_IRQ_INFO_EVENTFD;
shouldn't it be MASKABLE as well? I see skeletons for MASK.
> +		info.count = 1;
> +
> +		return copy_to_user((void __user *)arg, &info, minsz);
>  	}
>  	case VFIO_DEVICE_SET_IRQS:
>  	{
> -		return -ENOTTY;
> +		struct vfio_irq_set hdr;
> +		u8 *data = NULL;
> +		int ret = 0;
> +
> +		minsz = offsetofend(struct vfio_irq_set, count);
> +
> +		if (copy_from_user(&hdr, (void __user *)arg, minsz))
> +			return -EFAULT;
> +
> +		if (hdr.argsz < minsz)
> +			return -EINVAL;
> +
> +		if (hdr.index >= mc_dev->obj_desc.irq_count)
> +			return -EINVAL;
> +
> +		if (hdr.start != 0 || hdr.count > 1)
> +			return -EINVAL;
> +
> +		if (hdr.count == 0 &&
> +		    (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE) ||
> +		    !(hdr.flags & VFIO_IRQ_SET_ACTION_TRIGGER)))
> +			return -EINVAL;
> +
> +		if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
> +				  VFIO_IRQ_SET_ACTION_TYPE_MASK))
> +			return -EINVAL;
> +
> +		if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
> +			size_t size;
> +
> +			if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
> +				size = sizeof(uint8_t);
> +			else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
> +				size = sizeof(int32_t);
> +			else
> +				return -EINVAL;
> +
> +			if (hdr.argsz - minsz < hdr.count * size)
> +				return -EINVAL;
> +
> +			data = memdup_user((void __user *)(arg + minsz),
> +					   hdr.count * size);
> +			if (IS_ERR(data))
> +				return PTR_ERR(data);
> +		}
can't you reuse vfio_set_irqs_validate_and_prepare()?
> +
> +		mutex_lock(&vdev->igate);
> +		ret = vfio_fsl_mc_set_irqs_ioctl(vdev, hdr.flags,
> +						 hdr.index, hdr.start,
> +						 hdr.count, data);
> +		mutex_unlock(&vdev->igate);
> +		kfree(data);
> +
> +		return ret;
>  	}
>  	case VFIO_DEVICE_RESET:
>  	{
> @@ -413,6 +481,8 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
>  		return ret;
>  	}
>  
> +	mutex_init(&vdev->igate);
> +
>  	return ret;
>  }
>  
> @@ -436,6 +506,7 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
>  	mc_dev->mc_io = NULL;
>  
>  	vfio_fsl_mc_reflck_put(vdev->reflck);
> +	mutex_destroy(&vdev->igate);
>  
>  	vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
>  
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> new file mode 100644
> index 000000000000..058aa97aa54a
> --- /dev/null
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
> +/*
> + * Copyright 2013-2016 Freescale Semiconductor Inc.
> + * Copyright 2019 NXP
> + */
> +
> +#include <linux/vfio.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/eventfd.h>
> +#include <linux/msi.h>
> +
> +#include "linux/fsl/mc.h"
> +#include "vfio_fsl_mc_private.h"
> +
> +static int vfio_fsl_mc_irq_mask(struct vfio_fsl_mc_device *vdev,
> +				unsigned int index, unsigned int start,
> +				unsigned int count, u32 flags,
> +				void *data)
> +{
> +	return -EINVAL;
> +}
> +
> +static int vfio_fsl_mc_irq_unmask(struct vfio_fsl_mc_device *vdev,
> +				unsigned int index, unsigned int start,
> +				unsigned int count, u32 flags,
> +				void *data)
> +{
> +	return -EINVAL;
> +}
> +
> +static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev,
> +				       unsigned int index, unsigned int start,
> +				       unsigned int count, u32 flags,
> +				       void *data)
> +{
> +	return -EINVAL;
> +}
> +
> +int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> +			       u32 flags, unsigned int index,
> +			       unsigned int start, unsigned int count,
> +			       void *data)
> +{
> +	int ret = -ENOTTY;
> +
> +	switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
> +	case VFIO_IRQ_SET_ACTION_MASK:
> +		ret = vfio_fsl_mc_irq_mask(vdev, index, start, count,
> +					   flags, data);
> +		break;
> +	case VFIO_IRQ_SET_ACTION_UNMASK:
> +		ret = vfio_fsl_mc_irq_unmask(vdev, index, start, count,
> +					     flags, data);
> +		break;
> +	case VFIO_IRQ_SET_ACTION_TRIGGER:
> +		ret = vfio_fsl_mc_set_irq_trigger(vdev, index, start,
> +						  count, flags, data);
> +		break;
> +	}
> +
> +	return ret;
> +}
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> index 3b85d930e060..d5b6fe891a48 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
> @@ -34,7 +34,12 @@ struct vfio_fsl_mc_device {
>  	u32				num_regions;
>  	struct vfio_fsl_mc_region	*regions;
>  	struct vfio_fsl_mc_reflck   *reflck;
> -
> +	struct mutex         igate;
>  };
>  
> +extern int vfio_fsl_mc_set_irqs_ioctl(struct vfio_fsl_mc_device *vdev,
> +			       u32 flags, unsigned int index,
> +			       unsigned int start, unsigned int count,
> +			       void *data);
> +
>  #endif /* VFIO_FSL_MC_PRIVATE_H */
> 
Thanks

Eric