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

[Diana Craciun OSS <diana.craciun@oss.nxp.com>]

Hi Eric,

On 9/3/2020 11:15 PM, Auger Eric wrote:
> 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.

The skeletons for mask are not implemented. Maybe I should just remove 
the skeletons.

>> +		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()?

Yes, I think I can reuse it.

>> +
>> +		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
> 

Regards,
Diana