[dpdk-dev] [PATCH 1/7] bus/vdev: add DMA mapping ops

[Maxime Coquelin]

On 9/24/20 7:25 AM, Xia, Chenbo wrote:
> Hi Maxime,
> 
>> -----Original Message-----
>> From: dev <dev-bounces at dpdk.org> On Behalf Of Maxime Coquelin
>> Sent: Friday, September 11, 2020 11:08 PM
>> To: dev at dpdk.org; Fu, Patrick <patrick.fu at intel.com>; amorenoz at redhat.com
>> Cc: Maxime Coquelin <maxime.coquelin at redhat.com>
>> Subject: [dpdk-dev] [PATCH 1/7] bus/vdev: add DMA mapping ops
>>
>> Add DMA map/unmap operation callbacks to the vdev bus, which
>> could be used by DMA capable vdev drivers.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
>> ---
>>  drivers/bus/vdev/rte_bus_vdev.h | 46 +++++++++++++++++++++++++++--
>>  drivers/bus/vdev/vdev.c         | 52 +++++++++++++++++++++++++++++++++
>>  2 files changed, 95 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/bus/vdev/rte_bus_vdev.h
>> b/drivers/bus/vdev/rte_bus_vdev.h
>> index 78a032cea8..3fe0b35a82 100644
>> --- a/drivers/bus/vdev/rte_bus_vdev.h
>> +++ b/drivers/bus/vdev/rte_bus_vdev.h
>> @@ -63,14 +63,54 @@ typedef int (rte_vdev_probe_t)(struct rte_vdev_device
>> *dev);
>>   */
>>  typedef int (rte_vdev_remove_t)(struct rte_vdev_device *dev);
>>
>> +/**
>> + * Driver-specific DMA mapping. After a successful call the device
>> + * will be able to read/write from/to this segment.
>> + *
>> + * @param dev
>> + *   Pointer to the Virtual device.
>> + * @param addr
>> + *   Starting virtual address of memory to be mapped.
>> + * @param iova
>> + *   Starting IOVA address of memory to be mapped.
>> + * @param len
>> + *   Length of memory segment being mapped.
>> + * @return
>> + *   - 0 On success.
>> + *   - Negative value and rte_errno is set otherwise.
>> + */
>> +typedef int (rte_vdev_dma_map_t)(struct rte_vdev_device *dev, void *addr,
>> +			    uint64_t iova, size_t len);
>> +
>> +/**
>> + * Driver-specific DMA un-mapping. After a successful call the device
>> + * will not be able to read/write from/to this segment.
>> + *
>> + * @param dev
>> + *   Pointer to the Virtual device.
>> + * @param addr
>> + *   Starting virtual address of memory to be unmapped.
>> + * @param iova
>> + *   Starting IOVA address of memory to be unmapped.
>> + * @param len
>> + *   Length of memory segment being unmapped.
>> + * @return
>> + *   - 0 On success.
>> + *   - Negative value and rte_errno is set otherwise.
>> + */
>> +typedef int (rte_vdev_dma_unmap_t)(struct rte_vdev_device *dev, void
>> *addr,
>> +			      uint64_t iova, size_t len);
>> +
>>  /**
>>   * A virtual device driver abstraction.
>>   */
>>  struct rte_vdev_driver {
>>  	TAILQ_ENTRY(rte_vdev_driver) next; /**< Next in list. */
>> -	struct rte_driver driver;      /**< Inherited general driver. */
>> -	rte_vdev_probe_t *probe;       /**< Virtual device probe function.
>> */
>> -	rte_vdev_remove_t *remove;     /**< Virtual device remove function.
>> */
>> +	struct rte_driver driver;        /**< Inherited general driver. */
>> +	rte_vdev_probe_t *probe;         /**< Virtual device probe function.
>> */
>> +	rte_vdev_remove_t *remove;       /**< Virtual device remove function.
>> */
>> +	rte_vdev_dma_map_t *dma_map;     /**< vdev DMA map function. */
>> +	rte_vdev_dma_unmap_t *dma_unmap; /**< vdev DMA unmap function. */
>>  };
> 
> I think we'd better unify the term 'Virtual device' or 'vdev'? Maybe just
> use Virtual device.

Right, fixing it in v2.

>>
>>  /**
>> diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
>> index d746149a2e..455d0bd0c2 100644
>> --- a/drivers/bus/vdev/vdev.c
>> +++ b/drivers/bus/vdev/vdev.c
>> @@ -134,6 +134,56 @@ vdev_parse(const char *name, void *addr)
>>  	return driver == NULL;
>>  }
>>
>> +static int
>> +vdev_dma_map(struct rte_device *dev, void *addr, uint64_t iova, size_t
>> len)
>> +{
>> +	struct rte_vdev_device *vdev = RTE_DEV_TO_VDEV(dev);
>> +	const struct rte_vdev_driver *driver;
>> +
>> +	if (!vdev) {
>> +		rte_errno = EINVAL;
>> +		return -1;
>> +	}
>> +
>> +	if (!vdev->device.driver) {
>> +		VDEV_LOG(DEBUG, "no driver attach to device %s", dev->name);
>> +		return 1;
>> +	}
>> +
>> +	driver = container_of(vdev->device.driver, const struct
>> rte_vdev_driver,
>> +			driver);
>> +
>> +	if (driver->dma_map)
>> +		return driver->dma_map(vdev, addr, iova, len);
>> +
>> +	return 0;
>> +}
>> +
>> +static int
>> +vdev_dma_unmap(struct rte_device *dev, void *addr, uint64_t iova, size_t
>> len)
>> +{
>> +	struct rte_vdev_device *vdev = RTE_DEV_TO_VDEV(dev);
>> +	const struct rte_vdev_driver *driver;
>> +
>> +	if (!vdev) {
>> +		rte_errno = EINVAL;
>> +		return -1;
>> +	}
>> +
>> +	if (!vdev->device.driver) {
>> +		VDEV_LOG(DEBUG, "no driver attach to device %s", dev->name);
>> +		return 1;
>> +	}
>> +
>> +	driver = container_of(vdev->device.driver, const struct
>> rte_vdev_driver,
>> +			driver);
>> +
>> +	if (driver->dma_unmap)
>> +		return driver->dma_unmap(vdev, addr, iova, len);
>> +
>> +	return 0;	return 0;
> 
> Duplicate return here 😊

Oops!

Maxime

> Thanks!
> Chenbo
> 
>> +}
>> +
>>  static int
>>  vdev_probe_all_drivers(struct rte_vdev_device *dev)
>>  {
>> @@ -551,6 +601,8 @@ static struct rte_bus rte_vdev_bus = {
>>  	.plug = vdev_plug,
>>  	.unplug = vdev_unplug,
>>  	.parse = vdev_parse,
>> +	.dma_map = vdev_dma_map,
>> +	.dma_unmap = vdev_dma_unmap,
>>  	.dev_iterate = rte_vdev_dev_iterate,
>>  };
>>
>> --
>> 2.26.2
>