Re: [dpdk-dev] [PATCH 1/2] test: add test case to validate VFIO DMA map/unmap

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 12-Oct-20 9:11 AM, Nithin Dabilpuram wrote:
> Add test case in test_memory to test VFIO DMA map/unmap.
> 
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> ---
>   app/test/test_memory.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 79 insertions(+)
> 
> diff --git a/app/test/test_memory.c b/app/test/test_memory.c
> index 7d5ae99..1c56455 100644
> --- a/app/test/test_memory.c
> +++ b/app/test/test_memory.c
> @@ -4,11 +4,16 @@
>   
>   #include <stdio.h>
>   #include <stdint.h>
> +#include <string.h>
> +#include <sys/mman.h>
> +#include <unistd.h>
>   
>   #include <rte_eal.h>
> +#include <rte_errno.h>
>   #include <rte_memory.h>
>   #include <rte_common.h>
>   #include <rte_memzone.h>
> +#include <rte_vfio.h>
>   
>   #include "test.h"
>   
> @@ -70,6 +75,71 @@ check_seg_fds(const struct rte_memseg_list *msl, const struct rte_memseg *ms,
>   }
>   
>   static int
> +test_memory_vfio_dma_map(void)
> +{
> +	uint64_t sz = 2 * sysconf(_SC_PAGESIZE), sz1, sz2;

i think we now have a function for that, rte_page_size() ?

Also, i would prefer

uint64_t sz1, sz2, sz = 2 * rte_page_size();

Easier to parse IMO.

> +	uint64_t unmap1, unmap2;
> +	uint8_t *mem;
> +	int ret;
> +
> +	/* Check if vfio is enabled in both kernel and eal */
> +	ret = rte_vfio_is_enabled("vfio");
> +	if (!ret)
> +		return 1;

No need, rte_vfio_container_dma_map() should set errno to ENODEV if vfio 
is not enabled.

> +
> +	/* Allocate twice size of page */
> +	mem = mmap(NULL, sz, PROT_READ | PROT_WRITE,
> +		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> +	if (mem == MAP_FAILED) {
> +		printf("Failed to allocate memory for external heap\n");
> +		return -1;
> +	}
> +
> +	/* Force page allocation */
> +	memset(mem, 0, sz);
> +
> +	/* map the whole region */
> +	ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
> +					 (uint64_t)mem, (rte_iova_t)mem, sz);

should be (uintptr_t) perhaps?

Also, this can return -1 with rte_errno == ENOTSUP, i think this happens 
if there are no devices attached (or if there's no VFIO support, like it 
would be on FreeBSD or Windows).

> +	if (ret) {
> +		printf("Failed to dma map whole region, ret=%d\n", ret);
> +		goto fail;
> +	}
> +
> +	unmap1 = (uint64_t)mem + (sz / 2);
> +	sz1 = sz / 2;
> +	unmap2 = (uint64_t)mem;
> +	sz2 = sz / 2;
> +	/* unmap the partial region */
> +	ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
> +					   unmap1, (rte_iova_t)unmap1, sz1);
> +	if (ret) {
> +		if (rte_errno == ENOTSUP) {
> +			printf("Partial dma unmap not supported\n");
> +			unmap2 = (uint64_t)mem;
> +			sz2 = sz;
> +		} else {
> +			printf("Failed to unmap send half region, ret=%d(%d)\n",

I think "send half" is a typo? Also, here and in other places, i would 
prefer a rte_strerror() instead of raw rte_errno number.

> +			       ret, rte_errno);
> +			goto fail;
> +		}
> +	}
> +
> +	/* unmap the remaining region */
> +	ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
> +					   unmap2, (rte_iova_t)unmap2, sz2);
> +	if (ret) {
> +		printf("Failed to unmap remaining region, ret=%d(%d)\n", ret,
> +		       rte_errno);
> +		goto fail;
> +	}
> +
> +fail:
> +	munmap(mem, sz);
> +	return ret;
> +}
> +
> +static int
>   test_memory(void)
>   {
>   	uint64_t s;
> @@ -101,6 +171,15 @@ test_memory(void)
>   		return -1;
>   	}
>   
> +	/* test for vfio dma map/unmap */
> +	ret = test_memory_vfio_dma_map();
> +	if (ret == 1) {
> +		printf("VFIO dma map/unmap unsupported\n");
> +	} else if (ret < 0) {
> +		printf("Error vfio dma map/unmap, ret=%d\n", ret);
> +		return -1;
> +	}
> +

This looks odd in this autotest. Perhaps create a new autotest for VFIO?

>   	return 0;
>   }
>   
> 


-- 
Thanks,
Anatoly