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

[Nithin Dabilpuram]

On Wed, Oct 14, 2020 at 03:39:36PM +0100, Burakov, Anatoly wrote:
> External Email
> 
> ----------------------------------------------------------------------
> 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 at 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.

Ack, will use rte_mem_page_size().
> 
> > +	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.

Ack.

> 
> > +
> > +	/* 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).
Ok. Will return 1 if NOTSUP.
> 
> > +	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.
Ack.
> 
> > +			       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?
Ack, will add test_vfio.c
> 
> >   	return 0;
> >   }
> > 
> 
> 
> -- 
> Thanks,
> Anatoly