Thank you for your answer Bruce,
I think you refer to the example "l2fwd-ivshmem", Don't you?
I compiled and run it, it works.
I was reviewing the code and I found that the function rte_mempool_lookup
is not used in the guest.
In the host a structure containing pointers to the rings is allocated using
rte_memzone_reserve and then mapped to the guest with
rte_ivshmem_metadata_add_memzone.
In the guest rte_memzone_lookup is used to lookup for this structure.
It's clear to me that I could use this approach to do what I want to do,
but I don't understand why rte_mempool_lookup does not work in my case.
Thanks in advance.
On Tue, May 19, 2015 at 2:27 PM, Bruce Richardson <
bruce.richardson at intel.com> wrote:
> On Mon, May 18, 2015 at 10:32:37AM +0200, Mauricio V?squez wrote:
> > Hi all,
> >
> > I'm trying to map a mempool into a guest using the IVSHMEM library but
> the
> > mempool is not visible from the guest.
> >
> > The code I'm running is quite simple, on the host I run a primary DPDK
> > process that creates the mempool, creates a metadata file and then adds
> the
> > mempool to it.
>
> Can you perhaps try using the ivshmem example application with DPDK to
> start with
> and see if you can reproduce your issue with that?
>
> Regards,
> /Bruce
>
> >
> > The code is:
> > ...
> > int main(int argc, char * argv[])
> > {
> > int retval = 0;
> >
> > /* Init EAL, parsing EAL args */
> > retval = rte_eal_init(argc, argv);
> > if (retval < 0)
> > return -1;
> >
> > char cmdline[PATH_MAX] = {0};
> >
> > struct rte_mempool *packets_pool;
> > //Create mempool
> > packets_pool = rte_mempool_create(
> > "packets",
> > NUM_PKTS,
> > MBUF_SIZE,
> > CACHE_SIZE, //This is the size of the mempool
> > cache
> > sizeof(struct rte_pktmbuf_pool_private),
> > rte_pktmbuf_pool_init,
> > NULL,
> > rte_pktmbuf_init,
> > NULL,
> > rte_socket_id(),
> > 0 /*NO_FLAGS*/);
> >
> > if (packets_pool == NULL)
> > rte_exit(EXIT_FAILURE,"Cannot init the packets pool\n");
> >
> > //Create metadata file
> > if (rte_ivshmem_metadata_create(metadata_name) < 0)
> > rte_exit(EXIT_FAILURE, "Cannot create metadata file\n");
> >
> > //Add mempool to metadata file
> > if(rte_ivshmem_metadata_add_mempool(packets_pool, metadata_name) < 0)
> > rte_exit(EXIT_FAILURE, "Cannot add mempool metadata file\n");
> >
> > //Get qemu command line
> > if (rte_ivshmem_metadata_cmdline_generate(cmdline, sizeof(cmdline),
> > metadata_name) < 0)
> > rte_exit(EXIT_FAILURE, "Failed generating command line for
> qemu\n");
> >
> > RTE_LOG(INFO, APP, "Command line for qemu: %s\n", cmdline);
> > save_ivshmem_cmdline_to_file(cmdline);
> >
> > //Avoids the application closes
> > char x = getchar();
> > (void) x;
> > return 0;
> > }
> >
> > When I run it I can see clearly that the memzone is added:
> >
> > EAL: Adding memzone 'MP_packets' at 0x7ffec0e8c1c0 to metadata vm_1
> > EAL: Adding memzone 'RG_MP_packets' at 0x7ffec0d8c140 to metadata vm_1
> > APP: Command line for qemu: -device
> >
> ivshmem,size=2048M,shm=fd:/dev/hugepages/rtemap_0:0x0:0x40000000:/dev/zero:0x0:0x3fffc000:/var/run/.dpdk_ivshmem_metadata_vm_1:0x0:0x4000
> >
> > I run the modified version of QEMU provided by dpdk-ovs using the command
> > line generated by the host application, then in the guest I run an even
> > simpler application:
> >
> > ...
> > void mempool_walk_f(const struct rte_mempool *r, void * arg)
> > {
> > RTE_LOG(INFO, APP, "Mempool: %s\n", r->name);
> > (void) arg;
> > }
> >
> > int main(int argc, char *argv[])
> > {
> > int retval = 0;
> >
> > if ((retval = rte_eal_init(argc, argv)) < 0)
> > return -1;
> >
> > argc -= retval;
> > argv += retval;
> >
> > struct rte_mempool * packets;
> >
> > packets = rte_mempool_lookup("packets");
> >
> > if(packets == NULL)
> > {
> > RTE_LOG(ERR, APP, "Failed to find mempool\n");
> > }
> >
> > RTE_LOG(INFO, APP, "List of mempool: \n");
> > rte_mempool_walk(mempool_walk_f, NULL);
> >
> > return 0;
> > }
> > ...
> >
> > I can see in the application output that the mem zones that were added
> are
> > found:
> >
> > EAL: Found memzone: 'RG_MP_packets' at 0x7ffec0d8c140 (len 0x100080)
> > EAL: Found memzone: 'MP_packets' at 0x7ffec0e8c1c0 (len 0x3832100)
> >
> > But, the rte_mempool_lookup function returns NULL.
> > Using the rte_mempool_walker the program only prints a memzone called
> > log_history.
> >
> > Do you have any suggestion?
> >
> > Thank you very much for your help.
>
