Commit 1e21feb6 authored by Marc-André Lureau's avatar Marc-André Lureau
Browse files

ivshmem-server: fix hugetlbfs support 



As pointed out on the ML by Andrew Jones, glibc no longer permits
creating POSIX shm on hugetlbfs directly. When given a hugetlbfs path,
create a shareable file there.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
parent 022cffe3

contrib/ivshmem-server/ivshmem-server.c

+51 −1
Original line number Diff line number Diff line
@@ -12,6 +12,9 @@ 
#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#ifdef CONFIG_LINUX

#include <sys/vfs.h>

#endif



#include "ivshmem-server.h"
@@ -271,6 +274,31 @@ ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path, 
    return 0;

}



#ifdef CONFIG_LINUX



#define HUGETLBFS_MAGIC       0x958458f6



static long gethugepagesize(const char *path)

{

    struct statfs fs;

    int ret;



    do {

        ret = statfs(path, &fs);

    } while (ret != 0 && errno == EINTR);



    if (ret != 0) {

        return -1;

    }



    if (fs.f_type != HUGETLBFS_MAGIC) {

        return -1;

    }



    return fs.f_bsize;

}

#endif



/* open shm, create and bind to the unix socket */

int

ivshmem_server_start(IvshmemServer *server)
@@ -279,7 +307,29 @@ ivshmem_server_start(IvshmemServer *server) 
    int shm_fd, sock_fd, ret;



    /* open shm file */

#ifdef CONFIG_LINUX

    long hpagesize;



    hpagesize = gethugepagesize(server->shm_path);

    if (hpagesize < 0 && errno != ENOENT) {

        IVSHMEM_SERVER_DEBUG(server, "cannot stat shm file %s: %s\n",

                             server->shm_path, strerror(errno));

    }



    if (hpagesize > 0) {

        gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);

        IVSHMEM_SERVER_DEBUG(server, "Using hugepages: %s\n", server->shm_path);

        shm_fd = mkstemp(filename);

        unlink(filename);

        g_free(filename);

    } else

#endif

    {

        IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",

                             server->shm_path);

        shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU);

    }



    if (shm_fd < 0) {

        fprintf(stderr, "cannot open shm file %s: %s\n", server->shm_path,

                strerror(errno));

contrib/ivshmem-server/ivshmem-server.h

+1 −2
Original line number Diff line number Diff line
@@ -82,8 +82,7 @@ typedef struct IvshmemServer { 
 * @server:         A pointer to an uninitialized IvshmemServer structure

 * @unix_sock_path: The pointer to the unix socket file name

 * @shm_path:       Path to the shared memory. The path corresponds to a POSIX

 *                  shm name. To use a real file, for instance in a hugetlbfs,

 *                  it is possible to use /../../abspath/to/file.

 *                  shm name or a hugetlbfs mount point.

 * @shm_size:       Size of shared memory

 * @n_vectors:      Number of interrupt vectors per client

 * @verbose:        True to enable verbose mode

contrib/ivshmem-server/main.c

+2 −3
Original line number Diff line number Diff line
@@ -47,9 +47,8 @@ ivshmem_server_usage(const char *name, int code) 
                    "     to listen to.\n"

                    "     Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH);

    fprintf(stderr, "  -m <shm_path>: path to the shared memory.\n"

                    "     The path corresponds to a POSIX shm name. To use a\n"

                    "     real file, for instance in a hugetlbfs, use\n"

                    "     /../../abspath/to/file.\n"

                    "     The path corresponds to a POSIX shm name or a\n"

                    "     hugetlbfs mount point.\n"

                    "     default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);

    fprintf(stderr, "  -l <size>: size of shared memory in bytes. The suffix\n"

                    "     K, M and G can be used (ex: 1K means 1024).\n"