vhost: copy host memory mapping to a new cuse file

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Acked-by: Tetsuya Mukawa <mukawa@igel.co.jp>

diff --git a/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c b/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
new file mode 100644 (file)
index 0000000..baca379
--- /dev/null
+++ b/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
@@ -0,0 +1,257 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <dirent.h>
+#include <linux/vhost.h>
+#include <linux/virtio_net.h>
+#include <fuse/cuse_lowlevel.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/eventfd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <rte_log.h>
+
+#include "vhost-net.h"
+
+/* Line size for reading maps file. */
+static const uint32_t BUFSIZE = PATH_MAX;
+
+/* Size of prot char array in procmap. */
+#define PROT_SZ 5
+
+/* Number of elements in procmap struct. */
+#define PROCMAP_SZ 8
+
+/* Structure containing information gathered from maps file. */
+struct procmap {
+       uint64_t va_start;      /* Start virtual address in file. */
+       uint64_t len;           /* Size of file. */
+       uint64_t pgoff;         /* Not used. */
+       uint32_t maj;           /* Not used. */
+       uint32_t min;           /* Not used. */
+       uint32_t ino;           /* Not used. */
+       char prot[PROT_SZ];     /* Not used. */
+       char fname[PATH_MAX];   /* File name. */
+};
+
+/*
+ * Locate the file containing QEMU's memory space and
+ * map it to our address space.
+ */
+static int
+host_memory_map(struct virtio_net *dev, struct virtio_memory *mem,
+       pid_t pid, uint64_t addr)
+{
+       struct dirent *dptr = NULL;
+       struct procmap procmap;
+       DIR *dp = NULL;
+       int fd;
+       int i;
+       char memfile[PATH_MAX];
+       char mapfile[PATH_MAX];
+       char procdir[PATH_MAX];
+       char resolved_path[PATH_MAX];
+       char *path = NULL;
+       FILE *fmap;
+       void *map;
+       uint8_t found = 0;
+       char line[BUFSIZE];
+       char dlm[] = "-   :   ";
+       char *str, *sp, *in[PROCMAP_SZ];
+       char *end = NULL;
+
+       /* Path where mem files are located. */
+       snprintf(procdir, PATH_MAX, "/proc/%u/fd/", pid);
+       /* Maps file used to locate mem file. */
+       snprintf(mapfile, PATH_MAX, "/proc/%u/maps", pid);
+
+       fmap = fopen(mapfile, "r");
+       if (fmap == NULL) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Failed to open maps file for pid %d\n",
+                       dev->device_fh, pid);
+               return -1;
+       }
+
+       /* Read through maps file until we find out base_address. */
+       while (fgets(line, BUFSIZE, fmap) != 0) {
+               str = line;
+               errno = 0;
+               /* Split line into fields. */
+               for (i = 0; i < PROCMAP_SZ; i++) {
+                       in[i] = strtok_r(str, &dlm[i], &sp);
+                       if ((in[i] == NULL) || (errno != 0)) {
+                               fclose(fmap);
+                               return -1;
+                       }
+                       str = NULL;
+               }
+
+               /* Convert/Copy each field as needed. */
+               procmap.va_start = strtoull(in[0], &end, 16);
+               if ((in[0] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               procmap.len = strtoull(in[1], &end, 16);
+               if ((in[1] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               procmap.pgoff = strtoull(in[3], &end, 16);
+               if ((in[3] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               procmap.maj = strtoul(in[4], &end, 16);
+               if ((in[4] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               procmap.min = strtoul(in[5], &end, 16);
+               if ((in[5] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               procmap.ino = strtoul(in[6], &end, 16);
+               if ((in[6] == '\0') || (end == NULL) || (*end != '\0') ||
+                       (errno != 0)) {
+                       fclose(fmap);
+                       return -1;
+               }
+
+               memcpy(&procmap.prot, in[2], PROT_SZ);
+               memcpy(&procmap.fname, in[7], PATH_MAX);
+
+               if (procmap.va_start == addr) {
+                       procmap.len = procmap.len - procmap.va_start;
+                       found = 1;
+                       break;
+               }
+       }
+       fclose(fmap);
+
+       if (!found) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Failed to find memory file in pid %d maps file\n",
+                       dev->device_fh, pid);
+               return -1;
+       }
+
+       /* Find the guest memory file among the process fds. */
+       dp = opendir(procdir);
+       if (dp == NULL) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Cannot open pid %d process directory\n",
+                       dev->device_fh, pid);
+               return -1;
+       }
+
+       found = 0;
+
+       /* Read the fd directory contents. */
+       while (NULL != (dptr = readdir(dp))) {
+               snprintf(memfile, PATH_MAX, "/proc/%u/fd/%s",
+                               pid, dptr->d_name);
+               path = realpath(memfile, resolved_path);
+               if ((path == NULL) && (strlen(resolved_path) == 0)) {
+                       RTE_LOG(ERR, VHOST_CONFIG,
+                               "(%"PRIu64") Failed to resolve fd directory\n",
+                               dev->device_fh);
+                       closedir(dp);
+                       return -1;
+               }
+               if (strncmp(resolved_path, procmap.fname,
+                       strnlen(procmap.fname, PATH_MAX)) == 0) {
+                       found = 1;
+                       break;
+               }
+       }
+
+       closedir(dp);
+
+       if (found == 0) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Failed to find memory file for pid %d\n",
+                       dev->device_fh, pid);
+               return -1;
+       }
+       /* Open the shared memory file and map the memory into this process. */
+       fd = open(memfile, O_RDWR);
+
+       if (fd == -1) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Failed to open %s for pid %d\n",
+                       dev->device_fh, memfile, pid);
+               return -1;
+       }
+
+       map = mmap(0, (size_t)procmap.len, PROT_READ|PROT_WRITE,
+               MAP_POPULATE|MAP_SHARED, fd, 0);
+       close(fd);
+
+       if (map == MAP_FAILED) {
+               RTE_LOG(ERR, VHOST_CONFIG,
+                       "(%"PRIu64") Error mapping the file %s for pid %d\n",
+                       dev->device_fh, memfile, pid);
+               return -1;
+       }
+
+       /* Store the memory address and size in the device data structure */
+       mem->mapped_address = (uint64_t)(uintptr_t)map;
+       mem->mapped_size = procmap.len;
+
+       LOG_DEBUG(VHOST_CONFIG,
+               "(%"PRIu64") Mem File: %s->%s - Size: %llu - VA: %p\n",
+               dev->device_fh,
+               memfile, resolved_path,
+               (unsigned long long)mem->mapped_size, map);
+
+       return 0;
+}