Re: [dpdk-dev] [PATCH 05/12] lib/librte_vhost: copy host_memory_map from virtio-net.c to a new file virtio-net-cdev.c

[Tetsuya Mukawa <mukawa@igel.co.jp>]

On 2015/01/30 15:36, Huawei Xie wrote:
> Signed-off-by: Huawei Xie <huawei.xie@intel.com>
> ---
>  lib/librte_vhost/vhost_cuse/virtio-net-cdev.c | 258 ++++++++++++++++++++++++++
>  1 file changed, 258 insertions(+)
>  create mode 100644 lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
>
> 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
> index 0000000..fbfc403
> --- /dev/null
> +++ b/lib/librte_vhost/vhost_cuse/virtio-net-cdev.c
> @@ -0,0 +1,258 @@
> +/*-
> + *   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)
> +{

Hi Xie,

This patch only copy host_memory_map() to a new file.
And actually the original function is removed at below patch.
- "[PATCH 07/12] lib/librte_vhost: split set_memory_table into two parts"

Is it difficult to remove and copy the function in this patch?

Thanks,
Tetsuya

> +	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;
> +}
> +