[PATCH v3 3/6] EAL: Add new EAL "--range-virtaddr" option

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

The option specifies how to mmap EAL memory.
If the option is specified like '--range-virtaddr=<addr1>-<addr2>',
EAL will check /proc/maps, then tries to find free region between addr1
and addr2. If a region is found, EAL will treat it as if 'base-virtaddr'
is specified. Because of this, the option will not work with
'--base-virtaddr'.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 lib/librte_eal/common/eal_common_options.c |  9 ++++
 lib/librte_eal/common/eal_internal_cfg.h   |  2 +
 lib/librte_eal/common/eal_options.h        |  2 +
 lib/librte_eal/linuxapp/eal/eal.c          | 39 ++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_memory.c   | 82 +++++++++++++++++++++++++++++-
 5 files changed, 133 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 65bccbd..3b4f789 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -74,6 +74,7 @@ eal_short_options[] =
 const struct option
 eal_long_options[] = {
 	{OPT_BASE_VIRTADDR,     1, NULL, OPT_BASE_VIRTADDR_NUM    },
+	{OPT_RANGE_VIRTADDR,    1, NULL, OPT_RANGE_VIRTADDR_NUM   },
 	{OPT_CREATE_UIO_DEV,    0, NULL, OPT_CREATE_UIO_DEV_NUM   },
 	{OPT_FILE_PREFIX,       1, NULL, OPT_FILE_PREFIX_NUM      },
 	{OPT_HELP,              0, NULL, OPT_HELP_NUM             },
@@ -137,6 +138,8 @@ eal_reset_internal_config(struct internal_config *internal_cfg)
 	for (i = 0; i < MAX_HUGEPAGE_SIZES; i++)
 		internal_cfg->hugepage_info[i].lock_descriptor = -1;
 	internal_cfg->base_virtaddr = 0;
+	internal_cfg->range_virtaddr_start = 0;
+	internal_cfg->range_virtaddr_end = 0;
 
 	internal_cfg->syslog_facility = LOG_DAEMON;
 	/* default value from build option */
@@ -985,6 +988,12 @@ eal_check_common_options(struct internal_config *internal_cfg)
 		return -1;
 	}
 
+	if (internal_cfg->base_virtaddr && internal_cfg->range_virtaddr_end) {
+		RTE_LOG(ERR, EAL, "Option --"OPT_RANGE_VIRTADDR" cannot "
+			"be specified together with --"OPT_BASE_VIRTADDR"\n");
+		return -1;
+	}
+
 	return 0;
 }
 
diff --git a/lib/librte_eal/common/eal_internal_cfg.h b/lib/librte_eal/common/eal_internal_cfg.h
index 9117ed9..0734630 100644
--- a/lib/librte_eal/common/eal_internal_cfg.h
+++ b/lib/librte_eal/common/eal_internal_cfg.h
@@ -78,6 +78,8 @@ struct internal_config {
 	volatile unsigned force_sockets;
 	volatile uint64_t socket_mem[RTE_MAX_NUMA_NODES]; /**< amount of memory per socket */
 	uintptr_t base_virtaddr;          /**< base address to try and reserve memory from */
+	uintptr_t range_virtaddr_start;   /**< start address of mappable region */
+	uintptr_t range_virtaddr_end;     /**< end address of mappable region */
 	volatile int syslog_facility;	  /**< facility passed to openlog() */
 	volatile uint32_t log_level;	  /**< default log level */
 	/** default interrupt mode for VFIO */
diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index e5da14a..8e4cf1d 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -47,6 +47,8 @@ enum {
 	OPT_LONG_MIN_NUM = 256,
 #define OPT_BASE_VIRTADDR     "base-virtaddr"
 	OPT_BASE_VIRTADDR_NUM,
+#define OPT_RANGE_VIRTADDR    "range-virtaddr"
+	OPT_RANGE_VIRTADDR_NUM,
 #define OPT_CREATE_UIO_DEV    "create-uio-dev"
 	OPT_CREATE_UIO_DEV_NUM,
 #define OPT_FILE_PREFIX       "file-prefix"
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 82f34f7..80f1995 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -444,6 +444,35 @@ eal_parse_base_virtaddr(const char *arg)
 }
 
 static int
+eal_parse_range_virtaddr(const char *range)
+{
+	char *p, *endptr;
+	uint64_t tmp_start, tmp_end;
+
+	p = strchr(range, '-');
+	if (p == NULL)
+		return -1;
+	*p++ = '\0';
+
+	errno = 0;
+	tmp_start = strtoul(range, &endptr, 0);
+	if ((errno != 0) || endptr == NULL || (*endptr != '\0'))
+		return -1;
+
+	tmp_end = strtoul(p, &endptr, 0);
+	if ((errno != 0) || endptr == NULL || (*endptr != '\0'))
+		return -1;
+
+	if (tmp_start >= tmp_end)
+		return -1;
+
+	internal_config.range_virtaddr_start = tmp_start;
+	internal_config.range_virtaddr_end = tmp_end;
+
+	return 0;
+}
+
+static int
 eal_parse_vfio_intr(const char *mode)
 {
 	unsigned i;
@@ -604,6 +633,16 @@ eal_parse_args(int argc, char **argv)
 			}
 			break;
 
+		case OPT_RANGE_VIRTADDR_NUM:
+			if (eal_parse_range_virtaddr(optarg) < 0) {
+				RTE_LOG(ERR, EAL, "invalid parameter for --"
+						OPT_RANGE_VIRTADDR "\n");
+				eal_usage(prgname);
+				ret = -1;
+				goto out;
+			}
+			break;
+
 		case OPT_VFIO_INTR_NUM:
 			if (eal_parse_vfio_intr(optarg) < 0) {
 				RTE_LOG(ERR, EAL, "invalid parameters for --"
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index a6b3616..d608273 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -251,6 +251,66 @@ aslr_enabled(void)
 }
 
 /*
+ * Find memory space that fits user request.
+ */
+static uintptr_t
+rte_eal_get_free_region(uint64_t pagesz)
+{
+	uint64_t alloc_size, start, end, next_start;
+	uint64_t low_limit, high_limit;
+	uintptr_t addr = 0;
+	char buf[1024], *p;
+	FILE *fp;
+
+	alloc_size = internal_config.memory;
+	low_limit = internal_config.range_virtaddr_start;
+	high_limit = internal_config.range_virtaddr_end;
+
+	/* allocation size should be aligned by page size */
+	if (alloc_size != RTE_ALIGN_CEIL(alloc_size, pagesz)) {
+		rte_panic("Invalid allocation size 0x%lx\n", alloc_size);
+		return NULL;
+	}
+
+	fp = fopen("/proc/self/maps", "r");
+	if (fp == NULL) {
+		rte_panic("Cannot open /proc/self/maps\n");
+		return NULL;
+	}
+
+	next_start = 0;
+	do {
+		start = next_start;
+
+		if ((p = fgets(buf, sizeof(buf), fp)) != NULL) {
+			if (sscanf(p, "%lx-%lx ", &end, &next_start) < 2)
+				break;
+
+			next_start = RTE_ALIGN_CEIL(next_start, alloc_size);
+			end = RTE_ALIGN_CEIL(end, alloc_size) - 1;
+		} else
+			end = UINT64_MAX;
+
+		if (start >= high_limit)
+			break;
+		if (end < low_limit)
+			continue;
+
+		start = RTE_MAX(start, low_limit);
+		end = RTE_MIN(end, high_limit - 1);
+
+		if (end - start >= alloc_size - 1) {
+			addr = start;
+			break;
+		}
+	} while (end != UINT64_MAX);
+
+	fclose(fp);
+
+	return addr;
+}
+
+/*
  * Try to mmap *size bytes in /dev/zero. If it is successful, return the
  * pointer to the mmap'd area and keep *size unmodified. Else, retry
  * with a smaller zone: decrease *size by hugepage_sz until it reaches
@@ -1126,6 +1186,25 @@ rte_eal_hugepage_init(void)
 	/* get pointer to global configuration */
 	mcfg = rte_eal_get_configuration()->mem_config;
 
+	if (internal_config.range_virtaddr_end) {
+		uint64_t pagesize = RTE_PGSIZE_4K;
+		struct hugepage_info *hpi;
+		unsigned n;
+		uintptr_t addr;
+
+		/* determine maximum hugepage size */
+		for (n = 0; n < internal_config.num_hugepage_sizes; n++) {
+			hpi = &internal_config.hugepage_info[n];
+			pagesize = RTE_MAX(hpi->hugepage_sz, pagesize);
+		}
+
+		addr = rte_eal_get_free_region(pagesize);
+		if (addr == 0)
+			RTE_LOG(WARNING, EAL,
+				"no free space to mmap in specified region\n");
+		internal_config.base_virtaddr = addr;
+	}
+
 	/* when hugetlbfs is disabled or single-file option is specified */
 	if (internal_config.no_hugetlbfs || internal_config.single_file) {
 		int fd;
@@ -1158,7 +1237,8 @@ rte_eal_hugepage_init(void)
 			return -1;
 		}
 
-		addr = mmap(NULL, internal_config.memory,
+		addr = mmap((void *)internal_config.base_virtaddr,
+			    internal_config.memory,
 			    PROT_READ | PROT_WRITE,
 			    MAP_SHARED | MAP_POPULATE, fd, 0);
 		if (addr == MAP_FAILED) {
-- 
2.1.4