[dpdk-dev] [PATCH v3 4/6] EAL: Add a new "--align-memsize" option

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

The option will work with "--range-virtaddr", and if the option is
specified, mapped address will be align by EAL memory size.
Such an alignment is required for using virtio-net PMD extension
on container that uses QEMU QTest framework.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 lib/librte_eal/common/eal_common_options.c | 8 ++++++++
 lib/librte_eal/common/eal_internal_cfg.h   | 1 +
 lib/librte_eal/common/eal_options.h        | 2 ++
 lib/librte_eal/linuxapp/eal/eal.c          | 4 ++++
 lib/librte_eal/linuxapp/eal/eal_memory.c   | 9 +++++++++
 5 files changed, 24 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 3b4f789..853420a 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -75,6 +75,7 @@ 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_ALIGN_MEMSIZE,     0, NULL, OPT_ALIGN_MEMSIZE_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             },
@@ -140,6 +141,7 @@ eal_reset_internal_config(struct internal_config *internal_cfg)
 	internal_cfg->base_virtaddr = 0;
 	internal_cfg->range_virtaddr_start = 0;
 	internal_cfg->range_virtaddr_end = 0;
+	internal_cfg->align_memsize = 0;
 
 	internal_cfg->syslog_facility = LOG_DAEMON;
 	/* default value from build option */
@@ -994,6 +996,12 @@ eal_check_common_options(struct internal_config *internal_cfg)
 		return -1;
 	}
 
+	if (internal_cfg->range_virtaddr_end == 0 && internal_cfg->align_memsize) {
+		RTE_LOG(ERR, EAL, "Option --"OPT_RANGE_VIRTADDR" should be "
+			"specified together with --"OPT_ALIGN_MEMSIZE"\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 0734630..df33a9f 100644
--- a/lib/librte_eal/common/eal_internal_cfg.h
+++ b/lib/librte_eal/common/eal_internal_cfg.h
@@ -80,6 +80,7 @@ struct internal_config {
 	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 unsigned align_memsize;  /**< true to align virtaddr by memory size */
 	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 8e4cf1d..9e36f68 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -49,6 +49,8 @@ enum {
 	OPT_BASE_VIRTADDR_NUM,
 #define OPT_RANGE_VIRTADDR    "range-virtaddr"
 	OPT_RANGE_VIRTADDR_NUM,
+#define OPT_ALIGN_MEMSIZE     "align-memsize"
+	OPT_ALIGN_MEMSIZE_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 80f1995..095e866 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -643,6 +643,10 @@ eal_parse_args(int argc, char **argv)
 			}
 			break;
 
+		case OPT_ALIGN_MEMSIZE_NUM:
+			internal_config.align_memsize = 1;
+			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 d608273..221c358 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -272,6 +272,15 @@ rte_eal_get_free_region(uint64_t pagesz)
 		return NULL;
 	}
 
+	if (internal_config.align_memsize) {
+		/*
+		 * Typically, BAR register of PCI device requiers such
+		 * an alignment.
+		 */
+		low_limit = RTE_ALIGN_CEIL(low_limit, alloc_size);
+		high_limit = RTE_ALIGN_FLOOR(high_limit, alloc_size);
+	}
+
 	fp = fopen("/proc/self/maps", "r");
 	if (fp == NULL) {
 		rte_panic("Cannot open /proc/self/maps\n");
-- 
2.1.4