[dpdk-dev] [PATCH 2/2] eal/freebsd: add config reattach

[Anatoly Burakov]

Linux EAL will attach the shared config at an arbitrary address,
find out where the shared config is mapped in the primary, and
then will reattach it at that exact address.

FreeBSD version doesn't seem to go for that extra reattach step,
which makes one wonder how did it ever work in the first place.

Fix the FreeBSD init to also reattach shared config to the exact
same place the primary process has it.

Fixes: 764bf26873b9 ("add FreeBSD support")
Cc: bruce.richardson at intel.com
Cc: stable at dpdk.org

Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
---
 lib/librte_eal/freebsd/eal/eal.c | 36 ++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/lib/librte_eal/freebsd/eal/eal.c b/lib/librte_eal/freebsd/eal/eal.c
index 8c399c799..ce7a5f91d 100644
--- a/lib/librte_eal/freebsd/eal/eal.c
+++ b/lib/librte_eal/freebsd/eal/eal.c
@@ -280,6 +280,41 @@ rte_eal_config_attach(void)
 	rte_config.mem_config = rte_mem_cfg_addr;
 }
 
+/* reattach the shared config at exact memory location primary process has it */
+static void
+rte_eal_config_reattach(void)
+{
+	struct rte_mem_config *mem_config;
+	void *rte_mem_cfg_addr;
+
+	if (internal_config.no_shconf)
+		return;
+
+	/* save the address primary process has mapped shared config to */
+	rte_mem_cfg_addr =
+			(void *)(uintptr_t)rte_config.mem_config->mem_cfg_addr;
+
+	/* unmap original config */
+	munmap(rte_config.mem_config, sizeof(struct rte_mem_config));
+
+	/* remap the config at proper address */
+	mem_config = (struct rte_mem_config *) mmap(rte_mem_cfg_addr,
+			sizeof(*mem_config), PROT_READ | PROT_WRITE, MAP_SHARED,
+			mem_cfg_fd, 0);
+	if (mem_config == MAP_FAILED || mem_config != rte_mem_cfg_addr) {
+		if (mem_config != MAP_FAILED)
+			/* errno is stale, don't use */
+			rte_panic("Cannot mmap memory for rte_config at [%p], got [%p]\n",
+				  rte_mem_cfg_addr, mem_config);
+		else
+			rte_panic("Cannot mmap memory for rte_config! error %i (%s)\n",
+				  errno, strerror(errno));
+	}
+	close(mem_cfg_fd);
+
+	rte_config.mem_config = mem_config;
+}
+
 /* Detect if we are a primary or a secondary process */
 enum rte_proc_type_t
 eal_proc_type_detect(void)
@@ -318,6 +353,7 @@ rte_config_init(void)
 	case RTE_PROC_SECONDARY:
 		rte_eal_config_attach();
 		rte_eal_mcfg_wait_complete(rte_config.mem_config);
+		rte_eal_config_reattach();
 		break;
 	case RTE_PROC_AUTO:
 	case RTE_PROC_INVALID:
-- 
2.17.1