[dpdk-dev] [PATCH] eal: don't advertise a physical address when no hugepages

[Olivier Matz <olivier.matz@6wind.com>]

When populating a mempool with a virtual memory area, the mempool
library expects to be able to get the physical address of each page.

When started with --no-huge, the physical addresses may not be available
because the pages are not locked in memory. It sometimes returns
RTE_BAD_PHYS_ADDR, which makes the mempool_populate() function to fail.

This was working before the commit cdc242f260e7 ("eal/linux: support
running as unprivileged user"), because rte_mem_virt2phy() was returning
0 instead of RTE_BAD_PHYS_ADDR, which was seen as a valid physical
address.

Since --no-huge is a debug function that breaks the support of physical
drivers, always set physical addresses to RTE_BAD_PHYS_ADDR in memzones
or in rte_mem_virt2phy(), and ensure that mempool won't complain in that
case.

Fixes: cdc242f260e7 ("eal/linux: support running as unprivileged user")

CC: stable@dpdk.org
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_eal/common/eal_common_memzone.c | 5 ++++-
 lib/librte_eal/linuxapp/eal/eal_memory.c   | 7 +++++++
 lib/librte_mempool/rte_mempool.c           | 2 +-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_memzone.c b/lib/librte_eal/common/eal_common_memzone.c
index 3026e36b8..c465c8fc2 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -251,7 +251,10 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 
 	mcfg->memzone_cnt++;
 	snprintf(mz->name, sizeof(mz->name), "%s", name);
-	mz->phys_addr = rte_malloc_virt2phy(mz_addr);
+	if (rte_eal_has_hugepages())
+		mz->phys_addr = rte_malloc_virt2phy(mz_addr);
+	else
+		mz->phys_addr = RTE_BAD_PHYS_ADDR;
 	mz->addr = mz_addr;
 	mz->len = (requested_len == 0 ? elem->size : requested_len);
 	mz->hugepage_sz = elem->ms->hugepage_sz;
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index 9c9baf628..1c99852f6 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -108,6 +108,13 @@ test_phys_addrs_available(void)
 	if (rte_xen_dom0_supported())
 		return;
 
+	if (!rte_eal_has_hugepages()) {
+		RTE_LOG(ERR, EAL,
+			"Started without hugepages support, physical addresses not available\n");
+		phys_addrs_available = false;
+		return;
+	}
+
 	physaddr = rte_mem_virt2phy(&tmp);
 	if (physaddr == RTE_BAD_PHYS_ADDR) {
 		RTE_LOG(ERR, EAL,
diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index f65310f60..6fc3c9c7c 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -476,7 +476,7 @@ rte_mempool_populate_virt(struct rte_mempool *mp, char *addr,
 		/* required for xen_dom0 to get the machine address */
 		paddr = rte_mem_phy2mch(-1, paddr);
 
-		if (paddr == RTE_BAD_PHYS_ADDR) {
+		if (paddr == RTE_BAD_PHYS_ADDR && rte_eal_has_hugepages()) {
 			ret = -EINVAL;
 			goto fail;
 		}
-- 
2.11.0