[dpdk-dev] [PATCH 3/4] eal: fix retrieval of phys address with Xen Dom0

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

When using Xen Dom0, it looks that /proc/self/pagemap returns 0.
This breaks the creation of mbufs pool.

We can workaround this in rte_mem_virt2phy() by browsing the dpdk memory
segments. This only works for dpdk memory, but it's enough to fix the
mempool creation.

Fixes: c042ba20674a ("mempool: rework support of Xen dom0")
Fixes: 3097de6e6bfb ("mem: get physical address of any pointer")

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 lib/librte_eal/linuxapp/eal/eal_memory.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
index b663244..42a29fa 100644
--- a/lib/librte_eal/linuxapp/eal/eal_memory.c
+++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
@@ -164,6 +164,29 @@ rte_mem_virt2phy(const void *virtaddr)
 	int page_size;
 	off_t offset;
 
+	/* when using dom0, /proc/self/pagemap always returns 0, check in
+	 * dpdk memory by browsing the memsegs */
+	if (rte_xen_dom0_supported()) {
+		struct rte_mem_config *mcfg;
+		struct rte_memseg *memseg;
+		unsigned i;
+
+		mcfg = rte_eal_get_configuration()->mem_config;
+		for (i = 0; i < RTE_MAX_MEMSEG; i++) {
+			memseg = &mcfg->memseg[i];
+			if (memseg->addr == NULL)
+				break;
+			if (virtaddr > memseg->addr &&
+					virtaddr < RTE_PTR_ADD(memseg->addr,
+						memseg->len)) {
+				return memseg->phys_addr +
+					RTE_PTR_DIFF(virtaddr, memseg->addr);
+			}
+		}
+
+		return RTE_BAD_PHYS_ADDR;
+	}
+
 	/* Cannot parse /proc/self/pagemap, no need to log errors everywhere */
 	if (!proc_pagemap_readable)
 		return RTE_BAD_PHYS_ADDR;
-- 
2.8.1