[dpdk-dev] [PATCH dpdk v2] vfio/ppc64/spapr: Warn if DMA window was created at unexpected offset

[Alexey Kardashevskiy <aik@ozlabs.ru>]

VFIO_IOMMU_SPAPR_TCE_CREATE ioctl() returns the actual bus address for
just created DMA window. It happens to start from zero because the default
window is removed (leaving no windows) and new window starts from zero.
However this is not guaranteed and a new window may start from another
address, this adds a check and an error message.


Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* this just prints warning and fails instead of incorrectly changing
IOVA addresses
---
 lib/librte_eal/linuxapp/eal/eal_vfio.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/librte_eal/linuxapp/eal/eal_vfio.c
index 46f951f4d..530815790 100644
--- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
@@ -702,6 +702,13 @@ vfio_spapr_dma_map(int vfio_container_fd)
 		return -1;
 	}
 
+	if (create.start_addr) {
+		RTE_LOG(ERR, EAL,
+			"  DMA offsets other than zero is not supported, "
+			"new window is created at %lx\n", create.start_addr);
+		return -1;
+	}
+
 	/* map all DPDK segments for DMA. use 1:1 PA to IOVA mapping */
 	for (i = 0; i < RTE_MAX_MEMSEG; i++) {
 		struct vfio_iommu_type1_dma_map dma_map;
@@ -734,7 +741,6 @@ vfio_spapr_dma_map(int vfio_container_fd)
 				"error %i (%s)\n", errno, strerror(errno));
 			return -1;
 		}
-
 	}
 
 	return 0;
-- 
2.11.0