vfio: fix build on Linux < 4.2

The commit db90b4969e2e ("vfio: retry creating sPAPR DMA window")
introduced a build breakage on old Linux. Linux <4.2 does not define ddw in
struct vfio_iommu_spapr_tce_info. Without ddw, we cannot change window size
and so should give up the creation. I just exculuded the retrying code if
ddw is not supported.

Fixes: db90b4969e2e ("vfio: retry creating sPAPR DMA window")

Signed-off-by: Takeshi Yoshimura <tyos@jp.ibm.com>
Tested-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/linux/eal/eal_vfio.c b/lib/librte_eal/linux/eal/eal_vfio.c
index 7053ebe..fadef42 100644 (file)
--- a/lib/librte_eal/linux/eal/eal_vfio.c
+++ b/lib/librte_eal/linux/eal/eal_vfio.c
@@ -1445,6 +1445,7 @@ vfio_spapr_create_new_dma_window(int vfio_container_fd,
        /* create new DMA window */
        ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_CREATE, create);
        if (ret) {
+#ifdef VFIO_IOMMU_SPAPR_INFO_DDW
                /* try possible page_shift and levels for workaround */
                uint32_t levels;
 
@@ -1463,6 +1464,7 @@ vfio_spapr_create_new_dma_window(int vfio_container_fd,
                        if (!ret)
                                break;
                }
+#endif
                if (ret) {
                        RTE_LOG(ERR, EAL, "  cannot create new DMA window, "
                                        "error %i (%s)\n", errno, strerror(errno));