From: Joerg Roedel <jroedel@xxxxxxx> After enabling CONFIG_IOMMU_DMA on X86 a new warning appears when compiling vfio: drivers/vfio/vfio_iommu_type1.c: In function ‘vfio_iommu_type1_attach_group’: drivers/vfio/vfio_iommu_type1.c:1827:7: warning: ‘resv_msi_base’ may be used uninitialized in this function [-Wmaybe-uninitialized] ret = iommu_get_msi_cookie(domain->domain, resv_msi_base); ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The warning is a false positive, because the call to iommu_get_msi_cookie() only happens when vfio_iommu_has_sw_msi() returned true. And that only happens when it also set resv_msi_base. But initialize the variable anyway to get rid of the warning. Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> --- drivers/vfio/vfio_iommu_type1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 96fddc1dafc3..d864277ea16f 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -1658,7 +1658,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, struct bus_type *bus = NULL; int ret; bool resv_msi, msi_remap; - phys_addr_t resv_msi_base; + phys_addr_t resv_msi_base = 0; struct iommu_domain_geometry geo; LIST_HEAD(iova_copy); LIST_HEAD(group_resv_regions); -- 2.16.4