[PATCH] vfio/type1: Initialize resv_msi_base

From: Joerg Roedel
Date: Tue Oct 15 2019 - 11:16:57 EST


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 âvfio_iommu_type1_attach_groupâ:
drivers/vfio/vfio_iommu_type1.c:1827:7: warning: âresv_msi_baseâ 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