From: Mykyta Poturai <mykyta_poturai@epam.com>

These functions may be unimplemented, so check that they exist before
calling to prevent crashes.

Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com>
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
---
Introduced in patch series V3.
---
 xen/drivers/passthrough/iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 16aad86973..55b33c9719 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -613,7 +613,7 @@ int __init iommu_setup(void)
 
 int iommu_suspend(void)
 {
-    if ( iommu_enabled )
+    if ( iommu_enabled && iommu_get_ops() && iommu_get_ops()->suspend )
         return iommu_call(iommu_get_ops(), suspend);
 
     return 0;
@@ -621,7 +621,7 @@ int iommu_suspend(void)
 
 void iommu_resume(void)
 {
-    if ( iommu_enabled )
+    if ( iommu_enabled && iommu_get_ops() && iommu_get_ops()->resume )
         iommu_vcall(iommu_get_ops(), resume);
 }
 
-- 
2.43.0

On 05.03.2025 10:11, Mykola Kvach wrote:
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -613,7 +613,7 @@ int __init iommu_setup(void)
>  
>  int iommu_suspend(void)
>  {
> -    if ( iommu_enabled )
> +    if ( iommu_enabled && iommu_get_ops() && iommu_get_ops()->suspend )
>          return iommu_call(iommu_get_ops(), suspend);
>  
>      return 0;
> @@ -621,7 +621,7 @@ int iommu_suspend(void)
>  
>  void iommu_resume(void)
>  {
> -    if ( iommu_enabled )
> +    if ( iommu_enabled && iommu_get_ops() && iommu_get_ops()->resume )
>          iommu_vcall(iommu_get_ops(), resume);
>  }

When iommu_enabled is true, surely iommu_get_ops() is required to return
non-NULL?

Jan