[XEN PATCH] amd/iommu: add fixed size to function parameter of array type

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

The 'cmd' parameter of amd_iommu_send_guest_cmd is passed
to a function that expects arrays of size 4, therefore
specifying explicitly the size also in amd_iommu_send_guest_cmd
allows not to accidentally pass a smaller array or assume that
send_iommu_command handles array sizes >4 correctly.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
All current users pass an array of size 4, hence this patch is addressing
a potential issue noticed by the analyzer in the context of Rule 17.5
("The function argument corresponding to a parameter declared to have an array
type shall have an appropriate number of elements"), not an actual problem in
the sources.
---
 xen/drivers/passthrough/amd/iommu.h     | 2 +-
 xen/drivers/passthrough/amd/iommu_cmd.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/passthrough/amd/iommu.h 
b/xen/drivers/passthrough/amd/iommu.h
index 1b62c083ba67..be82bd950e30 100644
--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -346,7 +346,7 @@ void cf_check amd_iommu_crash_shutdown(void);
 
 /* guest iommu support */
 #ifdef CONFIG_HVM
-void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, u32 cmd[]);
+void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, u32 cmd[4]);
 void guest_iommu_add_ppr_log(struct domain *d, u32 entry[]);
 void guest_iommu_add_event_log(struct domain *d, u32 entry[]);
 int guest_iommu_init(struct domain* d);
diff --git a/xen/drivers/passthrough/amd/iommu_cmd.c 
b/xen/drivers/passthrough/amd/iommu_cmd.c
index 49b9fcac9410..321a814eb810 100644
--- a/xen/drivers/passthrough/amd/iommu_cmd.c
+++ b/xen/drivers/passthrough/amd/iommu_cmd.c
@@ -390,7 +390,7 @@ void amd_iommu_flush_all_caches(struct amd_iommu *iommu)
     flush_command_buffer(iommu, 0);
 }
 
-void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, u32 cmd[])
+void amd_iommu_send_guest_cmd(struct amd_iommu *iommu, u32 cmd[4])
 {
     send_iommu_command(iommu, cmd);
     /* TBD: Timeout selection may require peeking into cmd[]. */
-- 
2.34.1