[PATCH for-4.16] xen/arm: allocate_bank_memory: don't create memory banks of size zero

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>

allocate_bank_memory can be called with a tot_size of zero. In that
case, don't create an empty memory bank, just return immediately without
error. Otherwise a zero-sized memory bank will be added to the domain
device tree.

Fixes: f2931b4233ec "xen/arm: introduce allocate_memory"
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
---
 xen/arch/arm/domain_build.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 9e92b640cd..578ea80e40 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -395,6 +395,9 @@ static bool __init allocate_bank_memory(struct domain *d,
     struct membank *bank;
     unsigned int max_order = ~0;
 
+    if ( tot_size == 0 )
+        return true;
+
     bank = &kinfo->mem.bank[kinfo->mem.nr_banks];
     bank->start = gfn_to_gaddr(sgfn);
     bank->size = tot_size;
-- 
2.25.1