[PATCH v2 3/9] x86/xen: print a warning when HVMOP_get_mem_type fails

[David Hildenbrand]

HVMOP_get_mem_type is not expected to fail, "This call failing is
indication of something going quite wrong and it would be good to know
about this." [1]

Let's add a pr_warn_once().

[1] https://lkml.kernel.org/r/3b935aa0-6d85-0bcd-100e-15098add3c4c@oracle.com

Suggested-by: Boris Ostrovsky <boris.ostrovsky at oracle.com>
Signed-off-by: David Hildenbrand <david at redhat.com>
---
 arch/x86/xen/mmu_hvm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/mmu_hvm.c b/arch/x86/xen/mmu_hvm.c
index d1b38c77352b..6ba8826dcdcc 100644
--- a/arch/x86/xen/mmu_hvm.c
+++ b/arch/x86/xen/mmu_hvm.c
@@ -22,8 +22,10 @@ static int xen_oldmem_pfn_is_ram(unsigned long pfn)
 		.pfn = pfn,
 	};
 
-	if (HYPERVISOR_hvm_op(HVMOP_get_mem_type, &a))
+	if (HYPERVISOR_hvm_op(HVMOP_get_mem_type, &a)) {
+		pr_warn_once("Unexpected HVMOP_get_mem_type failure\n");
 		return -ENXIO;
+	}
 	return a.mem_type != HVMMEM_mmio_dm;
 }
 #endif
-- 
2.31.1