On 12/2/2021 10:43 PM, Wei Liu wrote:

On Wed, Dec 01, 2021 at 11:02:54AM -0500, Tianyu Lan wrote:
[...]

quoted

diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index 46df59aeaa06..30fd0600b008 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c

@@ -4,6 +4,7 @@
  
  #include <linux/dma-map-ops.h>
  #include <linux/pci.h>
+#include <linux/hyperv.h>
  #include <xen/swiotlb-xen.h>
  
  #include <asm/xen/hypervisor.h>

@@ -91,6 +92,6 @@ int pci_xen_swiotlb_init_late(void)
  EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
  
  IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
-		  NULL,
+		  hyperv_swiotlb_detect,

It is not immediately obvious why this is needed just by reading the
code. Please consider copying some of the text in the commit message to
a comment here.

Thanks for suggestion. Will update.