diff --git a/OvmfPkg/XenBusDxe/EventChannel.c b/OvmfPkg/XenBusDxe/EventChannel.c
index 03efaf9cb904..a86323e6adfd 100644
--- a/OvmfPkg/XenBusDxe/EventChannel.c
+++ b/OvmfPkg/XenBusDxe/EventChannel.c
@@ -28,7 +28,7 @@ XenEventChannelNotify (
   evtchn_send_t Send;
 
   Send.port = Port;
-  ReturnCode = XenHypercallEventChannelOp (Dev, EVTCHNOP_send, &Send);
+  ReturnCode = XenHypercallEventChannelOp (EVTCHNOP_send, &Send);
   return (UINT32)ReturnCode;
 }
 
@@ -40,15 +40,12 @@ XenBusEventChannelAllocate (
   OUT evtchn_port_t   *Port
   )
 {
-  XENBUS_PRIVATE_DATA *Private;
   evtchn_alloc_unbound_t Parameter;
   UINT32 ReturnCode;
 
-  Private = XENBUS_PRIVATE_DATA_FROM_THIS (This);
-
   Parameter.dom = DOMID_SELF;
   Parameter.remote_dom = DomainId;
-  ReturnCode = (UINT32)XenHypercallEventChannelOp (Private->Dev,
+  ReturnCode = (UINT32)XenHypercallEventChannelOp (
                                    EVTCHNOP_alloc_unbound,
                                    &Parameter);
   if (ReturnCode != 0) {
@@ -79,10 +76,8 @@ XenBusEventChannelClose (
   IN evtchn_port_t   Port
   )
 {
-  XENBUS_PRIVATE_DATA *Private;
   evtchn_close_t Close;
 
-  Private = XENBUS_PRIVATE_DATA_FROM_THIS (This);
   Close.port = Port;
-  return (UINT32)XenHypercallEventChannelOp (Private->Dev, EVTCHNOP_close, &Close);
+  return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
 }
diff --git a/OvmfPkg/XenBusDxe/GrantTable.c b/OvmfPkg/XenBusDxe/GrantTable.c
index 8405edc51bc4..53cb99f0e004 100644
--- a/OvmfPkg/XenBusDxe/GrantTable.c
+++ b/OvmfPkg/XenBusDxe/GrantTable.c
@@ -161,7 +161,7 @@ XenGrantTableInit (
     Parameters.idx = Index;
     Parameters.space = XENMAPSPACE_grant_table;
     Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;
-    ReturnCode = XenHypercallMemoryOp (Dev, XENMEM_add_to_physmap, &Parameters);
+    ReturnCode = XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameters);
     if (ReturnCode != 0) {
       DEBUG ((EFI_D_ERROR, "Xen GrantTable, add_to_physmap hypercall error: %d\n", ReturnCode));
     }
@@ -184,7 +184,7 @@ XenGrantTableDeinit (
     Parameters.domid = DOMID_SELF;
     Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;
     DEBUG ((EFI_D_INFO, "Xen GrantTable, removing %X\n", Parameters.gpfn));
-    ReturnCode = XenHypercallMemoryOp (Dev, XENMEM_remove_from_physmap, &Parameters);
+    ReturnCode = XenHypercallMemoryOp (XENMEM_remove_from_physmap, &Parameters);
     if (ReturnCode != 0) {
       DEBUG ((EFI_D_ERROR, "Xen GrantTable, remove_from_physmap hypercall error: %d\n", ReturnCode));
     }
diff --git a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
index 8547c30b81ee..e0fa71bb5ba8 100644
--- a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
+++ b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
@@ -2,13 +2,13 @@ SECTION .text
 
 ; INTN
 ; EFIAPI
-; XenHypercall2 (
+; __XenHypercall2 (
 ;   IN     VOID *HypercallAddr,
 ;   IN OUT INTN Arg1,
 ;   IN OUT INTN Arg2
 ;   );
-global ASM_PFX(XenHypercall2)
-ASM_PFX(XenHypercall2):
+global ASM_PFX(__XenHypercall2)
+ASM_PFX(__XenHypercall2):
   ; Save only ebx, ecx is supposed to be a scratch register and needs to be
   ; saved by the caller
   push ebx
diff --git a/OvmfPkg/XenBusDxe/X64/hypercall.nasm b/OvmfPkg/XenBusDxe/X64/hypercall.nasm
index 177f271ef094..5e6a0c05c5c4 100644
--- a/OvmfPkg/XenBusDxe/X64/hypercall.nasm
+++ b/OvmfPkg/XenBusDxe/X64/hypercall.nasm
@@ -3,13 +3,13 @@ SECTION .text
 
 ; INTN
 ; EFIAPI
-; XenHypercall2 (
+; __XenHypercall2 (
 ;   IN     VOID *HypercallAddr,
 ;   IN OUT INTN Arg1,
 ;   IN OUT INTN Arg2
 ;   );
-global ASM_PFX(XenHypercall2)
-ASM_PFX(XenHypercall2):
+global ASM_PFX(__XenHypercall2)
+ASM_PFX(__XenHypercall2):
   push rdi
   push rsi
   ; Copy HypercallAddr to rax
diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c
index 7a7fd82d559d..d333b331b6db 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.c
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.c
@@ -34,6 +34,8 @@
 #include "XenStore.h"
 #include "XenBus.h"
 
+#include <IndustryStandard/Xen/hvm/params.h>
+#include <IndustryStandard/Xen/memory.h>
 
 ///
 /// Driver Binding Protocol instance
@@ -52,6 +54,46 @@ STATIC EFI_LOCK       mMyDeviceLock = EFI_INITIALIZE_LOCK_VARIABLE (TPL_CALLBACK
 STATIC XENBUS_DEVICE *mMyDevice = NULL;
 
 /**
+  Map the shared_info_t page into memory.
+
+  @param Dev    A XENBUS_DEVICE instance.
+
+  @retval EFI_SUCCESS     Dev->SharedInfo whill contain a pointer to
+                          the shared info page
+  @retval EFI_LOAD_ERROR  The shared info page could not be mapped. The
+                          hypercall returned an error.
+**/
+STATIC
+EFI_STATUS
+XenGetSharedInfoPage (
+  IN OUT XENBUS_DEVICE *Dev
+  )
+{
+  xen_add_to_physmap_t Parameter;
+
+  ASSERT (Dev->SharedInfo == NULL);
+
+  Parameter.domid = DOMID_SELF;
+  Parameter.space = XENMAPSPACE_shared_info;
+  Parameter.idx = 0;
+
+  //
+  // using reserved page because the page is not released when Linux is
+  // starting because of the add_to_physmap. QEMU might try to access the
+  // page, and fail because it have no right to do so (segv).
+  //
+  Dev->SharedInfo = AllocateReservedPages (1);
+  Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
+  if (XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameter) != 0) {
+    FreePages (Dev->SharedInfo, 1);
+    Dev->SharedInfo = NULL;
+    return EFI_LOAD_ERROR;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
   Unloads an image.
 
   @param  ImageHandle           Handle that identifies the image to be unloaded.
@@ -348,7 +390,7 @@ XenBusDxeDriverBindingStart (
   MmioAddr = BarDesc->AddrRangeMin;
   FreePool (BarDesc);
 
-  Status = XenHyperpageInit (Dev);
+  Status = XenHyperpageInit ();
   if (EFI_ERROR (Status)) {
     DEBUG ((EFI_D_ERROR, "XenBus: Unable to retrieve the hyperpage.\n"));
     Status = EFI_UNSUPPORTED;
diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.h b/OvmfPkg/XenBusDxe/XenBusDxe.h
index 80253b7d1ca9..9b7219906a69 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.h
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.h
@@ -91,7 +91,6 @@ struct _XENBUS_DEVICE {
   EFI_DEVICE_PATH_PROTOCOL      *DevicePath;
   LIST_ENTRY                    ChildList;
 
-  VOID                          *Hyperpage;
   shared_info_t                 *SharedInfo;
 };
 
diff --git a/OvmfPkg/XenBusDxe/XenHypercall.c b/OvmfPkg/XenBusDxe/XenHypercall.c
index 34d92e76b7e3..e7134fcf74ce 100644
--- a/OvmfPkg/XenBusDxe/XenHypercall.c
+++ b/OvmfPkg/XenBusDxe/XenHypercall.c
@@ -23,9 +23,21 @@
 #include <IndustryStandard/Xen/hvm/params.h>
 #include <IndustryStandard/Xen/memory.h>
 
+STATIC VOID       *HyperPage;
+
+//
+// Interface exposed by the ASM implementation of the core hypercall
+//
+INTN
+EFIAPI
+__XenHypercall2 (
+  IN     VOID *HypercallAddr,
+  IN OUT INTN Arg1,
+  IN OUT INTN Arg2
+  );
+
 EFI_STATUS
 XenHyperpageInit (
-  IN OUT XENBUS_DEVICE *Dev
   )
 {
   EFI_HOB_GUID_TYPE   *GuidHob;
@@ -36,24 +48,21 @@ XenHyperpageInit (
     return EFI_NOT_FOUND;
   }
   XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
-  Dev->Hyperpage = XenInfo->HyperPages;
+  HyperPage = XenInfo->HyperPages;
   return EFI_SUCCESS;
 }
 
 UINT64
 XenHypercallHvmGetParam (
-  IN XENBUS_DEVICE *Dev,
   IN UINT32        Index
   )
 {
   xen_hvm_param_t     Parameter;
   INTN                Error;
 
-  ASSERT (Dev->Hyperpage != NULL);
-
   Parameter.domid = DOMID_SELF;
   Parameter.index = Index;
-  Error = XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_hvm_op * 32,
+  Error = XenHypercall2 (__HYPERVISOR_hvm_op,
                          HVMOP_get_param, (INTN) &Parameter);
   if (Error != 0) {
     DEBUG ((EFI_D_ERROR,
@@ -66,53 +75,33 @@ XenHypercallHvmGetParam (
 
 INTN
 XenHypercallMemoryOp (
-  IN     XENBUS_DEVICE *Dev,
   IN     UINTN Operation,
   IN OUT VOID *Arguments
   )
 {
-  ASSERT (Dev->Hyperpage != NULL);
-  return XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_memory_op * 32,
+  return XenHypercall2 (__HYPERVISOR_memory_op,
                         Operation, (INTN) Arguments);
 }
 
 INTN
 XenHypercallEventChannelOp (
-  IN     XENBUS_DEVICE *Dev,
   IN     INTN Operation,
   IN OUT VOID *Arguments
   )
 {
-  ASSERT (Dev->Hyperpage != NULL);
-  return XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_event_channel_op * 32,
+  return XenHypercall2 (__HYPERVISOR_event_channel_op,
                         Operation, (INTN) Arguments);
 }
 
-EFI_STATUS
-XenGetSharedInfoPage (
-  IN OUT XENBUS_DEVICE *Dev
+INTN
+EFIAPI
+XenHypercall2 (
+  IN     UINTN  HypercallID,
+  IN OUT INTN   Arg1,
+  IN OUT INTN   Arg2
   )
 {
-  xen_add_to_physmap_t Parameter;
+  ASSERT (HyperPage != NULL);
 
-  ASSERT (Dev->SharedInfo == NULL);
-
-  Parameter.domid = DOMID_SELF;
-  Parameter.space = XENMAPSPACE_shared_info;
-  Parameter.idx = 0;
-
-  //
-  // using reserved page because the page is not released when Linux is
-  // starting because of the add_to_physmap. QEMU might try to access the
-  // page, and fail because it have no right to do so (segv).
-  //
-  Dev->SharedInfo = AllocateReservedPages (1);
-  Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
-  if (XenHypercallMemoryOp (Dev, XENMEM_add_to_physmap, &Parameter) != 0) {
-    FreePages (Dev->SharedInfo, 1);
-    Dev->SharedInfo = NULL;
-    return EFI_LOAD_ERROR;
-  }
-
-  return EFI_SUCCESS;
+  return __XenHypercall2 ((UINT8*)HyperPage + HypercallID * 32, Arg1, Arg2);
 }
diff --git a/OvmfPkg/XenBusDxe/XenHypercall.h b/OvmfPkg/XenBusDxe/XenHypercall.h
index 06693830e16e..9d49e33eb5af 100644
--- a/OvmfPkg/XenBusDxe/XenHypercall.h
+++ b/OvmfPkg/XenBusDxe/XenHypercall.h
@@ -18,9 +18,9 @@
 
 /**
   This function will put the two arguments in the right place (registers) and
-  call HypercallAddr, which correspond to an entry in the hypercall pages.
+  invoke the hypercall identified by HypercallID.
 
-  @param HypercallAddr  A memory address where the hypercall to call is.
+  @param HypercallID    The symbolic ID of the hypercall to be invoked
   @param Arg1           First argument.
   @param Arg2           Second argument.
 
@@ -29,7 +29,7 @@
 INTN
 EFIAPI
 XenHypercall2 (
-  IN     VOID *HypercallAddr,
+  IN     INTN HypercallID,
   IN OUT INTN Arg1,
   IN OUT INTN Arg2
   );
@@ -44,27 +44,23 @@ XenHypercall2 (
 **/
 EFI_STATUS
 XenHyperpageInit (
-  XENBUS_DEVICE *Dev
   );
 
 /**
   Return the value of the HVM parameter Index.
 
-  @param Dev    A XENBUS_DEVICE instance.
   @param Index  The parameter to get, e.g. HVM_PARAM_STORE_EVTCHN.
 
   @return   The value of the asked parameter or 0 in case of error.
 **/
 UINT64
 XenHypercallHvmGetParam (
-  XENBUS_DEVICE *Dev,
   UINT32 Index
   );
 
 /**
   Hypercall to do different operation on the memory.
 
-  @param Dev        A XENBUS_DEVICE instance.
   @param Operation  The operation number, e.g. XENMEM_add_to_physmap.
   @param Arguments  The arguments associated to the operation.
 
@@ -73,7 +69,6 @@ XenHypercallHvmGetParam (
 **/
 INTN
 XenHypercallMemoryOp (
-  IN     XENBUS_DEVICE *Dev,
   IN     UINTN Operation,
   IN OUT VOID *Arguments
   );
@@ -81,7 +76,6 @@ XenHypercallMemoryOp (
 /**
   Do an operation on the event channels.
 
-  @param Dev        A XENBUS_DEVICE instance.
   @param Operation  The operation number, e.g. EVTCHNOP_send.
   @param Arguments  The argument associated to the operation.
 
@@ -90,24 +84,8 @@ XenHypercallMemoryOp (
 **/
 INTN
 XenHypercallEventChannelOp (
-  IN     XENBUS_DEVICE *Dev,
   IN     INTN Operation,
   IN OUT VOID *Arguments
   );
 
-/**
-  Map the shared_info_t page into memory.
-
-  @param Dev    A XENBUS_DEVICE instance.
-
-  @retval EFI_SUCCESS     Dev->SharedInfo whill contain a pointer to
-                          the shared info page
-  @retval EFI_LOAD_ERROR  The shared info page could not be mapped. The
-                          hypercall returned an error.
-**/
-EFI_STATUS
-XenGetSharedInfoPage (
-  IN OUT XENBUS_DEVICE *Dev
-  );
-
 #endif
diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c
index 2df8f5348585..7ec1e634bc5c 100644
--- a/OvmfPkg/XenBusDxe/XenStore.c
+++ b/OvmfPkg/XenBusDxe/XenStore.c
@@ -1057,8 +1057,8 @@ XenStoreInit (
 
   xs.Dev = Dev;
 
-  xs.EventChannel = (evtchn_port_t)XenHypercallHvmGetParam (Dev, HVM_PARAM_STORE_EVTCHN);
-  XenStoreGpfn = (UINTN)XenHypercallHvmGetParam (Dev, HVM_PARAM_STORE_PFN);
+  xs.EventChannel = (evtchn_port_t)XenHypercallHvmGetParam (HVM_PARAM_STORE_EVTCHN);
+  XenStoreGpfn = (UINTN)XenHypercallHvmGetParam (HVM_PARAM_STORE_PFN);
   xs.XenStore = (VOID *) (XenStoreGpfn << EFI_PAGE_SHIFT);
   DEBUG ((EFI_D_INFO, "XenBusInit: XenBus rings @%p, event channel %x\n",
           xs.XenStore, xs.EventChannel));
