OvmfPkg/XenBusDxe/XenHypercall.c

   1 /** @file
   2   Functions to make Xen hypercalls.
   3
   4   Copyright (C) 2014, Citrix Ltd.
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <PiDxe.h>
  17 #include <Library/HobLib.h>
  18 #include <Guid/XenInfo.h>
  19
  20 #include "XenBusDxe.h"
  21 #include "XenHypercall.h"
  22
  23 #include <IndustryStandard/Xen/hvm/params.h>
  24 #include <IndustryStandard/Xen/memory.h>
  25
  26 EFI_STATUS
  27 XenHyperpageInit (
  28   IN OUT XENBUS_DEVICE *Dev
  29   )
  30 {
  31   EFI_HOB_GUID_TYPE   *GuidHob;
  32   EFI_XEN_INFO        *XenInfo;
  33
  34   GuidHob = GetFirstGuidHob (&gEfiXenInfoGuid);
  35   if (GuidHob == NULL) {
  36     return EFI_NOT_FOUND;
  37   }
  38   XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
  39   Dev->Hyperpage = XenInfo->HyperPages;
  40   return EFI_SUCCESS;
  41 }
  42
  43 UINT64
  44 XenHypercallHvmGetParam (
  45   IN XENBUS_DEVICE *Dev,
  46   IN UINT32        Index
  47   )
  48 {
  49   xen_hvm_param_t     Parameter;
  50   INTN                Error;
  51
  52   ASSERT (Dev->Hyperpage != NULL);
  53
  54   Parameter.domid = DOMID_SELF;
  55   Parameter.index = Index;
  56   Error = XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_hvm_op * 32,
  57                          HVMOP_get_param, (INTN) &Parameter);
  58   if (Error != 0) {
  59     DEBUG ((EFI_D_ERROR,
  60             "XenHypercall: Error %d trying to get HVM parameter %d\n",
  61             Error, Index));
  62     return 0;
  63   }
  64   return Parameter.value;
  65 }
  66
  67 INTN
  68 XenHypercallMemoryOp (
  69   IN     XENBUS_DEVICE *Dev,
  70   IN     UINTN Operation,
  71   IN OUT VOID *Arguments
  72   )
  73 {
  74   ASSERT (Dev->Hyperpage != NULL);
  75   return XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_memory_op * 32,
  76                         Operation, (INTN) Arguments);
  77 }
  78
  79 INTN
  80 XenHypercallEventChannelOp (
  81   IN     XENBUS_DEVICE *Dev,
  82   IN     INTN Operation,
  83   IN OUT VOID *Arguments
  84   )
  85 {
  86   ASSERT (Dev->Hyperpage != NULL);
  87   return XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_event_channel_op * 32,
  88                         Operation, (INTN) Arguments);
  89 }
  90
  91 EFI_STATUS
  92 XenGetSharedInfoPage (
  93   IN OUT XENBUS_DEVICE *Dev
  94   )
  95 {
  96   xen_add_to_physmap_t Parameter;
  97
  98   ASSERT (Dev->SharedInfo == NULL);
  99
 100   Parameter.domid = DOMID_SELF;
 101   Parameter.space = XENMAPSPACE_shared_info;
 102   Parameter.idx = 0;
 103
 104   //
 105   // using reserved page because the page is not released when Linux is
 106   // starting because of the add_to_physmap. QEMU might try to access the
 107   // page, and fail because it have no right to do so (segv).
 108   //
 109   Dev->SharedInfo = AllocateReservedPages (1);
 110   Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
 111   if (XenHypercallMemoryOp (Dev, XENMEM_add_to_physmap, &Parameter) != 0) {
 112     FreePages (Dev->SharedInfo, 1);
 113     Dev->SharedInfo = NULL;
 114     return EFI_LOAD_ERROR;
 115   }
 116
 117   return EFI_SUCCESS;
 118 }