arch/x86/hyperv/nested.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Hyper-V nested virtualization code.
   5  *
   6  * Copyright (C) 2018, Microsoft, Inc.
   7  *
   8  * Author : Lan Tianyu <Tianyu.Lan@microsoft.com>
   9  */
  10
  11
  12 #include <linux/types.h>
  13 #include <asm/hyperv-tlfs.h>
  14 #include <asm/mshyperv.h>
  15 #include <asm/tlbflush.h>
  16
  17 #include <asm/trace/hyperv.h>
  18
  19 int hyperv_flush_guest_mapping(u64 as)
  20 {
  21         struct hv_guest_mapping_flush **flush_pcpu;
  22         struct hv_guest_mapping_flush *flush;
  23         u64 status;
  24         unsigned long flags;
  25         int ret = -ENOTSUPP;
  26
  27         if (!hv_hypercall_pg)
  28                 goto fault;
  29
  30         local_irq_save(flags);
  31
  32         flush_pcpu = (struct hv_guest_mapping_flush **)
  33                 this_cpu_ptr(hyperv_pcpu_input_arg);
  34
  35         flush = *flush_pcpu;
  36
  37         if (unlikely(!flush)) {
  38                 local_irq_restore(flags);
  39                 goto fault;
  40         }
  41
  42         flush->address_space = as;
  43         flush->flags = 0;
  44
  45         status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE,
  46                                  flush, NULL);
  47         local_irq_restore(flags);
  48
  49         if (!(status & HV_HYPERCALL_RESULT_MASK))
  50                 ret = 0;
  51
  52 fault:
  53         trace_hyperv_nested_flush_guest_mapping(as, ret);
  54         return ret;
  55 }
  56 EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping);