arch/x86/xen/enlighten_pvh.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/acpi.h>
   3
   4 #include <xen/hvc-console.h>
   5
   6 #include <asm/io_apic.h>
   7 #include <asm/hypervisor.h>
   8 #include <asm/e820/api.h>
   9 #include <asm/x86_init.h>
  10
  11 #include <asm/xen/interface.h>
  12 #include <asm/xen/hypercall.h>
  13
  14 #include <xen/interface/memory.h>
  15 #include <xen/interface/hvm/start_info.h>
  16
  17 #include "xen-ops.h"
  18
  19 /*
  20  * PVH variables.
  21  *
  22  * xen_pvh pvh_bootparams and pvh_start_info need to live in data segment
  23  * since they are used after startup_{32|64}, which clear .bss, are invoked.
  24  */
  25 bool xen_pvh __attribute__((section(".data"))) = 0;
  26 struct boot_params pvh_bootparams __attribute__((section(".data")));
  27 struct hvm_start_info pvh_start_info __attribute__((section(".data")));
  28
  29 unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
  30
  31 static u64 pvh_get_root_pointer(void)
  32 {
  33         return pvh_start_info.rsdp_paddr;
  34 }
  35
  36 static void __init init_pvh_bootparams(void)
  37 {
  38         struct xen_memory_map memmap;
  39         int rc;
  40
  41         memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
  42
  43         memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
  44         set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
  45         rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
  46         if (rc) {
  47                 xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
  48                 BUG();
  49         }
  50         pvh_bootparams.e820_entries = memmap.nr_entries;
  51
  52         if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
  53                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
  54                         ISA_START_ADDRESS;
  55                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
  56                         ISA_END_ADDRESS - ISA_START_ADDRESS;
  57                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
  58                         E820_TYPE_RESERVED;
  59                 pvh_bootparams.e820_entries++;
  60         } else
  61                 xen_raw_printk("Warning: Can fit ISA range into e820\n");
  62
  63         pvh_bootparams.hdr.cmd_line_ptr =
  64                 pvh_start_info.cmdline_paddr;
  65
  66         /* The first module is always ramdisk. */
  67         if (pvh_start_info.nr_modules) {
  68                 struct hvm_modlist_entry *modaddr =
  69                         __va(pvh_start_info.modlist_paddr);
  70                 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
  71                 pvh_bootparams.hdr.ramdisk_size = modaddr->size;
  72         }
  73
  74         /*
  75          * See Documentation/x86/boot.txt.
  76          *
  77          * Version 2.12 supports Xen entry point but we will use default x86/PC
  78          * environment (i.e. hardware_subarch 0).
  79          */
  80         pvh_bootparams.hdr.version = (2 << 8) | 12;
  81         pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
  82
  83         x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
  84
  85         xen_efi_init(&pvh_bootparams);
  86 }
  87
  88 /*
  89  * This routine (and those that it might call) should not use
  90  * anything that lives in .bss since that segment will be cleared later.
  91  */
  92 void __init xen_prepare_pvh(void)
  93 {
  94         u32 msr;
  95         u64 pfn;
  96
  97         if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
  98                 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
  99                                 pvh_start_info.magic);
 100                 BUG();
 101         }
 102
 103         xen_pvh = 1;
 104         xen_domain_type = XEN_HVM_DOMAIN;
 105         xen_start_flags = pvh_start_info.flags;
 106
 107         msr = cpuid_ebx(xen_cpuid_base() + 2);
 108         pfn = __pa(hypercall_page);
 109         wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
 110
 111         init_pvh_bootparams();
 112 }