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 /*
  18  * PVH variables.
  19  *
  20  * xen_pvh pvh_bootparams and pvh_start_info need to live in data segment
  21  * since they are used after startup_{32|64}, which clear .bss, are invoked.
  22  */
  23 bool xen_pvh __attribute__((section(".data"))) = 0;
  24 struct boot_params pvh_bootparams __attribute__((section(".data")));
  25 struct hvm_start_info pvh_start_info __attribute__((section(".data")));
  26
  27 unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
  28
  29 static u64 pvh_get_root_pointer(void)
  30 {
  31         return pvh_start_info.rsdp_paddr;
  32 }
  33
  34 static void __init init_pvh_bootparams(void)
  35 {
  36         struct xen_memory_map memmap;
  37         int rc;
  38
  39         memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
  40
  41         memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
  42         set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
  43         rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
  44         if (rc) {
  45                 xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
  46                 BUG();
  47         }
  48         pvh_bootparams.e820_entries = memmap.nr_entries;
  49
  50         if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
  51                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
  52                         ISA_START_ADDRESS;
  53                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
  54                         ISA_END_ADDRESS - ISA_START_ADDRESS;
  55                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
  56                         E820_TYPE_RESERVED;
  57                 pvh_bootparams.e820_entries++;
  58         } else
  59                 xen_raw_printk("Warning: Can fit ISA range into e820\n");
  60
  61         pvh_bootparams.hdr.cmd_line_ptr =
  62                 pvh_start_info.cmdline_paddr;
  63
  64         /* The first module is always ramdisk. */
  65         if (pvh_start_info.nr_modules) {
  66                 struct hvm_modlist_entry *modaddr =
  67                         __va(pvh_start_info.modlist_paddr);
  68                 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
  69                 pvh_bootparams.hdr.ramdisk_size = modaddr->size;
  70         }
  71
  72         /*
  73          * See Documentation/x86/boot.txt.
  74          *
  75          * Version 2.12 supports Xen entry point but we will use default x86/PC
  76          * environment (i.e. hardware_subarch 0).
  77          */
  78         pvh_bootparams.hdr.version = 0x212;
  79         pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
  80
  81         x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
  82 }
  83
  84 /*
  85  * This routine (and those that it might call) should not use
  86  * anything that lives in .bss since that segment will be cleared later.
  87  */
  88 void __init xen_prepare_pvh(void)
  89 {
  90         u32 msr;
  91         u64 pfn;
  92
  93         if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
  94                 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
  95                                 pvh_start_info.magic);
  96                 BUG();
  97         }
  98
  99         xen_pvh = 1;
 100         xen_start_flags = pvh_start_info.flags;
 101
 102         msr = cpuid_ebx(xen_cpuid_base() + 2);
 103         pfn = __pa(hypercall_page);
 104         wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
 105
 106         init_pvh_bootparams();
 107 }