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
  10 #include <asm/xen/interface.h>
  11 #include <asm/xen/hypercall.h>
  12
  13 #include <xen/interface/memory.h>
  14 #include <xen/interface/hvm/start_info.h>
  15
  16 /*
  17  * PVH variables.
  18  *
  19  * xen_pvh and pvh_bootparams need to live in data segment since they
  20  * are used after startup_{32|64}, which clear .bss, are invoked.
  21  */
  22 bool xen_pvh __attribute__((section(".data"))) = 0;
  23 struct boot_params pvh_bootparams __attribute__((section(".data")));
  24
  25 struct hvm_start_info pvh_start_info;
  26 unsigned int pvh_start_info_sz = sizeof(pvh_start_info);
  27
  28 static void __init init_pvh_bootparams(void)
  29 {
  30         struct xen_memory_map memmap;
  31         int rc;
  32
  33         memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
  34
  35         memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
  36         set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
  37         rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
  38         if (rc) {
  39                 xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
  40                 BUG();
  41         }
  42         pvh_bootparams.e820_entries = memmap.nr_entries;
  43
  44         if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
  45                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
  46                         ISA_START_ADDRESS;
  47                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
  48                         ISA_END_ADDRESS - ISA_START_ADDRESS;
  49                 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
  50                         E820_TYPE_RESERVED;
  51                 pvh_bootparams.e820_entries++;
  52         } else
  53                 xen_raw_printk("Warning: Can fit ISA range into e820\n");
  54
  55         pvh_bootparams.hdr.cmd_line_ptr =
  56                 pvh_start_info.cmdline_paddr;
  57
  58         /* The first module is always ramdisk. */
  59         if (pvh_start_info.nr_modules) {
  60                 struct hvm_modlist_entry *modaddr =
  61                         __va(pvh_start_info.modlist_paddr);
  62                 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
  63                 pvh_bootparams.hdr.ramdisk_size = modaddr->size;
  64         }
  65
  66         /*
  67          * See Documentation/x86/boot.txt.
  68          *
  69          * Version 2.12 supports Xen entry point but we will use default x86/PC
  70          * environment (i.e. hardware_subarch 0).
  71          */
  72         pvh_bootparams.hdr.version = 0x212;
  73         pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
  74 }
  75
  76 /*
  77  * This routine (and those that it might call) should not use
  78  * anything that lives in .bss since that segment will be cleared later.
  79  */
  80 void __init xen_prepare_pvh(void)
  81 {
  82         u32 msr;
  83         u64 pfn;
  84
  85         if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
  86                 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
  87                                 pvh_start_info.magic);
  88                 BUG();
  89         }
  90
  91         xen_pvh = 1;
  92
  93         msr = cpuid_ebx(xen_cpuid_base() + 2);
  94         pfn = __pa(hypercall_page);
  95         wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
  96
  97         init_pvh_bootparams();
  98 }