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