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 13 #include <xen/xen.h> 14 #include <xen/interface/hvm/start_info.h> 15 16 /* 17 * PVH variables. 18 * 19 * pvh_bootparams and pvh_start_info need to live in a data segment since 20 * they are used after startup_{32|64}, which clear .bss, are invoked. 21 */ 22 struct boot_params __initdata pvh_bootparams; 23 struct hvm_start_info __initdata pvh_start_info; 24 25 const unsigned int __initconst pvh_start_info_sz = sizeof(pvh_start_info); 26 27 static u64 __init pvh_get_root_pointer(void) 28 { 29 return pvh_start_info.rsdp_paddr; 30 } 31 32 /* 33 * Xen guests are able to obtain the memory map from the hypervisor via the 34 * HYPERVISOR_memory_op hypercall. 35 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 36 * will have been configured to provide an override for this routine to do 37 * just that. 38 */ 39 void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused) 40 { 41 xen_raw_printk("Error: Could not find memory map\n"); 42 BUG(); 43 } 44 45 static void __init init_pvh_bootparams(bool xen_guest) 46 { 47 if ((pvh_start_info.version > 0) && (pvh_start_info.memmap_entries)) { 48 struct hvm_memmap_table_entry *ep; 49 int i; 50 51 ep = __va(pvh_start_info.memmap_paddr); 52 pvh_bootparams.e820_entries = pvh_start_info.memmap_entries; 53 54 for (i = 0; i < pvh_bootparams.e820_entries ; i++, ep++) { 55 pvh_bootparams.e820_table[i].addr = ep->addr; 56 pvh_bootparams.e820_table[i].size = ep->size; 57 pvh_bootparams.e820_table[i].type = ep->type; 58 } 59 } else if (xen_guest) { 60 mem_map_via_hcall(&pvh_bootparams); 61 } else { 62 /* Non-xen guests are not supported by version 0 */ 63 BUG(); 64 } 65 66 if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) { 67 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr = 68 ISA_START_ADDRESS; 69 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size = 70 ISA_END_ADDRESS - ISA_START_ADDRESS; 71 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type = 72 E820_TYPE_RESERVED; 73 pvh_bootparams.e820_entries++; 74 } else 75 xen_raw_printk("Warning: Can fit ISA range into e820\n"); 76 77 if (xen_guest) 78 xen_reserve_extra_memory(&pvh_bootparams); 79 80 pvh_bootparams.hdr.cmd_line_ptr = 81 pvh_start_info.cmdline_paddr; 82 83 /* The first module is always ramdisk. */ 84 if (pvh_start_info.nr_modules) { 85 struct hvm_modlist_entry *modaddr = 86 __va(pvh_start_info.modlist_paddr); 87 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr; 88 pvh_bootparams.hdr.ramdisk_size = modaddr->size; 89 } 90 91 /* 92 * See Documentation/arch/x86/boot.rst. 93 * 94 * Version 2.12 supports Xen entry point but we will use default x86/PC 95 * environment (i.e. hardware_subarch 0). 96 */ 97 pvh_bootparams.hdr.version = (2 << 8) | 12; 98 pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0; 99 100 x86_init.acpi.get_root_pointer = pvh_get_root_pointer; 101 } 102 103 /* 104 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 105 * will have been configured to provide the required override for this routine. 106 */ 107 void __init __weak xen_pvh_init(struct boot_params *boot_params) 108 { 109 xen_raw_printk("Error: Missing xen PVH initialization\n"); 110 BUG(); 111 } 112 113 static void __init hypervisor_specific_init(bool xen_guest) 114 { 115 if (xen_guest) 116 xen_pvh_init(&pvh_bootparams); 117 } 118 119 /* 120 * This routine (and those that it might call) should not use 121 * anything that lives in .bss since that segment will be cleared later. 122 */ 123 void __init xen_prepare_pvh(void) 124 { 125 126 u32 msr = xen_cpuid_base(); 127 bool xen_guest = !!msr; 128 129 if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) { 130 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n", 131 pvh_start_info.magic); 132 BUG(); 133 } 134 135 memset(&pvh_bootparams, 0, sizeof(pvh_bootparams)); 136 137 hypervisor_specific_init(xen_guest); 138 139 init_pvh_bootparams(xen_guest); 140 } 141