1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/acpi.h> 3 4 #include <xen/hvc-console.h> 5 6 #include <asm/bootparam.h> 7 #include <asm/io_apic.h> 8 #include <asm/hypervisor.h> 9 #include <asm/e820/api.h> 10 #include <asm/x86_init.h> 11 12 #include <asm/xen/interface.h> 13 14 #include <xen/xen.h> 15 #include <xen/interface/hvm/start_info.h> 16 17 /* 18 * PVH variables. 19 * 20 * pvh_bootparams and pvh_start_info need to live in a data segment since 21 * they are used after startup_{32|64}, which clear .bss, are invoked. 22 */ 23 struct boot_params __initdata pvh_bootparams; 24 struct hvm_start_info __initdata pvh_start_info; 25 26 const unsigned int __initconst pvh_start_info_sz = sizeof(pvh_start_info); 27 pvh_get_root_pointer(void)28static u64 __init pvh_get_root_pointer(void) 29 { 30 return pvh_start_info.rsdp_paddr; 31 } 32 33 /* 34 * Xen guests are able to obtain the memory map from the hypervisor via the 35 * HYPERVISOR_memory_op hypercall. 36 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 37 * will have been configured to provide an override for this routine to do 38 * just that. 39 */ mem_map_via_hcall(struct boot_params * ptr __maybe_unused)40void __init __weak mem_map_via_hcall(struct boot_params *ptr __maybe_unused) 41 { 42 xen_raw_printk("Error: Could not find memory map\n"); 43 BUG(); 44 } 45 init_pvh_bootparams(bool xen_guest)46static void __init init_pvh_bootparams(bool xen_guest) 47 { 48 if ((pvh_start_info.version > 0) && (pvh_start_info.memmap_entries)) { 49 struct hvm_memmap_table_entry *ep; 50 int i; 51 52 ep = __va(pvh_start_info.memmap_paddr); 53 pvh_bootparams.e820_entries = pvh_start_info.memmap_entries; 54 55 for (i = 0; i < pvh_bootparams.e820_entries ; i++, ep++) { 56 pvh_bootparams.e820_table[i].addr = ep->addr; 57 pvh_bootparams.e820_table[i].size = ep->size; 58 pvh_bootparams.e820_table[i].type = ep->type; 59 } 60 } else if (xen_guest) { 61 mem_map_via_hcall(&pvh_bootparams); 62 } else { 63 /* Non-xen guests are not supported by version 0 */ 64 BUG(); 65 } 66 67 if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) { 68 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr = 69 ISA_START_ADDRESS; 70 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size = 71 ISA_END_ADDRESS - ISA_START_ADDRESS; 72 pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type = 73 E820_TYPE_RESERVED; 74 pvh_bootparams.e820_entries++; 75 } else 76 xen_raw_printk("Warning: Can fit ISA range into e820\n"); 77 78 pvh_bootparams.hdr.cmd_line_ptr = 79 pvh_start_info.cmdline_paddr; 80 81 /* The first module is always ramdisk. */ 82 if (pvh_start_info.nr_modules) { 83 struct hvm_modlist_entry *modaddr = 84 __va(pvh_start_info.modlist_paddr); 85 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr; 86 pvh_bootparams.hdr.ramdisk_size = modaddr->size; 87 } 88 89 /* 90 * See Documentation/arch/x86/boot.rst. 91 * 92 * Version 2.12 supports Xen entry point but we will use default x86/PC 93 * environment (i.e. hardware_subarch 0). 94 */ 95 pvh_bootparams.hdr.version = (2 << 8) | 12; 96 pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0; 97 98 x86_init.acpi.get_root_pointer = pvh_get_root_pointer; 99 } 100 101 /* 102 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 103 * will have been configured to provide the required override for this routine. 104 */ xen_pvh_init(struct boot_params * boot_params)105void __init __weak xen_pvh_init(struct boot_params *boot_params) 106 { 107 xen_raw_printk("Error: Missing xen PVH initialization\n"); 108 BUG(); 109 } 110 hypervisor_specific_init(bool xen_guest)111static void __init hypervisor_specific_init(bool xen_guest) 112 { 113 if (xen_guest) 114 xen_pvh_init(&pvh_bootparams); 115 } 116 117 /* 118 * This routine (and those that it might call) should not use 119 * anything that lives in .bss since that segment will be cleared later. 120 */ xen_prepare_pvh(void)121void __init xen_prepare_pvh(void) 122 { 123 124 u32 msr = xen_cpuid_base(); 125 bool xen_guest = !!msr; 126 127 if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) { 128 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n", 129 pvh_start_info.magic); 130 BUG(); 131 } 132 133 /* 134 * This must not compile to "call memset" because memset() may be 135 * instrumented. 136 */ 137 __builtin_memset(&pvh_bootparams, 0, sizeof(pvh_bootparams)); 138 139 hypervisor_specific_init(xen_guest); 140 141 init_pvh_bootparams(xen_guest); 142 } 143