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 pvh_bootparams.hdr.cmd_line_ptr = 78 pvh_start_info.cmdline_paddr; 79 80 /* The first module is always ramdisk. */ 81 if (pvh_start_info.nr_modules) { 82 struct hvm_modlist_entry *modaddr = 83 __va(pvh_start_info.modlist_paddr); 84 pvh_bootparams.hdr.ramdisk_image = modaddr->paddr; 85 pvh_bootparams.hdr.ramdisk_size = modaddr->size; 86 } 87 88 /* 89 * See Documentation/x86/boot.rst. 90 * 91 * Version 2.12 supports Xen entry point but we will use default x86/PC 92 * environment (i.e. hardware_subarch 0). 93 */ 94 pvh_bootparams.hdr.version = (2 << 8) | 12; 95 pvh_bootparams.hdr.type_of_loader = ((xen_guest ? 0x9 : 0xb) << 4) | 0; 96 97 x86_init.acpi.get_root_pointer = pvh_get_root_pointer; 98 } 99 100 /* 101 * If we are trying to boot a Xen PVH guest, it is expected that the kernel 102 * will have been configured to provide the required override for this routine. 103 */ 104 void __init __weak xen_pvh_init(struct boot_params *boot_params) 105 { 106 xen_raw_printk("Error: Missing xen PVH initialization\n"); 107 BUG(); 108 } 109 110 static void __init hypervisor_specific_init(bool xen_guest) 111 { 112 if (xen_guest) 113 xen_pvh_init(&pvh_bootparams); 114 } 115 116 /* 117 * This routine (and those that it might call) should not use 118 * anything that lives in .bss since that segment will be cleared later. 119 */ 120 void __init xen_prepare_pvh(void) 121 { 122 123 u32 msr = xen_cpuid_base(); 124 bool xen_guest = !!msr; 125 126 if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) { 127 xen_raw_printk("Error: Unexpected magic value (0x%08x)\n", 128 pvh_start_info.magic); 129 BUG(); 130 } 131 132 memset(&pvh_bootparams, 0, sizeof(pvh_bootparams)); 133 134 hypervisor_specific_init(xen_guest); 135 136 init_pvh_bootparams(xen_guest); 137 } 138