xref: /linux/arch/x86/xen/enlighten_pvh.c (revision e2be04c7f9958dde770eeb8b30e829ca969b37bb)
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 xen_pvh_arch_setup(void)
29 {
30 	/* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */
31 	if (nr_ioapics == 0)
32 		acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM;
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 = 0x212;
80 	pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
81 }
82 
83 /*
84  * This routine (and those that it might call) should not use
85  * anything that lives in .bss since that segment will be cleared later.
86  */
87 void __init xen_prepare_pvh(void)
88 {
89 	u32 msr;
90 	u64 pfn;
91 
92 	if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
93 		xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
94 				pvh_start_info.magic);
95 		BUG();
96 	}
97 
98 	xen_pvh = 1;
99 
100 	msr = cpuid_ebx(xen_cpuid_base() + 2);
101 	pfn = __pa(hypercall_page);
102 	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
103 
104 	init_pvh_bootparams();
105 
106 	x86_init.oem.arch_setup = xen_pvh_arch_setup;
107 }
108