xref: /openbmc/linux/arch/x86/xen/enlighten_pvh.c (revision e639c869)
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 __init init_pvh_bootparams(void)
29 {
30 	struct xen_memory_map memmap;
31 	int rc;
32 
33 	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
34 
35 	memmap.nr_entries = ARRAY_SIZE(pvh_bootparams.e820_table);
36 	set_xen_guest_handle(memmap.buffer, pvh_bootparams.e820_table);
37 	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
38 	if (rc) {
39 		xen_raw_printk("XENMEM_memory_map failed (%d)\n", rc);
40 		BUG();
41 	}
42 	pvh_bootparams.e820_entries = memmap.nr_entries;
43 
44 	if (pvh_bootparams.e820_entries < E820_MAX_ENTRIES_ZEROPAGE - 1) {
45 		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].addr =
46 			ISA_START_ADDRESS;
47 		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].size =
48 			ISA_END_ADDRESS - ISA_START_ADDRESS;
49 		pvh_bootparams.e820_table[pvh_bootparams.e820_entries].type =
50 			E820_TYPE_RESERVED;
51 		pvh_bootparams.e820_entries++;
52 	} else
53 		xen_raw_printk("Warning: Can fit ISA range into e820\n");
54 
55 	pvh_bootparams.hdr.cmd_line_ptr =
56 		pvh_start_info.cmdline_paddr;
57 
58 	/* The first module is always ramdisk. */
59 	if (pvh_start_info.nr_modules) {
60 		struct hvm_modlist_entry *modaddr =
61 			__va(pvh_start_info.modlist_paddr);
62 		pvh_bootparams.hdr.ramdisk_image = modaddr->paddr;
63 		pvh_bootparams.hdr.ramdisk_size = modaddr->size;
64 	}
65 
66 	/*
67 	 * See Documentation/x86/boot.txt.
68 	 *
69 	 * Version 2.12 supports Xen entry point but we will use default x86/PC
70 	 * environment (i.e. hardware_subarch 0).
71 	 */
72 	pvh_bootparams.hdr.version = 0x212;
73 	pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
74 }
75 
76 /*
77  * This routine (and those that it might call) should not use
78  * anything that lives in .bss since that segment will be cleared later.
79  */
80 void __init xen_prepare_pvh(void)
81 {
82 	u32 msr;
83 	u64 pfn;
84 
85 	if (pvh_start_info.magic != XEN_HVM_START_MAGIC_VALUE) {
86 		xen_raw_printk("Error: Unexpected magic value (0x%08x)\n",
87 				pvh_start_info.magic);
88 		BUG();
89 	}
90 
91 	xen_pvh = 1;
92 
93 	msr = cpuid_ebx(xen_cpuid_base() + 2);
94 	pfn = __pa(hypercall_page);
95 	wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
96 
97 	init_pvh_bootparams();
98 }
99