1 | // SPDX-License-Identifier: GPL-2.0 |
2 | |
3 | /* |
4 | * Core routines for interacting with Microsoft's Hyper-V hypervisor, |
5 | * including hypervisor initialization. |
6 | * |
7 | * Copyright (C) 2021, Microsoft, Inc. |
8 | * |
9 | * Author : Michael Kelley <mikelley@microsoft.com> |
10 | */ |
11 | |
12 | #include <linux/types.h> |
13 | #include <linux/acpi.h> |
14 | #include <linux/export.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/version.h> |
17 | #include <linux/cpuhotplug.h> |
18 | #include <asm/mshyperv.h> |
19 | |
20 | static bool hyperv_initialized; |
21 | |
22 | int hv_get_hypervisor_version(union hv_hypervisor_version_info *info) |
23 | { |
24 | hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, |
25 | (struct hv_get_vp_registers_output *)info); |
26 | |
27 | return 0; |
28 | } |
29 | |
30 | static int __init hyperv_init(void) |
31 | { |
32 | struct hv_get_vp_registers_output result; |
33 | u64 guest_id; |
34 | int ret; |
35 | |
36 | /* |
37 | * Allow for a kernel built with CONFIG_HYPERV to be running in |
38 | * a non-Hyper-V environment, including on DT instead of ACPI. |
39 | * In such cases, do nothing and return success. |
40 | */ |
41 | if (acpi_disabled) |
42 | return 0; |
43 | |
44 | if (strncmp((char *)&acpi_gbl_FADT.hypervisor_id, "MsHyperV" , 8)) |
45 | return 0; |
46 | |
47 | /* Setup the guest ID */ |
48 | guest_id = hv_generate_guest_id(LINUX_VERSION_CODE); |
49 | hv_set_vpreg(HV_REGISTER_GUEST_OS_ID, guest_id); |
50 | |
51 | /* Get the features and hints from Hyper-V */ |
52 | hv_get_vpreg_128(HV_REGISTER_FEATURES, &result); |
53 | ms_hyperv.features = result.as32.a; |
54 | ms_hyperv.priv_high = result.as32.b; |
55 | ms_hyperv.misc_features = result.as32.c; |
56 | |
57 | hv_get_vpreg_128(HV_REGISTER_ENLIGHTENMENTS, &result); |
58 | ms_hyperv.hints = result.as32.a; |
59 | |
60 | pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n" , |
61 | ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, |
62 | ms_hyperv.misc_features); |
63 | |
64 | ret = hv_common_init(); |
65 | if (ret) |
66 | return ret; |
67 | |
68 | ret = cpuhp_setup_state(state: CPUHP_AP_HYPERV_ONLINE, name: "arm64/hyperv_init:online" , |
69 | startup: hv_common_cpu_init, teardown: hv_common_cpu_die); |
70 | if (ret < 0) { |
71 | hv_common_free(); |
72 | return ret; |
73 | } |
74 | |
75 | ms_hyperv_late_init(); |
76 | |
77 | hyperv_initialized = true; |
78 | return 0; |
79 | } |
80 | |
81 | early_initcall(hyperv_init); |
82 | |
83 | bool hv_is_hyperv_initialized(void) |
84 | { |
85 | return hyperv_initialized; |
86 | } |
87 | EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); |
88 | |