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1/* SPDX-License-Identifier: GPL-2.0 */
2
3/*
4 * Linux-specific definitions for managing interactions with Microsoft's
5 * Hyper-V hypervisor. The definitions in this file are architecture
6 * independent. See arch/<arch>/include/asm/mshyperv.h for definitions
7 * that are specific to architecture <arch>.
8 *
9 * Definitions that are specified in the Hyper-V Top Level Functional
10 * Spec (TLFS) should not go in this file, but should instead go in
11 * hyperv-tlfs.h.
12 *
13 * Copyright (C) 2019, Microsoft, Inc.
14 *
15 * Author : Michael Kelley <mikelley@microsoft.com>
16 */
17
18#ifndef _ASM_GENERIC_MSHYPERV_H
19#define _ASM_GENERIC_MSHYPERV_H
20
21#include <linux/types.h>
22#include <linux/atomic.h>
23#include <linux/bitops.h>
24#include <linux/cpumask.h>
25#include <linux/nmi.h>
26#include <asm/ptrace.h>
27#include <asm/hyperv-tlfs.h>
28
29struct ms_hyperv_info {
30 u32 features;
31 u32 priv_high;
32 u32 misc_features;
33 u32 hints;
34 u32 nested_features;
35 u32 max_vp_index;
36 u32 max_lp_index;
37 u32 isolation_config_a;
38 u32 isolation_config_b;
39};
40extern struct ms_hyperv_info ms_hyperv;
41
42extern void __percpu **hyperv_pcpu_input_arg;
43extern void __percpu **hyperv_pcpu_output_arg;
44
45extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
46extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
47
48/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
49static inline int hv_result(u64 status)
50{
51 return status & HV_HYPERCALL_RESULT_MASK;
52}
53
54static inline bool hv_result_success(u64 status)
55{
56 return hv_result(status) == HV_STATUS_SUCCESS;
57}
58
59static inline unsigned int hv_repcomp(u64 status)
60{
61 /* Bits [43:32] of status have 'Reps completed' data. */
62 return (status & HV_HYPERCALL_REP_COMP_MASK) >>
63 HV_HYPERCALL_REP_COMP_OFFSET;
64}
65
66/*
67 * Rep hypercalls. Callers of this functions are supposed to ensure that
68 * rep_count and varhead_size comply with Hyper-V hypercall definition.
69 */
70static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
71 void *input, void *output)
72{
73 u64 control = code;
74 u64 status;
75 u16 rep_comp;
76
77 control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
78 control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
79
80 do {
81 status = hv_do_hypercall(control, input, output);
82 if (!hv_result_success(status))
83 return status;
84
85 rep_comp = hv_repcomp(status);
86
87 control &= ~HV_HYPERCALL_REP_START_MASK;
88 control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
89
90 touch_nmi_watchdog();
91 } while (rep_comp < rep_count);
92
93 return status;
94}
95
96/* Generate the guest OS identifier as described in the Hyper-V TLFS */
97static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
98 __u64 d_info2)
99{
100 __u64 guest_id = 0;
101
102 guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
103 guest_id |= (d_info1 << 48);
104 guest_id |= (kernel_version << 16);
105 guest_id |= d_info2;
106
107 return guest_id;
108}
109
110/* Free the message slot and signal end-of-message if required */
111static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
112{
113 /*
114 * On crash we're reading some other CPU's message page and we need
115 * to be careful: this other CPU may already had cleared the header
116 * and the host may already had delivered some other message there.
117 * In case we blindly write msg->header.message_type we're going
118 * to lose it. We can still lose a message of the same type but
119 * we count on the fact that there can only be one
120 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
121 * on crash.
122 */
123 if (cmpxchg(&msg->header.message_type, old_msg_type,
124 HVMSG_NONE) != old_msg_type)
125 return;
126
127 /*
128 * The cmxchg() above does an implicit memory barrier to
129 * ensure the write to MessageType (ie set to
130 * HVMSG_NONE) happens before we read the
131 * MessagePending and EOMing. Otherwise, the EOMing
132 * will not deliver any more messages since there is
133 * no empty slot
134 */
135 if (msg->header.message_flags.msg_pending) {
136 /*
137 * This will cause message queue rescan to
138 * possibly deliver another msg from the
139 * hypervisor
140 */
141 hv_set_register(HV_REGISTER_EOM, 0);
142 }
143}
144
145void hv_setup_vmbus_handler(void (*handler)(void));
146void hv_remove_vmbus_handler(void);
147void hv_setup_stimer0_handler(void (*handler)(void));
148void hv_remove_stimer0_handler(void);
149
150void hv_setup_kexec_handler(void (*handler)(void));
151void hv_remove_kexec_handler(void);
152void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
153void hv_remove_crash_handler(void);
154
155extern int vmbus_interrupt;
156extern int vmbus_irq;
157
158extern bool hv_root_partition;
159
160#if IS_ENABLED(CONFIG_HYPERV)
161/*
162 * Hypervisor's notion of virtual processor ID is different from
163 * Linux' notion of CPU ID. This information can only be retrieved
164 * in the context of the calling CPU. Setup a map for easy access
165 * to this information.
166 */
167extern u32 *hv_vp_index;
168extern u32 hv_max_vp_index;
169
170extern u64 (*hv_read_reference_counter)(void);
171
172/* Sentinel value for an uninitialized entry in hv_vp_index array */
173#define VP_INVAL U32_MAX
174
175int __init hv_common_init(void);
176void __init hv_common_free(void);
177int hv_common_cpu_init(unsigned int cpu);
178int hv_common_cpu_die(unsigned int cpu);
179
180void *hv_alloc_hyperv_page(void);
181void *hv_alloc_hyperv_zeroed_page(void);
182void hv_free_hyperv_page(unsigned long addr);
183
184/**
185 * hv_cpu_number_to_vp_number() - Map CPU to VP.
186 * @cpu_number: CPU number in Linux terms
187 *
188 * This function returns the mapping between the Linux processor
189 * number and the hypervisor's virtual processor number, useful
190 * in making hypercalls and such that talk about specific
191 * processors.
192 *
193 * Return: Virtual processor number in Hyper-V terms
194 */
195static inline int hv_cpu_number_to_vp_number(int cpu_number)
196{
197 return hv_vp_index[cpu_number];
198}
199
200static inline int cpumask_to_vpset(struct hv_vpset *vpset,
201 const struct cpumask *cpus)
202{
203 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
204
205 /* valid_bank_mask can represent up to 64 banks */
206 if (hv_max_vp_index / 64 >= 64)
207 return 0;
208
209 /*
210 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
211 * structs are not cleared between calls, we risk flushing unneeded
212 * vCPUs otherwise.
213 */
214 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
215 vpset->bank_contents[vcpu_bank] = 0;
216
217 /*
218 * Some banks may end up being empty but this is acceptable.
219 */
220 for_each_cpu(cpu, cpus) {
221 vcpu = hv_cpu_number_to_vp_number(cpu);
222 if (vcpu == VP_INVAL)
223 return -1;
224 vcpu_bank = vcpu / 64;
225 vcpu_offset = vcpu % 64;
226 __set_bit(vcpu_offset, (unsigned long *)
227 &vpset->bank_contents[vcpu_bank]);
228 if (vcpu_bank >= nr_bank)
229 nr_bank = vcpu_bank + 1;
230 }
231 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
232 return nr_bank;
233}
234
235void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
236bool hv_is_hyperv_initialized(void);
237bool hv_is_hibernation_supported(void);
238enum hv_isolation_type hv_get_isolation_type(void);
239bool hv_is_isolation_supported(void);
240void hyperv_cleanup(void);
241bool hv_query_ext_cap(u64 cap_query);
242#else /* CONFIG_HYPERV */
243static inline bool hv_is_hyperv_initialized(void) { return false; }
244static inline bool hv_is_hibernation_supported(void) { return false; }
245static inline void hyperv_cleanup(void) {}
246#endif /* CONFIG_HYPERV */
247
248#endif