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