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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 union {
39 u32 isolation_config_b;
40 struct {
41 u32 cvm_type : 4;
42 u32 reserved1 : 1;
43 u32 shared_gpa_boundary_active : 1;
44 u32 shared_gpa_boundary_bits : 6;
45 u32 reserved2 : 20;
46 };
47 };
48 u64 shared_gpa_boundary;
49};
50extern struct ms_hyperv_info ms_hyperv;
51
52extern void * __percpu *hyperv_pcpu_input_arg;
53extern void * __percpu *hyperv_pcpu_output_arg;
54
55extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
56extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
57extern bool hv_isolation_type_snp(void);
58
59/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
60static inline int hv_result(u64 status)
61{
62 return status & HV_HYPERCALL_RESULT_MASK;
63}
64
65static inline bool hv_result_success(u64 status)
66{
67 return hv_result(status) == HV_STATUS_SUCCESS;
68}
69
70static inline unsigned int hv_repcomp(u64 status)
71{
72 /* Bits [43:32] of status have 'Reps completed' data. */
73 return (status & HV_HYPERCALL_REP_COMP_MASK) >>
74 HV_HYPERCALL_REP_COMP_OFFSET;
75}
76
77/*
78 * Rep hypercalls. Callers of this functions are supposed to ensure that
79 * rep_count and varhead_size comply with Hyper-V hypercall definition.
80 */
81static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
82 void *input, void *output)
83{
84 u64 control = code;
85 u64 status;
86 u16 rep_comp;
87
88 control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
89 control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
90
91 do {
92 status = hv_do_hypercall(control, input, output);
93 if (!hv_result_success(status))
94 return status;
95
96 rep_comp = hv_repcomp(status);
97
98 control &= ~HV_HYPERCALL_REP_START_MASK;
99 control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
100
101 touch_nmi_watchdog();
102 } while (rep_comp < rep_count);
103
104 return status;
105}
106
107/* Generate the guest OS identifier as described in the Hyper-V TLFS */
108static inline u64 hv_generate_guest_id(u64 kernel_version)
109{
110 u64 guest_id;
111
112 guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
113 guest_id |= (kernel_version << 16);
114
115 return guest_id;
116}
117
118/* Free the message slot and signal end-of-message if required */
119static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
120{
121 /*
122 * On crash we're reading some other CPU's message page and we need
123 * to be careful: this other CPU may already had cleared the header
124 * and the host may already had delivered some other message there.
125 * In case we blindly write msg->header.message_type we're going
126 * to lose it. We can still lose a message of the same type but
127 * we count on the fact that there can only be one
128 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
129 * on crash.
130 */
131 if (cmpxchg(&msg->header.message_type, old_msg_type,
132 HVMSG_NONE) != old_msg_type)
133 return;
134
135 /*
136 * The cmxchg() above does an implicit memory barrier to
137 * ensure the write to MessageType (ie set to
138 * HVMSG_NONE) happens before we read the
139 * MessagePending and EOMing. Otherwise, the EOMing
140 * will not deliver any more messages since there is
141 * no empty slot
142 */
143 if (msg->header.message_flags.msg_pending) {
144 /*
145 * This will cause message queue rescan to
146 * possibly deliver another msg from the
147 * hypervisor
148 */
149 hv_set_register(HV_REGISTER_EOM, 0);
150 }
151}
152
153void hv_setup_vmbus_handler(void (*handler)(void));
154void hv_remove_vmbus_handler(void);
155void hv_setup_stimer0_handler(void (*handler)(void));
156void hv_remove_stimer0_handler(void);
157
158void hv_setup_kexec_handler(void (*handler)(void));
159void hv_remove_kexec_handler(void);
160void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
161void hv_remove_crash_handler(void);
162
163extern int vmbus_interrupt;
164extern int vmbus_irq;
165
166extern bool hv_root_partition;
167
168#if IS_ENABLED(CONFIG_HYPERV)
169/*
170 * Hypervisor's notion of virtual processor ID is different from
171 * Linux' notion of CPU ID. This information can only be retrieved
172 * in the context of the calling CPU. Setup a map for easy access
173 * to this information.
174 */
175extern u32 *hv_vp_index;
176extern u32 hv_max_vp_index;
177
178extern u64 (*hv_read_reference_counter)(void);
179
180/* Sentinel value for an uninitialized entry in hv_vp_index array */
181#define VP_INVAL U32_MAX
182
183int __init hv_common_init(void);
184void __init hv_common_free(void);
185int hv_common_cpu_init(unsigned int cpu);
186int hv_common_cpu_die(unsigned int cpu);
187
188void *hv_alloc_hyperv_page(void);
189void *hv_alloc_hyperv_zeroed_page(void);
190void hv_free_hyperv_page(unsigned long addr);
191
192/**
193 * hv_cpu_number_to_vp_number() - Map CPU to VP.
194 * @cpu_number: CPU number in Linux terms
195 *
196 * This function returns the mapping between the Linux processor
197 * number and the hypervisor's virtual processor number, useful
198 * in making hypercalls and such that talk about specific
199 * processors.
200 *
201 * Return: Virtual processor number in Hyper-V terms
202 */
203static inline int hv_cpu_number_to_vp_number(int cpu_number)
204{
205 return hv_vp_index[cpu_number];
206}
207
208static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
209 const struct cpumask *cpus,
210 bool exclude_self)
211{
212 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
213 int this_cpu = smp_processor_id();
214
215 /* valid_bank_mask can represent up to 64 banks */
216 if (hv_max_vp_index / 64 >= 64)
217 return 0;
218
219 /*
220 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
221 * structs are not cleared between calls, we risk flushing unneeded
222 * vCPUs otherwise.
223 */
224 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
225 vpset->bank_contents[vcpu_bank] = 0;
226
227 /*
228 * Some banks may end up being empty but this is acceptable.
229 */
230 for_each_cpu(cpu, cpus) {
231 if (exclude_self && cpu == this_cpu)
232 continue;
233 vcpu = hv_cpu_number_to_vp_number(cpu);
234 if (vcpu == VP_INVAL)
235 return -1;
236 vcpu_bank = vcpu / 64;
237 vcpu_offset = vcpu % 64;
238 __set_bit(vcpu_offset, (unsigned long *)
239 &vpset->bank_contents[vcpu_bank]);
240 if (vcpu_bank >= nr_bank)
241 nr_bank = vcpu_bank + 1;
242 }
243 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
244 return nr_bank;
245}
246
247static inline int cpumask_to_vpset(struct hv_vpset *vpset,
248 const struct cpumask *cpus)
249{
250 return __cpumask_to_vpset(vpset, cpus, false);
251}
252
253static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
254 const struct cpumask *cpus)
255{
256 WARN_ON_ONCE(preemptible());
257 return __cpumask_to_vpset(vpset, cpus, true);
258}
259
260void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
261bool hv_is_hyperv_initialized(void);
262bool hv_is_hibernation_supported(void);
263enum hv_isolation_type hv_get_isolation_type(void);
264bool hv_is_isolation_supported(void);
265bool hv_isolation_type_snp(void);
266u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
267void hyperv_cleanup(void);
268bool hv_query_ext_cap(u64 cap_query);
269void hv_setup_dma_ops(struct device *dev, bool coherent);
270void *hv_map_memory(void *addr, unsigned long size);
271void hv_unmap_memory(void *addr);
272#else /* CONFIG_HYPERV */
273static inline bool hv_is_hyperv_initialized(void) { return false; }
274static inline bool hv_is_hibernation_supported(void) { return false; }
275static inline void hyperv_cleanup(void) {}
276static inline bool hv_is_isolation_supported(void) { return false; }
277static inline enum hv_isolation_type hv_get_isolation_type(void)
278{
279 return HV_ISOLATION_TYPE_NONE;
280}
281#endif /* CONFIG_HYPERV */
282
283#endif