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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;
51extern bool hv_nested;
52
53extern void * __percpu *hyperv_pcpu_input_arg;
54extern void * __percpu *hyperv_pcpu_output_arg;
55
56extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
57extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
58extern bool hv_isolation_type_snp(void);
59
60/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
61static inline int hv_result(u64 status)
62{
63 return status & HV_HYPERCALL_RESULT_MASK;
64}
65
66static inline bool hv_result_success(u64 status)
67{
68 return hv_result(status) == HV_STATUS_SUCCESS;
69}
70
71static inline unsigned int hv_repcomp(u64 status)
72{
73 /* Bits [43:32] of status have 'Reps completed' data. */
74 return (status & HV_HYPERCALL_REP_COMP_MASK) >>
75 HV_HYPERCALL_REP_COMP_OFFSET;
76}
77
78/*
79 * Rep hypercalls. Callers of this functions are supposed to ensure that
80 * rep_count and varhead_size comply with Hyper-V hypercall definition.
81 */
82static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
83 void *input, void *output)
84{
85 u64 control = code;
86 u64 status;
87 u16 rep_comp;
88
89 control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
90 control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
91
92 do {
93 status = hv_do_hypercall(control, input, output);
94 if (!hv_result_success(status))
95 return status;
96
97 rep_comp = hv_repcomp(status);
98
99 control &= ~HV_HYPERCALL_REP_START_MASK;
100 control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
101
102 touch_nmi_watchdog();
103 } while (rep_comp < rep_count);
104
105 return status;
106}
107
108/* Generate the guest OS identifier as described in the Hyper-V TLFS */
109static inline u64 hv_generate_guest_id(u64 kernel_version)
110{
111 u64 guest_id;
112
113 guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
114 guest_id |= (kernel_version << 16);
115
116 return guest_id;
117}
118
119/* Free the message slot and signal end-of-message if required */
120static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
121{
122 /*
123 * On crash we're reading some other CPU's message page and we need
124 * to be careful: this other CPU may already had cleared the header
125 * and the host may already had delivered some other message there.
126 * In case we blindly write msg->header.message_type we're going
127 * to lose it. We can still lose a message of the same type but
128 * we count on the fact that there can only be one
129 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
130 * on crash.
131 */
132 if (cmpxchg(&msg->header.message_type, old_msg_type,
133 HVMSG_NONE) != old_msg_type)
134 return;
135
136 /*
137 * The cmxchg() above does an implicit memory barrier to
138 * ensure the write to MessageType (ie set to
139 * HVMSG_NONE) happens before we read the
140 * MessagePending and EOMing. Otherwise, the EOMing
141 * will not deliver any more messages since there is
142 * no empty slot
143 */
144 if (msg->header.message_flags.msg_pending) {
145 /*
146 * This will cause message queue rescan to
147 * possibly deliver another msg from the
148 * hypervisor
149 */
150 hv_set_register(HV_REGISTER_EOM, 0);
151 }
152}
153
154void hv_setup_vmbus_handler(void (*handler)(void));
155void hv_remove_vmbus_handler(void);
156void hv_setup_stimer0_handler(void (*handler)(void));
157void hv_remove_stimer0_handler(void);
158
159void hv_setup_kexec_handler(void (*handler)(void));
160void hv_remove_kexec_handler(void);
161void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
162void hv_remove_crash_handler(void);
163
164extern int vmbus_interrupt;
165extern int vmbus_irq;
166
167extern bool hv_root_partition;
168
169#if IS_ENABLED(CONFIG_HYPERV)
170/*
171 * Hypervisor's notion of virtual processor ID is different from
172 * Linux' notion of CPU ID. This information can only be retrieved
173 * in the context of the calling CPU. Setup a map for easy access
174 * to this information.
175 */
176extern u32 *hv_vp_index;
177extern u32 hv_max_vp_index;
178
179extern u64 (*hv_read_reference_counter)(void);
180
181/* Sentinel value for an uninitialized entry in hv_vp_index array */
182#define VP_INVAL U32_MAX
183
184int __init hv_common_init(void);
185void __init hv_common_free(void);
186int hv_common_cpu_init(unsigned int cpu);
187int hv_common_cpu_die(unsigned int cpu);
188
189void *hv_alloc_hyperv_page(void);
190void *hv_alloc_hyperv_zeroed_page(void);
191void hv_free_hyperv_page(unsigned long addr);
192
193/**
194 * hv_cpu_number_to_vp_number() - Map CPU to VP.
195 * @cpu_number: CPU number in Linux terms
196 *
197 * This function returns the mapping between the Linux processor
198 * number and the hypervisor's virtual processor number, useful
199 * in making hypercalls and such that talk about specific
200 * processors.
201 *
202 * Return: Virtual processor number in Hyper-V terms
203 */
204static inline int hv_cpu_number_to_vp_number(int cpu_number)
205{
206 return hv_vp_index[cpu_number];
207}
208
209static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
210 const struct cpumask *cpus,
211 bool exclude_self)
212{
213 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
214 int this_cpu = smp_processor_id();
215 int max_vcpu_bank = hv_max_vp_index / HV_VCPUS_PER_SPARSE_BANK;
216
217 /* vpset.valid_bank_mask can represent up to HV_MAX_SPARSE_VCPU_BANKS banks */
218 if (max_vcpu_bank >= HV_MAX_SPARSE_VCPU_BANKS)
219 return 0;
220
221 /*
222 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
223 * structs are not cleared between calls, we risk flushing unneeded
224 * vCPUs otherwise.
225 */
226 for (vcpu_bank = 0; vcpu_bank <= max_vcpu_bank; vcpu_bank++)
227 vpset->bank_contents[vcpu_bank] = 0;
228
229 /*
230 * Some banks may end up being empty but this is acceptable.
231 */
232 for_each_cpu(cpu, cpus) {
233 if (exclude_self && cpu == this_cpu)
234 continue;
235 vcpu = hv_cpu_number_to_vp_number(cpu);
236 if (vcpu == VP_INVAL)
237 return -1;
238 vcpu_bank = vcpu / HV_VCPUS_PER_SPARSE_BANK;
239 vcpu_offset = vcpu % HV_VCPUS_PER_SPARSE_BANK;
240 __set_bit(vcpu_offset, (unsigned long *)
241 &vpset->bank_contents[vcpu_bank]);
242 if (vcpu_bank >= nr_bank)
243 nr_bank = vcpu_bank + 1;
244 }
245 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
246 return nr_bank;
247}
248
249static inline int cpumask_to_vpset(struct hv_vpset *vpset,
250 const struct cpumask *cpus)
251{
252 return __cpumask_to_vpset(vpset, cpus, false);
253}
254
255static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
256 const struct cpumask *cpus)
257{
258 WARN_ON_ONCE(preemptible());
259 return __cpumask_to_vpset(vpset, cpus, true);
260}
261
262void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
263bool hv_is_hyperv_initialized(void);
264bool hv_is_hibernation_supported(void);
265enum hv_isolation_type hv_get_isolation_type(void);
266bool hv_is_isolation_supported(void);
267bool hv_isolation_type_snp(void);
268u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
269void hyperv_cleanup(void);
270bool hv_query_ext_cap(u64 cap_query);
271void hv_setup_dma_ops(struct device *dev, bool coherent);
272void *hv_map_memory(void *addr, unsigned long size);
273void hv_unmap_memory(void *addr);
274#else /* CONFIG_HYPERV */
275static inline bool hv_is_hyperv_initialized(void) { return false; }
276static inline bool hv_is_hibernation_supported(void) { return false; }
277static inline void hyperv_cleanup(void) {}
278static inline bool hv_is_isolation_supported(void) { return false; }
279static inline enum hv_isolation_type hv_get_isolation_type(void)
280{
281 return HV_ISOLATION_TYPE_NONE;
282}
283#endif /* CONFIG_HYPERV */
284
285#endif