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 
29 struct 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 };
50 extern struct ms_hyperv_info ms_hyperv;
51 
52 extern void * __percpu *hyperv_pcpu_input_arg;
53 extern void * __percpu *hyperv_pcpu_output_arg;
54 
55 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
56 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
57 extern bool hv_isolation_type_snp(void);
58 
59 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
60 static inline int hv_result(u64 status)
61 {
62 	return status & HV_HYPERCALL_RESULT_MASK;
63 }
64 
65 static inline bool hv_result_success(u64 status)
66 {
67 	return hv_result(status) == HV_STATUS_SUCCESS;
68 }
69 
70 static 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  */
81 static 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 */
108 static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
109 				       __u64 d_info2)
110 {
111 	__u64 guest_id = 0;
112 
113 	guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
114 	guest_id |= (d_info1 << 48);
115 	guest_id |= (kernel_version << 16);
116 	guest_id |= d_info2;
117 
118 	return guest_id;
119 }
120 
121 /* Free the message slot and signal end-of-message if required */
122 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
123 {
124 	/*
125 	 * On crash we're reading some other CPU's message page and we need
126 	 * to be careful: this other CPU may already had cleared the header
127 	 * and the host may already had delivered some other message there.
128 	 * In case we blindly write msg->header.message_type we're going
129 	 * to lose it. We can still lose a message of the same type but
130 	 * we count on the fact that there can only be one
131 	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
132 	 * on crash.
133 	 */
134 	if (cmpxchg(&msg->header.message_type, old_msg_type,
135 		    HVMSG_NONE) != old_msg_type)
136 		return;
137 
138 	/*
139 	 * The cmxchg() above does an implicit memory barrier to
140 	 * ensure the write to MessageType (ie set to
141 	 * HVMSG_NONE) happens before we read the
142 	 * MessagePending and EOMing. Otherwise, the EOMing
143 	 * will not deliver any more messages since there is
144 	 * no empty slot
145 	 */
146 	if (msg->header.message_flags.msg_pending) {
147 		/*
148 		 * This will cause message queue rescan to
149 		 * possibly deliver another msg from the
150 		 * hypervisor
151 		 */
152 		hv_set_register(HV_REGISTER_EOM, 0);
153 	}
154 }
155 
156 void hv_setup_vmbus_handler(void (*handler)(void));
157 void hv_remove_vmbus_handler(void);
158 void hv_setup_stimer0_handler(void (*handler)(void));
159 void hv_remove_stimer0_handler(void);
160 
161 void hv_setup_kexec_handler(void (*handler)(void));
162 void hv_remove_kexec_handler(void);
163 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
164 void hv_remove_crash_handler(void);
165 
166 extern int vmbus_interrupt;
167 extern int vmbus_irq;
168 
169 extern bool hv_root_partition;
170 
171 #if IS_ENABLED(CONFIG_HYPERV)
172 /*
173  * Hypervisor's notion of virtual processor ID is different from
174  * Linux' notion of CPU ID. This information can only be retrieved
175  * in the context of the calling CPU. Setup a map for easy access
176  * to this information.
177  */
178 extern u32 *hv_vp_index;
179 extern u32 hv_max_vp_index;
180 
181 extern u64 (*hv_read_reference_counter)(void);
182 
183 /* Sentinel value for an uninitialized entry in hv_vp_index array */
184 #define VP_INVAL	U32_MAX
185 
186 int __init hv_common_init(void);
187 void __init hv_common_free(void);
188 int hv_common_cpu_init(unsigned int cpu);
189 int hv_common_cpu_die(unsigned int cpu);
190 
191 void *hv_alloc_hyperv_page(void);
192 void *hv_alloc_hyperv_zeroed_page(void);
193 void hv_free_hyperv_page(unsigned long addr);
194 
195 /**
196  * hv_cpu_number_to_vp_number() - Map CPU to VP.
197  * @cpu_number: CPU number in Linux terms
198  *
199  * This function returns the mapping between the Linux processor
200  * number and the hypervisor's virtual processor number, useful
201  * in making hypercalls and such that talk about specific
202  * processors.
203  *
204  * Return: Virtual processor number in Hyper-V terms
205  */
206 static inline int hv_cpu_number_to_vp_number(int cpu_number)
207 {
208 	return hv_vp_index[cpu_number];
209 }
210 
211 static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
212 				    const struct cpumask *cpus,
213 				    bool exclude_self)
214 {
215 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
216 	int this_cpu = smp_processor_id();
217 
218 	/* valid_bank_mask can represent up to 64 banks */
219 	if (hv_max_vp_index / 64 >= 64)
220 		return 0;
221 
222 	/*
223 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
224 	 * structs are not cleared between calls, we risk flushing unneeded
225 	 * vCPUs otherwise.
226 	 */
227 	for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
228 		vpset->bank_contents[vcpu_bank] = 0;
229 
230 	/*
231 	 * Some banks may end up being empty but this is acceptable.
232 	 */
233 	for_each_cpu(cpu, cpus) {
234 		if (exclude_self && cpu == this_cpu)
235 			continue;
236 		vcpu = hv_cpu_number_to_vp_number(cpu);
237 		if (vcpu == VP_INVAL)
238 			return -1;
239 		vcpu_bank = vcpu / 64;
240 		vcpu_offset = vcpu % 64;
241 		__set_bit(vcpu_offset, (unsigned long *)
242 			  &vpset->bank_contents[vcpu_bank]);
243 		if (vcpu_bank >= nr_bank)
244 			nr_bank = vcpu_bank + 1;
245 	}
246 	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
247 	return nr_bank;
248 }
249 
250 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
251 				    const struct cpumask *cpus)
252 {
253 	return __cpumask_to_vpset(vpset, cpus, false);
254 }
255 
256 static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
257 				    const struct cpumask *cpus)
258 {
259 	WARN_ON_ONCE(preemptible());
260 	return __cpumask_to_vpset(vpset, cpus, true);
261 }
262 
263 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
264 bool hv_is_hyperv_initialized(void);
265 bool hv_is_hibernation_supported(void);
266 enum hv_isolation_type hv_get_isolation_type(void);
267 bool hv_is_isolation_supported(void);
268 bool hv_isolation_type_snp(void);
269 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
270 void hyperv_cleanup(void);
271 bool hv_query_ext_cap(u64 cap_query);
272 void *hv_map_memory(void *addr, unsigned long size);
273 void hv_unmap_memory(void *addr);
274 #else /* CONFIG_HYPERV */
275 static inline bool hv_is_hyperv_initialized(void) { return false; }
276 static inline bool hv_is_hibernation_supported(void) { return false; }
277 static inline void hyperv_cleanup(void) {}
278 static inline bool hv_is_isolation_supported(void) { return false; }
279 static 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
286