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 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 */
119 static 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 
153 void hv_setup_vmbus_handler(void (*handler)(void));
154 void hv_remove_vmbus_handler(void);
155 void hv_setup_stimer0_handler(void (*handler)(void));
156 void hv_remove_stimer0_handler(void);
157 
158 void hv_setup_kexec_handler(void (*handler)(void));
159 void hv_remove_kexec_handler(void);
160 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
161 void hv_remove_crash_handler(void);
162 
163 extern int vmbus_interrupt;
164 extern int vmbus_irq;
165 
166 extern 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  */
175 extern u32 *hv_vp_index;
176 extern u32 hv_max_vp_index;
177 
178 extern 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 
183 int __init hv_common_init(void);
184 void __init hv_common_free(void);
185 int hv_common_cpu_init(unsigned int cpu);
186 int hv_common_cpu_die(unsigned int cpu);
187 
188 void *hv_alloc_hyperv_page(void);
189 void *hv_alloc_hyperv_zeroed_page(void);
190 void 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  */
203 static inline int hv_cpu_number_to_vp_number(int cpu_number)
204 {
205 	return hv_vp_index[cpu_number];
206 }
207 
208 static 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 
247 static 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 
253 static 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 
260 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
261 bool hv_is_hyperv_initialized(void);
262 bool hv_is_hibernation_supported(void);
263 enum hv_isolation_type hv_get_isolation_type(void);
264 bool hv_is_isolation_supported(void);
265 bool hv_isolation_type_snp(void);
266 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
267 void hyperv_cleanup(void);
268 bool hv_query_ext_cap(u64 cap_query);
269 void hv_setup_dma_ops(struct device *dev, bool coherent);
270 void *hv_map_memory(void *addr, unsigned long size);
271 void hv_unmap_memory(void *addr);
272 #else /* CONFIG_HYPERV */
273 static inline bool hv_is_hyperv_initialized(void) { return false; }
274 static inline bool hv_is_hibernation_supported(void) { return false; }
275 static inline void hyperv_cleanup(void) {}
276 static inline bool hv_is_isolation_supported(void) { return false; }
277 static 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
284