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 #define VTPM_BASE_ADDRESS 0xfed40000
30 
31 struct ms_hyperv_info {
32 	u32 features;
33 	u32 priv_high;
34 	u32 misc_features;
35 	u32 hints;
36 	u32 nested_features;
37 	u32 max_vp_index;
38 	u32 max_lp_index;
39 	u8 vtl;
40 	union {
41 		u32 isolation_config_a;
42 		struct {
43 			u32 paravisor_present : 1;
44 			u32 reserved_a1 : 31;
45 		};
46 	};
47 	union {
48 		u32 isolation_config_b;
49 		struct {
50 			u32 cvm_type : 4;
51 			u32 reserved_b1 : 1;
52 			u32 shared_gpa_boundary_active : 1;
53 			u32 shared_gpa_boundary_bits : 6;
54 			u32 reserved_b2 : 20;
55 		};
56 	};
57 	u64 shared_gpa_boundary;
58 };
59 extern struct ms_hyperv_info ms_hyperv;
60 extern bool hv_nested;
61 
62 extern void * __percpu *hyperv_pcpu_input_arg;
63 extern void * __percpu *hyperv_pcpu_output_arg;
64 
65 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
66 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
67 bool hv_isolation_type_snp(void);
68 bool hv_isolation_type_tdx(void);
69 
70 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
71 static inline int hv_result(u64 status)
72 {
73 	return status & HV_HYPERCALL_RESULT_MASK;
74 }
75 
76 static inline bool hv_result_success(u64 status)
77 {
78 	return hv_result(status) == HV_STATUS_SUCCESS;
79 }
80 
81 static inline unsigned int hv_repcomp(u64 status)
82 {
83 	/* Bits [43:32] of status have 'Reps completed' data. */
84 	return (status & HV_HYPERCALL_REP_COMP_MASK) >>
85 			 HV_HYPERCALL_REP_COMP_OFFSET;
86 }
87 
88 /*
89  * Rep hypercalls. Callers of this functions are supposed to ensure that
90  * rep_count and varhead_size comply with Hyper-V hypercall definition.
91  */
92 static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
93 				      void *input, void *output)
94 {
95 	u64 control = code;
96 	u64 status;
97 	u16 rep_comp;
98 
99 	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
100 	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
101 
102 	do {
103 		status = hv_do_hypercall(control, input, output);
104 		if (!hv_result_success(status))
105 			return status;
106 
107 		rep_comp = hv_repcomp(status);
108 
109 		control &= ~HV_HYPERCALL_REP_START_MASK;
110 		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
111 
112 		touch_nmi_watchdog();
113 	} while (rep_comp < rep_count);
114 
115 	return status;
116 }
117 
118 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
119 static inline u64 hv_generate_guest_id(u64 kernel_version)
120 {
121 	u64 guest_id;
122 
123 	guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
124 	guest_id |= (kernel_version << 16);
125 
126 	return guest_id;
127 }
128 
129 /* Free the message slot and signal end-of-message if required */
130 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
131 {
132 	/*
133 	 * On crash we're reading some other CPU's message page and we need
134 	 * to be careful: this other CPU may already had cleared the header
135 	 * and the host may already had delivered some other message there.
136 	 * In case we blindly write msg->header.message_type we're going
137 	 * to lose it. We can still lose a message of the same type but
138 	 * we count on the fact that there can only be one
139 	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
140 	 * on crash.
141 	 */
142 	if (cmpxchg(&msg->header.message_type, old_msg_type,
143 		    HVMSG_NONE) != old_msg_type)
144 		return;
145 
146 	/*
147 	 * The cmxchg() above does an implicit memory barrier to
148 	 * ensure the write to MessageType (ie set to
149 	 * HVMSG_NONE) happens before we read the
150 	 * MessagePending and EOMing. Otherwise, the EOMing
151 	 * will not deliver any more messages since there is
152 	 * no empty slot
153 	 */
154 	if (msg->header.message_flags.msg_pending) {
155 		/*
156 		 * This will cause message queue rescan to
157 		 * possibly deliver another msg from the
158 		 * hypervisor
159 		 */
160 		hv_set_register(HV_REGISTER_EOM, 0);
161 	}
162 }
163 
164 void hv_setup_vmbus_handler(void (*handler)(void));
165 void hv_remove_vmbus_handler(void);
166 void hv_setup_stimer0_handler(void (*handler)(void));
167 void hv_remove_stimer0_handler(void);
168 
169 void hv_setup_kexec_handler(void (*handler)(void));
170 void hv_remove_kexec_handler(void);
171 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
172 void hv_remove_crash_handler(void);
173 
174 extern int vmbus_interrupt;
175 extern int vmbus_irq;
176 
177 extern bool hv_root_partition;
178 
179 #if IS_ENABLED(CONFIG_HYPERV)
180 /*
181  * Hypervisor's notion of virtual processor ID is different from
182  * Linux' notion of CPU ID. This information can only be retrieved
183  * in the context of the calling CPU. Setup a map for easy access
184  * to this information.
185  */
186 extern u32 *hv_vp_index;
187 extern u32 hv_max_vp_index;
188 
189 extern u64 (*hv_read_reference_counter)(void);
190 
191 /* Sentinel value for an uninitialized entry in hv_vp_index array */
192 #define VP_INVAL	U32_MAX
193 
194 int __init hv_common_init(void);
195 void __init hv_common_free(void);
196 int hv_common_cpu_init(unsigned int cpu);
197 int hv_common_cpu_die(unsigned int cpu);
198 
199 void *hv_alloc_hyperv_page(void);
200 void *hv_alloc_hyperv_zeroed_page(void);
201 void hv_free_hyperv_page(void *addr);
202 
203 /**
204  * hv_cpu_number_to_vp_number() - Map CPU to VP.
205  * @cpu_number: CPU number in Linux terms
206  *
207  * This function returns the mapping between the Linux processor
208  * number and the hypervisor's virtual processor number, useful
209  * in making hypercalls and such that talk about specific
210  * processors.
211  *
212  * Return: Virtual processor number in Hyper-V terms
213  */
214 static inline int hv_cpu_number_to_vp_number(int cpu_number)
215 {
216 	return hv_vp_index[cpu_number];
217 }
218 
219 static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
220 				    const struct cpumask *cpus,
221 				    bool (*func)(int cpu))
222 {
223 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
224 	int max_vcpu_bank = hv_max_vp_index / HV_VCPUS_PER_SPARSE_BANK;
225 
226 	/* vpset.valid_bank_mask can represent up to HV_MAX_SPARSE_VCPU_BANKS banks */
227 	if (max_vcpu_bank >= HV_MAX_SPARSE_VCPU_BANKS)
228 		return 0;
229 
230 	/*
231 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
232 	 * structs are not cleared between calls, we risk flushing unneeded
233 	 * vCPUs otherwise.
234 	 */
235 	for (vcpu_bank = 0; vcpu_bank <= max_vcpu_bank; vcpu_bank++)
236 		vpset->bank_contents[vcpu_bank] = 0;
237 
238 	/*
239 	 * Some banks may end up being empty but this is acceptable.
240 	 */
241 	for_each_cpu(cpu, cpus) {
242 		if (func && func(cpu))
243 			continue;
244 		vcpu = hv_cpu_number_to_vp_number(cpu);
245 		if (vcpu == VP_INVAL)
246 			return -1;
247 		vcpu_bank = vcpu / HV_VCPUS_PER_SPARSE_BANK;
248 		vcpu_offset = vcpu % HV_VCPUS_PER_SPARSE_BANK;
249 		__set_bit(vcpu_offset, (unsigned long *)
250 			  &vpset->bank_contents[vcpu_bank]);
251 		if (vcpu_bank >= nr_bank)
252 			nr_bank = vcpu_bank + 1;
253 	}
254 	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
255 	return nr_bank;
256 }
257 
258 /*
259  * Convert a Linux cpumask into a Hyper-V VPset. In the _skip variant,
260  * 'func' is called for each CPU present in cpumask.  If 'func' returns
261  * true, that CPU is skipped -- i.e., that CPU from cpumask is *not*
262  * added to the Hyper-V VPset. If 'func' is NULL, no CPUs are
263  * skipped.
264  */
265 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
266 				    const struct cpumask *cpus)
267 {
268 	return __cpumask_to_vpset(vpset, cpus, NULL);
269 }
270 
271 static inline int cpumask_to_vpset_skip(struct hv_vpset *vpset,
272 				    const struct cpumask *cpus,
273 				    bool (*func)(int cpu))
274 {
275 	return __cpumask_to_vpset(vpset, cpus, func);
276 }
277 
278 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
279 bool hv_is_hyperv_initialized(void);
280 bool hv_is_hibernation_supported(void);
281 enum hv_isolation_type hv_get_isolation_type(void);
282 bool hv_is_isolation_supported(void);
283 bool hv_isolation_type_snp(void);
284 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
285 u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
286 void hyperv_cleanup(void);
287 bool hv_query_ext_cap(u64 cap_query);
288 void hv_setup_dma_ops(struct device *dev, bool coherent);
289 #else /* CONFIG_HYPERV */
290 static inline bool hv_is_hyperv_initialized(void) { return false; }
291 static inline bool hv_is_hibernation_supported(void) { return false; }
292 static inline void hyperv_cleanup(void) {}
293 static inline bool hv_is_isolation_supported(void) { return false; }
294 static inline enum hv_isolation_type hv_get_isolation_type(void)
295 {
296 	return HV_ISOLATION_TYPE_NONE;
297 }
298 #endif /* CONFIG_HYPERV */
299 
300 #endif
301