xref: /linux/include/asm-generic/mshyperv.h (revision f971f6dd3742d22dd13710306fb4365ea7bcb536)
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 <acpi/acpi_numa.h>
25 #include <linux/cpumask.h>
26 #include <linux/nmi.h>
27 #include <asm/ptrace.h>
28 #include <asm/hyperv-tlfs.h>
29 
30 #define VTPM_BASE_ADDRESS 0xfed40000
31 
32 struct ms_hyperv_info {
33 	u32 features;
34 	u32 priv_high;
35 	u32 misc_features;
36 	u32 hints;
37 	u32 nested_features;
38 	u32 max_vp_index;
39 	u32 max_lp_index;
40 	u8 vtl;
41 	union {
42 		u32 isolation_config_a;
43 		struct {
44 			u32 paravisor_present : 1;
45 			u32 reserved_a1 : 31;
46 		};
47 	};
48 	union {
49 		u32 isolation_config_b;
50 		struct {
51 			u32 cvm_type : 4;
52 			u32 reserved_b1 : 1;
53 			u32 shared_gpa_boundary_active : 1;
54 			u32 shared_gpa_boundary_bits : 6;
55 			u32 reserved_b2 : 20;
56 		};
57 	};
58 	u64 shared_gpa_boundary;
59 };
60 extern struct ms_hyperv_info ms_hyperv;
61 extern bool hv_nested;
62 
63 extern void * __percpu *hyperv_pcpu_input_arg;
64 extern void * __percpu *hyperv_pcpu_output_arg;
65 
66 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
67 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
68 bool hv_isolation_type_snp(void);
69 bool hv_isolation_type_tdx(void);
70 
71 static inline struct hv_proximity_domain_info hv_numa_node_to_pxm_info(int node)
72 {
73 	struct hv_proximity_domain_info pxm_info = {};
74 
75 	if (node != NUMA_NO_NODE) {
76 		pxm_info.domain_id = node_to_pxm(node);
77 		pxm_info.flags.proximity_info_valid = 1;
78 		pxm_info.flags.proximity_preferred = 1;
79 	}
80 
81 	return pxm_info;
82 }
83 
84 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
85 static inline int hv_result(u64 status)
86 {
87 	return status & HV_HYPERCALL_RESULT_MASK;
88 }
89 
90 static inline bool hv_result_success(u64 status)
91 {
92 	return hv_result(status) == HV_STATUS_SUCCESS;
93 }
94 
95 static inline unsigned int hv_repcomp(u64 status)
96 {
97 	/* Bits [43:32] of status have 'Reps completed' data. */
98 	return (status & HV_HYPERCALL_REP_COMP_MASK) >>
99 			 HV_HYPERCALL_REP_COMP_OFFSET;
100 }
101 
102 /*
103  * Rep hypercalls. Callers of this functions are supposed to ensure that
104  * rep_count and varhead_size comply with Hyper-V hypercall definition.
105  */
106 static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
107 				      void *input, void *output)
108 {
109 	u64 control = code;
110 	u64 status;
111 	u16 rep_comp;
112 
113 	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
114 	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
115 
116 	do {
117 		status = hv_do_hypercall(control, input, output);
118 		if (!hv_result_success(status))
119 			return status;
120 
121 		rep_comp = hv_repcomp(status);
122 
123 		control &= ~HV_HYPERCALL_REP_START_MASK;
124 		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
125 
126 		touch_nmi_watchdog();
127 	} while (rep_comp < rep_count);
128 
129 	return status;
130 }
131 
132 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
133 static inline u64 hv_generate_guest_id(u64 kernel_version)
134 {
135 	u64 guest_id;
136 
137 	guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
138 	guest_id |= (kernel_version << 16);
139 
140 	return guest_id;
141 }
142 
143 /* Free the message slot and signal end-of-message if required */
144 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
145 {
146 	/*
147 	 * On crash we're reading some other CPU's message page and we need
148 	 * to be careful: this other CPU may already had cleared the header
149 	 * and the host may already had delivered some other message there.
150 	 * In case we blindly write msg->header.message_type we're going
151 	 * to lose it. We can still lose a message of the same type but
152 	 * we count on the fact that there can only be one
153 	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
154 	 * on crash.
155 	 */
156 	if (cmpxchg(&msg->header.message_type, old_msg_type,
157 		    HVMSG_NONE) != old_msg_type)
158 		return;
159 
160 	/*
161 	 * The cmxchg() above does an implicit memory barrier to
162 	 * ensure the write to MessageType (ie set to
163 	 * HVMSG_NONE) happens before we read the
164 	 * MessagePending and EOMing. Otherwise, the EOMing
165 	 * will not deliver any more messages since there is
166 	 * no empty slot
167 	 */
168 	if (msg->header.message_flags.msg_pending) {
169 		/*
170 		 * This will cause message queue rescan to
171 		 * possibly deliver another msg from the
172 		 * hypervisor
173 		 */
174 		hv_set_register(HV_REGISTER_EOM, 0);
175 	}
176 }
177 
178 void hv_setup_vmbus_handler(void (*handler)(void));
179 void hv_remove_vmbus_handler(void);
180 void hv_setup_stimer0_handler(void (*handler)(void));
181 void hv_remove_stimer0_handler(void);
182 
183 void hv_setup_kexec_handler(void (*handler)(void));
184 void hv_remove_kexec_handler(void);
185 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
186 void hv_remove_crash_handler(void);
187 
188 extern int vmbus_interrupt;
189 extern int vmbus_irq;
190 
191 extern bool hv_root_partition;
192 
193 #if IS_ENABLED(CONFIG_HYPERV)
194 /*
195  * Hypervisor's notion of virtual processor ID is different from
196  * Linux' notion of CPU ID. This information can only be retrieved
197  * in the context of the calling CPU. Setup a map for easy access
198  * to this information.
199  */
200 extern u32 *hv_vp_index;
201 extern u32 hv_max_vp_index;
202 
203 extern u64 (*hv_read_reference_counter)(void);
204 
205 /* Sentinel value for an uninitialized entry in hv_vp_index array */
206 #define VP_INVAL	U32_MAX
207 
208 int __init hv_common_init(void);
209 void __init hv_common_free(void);
210 int hv_common_cpu_init(unsigned int cpu);
211 int hv_common_cpu_die(unsigned int cpu);
212 
213 void *hv_alloc_hyperv_page(void);
214 void *hv_alloc_hyperv_zeroed_page(void);
215 void hv_free_hyperv_page(void *addr);
216 
217 /**
218  * hv_cpu_number_to_vp_number() - Map CPU to VP.
219  * @cpu_number: CPU number in Linux terms
220  *
221  * This function returns the mapping between the Linux processor
222  * number and the hypervisor's virtual processor number, useful
223  * in making hypercalls and such that talk about specific
224  * processors.
225  *
226  * Return: Virtual processor number in Hyper-V terms
227  */
228 static inline int hv_cpu_number_to_vp_number(int cpu_number)
229 {
230 	return hv_vp_index[cpu_number];
231 }
232 
233 static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
234 				    const struct cpumask *cpus,
235 				    bool (*func)(int cpu))
236 {
237 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
238 	int max_vcpu_bank = hv_max_vp_index / HV_VCPUS_PER_SPARSE_BANK;
239 
240 	/* vpset.valid_bank_mask can represent up to HV_MAX_SPARSE_VCPU_BANKS banks */
241 	if (max_vcpu_bank >= HV_MAX_SPARSE_VCPU_BANKS)
242 		return 0;
243 
244 	/*
245 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
246 	 * structs are not cleared between calls, we risk flushing unneeded
247 	 * vCPUs otherwise.
248 	 */
249 	for (vcpu_bank = 0; vcpu_bank <= max_vcpu_bank; vcpu_bank++)
250 		vpset->bank_contents[vcpu_bank] = 0;
251 
252 	/*
253 	 * Some banks may end up being empty but this is acceptable.
254 	 */
255 	for_each_cpu(cpu, cpus) {
256 		if (func && func(cpu))
257 			continue;
258 		vcpu = hv_cpu_number_to_vp_number(cpu);
259 		if (vcpu == VP_INVAL)
260 			return -1;
261 		vcpu_bank = vcpu / HV_VCPUS_PER_SPARSE_BANK;
262 		vcpu_offset = vcpu % HV_VCPUS_PER_SPARSE_BANK;
263 		__set_bit(vcpu_offset, (unsigned long *)
264 			  &vpset->bank_contents[vcpu_bank]);
265 		if (vcpu_bank >= nr_bank)
266 			nr_bank = vcpu_bank + 1;
267 	}
268 	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
269 	return nr_bank;
270 }
271 
272 /*
273  * Convert a Linux cpumask into a Hyper-V VPset. In the _skip variant,
274  * 'func' is called for each CPU present in cpumask.  If 'func' returns
275  * true, that CPU is skipped -- i.e., that CPU from cpumask is *not*
276  * added to the Hyper-V VPset. If 'func' is NULL, no CPUs are
277  * skipped.
278  */
279 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
280 				    const struct cpumask *cpus)
281 {
282 	return __cpumask_to_vpset(vpset, cpus, NULL);
283 }
284 
285 static inline int cpumask_to_vpset_skip(struct hv_vpset *vpset,
286 				    const struct cpumask *cpus,
287 				    bool (*func)(int cpu))
288 {
289 	return __cpumask_to_vpset(vpset, cpus, func);
290 }
291 
292 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
293 bool hv_is_hyperv_initialized(void);
294 bool hv_is_hibernation_supported(void);
295 enum hv_isolation_type hv_get_isolation_type(void);
296 bool hv_is_isolation_supported(void);
297 bool hv_isolation_type_snp(void);
298 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
299 u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
300 void hyperv_cleanup(void);
301 bool hv_query_ext_cap(u64 cap_query);
302 void hv_setup_dma_ops(struct device *dev, bool coherent);
303 #else /* CONFIG_HYPERV */
304 static inline bool hv_is_hyperv_initialized(void) { return false; }
305 static inline bool hv_is_hibernation_supported(void) { return false; }
306 static inline void hyperv_cleanup(void) {}
307 static inline bool hv_is_isolation_supported(void) { return false; }
308 static inline enum hv_isolation_type hv_get_isolation_type(void)
309 {
310 	return HV_ISOLATION_TYPE_NONE;
311 }
312 #endif /* CONFIG_HYPERV */
313 
314 #endif
315