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 derived from Hyper-V code or headers should not go in
10  * this file, but should instead go in the relevant files in include/hyperv.
11  *
12  * Copyright (C) 2019, Microsoft, Inc.
13  *
14  * Author : Michael Kelley <[email protected]>
15  */
16 
17 #ifndef _ASM_GENERIC_MSHYPERV_H
18 #define _ASM_GENERIC_MSHYPERV_H
19 
20 #include <linux/types.h>
21 #include <linux/atomic.h>
22 #include <linux/bitops.h>
23 #include <acpi/acpi_numa.h>
24 #include <linux/cpumask.h>
25 #include <linux/nmi.h>
26 #include <asm/ptrace.h>
27 #include <hyperv/hvhdk.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 
hv_numa_node_to_pxm_info(int node)70 static inline struct hv_proximity_domain_info hv_numa_node_to_pxm_info(int node)
71 {
72 	struct hv_proximity_domain_info pxm_info = {};
73 
74 	if (node != NUMA_NO_NODE) {
75 		pxm_info.domain_id = node_to_pxm(node);
76 		pxm_info.flags.proximity_info_valid = 1;
77 		pxm_info.flags.proximity_preferred = 1;
78 	}
79 
80 	return pxm_info;
81 }
82 
83 /* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
hv_result(u64 status)84 static inline int hv_result(u64 status)
85 {
86 	return status & HV_HYPERCALL_RESULT_MASK;
87 }
88 
hv_result_success(u64 status)89 static inline bool hv_result_success(u64 status)
90 {
91 	return hv_result(status) == HV_STATUS_SUCCESS;
92 }
93 
hv_repcomp(u64 status)94 static inline unsigned int hv_repcomp(u64 status)
95 {
96 	/* Bits [43:32] of status have 'Reps completed' data. */
97 	return (status & HV_HYPERCALL_REP_COMP_MASK) >>
98 			 HV_HYPERCALL_REP_COMP_OFFSET;
99 }
100 
101 /*
102  * Rep hypercalls. Callers of this functions are supposed to ensure that
103  * rep_count and varhead_size comply with Hyper-V hypercall definition.
104  */
hv_do_rep_hypercall(u16 code,u16 rep_count,u16 varhead_size,void * input,void * output)105 static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
106 				      void *input, void *output)
107 {
108 	u64 control = code;
109 	u64 status;
110 	u16 rep_comp;
111 
112 	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
113 	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
114 
115 	do {
116 		status = hv_do_hypercall(control, input, output);
117 		if (!hv_result_success(status))
118 			return status;
119 
120 		rep_comp = hv_repcomp(status);
121 
122 		control &= ~HV_HYPERCALL_REP_START_MASK;
123 		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
124 
125 		touch_nmi_watchdog();
126 	} while (rep_comp < rep_count);
127 
128 	return status;
129 }
130 
131 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
hv_generate_guest_id(u64 kernel_version)132 static inline u64 hv_generate_guest_id(u64 kernel_version)
133 {
134 	u64 guest_id;
135 
136 	guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
137 	guest_id |= (kernel_version << 16);
138 
139 	return guest_id;
140 }
141 
142 /* Free the message slot and signal end-of-message if required */
vmbus_signal_eom(struct hv_message * msg,u32 old_msg_type)143 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
144 {
145 	/*
146 	 * On crash we're reading some other CPU's message page and we need
147 	 * to be careful: this other CPU may already had cleared the header
148 	 * and the host may already had delivered some other message there.
149 	 * In case we blindly write msg->header.message_type we're going
150 	 * to lose it. We can still lose a message of the same type but
151 	 * we count on the fact that there can only be one
152 	 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages
153 	 * on crash.
154 	 */
155 	if (cmpxchg(&msg->header.message_type, old_msg_type,
156 		    HVMSG_NONE) != old_msg_type)
157 		return;
158 
159 	/*
160 	 * The cmxchg() above does an implicit memory barrier to
161 	 * ensure the write to MessageType (ie set to
162 	 * HVMSG_NONE) happens before we read the
163 	 * MessagePending and EOMing. Otherwise, the EOMing
164 	 * will not deliver any more messages since there is
165 	 * no empty slot
166 	 */
167 	if (msg->header.message_flags.msg_pending) {
168 		/*
169 		 * This will cause message queue rescan to
170 		 * possibly deliver another msg from the
171 		 * hypervisor
172 		 */
173 		hv_set_msr(HV_MSR_EOM, 0);
174 	}
175 }
176 
177 int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
178 
179 void hv_setup_vmbus_handler(void (*handler)(void));
180 void hv_remove_vmbus_handler(void);
181 void hv_setup_stimer0_handler(void (*handler)(void));
182 void hv_remove_stimer0_handler(void);
183 
184 void hv_setup_kexec_handler(void (*handler)(void));
185 void hv_remove_kexec_handler(void);
186 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
187 void hv_remove_crash_handler(void);
188 
189 extern int vmbus_interrupt;
190 extern int vmbus_irq;
191 
192 extern bool hv_root_partition;
193 
194 #if IS_ENABLED(CONFIG_HYPERV)
195 /*
196  * Hypervisor's notion of virtual processor ID is different from
197  * Linux' notion of CPU ID. This information can only be retrieved
198  * in the context of the calling CPU. Setup a map for easy access
199  * to this information.
200  */
201 extern u32 *hv_vp_index;
202 extern u32 hv_max_vp_index;
203 
204 extern u64 (*hv_read_reference_counter)(void);
205 
206 /* Sentinel value for an uninitialized entry in hv_vp_index array */
207 #define VP_INVAL	U32_MAX
208 
209 int __init hv_common_init(void);
210 void __init hv_common_free(void);
211 void __init ms_hyperv_late_init(void);
212 int hv_common_cpu_init(unsigned int cpu);
213 int hv_common_cpu_die(unsigned int cpu);
214 
215 void *hv_alloc_hyperv_page(void);
216 void *hv_alloc_hyperv_zeroed_page(void);
217 void hv_free_hyperv_page(void *addr);
218 
219 /**
220  * hv_cpu_number_to_vp_number() - Map CPU to VP.
221  * @cpu_number: CPU number in Linux terms
222  *
223  * This function returns the mapping between the Linux processor
224  * number and the hypervisor's virtual processor number, useful
225  * in making hypercalls and such that talk about specific
226  * processors.
227  *
228  * Return: Virtual processor number in Hyper-V terms
229  */
hv_cpu_number_to_vp_number(int cpu_number)230 static inline int hv_cpu_number_to_vp_number(int cpu_number)
231 {
232 	return hv_vp_index[cpu_number];
233 }
234 
__cpumask_to_vpset(struct hv_vpset * vpset,const struct cpumask * cpus,bool (* func)(int cpu))235 static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
236 				    const struct cpumask *cpus,
237 				    bool (*func)(int cpu))
238 {
239 	int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
240 	int max_vcpu_bank = hv_max_vp_index / HV_VCPUS_PER_SPARSE_BANK;
241 
242 	/* vpset.valid_bank_mask can represent up to HV_MAX_SPARSE_VCPU_BANKS banks */
243 	if (max_vcpu_bank >= HV_MAX_SPARSE_VCPU_BANKS)
244 		return 0;
245 
246 	/*
247 	 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex
248 	 * structs are not cleared between calls, we risk flushing unneeded
249 	 * vCPUs otherwise.
250 	 */
251 	for (vcpu_bank = 0; vcpu_bank <= max_vcpu_bank; vcpu_bank++)
252 		vpset->bank_contents[vcpu_bank] = 0;
253 
254 	/*
255 	 * Some banks may end up being empty but this is acceptable.
256 	 */
257 	for_each_cpu(cpu, cpus) {
258 		if (func && func(cpu))
259 			continue;
260 		vcpu = hv_cpu_number_to_vp_number(cpu);
261 		if (vcpu == VP_INVAL)
262 			return -1;
263 		vcpu_bank = vcpu / HV_VCPUS_PER_SPARSE_BANK;
264 		vcpu_offset = vcpu % HV_VCPUS_PER_SPARSE_BANK;
265 		__set_bit(vcpu_offset, (unsigned long *)
266 			  &vpset->bank_contents[vcpu_bank]);
267 		if (vcpu_bank >= nr_bank)
268 			nr_bank = vcpu_bank + 1;
269 	}
270 	vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
271 	return nr_bank;
272 }
273 
274 /*
275  * Convert a Linux cpumask into a Hyper-V VPset. In the _skip variant,
276  * 'func' is called for each CPU present in cpumask.  If 'func' returns
277  * true, that CPU is skipped -- i.e., that CPU from cpumask is *not*
278  * added to the Hyper-V VPset. If 'func' is NULL, no CPUs are
279  * skipped.
280  */
cpumask_to_vpset(struct hv_vpset * vpset,const struct cpumask * cpus)281 static inline int cpumask_to_vpset(struct hv_vpset *vpset,
282 				    const struct cpumask *cpus)
283 {
284 	return __cpumask_to_vpset(vpset, cpus, NULL);
285 }
286 
cpumask_to_vpset_skip(struct hv_vpset * vpset,const struct cpumask * cpus,bool (* func)(int cpu))287 static inline int cpumask_to_vpset_skip(struct hv_vpset *vpset,
288 				    const struct cpumask *cpus,
289 				    bool (*func)(int cpu))
290 {
291 	return __cpumask_to_vpset(vpset, cpus, func);
292 }
293 
294 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
295 bool hv_is_hyperv_initialized(void);
296 bool hv_is_hibernation_supported(void);
297 enum hv_isolation_type hv_get_isolation_type(void);
298 bool hv_is_isolation_supported(void);
299 bool hv_isolation_type_snp(void);
300 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
301 u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
302 void hyperv_cleanup(void);
303 bool hv_query_ext_cap(u64 cap_query);
304 void hv_setup_dma_ops(struct device *dev, bool coherent);
305 #else /* CONFIG_HYPERV */
hv_is_hyperv_initialized(void)306 static inline bool hv_is_hyperv_initialized(void) { return false; }
hv_is_hibernation_supported(void)307 static inline bool hv_is_hibernation_supported(void) { return false; }
hyperv_cleanup(void)308 static inline void hyperv_cleanup(void) {}
ms_hyperv_late_init(void)309 static inline void ms_hyperv_late_init(void) {}
hv_is_isolation_supported(void)310 static inline bool hv_is_isolation_supported(void) { return false; }
hv_get_isolation_type(void)311 static inline enum hv_isolation_type hv_get_isolation_type(void)
312 {
313 	return HV_ISOLATION_TYPE_NONE;
314 }
315 #endif /* CONFIG_HYPERV */
316 
317 #endif
318