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 #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