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