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 hv_generate_guest_id(u64 kernel_version) 109 { 110 u64 guest_id; 111 112 guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48); 113 guest_id |= (kernel_version << 16); 114 115 return guest_id; 116 } 117 118 /* Free the message slot and signal end-of-message if required */ 119 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) 120 { 121 /* 122 * On crash we're reading some other CPU's message page and we need 123 * to be careful: this other CPU may already had cleared the header 124 * and the host may already had delivered some other message there. 125 * In case we blindly write msg->header.message_type we're going 126 * to lose it. We can still lose a message of the same type but 127 * we count on the fact that there can only be one 128 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages 129 * on crash. 130 */ 131 if (cmpxchg(&msg->header.message_type, old_msg_type, 132 HVMSG_NONE) != old_msg_type) 133 return; 134 135 /* 136 * The cmxchg() above does an implicit memory barrier to 137 * ensure the write to MessageType (ie set to 138 * HVMSG_NONE) happens before we read the 139 * MessagePending and EOMing. Otherwise, the EOMing 140 * will not deliver any more messages since there is 141 * no empty slot 142 */ 143 if (msg->header.message_flags.msg_pending) { 144 /* 145 * This will cause message queue rescan to 146 * possibly deliver another msg from the 147 * hypervisor 148 */ 149 hv_set_register(HV_REGISTER_EOM, 0); 150 } 151 } 152 153 void hv_setup_vmbus_handler(void (*handler)(void)); 154 void hv_remove_vmbus_handler(void); 155 void hv_setup_stimer0_handler(void (*handler)(void)); 156 void hv_remove_stimer0_handler(void); 157 158 void hv_setup_kexec_handler(void (*handler)(void)); 159 void hv_remove_kexec_handler(void); 160 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); 161 void hv_remove_crash_handler(void); 162 163 extern int vmbus_interrupt; 164 extern int vmbus_irq; 165 166 extern bool hv_root_partition; 167 168 #if IS_ENABLED(CONFIG_HYPERV) 169 /* 170 * Hypervisor's notion of virtual processor ID is different from 171 * Linux' notion of CPU ID. This information can only be retrieved 172 * in the context of the calling CPU. Setup a map for easy access 173 * to this information. 174 */ 175 extern u32 *hv_vp_index; 176 extern u32 hv_max_vp_index; 177 178 extern u64 (*hv_read_reference_counter)(void); 179 180 /* Sentinel value for an uninitialized entry in hv_vp_index array */ 181 #define VP_INVAL U32_MAX 182 183 int __init hv_common_init(void); 184 void __init hv_common_free(void); 185 int hv_common_cpu_init(unsigned int cpu); 186 int hv_common_cpu_die(unsigned int cpu); 187 188 void *hv_alloc_hyperv_page(void); 189 void *hv_alloc_hyperv_zeroed_page(void); 190 void hv_free_hyperv_page(unsigned long addr); 191 192 /** 193 * hv_cpu_number_to_vp_number() - Map CPU to VP. 194 * @cpu_number: CPU number in Linux terms 195 * 196 * This function returns the mapping between the Linux processor 197 * number and the hypervisor's virtual processor number, useful 198 * in making hypercalls and such that talk about specific 199 * processors. 200 * 201 * Return: Virtual processor number in Hyper-V terms 202 */ 203 static inline int hv_cpu_number_to_vp_number(int cpu_number) 204 { 205 return hv_vp_index[cpu_number]; 206 } 207 208 static inline int __cpumask_to_vpset(struct hv_vpset *vpset, 209 const struct cpumask *cpus, 210 bool exclude_self) 211 { 212 int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1; 213 int this_cpu = smp_processor_id(); 214 215 /* valid_bank_mask can represent up to 64 banks */ 216 if (hv_max_vp_index / 64 >= 64) 217 return 0; 218 219 /* 220 * Clear all banks up to the maximum possible bank as hv_tlb_flush_ex 221 * structs are not cleared between calls, we risk flushing unneeded 222 * vCPUs otherwise. 223 */ 224 for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++) 225 vpset->bank_contents[vcpu_bank] = 0; 226 227 /* 228 * Some banks may end up being empty but this is acceptable. 229 */ 230 for_each_cpu(cpu, cpus) { 231 if (exclude_self && cpu == this_cpu) 232 continue; 233 vcpu = hv_cpu_number_to_vp_number(cpu); 234 if (vcpu == VP_INVAL) 235 return -1; 236 vcpu_bank = vcpu / 64; 237 vcpu_offset = vcpu % 64; 238 __set_bit(vcpu_offset, (unsigned long *) 239 &vpset->bank_contents[vcpu_bank]); 240 if (vcpu_bank >= nr_bank) 241 nr_bank = vcpu_bank + 1; 242 } 243 vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0); 244 return nr_bank; 245 } 246 247 static inline int cpumask_to_vpset(struct hv_vpset *vpset, 248 const struct cpumask *cpus) 249 { 250 return __cpumask_to_vpset(vpset, cpus, false); 251 } 252 253 static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset, 254 const struct cpumask *cpus) 255 { 256 WARN_ON_ONCE(preemptible()); 257 return __cpumask_to_vpset(vpset, cpus, true); 258 } 259 260 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die); 261 bool hv_is_hyperv_initialized(void); 262 bool hv_is_hibernation_supported(void); 263 enum hv_isolation_type hv_get_isolation_type(void); 264 bool hv_is_isolation_supported(void); 265 bool hv_isolation_type_snp(void); 266 u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size); 267 void hyperv_cleanup(void); 268 bool hv_query_ext_cap(u64 cap_query); 269 void hv_setup_dma_ops(struct device *dev, bool coherent); 270 void *hv_map_memory(void *addr, unsigned long size); 271 void hv_unmap_memory(void *addr); 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