include/asm-generic/mshyperv.h

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