1 #ifndef _ASM_X86_MSHYPER_H 2 #define _ASM_X86_MSHYPER_H 3 4 #include <linux/types.h> 5 #include <linux/atomic.h> 6 #include <asm/hyperv.h> 7 8 /* 9 * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent 10 * is set by CPUID(HVCPUID_VERSION_FEATURES). 11 */ 12 enum hv_cpuid_function { 13 HVCPUID_VERSION_FEATURES = 0x00000001, 14 HVCPUID_VENDOR_MAXFUNCTION = 0x40000000, 15 HVCPUID_INTERFACE = 0x40000001, 16 17 /* 18 * The remaining functions depend on the value of 19 * HVCPUID_INTERFACE 20 */ 21 HVCPUID_VERSION = 0x40000002, 22 HVCPUID_FEATURES = 0x40000003, 23 HVCPUID_ENLIGHTENMENT_INFO = 0x40000004, 24 HVCPUID_IMPLEMENTATION_LIMITS = 0x40000005, 25 }; 26 27 struct ms_hyperv_info { 28 u32 features; 29 u32 misc_features; 30 u32 hints; 31 }; 32 33 extern struct ms_hyperv_info ms_hyperv; 34 35 /* 36 * Declare the MSR used to setup pages used to communicate with the hypervisor. 37 */ 38 union hv_x64_msr_hypercall_contents { 39 u64 as_uint64; 40 struct { 41 u64 enable:1; 42 u64 reserved:11; 43 u64 guest_physical_address:52; 44 }; 45 }; 46 47 /* 48 * TSC page layout. 49 */ 50 51 struct ms_hyperv_tsc_page { 52 volatile u32 tsc_sequence; 53 u32 reserved1; 54 volatile u64 tsc_scale; 55 volatile s64 tsc_offset; 56 u64 reserved2[509]; 57 }; 58 59 /* 60 * The guest OS needs to register the guest ID with the hypervisor. 61 * The guest ID is a 64 bit entity and the structure of this ID is 62 * specified in the Hyper-V specification: 63 * 64 * msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx 65 * 66 * While the current guideline does not specify how Linux guest ID(s) 67 * need to be generated, our plan is to publish the guidelines for 68 * Linux and other guest operating systems that currently are hosted 69 * on Hyper-V. The implementation here conforms to this yet 70 * unpublished guidelines. 71 * 72 * 73 * Bit(s) 74 * 63 - Indicates if the OS is Open Source or not; 1 is Open Source 75 * 62:56 - Os Type; Linux is 0x100 76 * 55:48 - Distro specific identification 77 * 47:16 - Linux kernel version number 78 * 15:0 - Distro specific identification 79 * 80 * 81 */ 82 83 #define HV_LINUX_VENDOR_ID 0x8100 84 85 /* 86 * Generate the guest ID based on the guideline described above. 87 */ 88 89 static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, 90 __u64 d_info2) 91 { 92 __u64 guest_id = 0; 93 94 guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); 95 guest_id |= (d_info1 << 48); 96 guest_id |= (kernel_version << 16); 97 guest_id |= d_info2; 98 99 return guest_id; 100 } 101 102 103 /* Free the message slot and signal end-of-message if required */ 104 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) 105 { 106 /* 107 * On crash we're reading some other CPU's message page and we need 108 * to be careful: this other CPU may already had cleared the header 109 * and the host may already had delivered some other message there. 110 * In case we blindly write msg->header.message_type we're going 111 * to lose it. We can still lose a message of the same type but 112 * we count on the fact that there can only be one 113 * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages 114 * on crash. 115 */ 116 if (cmpxchg(&msg->header.message_type, old_msg_type, 117 HVMSG_NONE) != old_msg_type) 118 return; 119 120 /* 121 * Make sure the write to MessageType (ie set to 122 * HVMSG_NONE) happens before we read the 123 * MessagePending and EOMing. Otherwise, the EOMing 124 * will not deliver any more messages since there is 125 * no empty slot 126 */ 127 mb(); 128 129 if (msg->header.message_flags.msg_pending) { 130 /* 131 * This will cause message queue rescan to 132 * possibly deliver another msg from the 133 * hypervisor 134 */ 135 wrmsrl(HV_X64_MSR_EOM, 0); 136 } 137 } 138 139 #define hv_init_timer(timer, tick) wrmsrl(timer, tick) 140 #define hv_init_timer_config(config, val) wrmsrl(config, val) 141 142 #define hv_get_simp(val) rdmsrl(HV_X64_MSR_SIMP, val) 143 #define hv_set_simp(val) wrmsrl(HV_X64_MSR_SIMP, val) 144 145 #define hv_get_siefp(val) rdmsrl(HV_X64_MSR_SIEFP, val) 146 #define hv_set_siefp(val) wrmsrl(HV_X64_MSR_SIEFP, val) 147 148 #define hv_get_synic_state(val) rdmsrl(HV_X64_MSR_SCONTROL, val) 149 #define hv_set_synic_state(val) wrmsrl(HV_X64_MSR_SCONTROL, val) 150 151 #define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index) 152 153 #define hv_get_synint_state(int_num, val) rdmsrl(int_num, val) 154 #define hv_set_synint_state(int_num, val) wrmsrl(int_num, val) 155 156 void hyperv_callback_vector(void); 157 #ifdef CONFIG_TRACING 158 #define trace_hyperv_callback_vector hyperv_callback_vector 159 #endif 160 void hyperv_vector_handler(struct pt_regs *regs); 161 void hv_setup_vmbus_irq(void (*handler)(void)); 162 void hv_remove_vmbus_irq(void); 163 164 void hv_setup_kexec_handler(void (*handler)(void)); 165 void hv_remove_kexec_handler(void); 166 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); 167 void hv_remove_crash_handler(void); 168 169 #if IS_ENABLED(CONFIG_HYPERV) 170 extern struct clocksource *hyperv_cs; 171 172 void hyperv_init(void); 173 void hyperv_report_panic(struct pt_regs *regs); 174 bool hv_is_hypercall_page_setup(void); 175 void hyperv_cleanup(void); 176 #endif 177 #ifdef CONFIG_HYPERV_TSCPAGE 178 struct ms_hyperv_tsc_page *hv_get_tsc_page(void); 179 static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) 180 { 181 u64 scale, offset, cur_tsc; 182 u32 sequence; 183 184 /* 185 * The protocol for reading Hyper-V TSC page is specified in Hypervisor 186 * Top-Level Functional Specification ver. 3.0 and above. To get the 187 * reference time we must do the following: 188 * - READ ReferenceTscSequence 189 * A special '0' value indicates the time source is unreliable and we 190 * need to use something else. The currently published specification 191 * versions (up to 4.0b) contain a mistake and wrongly claim '-1' 192 * instead of '0' as the special value, see commit c35b82ef0294. 193 * - ReferenceTime = 194 * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset 195 * - READ ReferenceTscSequence again. In case its value has changed 196 * since our first reading we need to discard ReferenceTime and repeat 197 * the whole sequence as the hypervisor was updating the page in 198 * between. 199 */ 200 do { 201 sequence = READ_ONCE(tsc_pg->tsc_sequence); 202 if (!sequence) 203 return U64_MAX; 204 /* 205 * Make sure we read sequence before we read other values from 206 * TSC page. 207 */ 208 smp_rmb(); 209 210 scale = READ_ONCE(tsc_pg->tsc_scale); 211 offset = READ_ONCE(tsc_pg->tsc_offset); 212 cur_tsc = rdtsc_ordered(); 213 214 /* 215 * Make sure we read sequence after we read all other values 216 * from TSC page. 217 */ 218 smp_rmb(); 219 220 } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence); 221 222 return mul_u64_u64_shr(cur_tsc, scale, 64) + offset; 223 } 224 225 #else 226 static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) 227 { 228 return NULL; 229 } 230 #endif 231 #endif 232