1 #define pr_fmt(fmt) "Hyper-V: " fmt 2 3 #include <linux/hyperv.h> 4 #include <linux/log2.h> 5 #include <linux/slab.h> 6 #include <linux/types.h> 7 8 #include <asm/fpu/api.h> 9 #include <asm/mshyperv.h> 10 #include <asm/msr.h> 11 #include <asm/tlbflush.h> 12 #include <asm/tlb.h> 13 14 #define CREATE_TRACE_POINTS 15 #include <asm/trace/hyperv.h> 16 17 /* Each gva in gva_list encodes up to 4096 pages to flush */ 18 #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE) 19 20 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, 21 const struct flush_tlb_info *info); 22 23 /* 24 * Fills in gva_list starting from offset. Returns the number of items added. 25 */ 26 static inline int fill_gva_list(u64 gva_list[], int offset, 27 unsigned long start, unsigned long end) 28 { 29 int gva_n = offset; 30 unsigned long cur = start, diff; 31 32 do { 33 diff = end > cur ? end - cur : 0; 34 35 gva_list[gva_n] = cur & PAGE_MASK; 36 /* 37 * Lower 12 bits encode the number of additional 38 * pages to flush (in addition to the 'cur' page). 39 */ 40 if (diff >= HV_TLB_FLUSH_UNIT) { 41 gva_list[gva_n] |= ~PAGE_MASK; 42 cur += HV_TLB_FLUSH_UNIT; 43 } else if (diff) { 44 gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT; 45 cur = end; 46 } 47 48 gva_n++; 49 50 } while (cur < end); 51 52 return gva_n - offset; 53 } 54 55 static void hyperv_flush_tlb_multi(const struct cpumask *cpus, 56 const struct flush_tlb_info *info) 57 { 58 int cpu, vcpu, gva_n, max_gvas; 59 struct hv_tlb_flush **flush_pcpu; 60 struct hv_tlb_flush *flush; 61 u64 status; 62 unsigned long flags; 63 64 trace_hyperv_mmu_flush_tlb_multi(cpus, info); 65 66 if (!hv_hypercall_pg) 67 goto do_native; 68 69 local_irq_save(flags); 70 71 flush_pcpu = (struct hv_tlb_flush **) 72 this_cpu_ptr(hyperv_pcpu_input_arg); 73 74 flush = *flush_pcpu; 75 76 if (unlikely(!flush)) { 77 local_irq_restore(flags); 78 goto do_native; 79 } 80 81 if (info->mm) { 82 /* 83 * AddressSpace argument must match the CR3 with PCID bits 84 * stripped out. 85 */ 86 flush->address_space = virt_to_phys(info->mm->pgd); 87 flush->address_space &= CR3_ADDR_MASK; 88 flush->flags = 0; 89 } else { 90 flush->address_space = 0; 91 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 92 } 93 94 flush->processor_mask = 0; 95 if (cpumask_equal(cpus, cpu_present_mask)) { 96 flush->flags |= HV_FLUSH_ALL_PROCESSORS; 97 } else { 98 /* 99 * From the supplied CPU set we need to figure out if we can get 100 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} 101 * hypercalls. This is possible when the highest VP number in 102 * the set is < 64. As VP numbers are usually in ascending order 103 * and match Linux CPU ids, here is an optimization: we check 104 * the VP number for the highest bit in the supplied set first 105 * so we can quickly find out if using *_EX hypercalls is a 106 * must. We will also check all VP numbers when walking the 107 * supplied CPU set to remain correct in all cases. 108 */ 109 cpu = cpumask_last(cpus); 110 111 if (cpu < nr_cpumask_bits && hv_cpu_number_to_vp_number(cpu) >= 64) 112 goto do_ex_hypercall; 113 114 for_each_cpu(cpu, cpus) { 115 vcpu = hv_cpu_number_to_vp_number(cpu); 116 if (vcpu == VP_INVAL) { 117 local_irq_restore(flags); 118 goto do_native; 119 } 120 121 if (vcpu >= 64) 122 goto do_ex_hypercall; 123 124 __set_bit(vcpu, (unsigned long *) 125 &flush->processor_mask); 126 } 127 128 /* nothing to flush if 'processor_mask' ends up being empty */ 129 if (!flush->processor_mask) { 130 local_irq_restore(flags); 131 return; 132 } 133 } 134 135 /* 136 * We can flush not more than max_gvas with one hypercall. Flush the 137 * whole address space if we were asked to do more. 138 */ 139 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]); 140 141 if (info->end == TLB_FLUSH_ALL) { 142 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 143 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 144 flush, NULL); 145 } else if (info->end && 146 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 147 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 148 flush, NULL); 149 } else { 150 gva_n = fill_gva_list(flush->gva_list, 0, 151 info->start, info->end); 152 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST, 153 gva_n, 0, flush, NULL); 154 } 155 goto check_status; 156 157 do_ex_hypercall: 158 status = hyperv_flush_tlb_others_ex(cpus, info); 159 160 check_status: 161 local_irq_restore(flags); 162 163 if (hv_result_success(status)) 164 return; 165 do_native: 166 native_flush_tlb_multi(cpus, info); 167 } 168 169 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, 170 const struct flush_tlb_info *info) 171 { 172 int nr_bank = 0, max_gvas, gva_n; 173 struct hv_tlb_flush_ex **flush_pcpu; 174 struct hv_tlb_flush_ex *flush; 175 u64 status; 176 177 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) 178 return HV_STATUS_INVALID_PARAMETER; 179 180 flush_pcpu = (struct hv_tlb_flush_ex **) 181 this_cpu_ptr(hyperv_pcpu_input_arg); 182 183 flush = *flush_pcpu; 184 185 if (info->mm) { 186 /* 187 * AddressSpace argument must match the CR3 with PCID bits 188 * stripped out. 189 */ 190 flush->address_space = virt_to_phys(info->mm->pgd); 191 flush->address_space &= CR3_ADDR_MASK; 192 flush->flags = 0; 193 } else { 194 flush->address_space = 0; 195 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 196 } 197 198 flush->hv_vp_set.valid_bank_mask = 0; 199 200 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K; 201 nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus); 202 if (nr_bank < 0) 203 return HV_STATUS_INVALID_PARAMETER; 204 205 /* 206 * We can flush not more than max_gvas with one hypercall. Flush the 207 * whole address space if we were asked to do more. 208 */ 209 max_gvas = 210 (PAGE_SIZE - sizeof(*flush) - nr_bank * 211 sizeof(flush->hv_vp_set.bank_contents[0])) / 212 sizeof(flush->gva_list[0]); 213 214 if (info->end == TLB_FLUSH_ALL) { 215 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 216 status = hv_do_rep_hypercall( 217 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 218 0, nr_bank, flush, NULL); 219 } else if (info->end && 220 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 221 status = hv_do_rep_hypercall( 222 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 223 0, nr_bank, flush, NULL); 224 } else { 225 gva_n = fill_gva_list(flush->gva_list, nr_bank, 226 info->start, info->end); 227 status = hv_do_rep_hypercall( 228 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX, 229 gva_n, nr_bank, flush, NULL); 230 } 231 232 return status; 233 } 234 235 void hyperv_setup_mmu_ops(void) 236 { 237 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)) 238 return; 239 240 pr_info("Using hypercall for remote TLB flush\n"); 241 pv_ops.mmu.flush_tlb_multi = hyperv_flush_tlb_multi; 242 pv_ops.mmu.tlb_remove_table = tlb_remove_table; 243 } 244