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_others(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 = U64_MAX; 62 unsigned long flags; 63 64 trace_hyperv_mmu_flush_tlb_others(cpus, info); 65 66 if (!hv_hypercall_pg) 67 goto do_native; 68 69 if (cpumask_empty(cpus)) 70 return; 71 72 local_irq_save(flags); 73 74 flush_pcpu = (struct hv_tlb_flush **) 75 this_cpu_ptr(hyperv_pcpu_input_arg); 76 77 flush = *flush_pcpu; 78 79 if (unlikely(!flush)) { 80 local_irq_restore(flags); 81 goto do_native; 82 } 83 84 if (info->mm) { 85 /* 86 * AddressSpace argument must match the CR3 with PCID bits 87 * stripped out. 88 */ 89 flush->address_space = virt_to_phys(info->mm->pgd); 90 flush->address_space &= CR3_ADDR_MASK; 91 flush->flags = 0; 92 } else { 93 flush->address_space = 0; 94 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 95 } 96 97 flush->processor_mask = 0; 98 if (cpumask_equal(cpus, cpu_present_mask)) { 99 flush->flags |= HV_FLUSH_ALL_PROCESSORS; 100 } else { 101 /* 102 * From the supplied CPU set we need to figure out if we can get 103 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} 104 * hypercalls. This is possible when the highest VP number in 105 * the set is < 64. As VP numbers are usually in ascending order 106 * and match Linux CPU ids, here is an optimization: we check 107 * the VP number for the highest bit in the supplied set first 108 * so we can quickly find out if using *_EX hypercalls is a 109 * must. We will also check all VP numbers when walking the 110 * supplied CPU set to remain correct in all cases. 111 */ 112 if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64) 113 goto do_ex_hypercall; 114 115 for_each_cpu(cpu, cpus) { 116 vcpu = hv_cpu_number_to_vp_number(cpu); 117 if (vcpu == VP_INVAL) { 118 local_irq_restore(flags); 119 goto do_native; 120 } 121 122 if (vcpu >= 64) 123 goto do_ex_hypercall; 124 125 __set_bit(vcpu, (unsigned long *) 126 &flush->processor_mask); 127 } 128 } 129 130 /* 131 * We can flush not more than max_gvas with one hypercall. Flush the 132 * whole address space if we were asked to do more. 133 */ 134 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]); 135 136 if (info->end == TLB_FLUSH_ALL) { 137 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 138 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 139 flush, NULL); 140 } else if (info->end && 141 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 142 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE, 143 flush, NULL); 144 } else { 145 gva_n = fill_gva_list(flush->gva_list, 0, 146 info->start, info->end); 147 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST, 148 gva_n, 0, flush, NULL); 149 } 150 goto check_status; 151 152 do_ex_hypercall: 153 status = hyperv_flush_tlb_others_ex(cpus, info); 154 155 check_status: 156 local_irq_restore(flags); 157 158 if (!(status & HV_HYPERCALL_RESULT_MASK)) 159 return; 160 do_native: 161 native_flush_tlb_others(cpus, info); 162 } 163 164 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus, 165 const struct flush_tlb_info *info) 166 { 167 int nr_bank = 0, max_gvas, gva_n; 168 struct hv_tlb_flush_ex **flush_pcpu; 169 struct hv_tlb_flush_ex *flush; 170 u64 status; 171 172 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) 173 return U64_MAX; 174 175 flush_pcpu = (struct hv_tlb_flush_ex **) 176 this_cpu_ptr(hyperv_pcpu_input_arg); 177 178 flush = *flush_pcpu; 179 180 if (info->mm) { 181 /* 182 * AddressSpace argument must match the CR3 with PCID bits 183 * stripped out. 184 */ 185 flush->address_space = virt_to_phys(info->mm->pgd); 186 flush->address_space &= CR3_ADDR_MASK; 187 flush->flags = 0; 188 } else { 189 flush->address_space = 0; 190 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES; 191 } 192 193 flush->hv_vp_set.valid_bank_mask = 0; 194 195 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K; 196 nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus); 197 if (nr_bank < 0) 198 return U64_MAX; 199 200 /* 201 * We can flush not more than max_gvas with one hypercall. Flush the 202 * whole address space if we were asked to do more. 203 */ 204 max_gvas = 205 (PAGE_SIZE - sizeof(*flush) - nr_bank * 206 sizeof(flush->hv_vp_set.bank_contents[0])) / 207 sizeof(flush->gva_list[0]); 208 209 if (info->end == TLB_FLUSH_ALL) { 210 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY; 211 status = hv_do_rep_hypercall( 212 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 213 0, nr_bank, flush, NULL); 214 } else if (info->end && 215 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) { 216 status = hv_do_rep_hypercall( 217 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX, 218 0, nr_bank, flush, NULL); 219 } else { 220 gva_n = fill_gva_list(flush->gva_list, nr_bank, 221 info->start, info->end); 222 status = hv_do_rep_hypercall( 223 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX, 224 gva_n, nr_bank, flush, NULL); 225 } 226 227 return status; 228 } 229 230 void hyperv_setup_mmu_ops(void) 231 { 232 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)) 233 return; 234 235 pr_info("Using hypercall for remote TLB flush\n"); 236 pv_ops.mmu.flush_tlb_others = hyperv_flush_tlb_others; 237 pv_ops.mmu.tlb_remove_table = tlb_remove_table; 238 } 239