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 */
fill_gva_list(u64 gva_list[],int offset,unsigned long start,unsigned long end)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
hyperv_flush_tlb_multi(const struct cpumask * cpus,const struct flush_tlb_info * info)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
hyperv_flush_tlb_others_ex(const struct cpumask * cpus,const struct flush_tlb_info * info)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
hyperv_setup_mmu_ops(void)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