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 bool cpu_is_lazy(int cpu)
56 {
57 return per_cpu(cpu_tlbstate_shared.is_lazy, cpu);
58 }
59
60 static void hyperv_flush_tlb_multi(const struct cpumask *cpus,
61 const struct flush_tlb_info *info)
62 {
63 int cpu, vcpu, gva_n, max_gvas;
64 struct hv_tlb_flush *flush;
65 u64 status;
66 unsigned long flags;
67 bool do_lazy = !info->freed_tables;
68
69 trace_hyperv_mmu_flush_tlb_multi(cpus, info);
70
71 if (!hv_hypercall_pg)
72 goto do_native;
73
74 local_irq_save(flags);
75
76 flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
77
78 if (unlikely(!flush)) {
79 local_irq_restore(flags);
80 goto do_native;
81 }
82
83 if (info->mm) {
84 /*
85 * AddressSpace argument must match the CR3 with PCID bits
86 * stripped out.
87 */
88 flush->address_space = virt_to_phys(info->mm->pgd);
89 flush->address_space &= CR3_ADDR_MASK;
90 flush->flags = 0;
91 } else {
92 flush->address_space = 0;
93 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
94 }
95
96 flush->processor_mask = 0;
97 if (cpumask_equal(cpus, cpu_present_mask)) {
98 flush->flags |= HV_FLUSH_ALL_PROCESSORS;
99 } else {
100 /*
101 * From the supplied CPU set we need to figure out if we can get
102 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}
103 * hypercalls. This is possible when the highest VP number in
104 * the set is < 64. As VP numbers are usually in ascending order
105 * and match Linux CPU ids, here is an optimization: we check
106 * the VP number for the highest bit in the supplied set first
107 * so we can quickly find out if using *_EX hypercalls is a
108 * must. We will also check all VP numbers when walking the
109 * supplied CPU set to remain correct in all cases.
110 */
111 cpu = cpumask_last(cpus);
112
113 if (cpu < nr_cpumask_bits && hv_cpu_number_to_vp_number(cpu) >= 64)
114 goto do_ex_hypercall;
115
116 for_each_cpu(cpu, cpus) {
117 if (do_lazy && cpu_is_lazy(cpu))
118 continue;
119 vcpu = hv_cpu_number_to_vp_number(cpu);
120 if (vcpu == VP_INVAL) {
121 local_irq_restore(flags);
122 goto do_native;
123 }
124
125 if (vcpu >= 64)
126 goto do_ex_hypercall;
127
128 __set_bit(vcpu, (unsigned long *)
129 &flush->processor_mask);
130 }
131
132 /* nothing to flush if 'processor_mask' ends up being empty */
133 if (!flush->processor_mask) {
134 local_irq_restore(flags);
135 return;
136 }
137 }
138
139 /*
140 * We can flush not more than max_gvas with one hypercall. Flush the
141 * whole address space if we were asked to do more.
142 */
143 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
144
145 if (info->end == TLB_FLUSH_ALL) {
146 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
147 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
148 flush, NULL);
149 } else if (info->end &&
150 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
151 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
152 flush, NULL);
153 } else {
154 gva_n = fill_gva_list(flush->gva_list, 0,
155 info->start, info->end);
156 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
157 gva_n, 0, flush, NULL);
158 }
159 goto check_status;
160
161 do_ex_hypercall:
162 status = hyperv_flush_tlb_others_ex(cpus, info);
163
164 check_status:
165 local_irq_restore(flags);
166
167 if (hv_result_success(status))
168 return;
169 do_native:
170 native_flush_tlb_multi(cpus, info);
171 }
172
173 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
174 const struct flush_tlb_info *info)
175 {
176 int nr_bank = 0, max_gvas, gva_n;
177 struct hv_tlb_flush_ex *flush;
178 u64 status;
179
180 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
181 return HV_STATUS_INVALID_PARAMETER;
182
183 flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
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_skip(&flush->hv_vp_set, cpus,
202 info->freed_tables ? NULL : cpu_is_lazy);
203 if (nr_bank < 0)
204 return HV_STATUS_INVALID_PARAMETER;
205
206 /*
207 * We can flush not more than max_gvas with one hypercall. Flush the
208 * whole address space if we were asked to do more.
209 */
210 max_gvas =
211 (PAGE_SIZE - sizeof(*flush) - nr_bank *
212 sizeof(flush->hv_vp_set.bank_contents[0])) /
213 sizeof(flush->gva_list[0]);
214
215 if (info->end == TLB_FLUSH_ALL) {
216 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
217 status = hv_do_rep_hypercall(
218 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
219 0, nr_bank, flush, NULL);
220 } else if (info->end &&
221 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
222 status = hv_do_rep_hypercall(
223 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
224 0, nr_bank, flush, NULL);
225 } else {
226 gva_n = fill_gva_list(flush->gva_list, nr_bank,
227 info->start, info->end);
228 status = hv_do_rep_hypercall(
229 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
230 gva_n, nr_bank, flush, NULL);
231 }
232
233 return status;
234 }
235
236 void hyperv_setup_mmu_ops(void)
237 {
238 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
239 return;
240
241 pr_info("Using hypercall for remote TLB flush\n");
242 pv_ops.mmu.flush_tlb_multi = hyperv_flush_tlb_multi;
243 pv_ops.mmu.tlb_remove_table = tlb_remove_table;
244 }
245
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