1 #define pr_fmt(fmt) "Hyper-V: " fmt
2
3 #include <linux/log2.h>
4 #include <linux/slab.h>
5 #include <linux/types.h>
6
7 #include <asm/fpu/api.h>
8 #include <asm/mshyperv.h>
9 #include <asm/msr.h>
10 #include <asm/tlbflush.h>
11 #include <asm/tlb.h>
12
13 #define CREATE_TRACE_POINTS
14 #include <asm/trace/hyperv.h>
15
16 /* Each gva in gva_list encodes up to 4096 pages to flush */
17 #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)
18
19 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
20 const struct flush_tlb_info *info);
21
22 /*
23 * Fills in gva_list starting from offset. Returns the number of items added.
24 */
fill_gva_list(u64 gva_list[],int offset,unsigned long start,unsigned long end)25 static inline int fill_gva_list(u64 gva_list[], int offset,
26 unsigned long start, unsigned long end)
27 {
28 int gva_n = offset;
29 unsigned long cur = start, diff;
30
31 do {
32 diff = end > cur ? end - cur : 0;
33
34 gva_list[gva_n] = cur & PAGE_MASK;
35 /*
36 * Lower 12 bits encode the number of additional
37 * pages to flush (in addition to the 'cur' page).
38 */
39 if (diff >= HV_TLB_FLUSH_UNIT) {
40 gva_list[gva_n] |= ~PAGE_MASK;
41 cur += HV_TLB_FLUSH_UNIT;
42 } else if (diff) {
43 gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;
44 cur = end;
45 }
46
47 gva_n++;
48
49 } while (cur < end);
50
51 return gva_n - offset;
52 }
53
cpu_is_lazy(int cpu)54 static bool cpu_is_lazy(int cpu)
55 {
56 return per_cpu(cpu_tlbstate_shared.is_lazy, cpu);
57 }
58
hyperv_flush_tlb_multi(const struct cpumask * cpus,const struct flush_tlb_info * info)59 static void hyperv_flush_tlb_multi(const struct cpumask *cpus,
60 const struct flush_tlb_info *info)
61 {
62 int cpu, vcpu, gva_n, max_gvas;
63 struct hv_tlb_flush *flush;
64 u64 status;
65 unsigned long flags;
66 bool do_lazy = !info->freed_tables;
67
68 trace_hyperv_mmu_flush_tlb_multi(cpus, info);
69
70 if (!hv_hypercall_pg)
71 goto do_native;
72
73 local_irq_save(flags);
74
75 flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
76
77 if (unlikely(!flush)) {
78 local_irq_restore(flags);
79 goto do_native;
80 }
81
82 if (info->mm) {
83 /*
84 * AddressSpace argument must match the CR3 with PCID bits
85 * stripped out.
86 */
87 flush->address_space = virt_to_phys(info->mm->pgd);
88 flush->address_space &= CR3_ADDR_MASK;
89 flush->flags = 0;
90 } else {
91 flush->address_space = 0;
92 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
93 }
94
95 flush->processor_mask = 0;
96 if (cpumask_equal(cpus, cpu_present_mask)) {
97 flush->flags |= HV_FLUSH_ALL_PROCESSORS;
98 } else {
99 /*
100 * From the supplied CPU set we need to figure out if we can get
101 * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}
102 * hypercalls. This is possible when the highest VP number in
103 * the set is < 64. As VP numbers are usually in ascending order
104 * and match Linux CPU ids, here is an optimization: we check
105 * the VP number for the highest bit in the supplied set first
106 * so we can quickly find out if using *_EX hypercalls is a
107 * must. We will also check all VP numbers when walking the
108 * supplied CPU set to remain correct in all cases.
109 */
110 cpu = cpumask_last(cpus);
111
112 if (cpu < nr_cpumask_bits && hv_cpu_number_to_vp_number(cpu) >= 64)
113 goto do_ex_hypercall;
114
115 for_each_cpu(cpu, cpus) {
116 if (do_lazy && cpu_is_lazy(cpu))
117 continue;
118 vcpu = hv_cpu_number_to_vp_number(cpu);
119 if (vcpu == VP_INVAL) {
120 local_irq_restore(flags);
121 goto do_native;
122 }
123
124 if (vcpu >= 64)
125 goto do_ex_hypercall;
126
127 __set_bit(vcpu, (unsigned long *)
128 &flush->processor_mask);
129 }
130
131 /* nothing to flush if 'processor_mask' ends up being empty */
132 if (!flush->processor_mask) {
133 local_irq_restore(flags);
134 return;
135 }
136 }
137
138 /*
139 * We can flush not more than max_gvas with one hypercall. Flush the
140 * whole address space if we were asked to do more.
141 */
142 max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
143
144 if (info->end == TLB_FLUSH_ALL) {
145 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
146 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
147 flush, NULL);
148 } else if (info->end &&
149 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
150 status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
151 flush, NULL);
152 } else {
153 gva_n = fill_gva_list(flush->gva_list, 0,
154 info->start, info->end);
155 status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
156 gva_n, 0, flush, NULL);
157 }
158 goto check_status;
159
160 do_ex_hypercall:
161 status = hyperv_flush_tlb_others_ex(cpus, info);
162
163 check_status:
164 local_irq_restore(flags);
165
166 if (hv_result_success(status))
167 return;
168 do_native:
169 native_flush_tlb_multi(cpus, info);
170 }
171
hyperv_flush_tlb_others_ex(const struct cpumask * cpus,const struct flush_tlb_info * info)172 static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
173 const struct flush_tlb_info *info)
174 {
175 int nr_bank = 0, max_gvas, gva_n;
176 struct hv_tlb_flush_ex *flush;
177 u64 status;
178
179 if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
180 return HV_STATUS_INVALID_PARAMETER;
181
182 flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
183
184 if (info->mm) {
185 /*
186 * AddressSpace argument must match the CR3 with PCID bits
187 * stripped out.
188 */
189 flush->address_space = virt_to_phys(info->mm->pgd);
190 flush->address_space &= CR3_ADDR_MASK;
191 flush->flags = 0;
192 } else {
193 flush->address_space = 0;
194 flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
195 }
196
197 flush->hv_vp_set.valid_bank_mask = 0;
198
199 flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
200 nr_bank = cpumask_to_vpset_skip(&flush->hv_vp_set, cpus,
201 info->freed_tables ? NULL : cpu_is_lazy);
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 * For these hypercalls, Hyper-V treats the valid_bank_mask field
210 * of flush->hv_vp_set as part of the fixed size input header.
211 * So the variable input header size is equal to nr_bank.
212 */
213 max_gvas =
214 (PAGE_SIZE - sizeof(*flush) - nr_bank *
215 sizeof(flush->hv_vp_set.bank_contents[0])) /
216 sizeof(flush->gva_list[0]);
217
218 if (info->end == TLB_FLUSH_ALL) {
219 flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
220 status = hv_do_rep_hypercall(
221 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
222 0, nr_bank, flush, NULL);
223 } else if (info->end &&
224 ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
225 status = hv_do_rep_hypercall(
226 HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
227 0, nr_bank, flush, NULL);
228 } else {
229 gva_n = fill_gva_list(flush->gva_list, nr_bank,
230 info->start, info->end);
231 status = hv_do_rep_hypercall(
232 HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
233 gva_n, nr_bank, flush, NULL);
234 }
235
236 return status;
237 }
238
hyperv_setup_mmu_ops(void)239 void hyperv_setup_mmu_ops(void)
240 {
241 if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
242 return;
243
244 pr_info("Using hypercall for remote TLB flush\n");
245 pv_ops.mmu.flush_tlb_multi = hyperv_flush_tlb_multi;
246 }
247