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aa04b4cc PM |
1 | /* |
2 | * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License, version 2, as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
441c19c8 | 9 | #include <linux/cpu.h> |
aa04b4cc PM |
10 | #include <linux/kvm_host.h> |
11 | #include <linux/preempt.h> | |
66b15db6 | 12 | #include <linux/export.h> |
aa04b4cc PM |
13 | #include <linux/sched.h> |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/bootmem.h> | |
16 | #include <linux/init.h> | |
fa61a4e3 AK |
17 | #include <linux/memblock.h> |
18 | #include <linux/sizes.h> | |
aa04b4cc PM |
19 | |
20 | #include <asm/cputable.h> | |
21 | #include <asm/kvm_ppc.h> | |
22 | #include <asm/kvm_book3s.h> | |
23 | ||
fa61a4e3 | 24 | #include "book3s_hv_cma.h" |
fa61a4e3 AK |
25 | /* |
26 | * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206) | |
27 | * should be power of 2. | |
28 | */ | |
29 | #define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */ | |
30 | /* | |
31 | * By default we reserve 5% of memory for hash pagetable allocation. | |
32 | */ | |
33 | static unsigned long kvm_cma_resv_ratio = 5; | |
aa04b4cc | 34 | /* |
6c45b810 | 35 | * We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area. |
aa04b4cc PM |
36 | * Each RMA has to be physically contiguous and of a size that the |
37 | * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB, | |
38 | * and other larger sizes. Since we are unlikely to be allocate that | |
39 | * much physically contiguous memory after the system is up and running, | |
6c45b810 AK |
40 | * we preallocate a set of RMAs in early boot using CMA. |
41 | * should be power of 2. | |
aa04b4cc | 42 | */ |
6c45b810 AK |
43 | unsigned long kvm_rma_pages = (1 << 27) >> PAGE_SHIFT; /* 128MB */ |
44 | EXPORT_SYMBOL_GPL(kvm_rma_pages); | |
aa04b4cc | 45 | |
aa04b4cc | 46 | /* Work out RMLS (real mode limit selector) field value for a given RMA size. |
9e368f29 | 47 | Assumes POWER7 or PPC970. */ |
aa04b4cc PM |
48 | static inline int lpcr_rmls(unsigned long rma_size) |
49 | { | |
50 | switch (rma_size) { | |
51 | case 32ul << 20: /* 32 MB */ | |
9e368f29 PM |
52 | if (cpu_has_feature(CPU_FTR_ARCH_206)) |
53 | return 8; /* only supported on POWER7 */ | |
54 | return -1; | |
aa04b4cc PM |
55 | case 64ul << 20: /* 64 MB */ |
56 | return 3; | |
57 | case 128ul << 20: /* 128 MB */ | |
58 | return 7; | |
59 | case 256ul << 20: /* 256 MB */ | |
60 | return 4; | |
61 | case 1ul << 30: /* 1 GB */ | |
62 | return 2; | |
63 | case 16ul << 30: /* 16 GB */ | |
64 | return 1; | |
65 | case 256ul << 30: /* 256 GB */ | |
66 | return 0; | |
67 | default: | |
68 | return -1; | |
69 | } | |
70 | } | |
71 | ||
b4e70611 AG |
72 | static int __init early_parse_rma_size(char *p) |
73 | { | |
6c45b810 | 74 | unsigned long kvm_rma_size; |
b4e70611 | 75 | |
6c45b810 AK |
76 | pr_debug("%s(%s)\n", __func__, p); |
77 | if (!p) | |
78 | return -EINVAL; | |
b4e70611 | 79 | kvm_rma_size = memparse(p, &p); |
6c45b810 AK |
80 | /* |
81 | * Check that the requested size is one supported in hardware | |
82 | */ | |
83 | if (lpcr_rmls(kvm_rma_size) < 0) { | |
84 | pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size); | |
85 | return -EINVAL; | |
86 | } | |
87 | kvm_rma_pages = kvm_rma_size >> PAGE_SHIFT; | |
b4e70611 AG |
88 | return 0; |
89 | } | |
90 | early_param("kvm_rma_size", early_parse_rma_size); | |
91 | ||
6c45b810 | 92 | struct kvm_rma_info *kvm_alloc_rma() |
b4e70611 | 93 | { |
6c45b810 AK |
94 | struct page *page; |
95 | struct kvm_rma_info *ri; | |
96 | ||
97 | ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); | |
98 | if (!ri) | |
99 | return NULL; | |
100 | page = kvm_alloc_cma(kvm_rma_pages, kvm_rma_pages); | |
101 | if (!page) | |
102 | goto err_out; | |
103 | atomic_set(&ri->use_count, 1); | |
104 | ri->base_pfn = page_to_pfn(page); | |
105 | return ri; | |
106 | err_out: | |
107 | kfree(ri); | |
108 | return NULL; | |
b4e70611 AG |
109 | } |
110 | EXPORT_SYMBOL_GPL(kvm_alloc_rma); | |
111 | ||
6c45b810 | 112 | void kvm_release_rma(struct kvm_rma_info *ri) |
b4e70611 | 113 | { |
6c45b810 AK |
114 | if (atomic_dec_and_test(&ri->use_count)) { |
115 | kvm_release_cma(pfn_to_page(ri->base_pfn), kvm_rma_pages); | |
116 | kfree(ri); | |
117 | } | |
b4e70611 AG |
118 | } |
119 | EXPORT_SYMBOL_GPL(kvm_release_rma); | |
120 | ||
fa61a4e3 | 121 | static int __init early_parse_kvm_cma_resv(char *p) |
d2a1b483 | 122 | { |
fa61a4e3 | 123 | pr_debug("%s(%s)\n", __func__, p); |
d2a1b483 | 124 | if (!p) |
fa61a4e3 AK |
125 | return -EINVAL; |
126 | return kstrtoul(p, 0, &kvm_cma_resv_ratio); | |
d2a1b483 | 127 | } |
fa61a4e3 | 128 | early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv); |
d2a1b483 | 129 | |
fa61a4e3 | 130 | struct page *kvm_alloc_hpt(unsigned long nr_pages) |
d2a1b483 | 131 | { |
fa61a4e3 AK |
132 | unsigned long align_pages = HPT_ALIGN_PAGES; |
133 | ||
134 | /* Old CPUs require HPT aligned on a multiple of its size */ | |
135 | if (!cpu_has_feature(CPU_FTR_ARCH_206)) | |
136 | align_pages = nr_pages; | |
137 | return kvm_alloc_cma(nr_pages, align_pages); | |
d2a1b483 AG |
138 | } |
139 | EXPORT_SYMBOL_GPL(kvm_alloc_hpt); | |
140 | ||
fa61a4e3 | 141 | void kvm_release_hpt(struct page *page, unsigned long nr_pages) |
d2a1b483 | 142 | { |
fa61a4e3 | 143 | kvm_release_cma(page, nr_pages); |
d2a1b483 AG |
144 | } |
145 | EXPORT_SYMBOL_GPL(kvm_release_hpt); | |
146 | ||
fa61a4e3 AK |
147 | /** |
148 | * kvm_cma_reserve() - reserve area for kvm hash pagetable | |
149 | * | |
150 | * This function reserves memory from early allocator. It should be | |
151 | * called by arch specific code once the early allocator (memblock or bootmem) | |
152 | * has been activated and all other subsystems have already allocated/reserved | |
153 | * memory. | |
154 | */ | |
155 | void __init kvm_cma_reserve(void) | |
156 | { | |
157 | unsigned long align_size; | |
158 | struct memblock_region *reg; | |
159 | phys_addr_t selected_size = 0; | |
160 | /* | |
161 | * We cannot use memblock_phys_mem_size() here, because | |
162 | * memblock_analyze() has not been called yet. | |
163 | */ | |
164 | for_each_memblock(memory, reg) | |
165 | selected_size += memblock_region_memory_end_pfn(reg) - | |
166 | memblock_region_memory_base_pfn(reg); | |
167 | ||
168 | selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT; | |
169 | if (selected_size) { | |
170 | pr_debug("%s: reserving %ld MiB for global area\n", __func__, | |
171 | (unsigned long)selected_size / SZ_1M); | |
172 | /* | |
173 | * Old CPUs require HPT aligned on a multiple of its size. So for them | |
174 | * make the alignment as max size we could request. | |
175 | */ | |
176 | if (!cpu_has_feature(CPU_FTR_ARCH_206)) | |
177 | align_size = __rounddown_pow_of_two(selected_size); | |
178 | else | |
179 | align_size = HPT_ALIGN_PAGES << PAGE_SHIFT; | |
6c45b810 AK |
180 | |
181 | align_size = max(kvm_rma_pages << PAGE_SHIFT, align_size); | |
fa61a4e3 AK |
182 | kvm_cma_declare_contiguous(selected_size, align_size); |
183 | } | |
184 | } | |
441c19c8 ME |
185 | |
186 | /* | |
187 | * When running HV mode KVM we need to block certain operations while KVM VMs | |
188 | * exist in the system. We use a counter of VMs to track this. | |
189 | * | |
190 | * One of the operations we need to block is onlining of secondaries, so we | |
191 | * protect hv_vm_count with get/put_online_cpus(). | |
192 | */ | |
193 | static atomic_t hv_vm_count; | |
194 | ||
195 | void kvm_hv_vm_activated(void) | |
196 | { | |
197 | get_online_cpus(); | |
198 | atomic_inc(&hv_vm_count); | |
199 | put_online_cpus(); | |
200 | } | |
201 | EXPORT_SYMBOL_GPL(kvm_hv_vm_activated); | |
202 | ||
203 | void kvm_hv_vm_deactivated(void) | |
204 | { | |
205 | get_online_cpus(); | |
206 | atomic_dec(&hv_vm_count); | |
207 | put_online_cpus(); | |
208 | } | |
209 | EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated); | |
210 | ||
211 | bool kvm_hv_mode_active(void) | |
212 | { | |
213 | return atomic_read(&hv_vm_count) != 0; | |
214 | } |