tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2012,2013 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#ifndef __ARM64_KVM_MMU_H__
19#define __ARM64_KVM_MMU_H__
20
21#include <asm/page.h>
22#include <asm/memory.h>
23#include <asm/cpufeature.h>
24
25/*
26 * As ARMv8.0 only has the TTBR0_EL2 register, we cannot express
27 * "negative" addresses. This makes it impossible to directly share
28 * mappings with the kernel.
29 *
30 * Instead, give the HYP mode its own VA region at a fixed offset from
31 * the kernel by just masking the top bits (which are all ones for a
32 * kernel address).
33 *
34 * ARMv8.1 (using VHE) does have a TTBR1_EL2, and doesn't use these
35 * macros (the entire kernel runs at EL2).
36 */
37#define HYP_PAGE_OFFSET_SHIFT VA_BITS
38#define HYP_PAGE_OFFSET_MASK ((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
39#define HYP_PAGE_OFFSET (PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)
40
41/*
42 * Our virtual mapping for the idmap-ed MMU-enable code. Must be
43 * shared across all the page-tables. Conveniently, we use the last
44 * possible page, where no kernel mapping will ever exist.
45 */
46#define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK)
47
48#ifdef __ASSEMBLY__
49
50#include <asm/alternative.h>
51#include <asm/cpufeature.h>
52
53/*
54 * Convert a kernel VA into a HYP VA.
55 * reg: VA to be converted.
56 */
57.macro kern_hyp_va reg
58alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
59 and \reg, \reg, #HYP_PAGE_OFFSET_MASK
60alternative_else
61 nop
62alternative_endif
63.endm
64
65#else
66
67#include <asm/pgalloc.h>
68#include <asm/cachetype.h>
69#include <asm/cacheflush.h>
70#include <asm/mmu_context.h>
71#include <asm/pgtable.h>
72
73#define KERN_TO_HYP(kva) ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)
74
75/*
76 * We currently only support a 40bit IPA.
77 */
78#define KVM_PHYS_SHIFT (40)
79#define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT)
80#define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL)
81
82#include <asm/stage2_pgtable.h>
83
84int create_hyp_mappings(void *from, void *to);
85int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
86void free_boot_hyp_pgd(void);
87void free_hyp_pgds(void);
88
89void stage2_unmap_vm(struct kvm *kvm);
90int kvm_alloc_stage2_pgd(struct kvm *kvm);
91void kvm_free_stage2_pgd(struct kvm *kvm);
92int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
93 phys_addr_t pa, unsigned long size, bool writable);
94
95int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
96
97void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
98
99phys_addr_t kvm_mmu_get_httbr(void);
100phys_addr_t kvm_mmu_get_boot_httbr(void);
101phys_addr_t kvm_get_idmap_vector(void);
102phys_addr_t kvm_get_idmap_start(void);
103int kvm_mmu_init(void);
104void kvm_clear_hyp_idmap(void);
105
106#define kvm_set_pte(ptep, pte) set_pte(ptep, pte)
107#define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd)
108
109static inline void kvm_clean_pgd(pgd_t *pgd) {}
110static inline void kvm_clean_pmd(pmd_t *pmd) {}
111static inline void kvm_clean_pmd_entry(pmd_t *pmd) {}
112static inline void kvm_clean_pte(pte_t *pte) {}
113static inline void kvm_clean_pte_entry(pte_t *pte) {}
114
115static inline pte_t kvm_s2pte_mkwrite(pte_t pte)
116{
117 pte_val(pte) |= PTE_S2_RDWR;
118 return pte;
119}
120
121static inline pmd_t kvm_s2pmd_mkwrite(pmd_t pmd)
122{
123 pmd_val(pmd) |= PMD_S2_RDWR;
124 return pmd;
125}
126
127static inline void kvm_set_s2pte_readonly(pte_t *pte)
128{
129 pteval_t pteval;
130 unsigned long tmp;
131
132 asm volatile("// kvm_set_s2pte_readonly\n"
133 " prfm pstl1strm, %2\n"
134 "1: ldxr %0, %2\n"
135 " and %0, %0, %3 // clear PTE_S2_RDWR\n"
136 " orr %0, %0, %4 // set PTE_S2_RDONLY\n"
137 " stxr %w1, %0, %2\n"
138 " cbnz %w1, 1b\n"
139 : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*pte))
140 : "L" (~PTE_S2_RDWR), "L" (PTE_S2_RDONLY));
141}
142
143static inline bool kvm_s2pte_readonly(pte_t *pte)
144{
145 return (pte_val(*pte) & PTE_S2_RDWR) == PTE_S2_RDONLY;
146}
147
148static inline void kvm_set_s2pmd_readonly(pmd_t *pmd)
149{
150 kvm_set_s2pte_readonly((pte_t *)pmd);
151}
152
153static inline bool kvm_s2pmd_readonly(pmd_t *pmd)
154{
155 return kvm_s2pte_readonly((pte_t *)pmd);
156}
157
158static inline bool kvm_page_empty(void *ptr)
159{
160 struct page *ptr_page = virt_to_page(ptr);
161 return page_count(ptr_page) == 1;
162}
163
164#define hyp_pte_table_empty(ptep) kvm_page_empty(ptep)
165
166#ifdef __PAGETABLE_PMD_FOLDED
167#define hyp_pmd_table_empty(pmdp) (0)
168#else
169#define hyp_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
170#endif
171
172#ifdef __PAGETABLE_PUD_FOLDED
173#define hyp_pud_table_empty(pudp) (0)
174#else
175#define hyp_pud_table_empty(pudp) kvm_page_empty(pudp)
176#endif
177
178struct kvm;
179
180#define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l))
181
182static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
183{
184 return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
185}
186
187static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu,
188 kvm_pfn_t pfn,
189 unsigned long size,
190 bool ipa_uncached)
191{
192 void *va = page_address(pfn_to_page(pfn));
193
194 if (!vcpu_has_cache_enabled(vcpu) || ipa_uncached)
195 kvm_flush_dcache_to_poc(va, size);
196
197 if (!icache_is_aliasing()) { /* PIPT */
198 flush_icache_range((unsigned long)va,
199 (unsigned long)va + size);
200 } else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */
201 /* any kind of VIPT cache */
202 __flush_icache_all();
203 }
204}
205
206static inline void __kvm_flush_dcache_pte(pte_t pte)
207{
208 struct page *page = pte_page(pte);
209 kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE);
210}
211
212static inline void __kvm_flush_dcache_pmd(pmd_t pmd)
213{
214 struct page *page = pmd_page(pmd);
215 kvm_flush_dcache_to_poc(page_address(page), PMD_SIZE);
216}
217
218static inline void __kvm_flush_dcache_pud(pud_t pud)
219{
220 struct page *page = pud_page(pud);
221 kvm_flush_dcache_to_poc(page_address(page), PUD_SIZE);
222}
223
224#define kvm_virt_to_phys(x) __virt_to_phys((unsigned long)(x))
225
226void kvm_set_way_flush(struct kvm_vcpu *vcpu);
227void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
228
229static inline bool __kvm_cpu_uses_extended_idmap(void)
230{
231 return __cpu_uses_extended_idmap();
232}
233
234static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd,
235 pgd_t *hyp_pgd,
236 pgd_t *merged_hyp_pgd,
237 unsigned long hyp_idmap_start)
238{
239 int idmap_idx;
240
241 /*
242 * Use the first entry to access the HYP mappings. It is
243 * guaranteed to be free, otherwise we wouldn't use an
244 * extended idmap.
245 */
246 VM_BUG_ON(pgd_val(merged_hyp_pgd[0]));
247 merged_hyp_pgd[0] = __pgd(__pa(hyp_pgd) | PMD_TYPE_TABLE);
248
249 /*
250 * Create another extended level entry that points to the boot HYP map,
251 * which contains an ID mapping of the HYP init code. We essentially
252 * merge the boot and runtime HYP maps by doing so, but they don't
253 * overlap anyway, so this is fine.
254 */
255 idmap_idx = hyp_idmap_start >> VA_BITS;
256 VM_BUG_ON(pgd_val(merged_hyp_pgd[idmap_idx]));
257 merged_hyp_pgd[idmap_idx] = __pgd(__pa(boot_hyp_pgd) | PMD_TYPE_TABLE);
258}
259
260static inline unsigned int kvm_get_vmid_bits(void)
261{
262 int reg = read_system_reg(SYS_ID_AA64MMFR1_EL1);
263
264 return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8;
265}
266
267#endif /* __ASSEMBLY__ */
268#endif /* __ARM64_KVM_MMU_H__ */