xref: /linux/arch/x86/xen/mmu.c (revision 5bdd5fbb35ab0fe21bf2263106f51c5bee466a07)
1 #include <linux/pfn.h>
2 #include <asm/xen/page.h>
3 #include <asm/xen/hypercall.h>
4 #include <xen/interface/memory.h>
5 
6 #include "multicalls.h"
7 #include "mmu.h"
8 
9 /*
10  * Protects atomic reservation decrease/increase against concurrent increases.
11  * Also protects non-atomic updates of current_pages and balloon lists.
12  */
13 DEFINE_SPINLOCK(xen_reservation_lock);
14 
15 unsigned long arbitrary_virt_to_mfn(void *vaddr)
16 {
17 	xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
18 
19 	return PFN_DOWN(maddr.maddr);
20 }
21 
22 xmaddr_t arbitrary_virt_to_machine(void *vaddr)
23 {
24 	unsigned long address = (unsigned long)vaddr;
25 	unsigned int level;
26 	pte_t *pte;
27 	unsigned offset;
28 
29 	/*
30 	 * if the PFN is in the linear mapped vaddr range, we can just use
31 	 * the (quick) virt_to_machine() p2m lookup
32 	 */
33 	if (virt_addr_valid(vaddr))
34 		return virt_to_machine(vaddr);
35 
36 	/* otherwise we have to do a (slower) full page-table walk */
37 
38 	pte = lookup_address(address, &level);
39 	BUG_ON(pte == NULL);
40 	offset = address & ~PAGE_MASK;
41 	return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
42 }
43 EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine);
44 
45 static noinline void xen_flush_tlb_all(void)
46 {
47 	struct mmuext_op *op;
48 	struct multicall_space mcs;
49 
50 	preempt_disable();
51 
52 	mcs = xen_mc_entry(sizeof(*op));
53 
54 	op = mcs.args;
55 	op->cmd = MMUEXT_TLB_FLUSH_ALL;
56 	MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
57 
58 	xen_mc_issue(PARAVIRT_LAZY_MMU);
59 
60 	preempt_enable();
61 }
62 
63 #define REMAP_BATCH_SIZE 16
64 
65 struct remap_data {
66 	xen_pfn_t *pfn;
67 	bool contiguous;
68 	bool no_translate;
69 	pgprot_t prot;
70 	struct mmu_update *mmu_update;
71 };
72 
73 static int remap_area_pfn_pte_fn(pte_t *ptep, pgtable_t token,
74 				 unsigned long addr, void *data)
75 {
76 	struct remap_data *rmd = data;
77 	pte_t pte = pte_mkspecial(mfn_pte(*rmd->pfn, rmd->prot));
78 
79 	/*
80 	 * If we have a contiguous range, just update the pfn itself,
81 	 * else update pointer to be "next pfn".
82 	 */
83 	if (rmd->contiguous)
84 		(*rmd->pfn)++;
85 	else
86 		rmd->pfn++;
87 
88 	rmd->mmu_update->ptr = virt_to_machine(ptep).maddr;
89 	rmd->mmu_update->ptr |= rmd->no_translate ?
90 		MMU_PT_UPDATE_NO_TRANSLATE :
91 		MMU_NORMAL_PT_UPDATE;
92 	rmd->mmu_update->val = pte_val_ma(pte);
93 	rmd->mmu_update++;
94 
95 	return 0;
96 }
97 
98 static int do_remap_pfn(struct vm_area_struct *vma,
99 			unsigned long addr,
100 			xen_pfn_t *pfn, int nr,
101 			int *err_ptr, pgprot_t prot,
102 			unsigned int domid,
103 			bool no_translate,
104 			struct page **pages)
105 {
106 	int err = 0;
107 	struct remap_data rmd;
108 	struct mmu_update mmu_update[REMAP_BATCH_SIZE];
109 	unsigned long range;
110 	int mapped = 0;
111 
112 	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
113 
114 	rmd.pfn = pfn;
115 	rmd.prot = prot;
116 	/*
117 	 * We use the err_ptr to indicate if there we are doing a contiguous
118 	 * mapping or a discontigious mapping.
119 	 */
120 	rmd.contiguous = !err_ptr;
121 	rmd.no_translate = no_translate;
122 
123 	while (nr) {
124 		int index = 0;
125 		int done = 0;
126 		int batch = min(REMAP_BATCH_SIZE, nr);
127 		int batch_left = batch;
128 		range = (unsigned long)batch << PAGE_SHIFT;
129 
130 		rmd.mmu_update = mmu_update;
131 		err = apply_to_page_range(vma->vm_mm, addr, range,
132 					  remap_area_pfn_pte_fn, &rmd);
133 		if (err)
134 			goto out;
135 
136 		/* We record the error for each page that gives an error, but
137 		 * continue mapping until the whole set is done */
138 		do {
139 			int i;
140 
141 			err = HYPERVISOR_mmu_update(&mmu_update[index],
142 						    batch_left, &done, domid);
143 
144 			/*
145 			 * @err_ptr may be the same buffer as @gfn, so
146 			 * only clear it after each chunk of @gfn is
147 			 * used.
148 			 */
149 			if (err_ptr) {
150 				for (i = index; i < index + done; i++)
151 					err_ptr[i] = 0;
152 			}
153 			if (err < 0) {
154 				if (!err_ptr)
155 					goto out;
156 				err_ptr[i] = err;
157 				done++; /* Skip failed frame. */
158 			} else
159 				mapped += done;
160 			batch_left -= done;
161 			index += done;
162 		} while (batch_left);
163 
164 		nr -= batch;
165 		addr += range;
166 		if (err_ptr)
167 			err_ptr += batch;
168 		cond_resched();
169 	}
170 out:
171 
172 	xen_flush_tlb_all();
173 
174 	return err < 0 ? err : mapped;
175 }
176 
177 int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
178 			       unsigned long addr,
179 			       xen_pfn_t gfn, int nr,
180 			       pgprot_t prot, unsigned domid,
181 			       struct page **pages)
182 {
183 	if (xen_feature(XENFEAT_auto_translated_physmap))
184 		return -EOPNOTSUPP;
185 
186 	return do_remap_pfn(vma, addr, &gfn, nr, NULL, prot, domid, false,
187 			    pages);
188 }
189 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
190 
191 int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
192 			       unsigned long addr,
193 			       xen_pfn_t *gfn, int nr,
194 			       int *err_ptr, pgprot_t prot,
195 			       unsigned domid, struct page **pages)
196 {
197 	if (xen_feature(XENFEAT_auto_translated_physmap))
198 		return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
199 						 prot, domid, pages);
200 
201 	/* We BUG_ON because it's a programmer error to pass a NULL err_ptr,
202 	 * and the consequences later is quite hard to detect what the actual
203 	 * cause of "wrong memory was mapped in".
204 	 */
205 	BUG_ON(err_ptr == NULL);
206 	return do_remap_pfn(vma, addr, gfn, nr, err_ptr, prot, domid,
207 			    false, pages);
208 }
209 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
210 
211 int xen_remap_domain_mfn_array(struct vm_area_struct *vma,
212 			       unsigned long addr,
213 			       xen_pfn_t *mfn, int nr,
214 			       int *err_ptr, pgprot_t prot,
215 			       unsigned int domid, struct page **pages)
216 {
217 	if (xen_feature(XENFEAT_auto_translated_physmap))
218 		return -EOPNOTSUPP;
219 
220 	return do_remap_pfn(vma, addr, mfn, nr, err_ptr, prot, domid,
221 			    true, pages);
222 }
223 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_array);
224 
225 /* Returns: 0 success */
226 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
227 			       int nr, struct page **pages)
228 {
229 	if (xen_feature(XENFEAT_auto_translated_physmap))
230 		return xen_xlate_unmap_gfn_range(vma, nr, pages);
231 
232 	if (!pages)
233 		return 0;
234 
235 	return -EINVAL;
236 }
237 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
238