xref: /openbmc/linux/arch/powerpc/kvm/book3s_32_mmu.c (revision 85250a24)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright SUSE Linux Products GmbH 2009
5  *
6  * Authors: Alexander Graf <agraf@suse.de>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/string.h>
11 #include <linux/kvm.h>
12 #include <linux/kvm_host.h>
13 #include <linux/highmem.h>
14 
15 #include <asm/kvm_ppc.h>
16 #include <asm/kvm_book3s.h>
17 
18 /* #define DEBUG_MMU */
19 /* #define DEBUG_MMU_PTE */
20 /* #define DEBUG_MMU_PTE_IP 0xfff14c40 */
21 
22 #ifdef DEBUG_MMU
23 #define dprintk(X...) printk(KERN_INFO X)
24 #else
25 #define dprintk(X...) do { } while(0)
26 #endif
27 
28 #ifdef DEBUG_MMU_PTE
29 #define dprintk_pte(X...) printk(KERN_INFO X)
30 #else
31 #define dprintk_pte(X...) do { } while(0)
32 #endif
33 
34 #define PTEG_FLAG_ACCESSED	0x00000100
35 #define PTEG_FLAG_DIRTY		0x00000080
36 #ifndef SID_SHIFT
37 #define SID_SHIFT		28
38 #endif
39 
40 static inline bool check_debug_ip(struct kvm_vcpu *vcpu)
41 {
42 #ifdef DEBUG_MMU_PTE_IP
43 	return vcpu->arch.regs.nip == DEBUG_MMU_PTE_IP;
44 #else
45 	return true;
46 #endif
47 }
48 
49 static inline u32 sr_vsid(u32 sr_raw)
50 {
51 	return sr_raw & 0x0fffffff;
52 }
53 
54 static inline bool sr_valid(u32 sr_raw)
55 {
56 	return (sr_raw & 0x80000000) ? false : true;
57 }
58 
59 static inline bool sr_ks(u32 sr_raw)
60 {
61 	return (sr_raw & 0x40000000) ? true: false;
62 }
63 
64 static inline bool sr_kp(u32 sr_raw)
65 {
66 	return (sr_raw & 0x20000000) ? true: false;
67 }
68 
69 static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
70 					  struct kvmppc_pte *pte, bool data,
71 					  bool iswrite);
72 static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
73 					     u64 *vsid);
74 
75 static u32 find_sr(struct kvm_vcpu *vcpu, gva_t eaddr)
76 {
77 	return kvmppc_get_sr(vcpu, (eaddr >> 28) & 0xf);
78 }
79 
80 static u64 kvmppc_mmu_book3s_32_ea_to_vp(struct kvm_vcpu *vcpu, gva_t eaddr,
81 					 bool data)
82 {
83 	u64 vsid;
84 	struct kvmppc_pte pte;
85 
86 	if (!kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, &pte, data, false))
87 		return pte.vpage;
88 
89 	kvmppc_mmu_book3s_32_esid_to_vsid(vcpu, eaddr >> SID_SHIFT, &vsid);
90 	return (((u64)eaddr >> 12) & 0xffff) | (vsid << 16);
91 }
92 
93 static hva_t kvmppc_mmu_book3s_32_get_pteg(struct kvm_vcpu *vcpu,
94 				      u32 sre, gva_t eaddr,
95 				      bool primary)
96 {
97 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
98 	u32 page, hash, pteg, htabmask;
99 	hva_t r;
100 
101 	page = (eaddr & 0x0FFFFFFF) >> 12;
102 	htabmask = ((vcpu_book3s->sdr1 & 0x1FF) << 16) | 0xFFC0;
103 
104 	hash = ((sr_vsid(sre) ^ page) << 6);
105 	if (!primary)
106 		hash = ~hash;
107 	hash &= htabmask;
108 
109 	pteg = (vcpu_book3s->sdr1 & 0xffff0000) | hash;
110 
111 	dprintk("MMU: pc=0x%lx eaddr=0x%lx sdr1=0x%llx pteg=0x%x vsid=0x%x\n",
112 		kvmppc_get_pc(vcpu), eaddr, vcpu_book3s->sdr1, pteg,
113 		sr_vsid(sre));
114 
115 	r = gfn_to_hva(vcpu->kvm, pteg >> PAGE_SHIFT);
116 	if (kvm_is_error_hva(r))
117 		return r;
118 	return r | (pteg & ~PAGE_MASK);
119 }
120 
121 static u32 kvmppc_mmu_book3s_32_get_ptem(u32 sre, gva_t eaddr, bool primary)
122 {
123 	return ((eaddr & 0x0fffffff) >> 22) | (sr_vsid(sre) << 7) |
124 	       (primary ? 0 : 0x40) | 0x80000000;
125 }
126 
127 static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
128 					  struct kvmppc_pte *pte, bool data,
129 					  bool iswrite)
130 {
131 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
132 	struct kvmppc_bat *bat;
133 	int i;
134 
135 	for (i = 0; i < 8; i++) {
136 		if (data)
137 			bat = &vcpu_book3s->dbat[i];
138 		else
139 			bat = &vcpu_book3s->ibat[i];
140 
141 		if (kvmppc_get_msr(vcpu) & MSR_PR) {
142 			if (!bat->vp)
143 				continue;
144 		} else {
145 			if (!bat->vs)
146 				continue;
147 		}
148 
149 		if (check_debug_ip(vcpu))
150 		{
151 			dprintk_pte("%cBAT %02d: 0x%lx - 0x%x (0x%x)\n",
152 				    data ? 'd' : 'i', i, eaddr, bat->bepi,
153 				    bat->bepi_mask);
154 		}
155 		if ((eaddr & bat->bepi_mask) == bat->bepi) {
156 			u64 vsid;
157 			kvmppc_mmu_book3s_32_esid_to_vsid(vcpu,
158 				eaddr >> SID_SHIFT, &vsid);
159 			vsid <<= 16;
160 			pte->vpage = (((u64)eaddr >> 12) & 0xffff) | vsid;
161 
162 			pte->raddr = bat->brpn | (eaddr & ~bat->bepi_mask);
163 			pte->may_read = bat->pp;
164 			pte->may_write = bat->pp > 1;
165 			pte->may_execute = true;
166 			if (!pte->may_read) {
167 				printk(KERN_INFO "BAT is not readable!\n");
168 				continue;
169 			}
170 			if (iswrite && !pte->may_write) {
171 				dprintk_pte("BAT is read-only!\n");
172 				continue;
173 			}
174 
175 			return 0;
176 		}
177 	}
178 
179 	return -ENOENT;
180 }
181 
182 static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
183 				     struct kvmppc_pte *pte, bool data,
184 				     bool iswrite, bool primary)
185 {
186 	u32 sre;
187 	hva_t ptegp;
188 	u32 pteg[16];
189 	u32 pte0, pte1;
190 	u32 ptem = 0;
191 	int i;
192 	int found = 0;
193 
194 	sre = find_sr(vcpu, eaddr);
195 
196 	dprintk_pte("SR 0x%lx: vsid=0x%x, raw=0x%x\n", eaddr >> 28,
197 		    sr_vsid(sre), sre);
198 
199 	pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
200 
201 	ptegp = kvmppc_mmu_book3s_32_get_pteg(vcpu, sre, eaddr, primary);
202 	if (kvm_is_error_hva(ptegp)) {
203 		printk(KERN_INFO "KVM: Invalid PTEG!\n");
204 		goto no_page_found;
205 	}
206 
207 	ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
208 
209 	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
210 		printk_ratelimited(KERN_ERR
211 			"KVM: Can't copy data from 0x%lx!\n", ptegp);
212 		goto no_page_found;
213 	}
214 
215 	for (i=0; i<16; i+=2) {
216 		pte0 = be32_to_cpu(pteg[i]);
217 		pte1 = be32_to_cpu(pteg[i + 1]);
218 		if (ptem == pte0) {
219 			u8 pp;
220 
221 			pte->raddr = (pte1 & ~(0xFFFULL)) | (eaddr & 0xFFF);
222 			pp = pte1 & 3;
223 
224 			if ((sr_kp(sre) &&  (kvmppc_get_msr(vcpu) & MSR_PR)) ||
225 			    (sr_ks(sre) && !(kvmppc_get_msr(vcpu) & MSR_PR)))
226 				pp |= 4;
227 
228 			pte->may_write = false;
229 			pte->may_read = false;
230 			pte->may_execute = true;
231 			switch (pp) {
232 				case 0:
233 				case 1:
234 				case 2:
235 				case 6:
236 					pte->may_write = true;
237 					fallthrough;
238 				case 3:
239 				case 5:
240 				case 7:
241 					pte->may_read = true;
242 					break;
243 			}
244 
245 			dprintk_pte("MMU: Found PTE -> %x %x - %x\n",
246 				    pte0, pte1, pp);
247 			found = 1;
248 			break;
249 		}
250 	}
251 
252 	/* Update PTE C and A bits, so the guest's swapper knows we used the
253 	   page */
254 	if (found) {
255 		u32 pte_r = pte1;
256 		char __user *addr = (char __user *) (ptegp + (i+1) * sizeof(u32));
257 
258 		/*
259 		 * Use single-byte writes to update the HPTE, to
260 		 * conform to what real hardware does.
261 		 */
262 		if (pte->may_read && !(pte_r & PTEG_FLAG_ACCESSED)) {
263 			pte_r |= PTEG_FLAG_ACCESSED;
264 			put_user(pte_r >> 8, addr + 2);
265 		}
266 		if (iswrite && pte->may_write && !(pte_r & PTEG_FLAG_DIRTY)) {
267 			pte_r |= PTEG_FLAG_DIRTY;
268 			put_user(pte_r, addr + 3);
269 		}
270 		if (!pte->may_read || (iswrite && !pte->may_write))
271 			return -EPERM;
272 		return 0;
273 	}
274 
275 no_page_found:
276 
277 	if (check_debug_ip(vcpu)) {
278 		dprintk_pte("KVM MMU: No PTE found (sdr1=0x%llx ptegp=0x%lx)\n",
279 			    to_book3s(vcpu)->sdr1, ptegp);
280 		for (i=0; i<16; i+=2) {
281 			dprintk_pte("   %02d: 0x%x - 0x%x (0x%x)\n",
282 				    i, be32_to_cpu(pteg[i]),
283 				    be32_to_cpu(pteg[i+1]), ptem);
284 		}
285 	}
286 
287 	return -ENOENT;
288 }
289 
290 static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
291 				      struct kvmppc_pte *pte, bool data,
292 				      bool iswrite)
293 {
294 	int r;
295 	ulong mp_ea = vcpu->arch.magic_page_ea;
296 
297 	pte->eaddr = eaddr;
298 	pte->page_size = MMU_PAGE_4K;
299 
300 	/* Magic page override */
301 	if (unlikely(mp_ea) &&
302 	    unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
303 	    !(kvmppc_get_msr(vcpu) & MSR_PR)) {
304 		pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
305 		pte->raddr = vcpu->arch.magic_page_pa | (pte->raddr & 0xfff);
306 		pte->raddr &= KVM_PAM;
307 		pte->may_execute = true;
308 		pte->may_read = true;
309 		pte->may_write = true;
310 
311 		return 0;
312 	}
313 
314 	r = kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, pte, data, iswrite);
315 	if (r < 0)
316 		r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte,
317 						   data, iswrite, true);
318 	if (r == -ENOENT)
319 		r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte,
320 						   data, iswrite, false);
321 
322 	return r;
323 }
324 
325 
326 static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
327 {
328 	return kvmppc_get_sr(vcpu, srnum);
329 }
330 
331 static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
332 					ulong value)
333 {
334 	kvmppc_set_sr(vcpu, srnum, value);
335 	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
336 }
337 
338 static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool large)
339 {
340 	unsigned long i;
341 	struct kvm_vcpu *v;
342 
343 	/* flush this VA on all cpus */
344 	kvm_for_each_vcpu(i, v, vcpu->kvm)
345 		kvmppc_mmu_pte_flush(v, ea, 0x0FFFF000);
346 }
347 
348 static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
349 					     u64 *vsid)
350 {
351 	ulong ea = esid << SID_SHIFT;
352 	u32 sr;
353 	u64 gvsid = esid;
354 	u64 msr = kvmppc_get_msr(vcpu);
355 
356 	if (msr & (MSR_DR|MSR_IR)) {
357 		sr = find_sr(vcpu, ea);
358 		if (sr_valid(sr))
359 			gvsid = sr_vsid(sr);
360 	}
361 
362 	/* In case we only have one of MSR_IR or MSR_DR set, let's put
363 	   that in the real-mode context (and hope RM doesn't access
364 	   high memory) */
365 	switch (msr & (MSR_DR|MSR_IR)) {
366 	case 0:
367 		*vsid = VSID_REAL | esid;
368 		break;
369 	case MSR_IR:
370 		*vsid = VSID_REAL_IR | gvsid;
371 		break;
372 	case MSR_DR:
373 		*vsid = VSID_REAL_DR | gvsid;
374 		break;
375 	case MSR_DR|MSR_IR:
376 		if (sr_valid(sr))
377 			*vsid = sr_vsid(sr);
378 		else
379 			*vsid = VSID_BAT | gvsid;
380 		break;
381 	default:
382 		BUG();
383 	}
384 
385 	if (msr & MSR_PR)
386 		*vsid |= VSID_PR;
387 
388 	return 0;
389 }
390 
391 static bool kvmppc_mmu_book3s_32_is_dcbz32(struct kvm_vcpu *vcpu)
392 {
393 	return true;
394 }
395 
396 
397 void kvmppc_mmu_book3s_32_init(struct kvm_vcpu *vcpu)
398 {
399 	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
400 
401 	mmu->mtsrin = kvmppc_mmu_book3s_32_mtsrin;
402 	mmu->mfsrin = kvmppc_mmu_book3s_32_mfsrin;
403 	mmu->xlate = kvmppc_mmu_book3s_32_xlate;
404 	mmu->tlbie = kvmppc_mmu_book3s_32_tlbie;
405 	mmu->esid_to_vsid = kvmppc_mmu_book3s_32_esid_to_vsid;
406 	mmu->ea_to_vp = kvmppc_mmu_book3s_32_ea_to_vp;
407 	mmu->is_dcbz32 = kvmppc_mmu_book3s_32_is_dcbz32;
408 
409 	mmu->slbmte = NULL;
410 	mmu->slbmfee = NULL;
411 	mmu->slbmfev = NULL;
412 	mmu->slbfee = NULL;
413 	mmu->slbie = NULL;
414 	mmu->slbia = NULL;
415 }
416