xref: /openbmc/linux/arch/powerpc/kvm/book3s_32_mmu.c (revision 3dc4b6fb)
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 void kvmppc_mmu_book3s_32_reset_msr(struct kvm_vcpu *vcpu)
94 {
95 	kvmppc_set_msr(vcpu, 0);
96 }
97 
98 static hva_t kvmppc_mmu_book3s_32_get_pteg(struct kvm_vcpu *vcpu,
99 				      u32 sre, gva_t eaddr,
100 				      bool primary)
101 {
102 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
103 	u32 page, hash, pteg, htabmask;
104 	hva_t r;
105 
106 	page = (eaddr & 0x0FFFFFFF) >> 12;
107 	htabmask = ((vcpu_book3s->sdr1 & 0x1FF) << 16) | 0xFFC0;
108 
109 	hash = ((sr_vsid(sre) ^ page) << 6);
110 	if (!primary)
111 		hash = ~hash;
112 	hash &= htabmask;
113 
114 	pteg = (vcpu_book3s->sdr1 & 0xffff0000) | hash;
115 
116 	dprintk("MMU: pc=0x%lx eaddr=0x%lx sdr1=0x%llx pteg=0x%x vsid=0x%x\n",
117 		kvmppc_get_pc(vcpu), eaddr, vcpu_book3s->sdr1, pteg,
118 		sr_vsid(sre));
119 
120 	r = gfn_to_hva(vcpu->kvm, pteg >> PAGE_SHIFT);
121 	if (kvm_is_error_hva(r))
122 		return r;
123 	return r | (pteg & ~PAGE_MASK);
124 }
125 
126 static u32 kvmppc_mmu_book3s_32_get_ptem(u32 sre, gva_t eaddr, bool primary)
127 {
128 	return ((eaddr & 0x0fffffff) >> 22) | (sr_vsid(sre) << 7) |
129 	       (primary ? 0 : 0x40) | 0x80000000;
130 }
131 
132 static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
133 					  struct kvmppc_pte *pte, bool data,
134 					  bool iswrite)
135 {
136 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
137 	struct kvmppc_bat *bat;
138 	int i;
139 
140 	for (i = 0; i < 8; i++) {
141 		if (data)
142 			bat = &vcpu_book3s->dbat[i];
143 		else
144 			bat = &vcpu_book3s->ibat[i];
145 
146 		if (kvmppc_get_msr(vcpu) & MSR_PR) {
147 			if (!bat->vp)
148 				continue;
149 		} else {
150 			if (!bat->vs)
151 				continue;
152 		}
153 
154 		if (check_debug_ip(vcpu))
155 		{
156 			dprintk_pte("%cBAT %02d: 0x%lx - 0x%x (0x%x)\n",
157 				    data ? 'd' : 'i', i, eaddr, bat->bepi,
158 				    bat->bepi_mask);
159 		}
160 		if ((eaddr & bat->bepi_mask) == bat->bepi) {
161 			u64 vsid;
162 			kvmppc_mmu_book3s_32_esid_to_vsid(vcpu,
163 				eaddr >> SID_SHIFT, &vsid);
164 			vsid <<= 16;
165 			pte->vpage = (((u64)eaddr >> 12) & 0xffff) | vsid;
166 
167 			pte->raddr = bat->brpn | (eaddr & ~bat->bepi_mask);
168 			pte->may_read = bat->pp;
169 			pte->may_write = bat->pp > 1;
170 			pte->may_execute = true;
171 			if (!pte->may_read) {
172 				printk(KERN_INFO "BAT is not readable!\n");
173 				continue;
174 			}
175 			if (iswrite && !pte->may_write) {
176 				dprintk_pte("BAT is read-only!\n");
177 				continue;
178 			}
179 
180 			return 0;
181 		}
182 	}
183 
184 	return -ENOENT;
185 }
186 
187 static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
188 				     struct kvmppc_pte *pte, bool data,
189 				     bool iswrite, bool primary)
190 {
191 	u32 sre;
192 	hva_t ptegp;
193 	u32 pteg[16];
194 	u32 pte0, pte1;
195 	u32 ptem = 0;
196 	int i;
197 	int found = 0;
198 
199 	sre = find_sr(vcpu, eaddr);
200 
201 	dprintk_pte("SR 0x%lx: vsid=0x%x, raw=0x%x\n", eaddr >> 28,
202 		    sr_vsid(sre), sre);
203 
204 	pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
205 
206 	ptegp = kvmppc_mmu_book3s_32_get_pteg(vcpu, sre, eaddr, primary);
207 	if (kvm_is_error_hva(ptegp)) {
208 		printk(KERN_INFO "KVM: Invalid PTEG!\n");
209 		goto no_page_found;
210 	}
211 
212 	ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
213 
214 	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
215 		printk_ratelimited(KERN_ERR
216 			"KVM: Can't copy data from 0x%lx!\n", ptegp);
217 		goto no_page_found;
218 	}
219 
220 	for (i=0; i<16; i+=2) {
221 		pte0 = be32_to_cpu(pteg[i]);
222 		pte1 = be32_to_cpu(pteg[i + 1]);
223 		if (ptem == pte0) {
224 			u8 pp;
225 
226 			pte->raddr = (pte1 & ~(0xFFFULL)) | (eaddr & 0xFFF);
227 			pp = pte1 & 3;
228 
229 			if ((sr_kp(sre) &&  (kvmppc_get_msr(vcpu) & MSR_PR)) ||
230 			    (sr_ks(sre) && !(kvmppc_get_msr(vcpu) & MSR_PR)))
231 				pp |= 4;
232 
233 			pte->may_write = false;
234 			pte->may_read = false;
235 			pte->may_execute = true;
236 			switch (pp) {
237 				case 0:
238 				case 1:
239 				case 2:
240 				case 6:
241 					pte->may_write = true;
242 					/* fall through */
243 				case 3:
244 				case 5:
245 				case 7:
246 					pte->may_read = true;
247 					break;
248 			}
249 
250 			dprintk_pte("MMU: Found PTE -> %x %x - %x\n",
251 				    pte0, pte1, pp);
252 			found = 1;
253 			break;
254 		}
255 	}
256 
257 	/* Update PTE C and A bits, so the guest's swapper knows we used the
258 	   page */
259 	if (found) {
260 		u32 pte_r = pte1;
261 		char __user *addr = (char __user *) (ptegp + (i+1) * sizeof(u32));
262 
263 		/*
264 		 * Use single-byte writes to update the HPTE, to
265 		 * conform to what real hardware does.
266 		 */
267 		if (pte->may_read && !(pte_r & PTEG_FLAG_ACCESSED)) {
268 			pte_r |= PTEG_FLAG_ACCESSED;
269 			put_user(pte_r >> 8, addr + 2);
270 		}
271 		if (iswrite && pte->may_write && !(pte_r & PTEG_FLAG_DIRTY)) {
272 			pte_r |= PTEG_FLAG_DIRTY;
273 			put_user(pte_r, addr + 3);
274 		}
275 		if (!pte->may_read || (iswrite && !pte->may_write))
276 			return -EPERM;
277 		return 0;
278 	}
279 
280 no_page_found:
281 
282 	if (check_debug_ip(vcpu)) {
283 		dprintk_pte("KVM MMU: No PTE found (sdr1=0x%llx ptegp=0x%lx)\n",
284 			    to_book3s(vcpu)->sdr1, ptegp);
285 		for (i=0; i<16; i+=2) {
286 			dprintk_pte("   %02d: 0x%x - 0x%x (0x%x)\n",
287 				    i, be32_to_cpu(pteg[i]),
288 				    be32_to_cpu(pteg[i+1]), ptem);
289 		}
290 	}
291 
292 	return -ENOENT;
293 }
294 
295 static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
296 				      struct kvmppc_pte *pte, bool data,
297 				      bool iswrite)
298 {
299 	int r;
300 	ulong mp_ea = vcpu->arch.magic_page_ea;
301 
302 	pte->eaddr = eaddr;
303 	pte->page_size = MMU_PAGE_4K;
304 
305 	/* Magic page override */
306 	if (unlikely(mp_ea) &&
307 	    unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
308 	    !(kvmppc_get_msr(vcpu) & MSR_PR)) {
309 		pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
310 		pte->raddr = vcpu->arch.magic_page_pa | (pte->raddr & 0xfff);
311 		pte->raddr &= KVM_PAM;
312 		pte->may_execute = true;
313 		pte->may_read = true;
314 		pte->may_write = true;
315 
316 		return 0;
317 	}
318 
319 	r = kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, pte, data, iswrite);
320 	if (r < 0)
321 		r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte,
322 						   data, iswrite, true);
323 	if (r == -ENOENT)
324 		r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte,
325 						   data, iswrite, false);
326 
327 	return r;
328 }
329 
330 
331 static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
332 {
333 	return kvmppc_get_sr(vcpu, srnum);
334 }
335 
336 static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
337 					ulong value)
338 {
339 	kvmppc_set_sr(vcpu, srnum, value);
340 	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
341 }
342 
343 static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool large)
344 {
345 	int i;
346 	struct kvm_vcpu *v;
347 
348 	/* flush this VA on all cpus */
349 	kvm_for_each_vcpu(i, v, vcpu->kvm)
350 		kvmppc_mmu_pte_flush(v, ea, 0x0FFFF000);
351 }
352 
353 static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
354 					     u64 *vsid)
355 {
356 	ulong ea = esid << SID_SHIFT;
357 	u32 sr;
358 	u64 gvsid = esid;
359 	u64 msr = kvmppc_get_msr(vcpu);
360 
361 	if (msr & (MSR_DR|MSR_IR)) {
362 		sr = find_sr(vcpu, ea);
363 		if (sr_valid(sr))
364 			gvsid = sr_vsid(sr);
365 	}
366 
367 	/* In case we only have one of MSR_IR or MSR_DR set, let's put
368 	   that in the real-mode context (and hope RM doesn't access
369 	   high memory) */
370 	switch (msr & (MSR_DR|MSR_IR)) {
371 	case 0:
372 		*vsid = VSID_REAL | esid;
373 		break;
374 	case MSR_IR:
375 		*vsid = VSID_REAL_IR | gvsid;
376 		break;
377 	case MSR_DR:
378 		*vsid = VSID_REAL_DR | gvsid;
379 		break;
380 	case MSR_DR|MSR_IR:
381 		if (sr_valid(sr))
382 			*vsid = sr_vsid(sr);
383 		else
384 			*vsid = VSID_BAT | gvsid;
385 		break;
386 	default:
387 		BUG();
388 	}
389 
390 	if (msr & MSR_PR)
391 		*vsid |= VSID_PR;
392 
393 	return 0;
394 }
395 
396 static bool kvmppc_mmu_book3s_32_is_dcbz32(struct kvm_vcpu *vcpu)
397 {
398 	return true;
399 }
400 
401 
402 void kvmppc_mmu_book3s_32_init(struct kvm_vcpu *vcpu)
403 {
404 	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
405 
406 	mmu->mtsrin = kvmppc_mmu_book3s_32_mtsrin;
407 	mmu->mfsrin = kvmppc_mmu_book3s_32_mfsrin;
408 	mmu->xlate = kvmppc_mmu_book3s_32_xlate;
409 	mmu->reset_msr = kvmppc_mmu_book3s_32_reset_msr;
410 	mmu->tlbie = kvmppc_mmu_book3s_32_tlbie;
411 	mmu->esid_to_vsid = kvmppc_mmu_book3s_32_esid_to_vsid;
412 	mmu->ea_to_vp = kvmppc_mmu_book3s_32_ea_to_vp;
413 	mmu->is_dcbz32 = kvmppc_mmu_book3s_32_is_dcbz32;
414 
415 	mmu->slbmte = NULL;
416 	mmu->slbmfee = NULL;
417 	mmu->slbmfev = NULL;
418 	mmu->slbfee = NULL;
419 	mmu->slbie = NULL;
420 	mmu->slbia = NULL;
421 }
422