xref: /openbmc/linux/arch/powerpc/kvm/book3s_32_mmu.c (revision e23feb16)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License, version 2, as
4  * published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  * GNU General Public License for more details.
10  *
11  * You should have received a copy of the GNU General Public License
12  * along with this program; if not, write to the Free Software
13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14  *
15  * Copyright SUSE Linux Products GmbH 2009
16  *
17  * Authors: Alexander Graf <agraf@suse.de>
18  */
19 
20 #include <linux/types.h>
21 #include <linux/string.h>
22 #include <linux/kvm.h>
23 #include <linux/kvm_host.h>
24 #include <linux/highmem.h>
25 
26 #include <asm/tlbflush.h>
27 #include <asm/kvm_ppc.h>
28 #include <asm/kvm_book3s.h>
29 
30 /* #define DEBUG_MMU */
31 /* #define DEBUG_MMU_PTE */
32 /* #define DEBUG_MMU_PTE_IP 0xfff14c40 */
33 
34 #ifdef DEBUG_MMU
35 #define dprintk(X...) printk(KERN_INFO X)
36 #else
37 #define dprintk(X...) do { } while(0)
38 #endif
39 
40 #ifdef DEBUG_MMU_PTE
41 #define dprintk_pte(X...) printk(KERN_INFO X)
42 #else
43 #define dprintk_pte(X...) do { } while(0)
44 #endif
45 
46 #define PTEG_FLAG_ACCESSED	0x00000100
47 #define PTEG_FLAG_DIRTY		0x00000080
48 #ifndef SID_SHIFT
49 #define SID_SHIFT		28
50 #endif
51 
52 static inline bool check_debug_ip(struct kvm_vcpu *vcpu)
53 {
54 #ifdef DEBUG_MMU_PTE_IP
55 	return vcpu->arch.pc == DEBUG_MMU_PTE_IP;
56 #else
57 	return true;
58 #endif
59 }
60 
61 static inline u32 sr_vsid(u32 sr_raw)
62 {
63 	return sr_raw & 0x0fffffff;
64 }
65 
66 static inline bool sr_valid(u32 sr_raw)
67 {
68 	return (sr_raw & 0x80000000) ? false : true;
69 }
70 
71 static inline bool sr_ks(u32 sr_raw)
72 {
73 	return (sr_raw & 0x40000000) ? true: false;
74 }
75 
76 static inline bool sr_kp(u32 sr_raw)
77 {
78 	return (sr_raw & 0x20000000) ? true: false;
79 }
80 
81 static inline bool sr_nx(u32 sr_raw)
82 {
83 	return (sr_raw & 0x10000000) ? true: false;
84 }
85 
86 static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
87 					  struct kvmppc_pte *pte, bool data);
88 static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
89 					     u64 *vsid);
90 
91 static u32 find_sr(struct kvm_vcpu *vcpu, gva_t eaddr)
92 {
93 	return vcpu->arch.shared->sr[(eaddr >> 28) & 0xf];
94 }
95 
96 static u64 kvmppc_mmu_book3s_32_ea_to_vp(struct kvm_vcpu *vcpu, gva_t eaddr,
97 					 bool data)
98 {
99 	u64 vsid;
100 	struct kvmppc_pte pte;
101 
102 	if (!kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, &pte, data))
103 		return pte.vpage;
104 
105 	kvmppc_mmu_book3s_32_esid_to_vsid(vcpu, eaddr >> SID_SHIFT, &vsid);
106 	return (((u64)eaddr >> 12) & 0xffff) | (vsid << 16);
107 }
108 
109 static void kvmppc_mmu_book3s_32_reset_msr(struct kvm_vcpu *vcpu)
110 {
111 	kvmppc_set_msr(vcpu, 0);
112 }
113 
114 static hva_t kvmppc_mmu_book3s_32_get_pteg(struct kvmppc_vcpu_book3s *vcpu_book3s,
115 				      u32 sre, gva_t eaddr,
116 				      bool primary)
117 {
118 	u32 page, hash, pteg, htabmask;
119 	hva_t r;
120 
121 	page = (eaddr & 0x0FFFFFFF) >> 12;
122 	htabmask = ((vcpu_book3s->sdr1 & 0x1FF) << 16) | 0xFFC0;
123 
124 	hash = ((sr_vsid(sre) ^ page) << 6);
125 	if (!primary)
126 		hash = ~hash;
127 	hash &= htabmask;
128 
129 	pteg = (vcpu_book3s->sdr1 & 0xffff0000) | hash;
130 
131 	dprintk("MMU: pc=0x%lx eaddr=0x%lx sdr1=0x%llx pteg=0x%x vsid=0x%x\n",
132 		kvmppc_get_pc(&vcpu_book3s->vcpu), eaddr, vcpu_book3s->sdr1, pteg,
133 		sr_vsid(sre));
134 
135 	r = gfn_to_hva(vcpu_book3s->vcpu.kvm, pteg >> PAGE_SHIFT);
136 	if (kvm_is_error_hva(r))
137 		return r;
138 	return r | (pteg & ~PAGE_MASK);
139 }
140 
141 static u32 kvmppc_mmu_book3s_32_get_ptem(u32 sre, gva_t eaddr, bool primary)
142 {
143 	return ((eaddr & 0x0fffffff) >> 22) | (sr_vsid(sre) << 7) |
144 	       (primary ? 0 : 0x40) | 0x80000000;
145 }
146 
147 static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
148 					  struct kvmppc_pte *pte, bool data)
149 {
150 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
151 	struct kvmppc_bat *bat;
152 	int i;
153 
154 	for (i = 0; i < 8; i++) {
155 		if (data)
156 			bat = &vcpu_book3s->dbat[i];
157 		else
158 			bat = &vcpu_book3s->ibat[i];
159 
160 		if (vcpu->arch.shared->msr & MSR_PR) {
161 			if (!bat->vp)
162 				continue;
163 		} else {
164 			if (!bat->vs)
165 				continue;
166 		}
167 
168 		if (check_debug_ip(vcpu))
169 		{
170 			dprintk_pte("%cBAT %02d: 0x%lx - 0x%x (0x%x)\n",
171 				    data ? 'd' : 'i', i, eaddr, bat->bepi,
172 				    bat->bepi_mask);
173 		}
174 		if ((eaddr & bat->bepi_mask) == bat->bepi) {
175 			u64 vsid;
176 			kvmppc_mmu_book3s_32_esid_to_vsid(vcpu,
177 				eaddr >> SID_SHIFT, &vsid);
178 			vsid <<= 16;
179 			pte->vpage = (((u64)eaddr >> 12) & 0xffff) | vsid;
180 
181 			pte->raddr = bat->brpn | (eaddr & ~bat->bepi_mask);
182 			pte->may_read = bat->pp;
183 			pte->may_write = bat->pp > 1;
184 			pte->may_execute = true;
185 			if (!pte->may_read) {
186 				printk(KERN_INFO "BAT is not readable!\n");
187 				continue;
188 			}
189 			if (!pte->may_write) {
190 				/* let's treat r/o BATs as not-readable for now */
191 				dprintk_pte("BAT is read-only!\n");
192 				continue;
193 			}
194 
195 			return 0;
196 		}
197 	}
198 
199 	return -ENOENT;
200 }
201 
202 static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
203 				     struct kvmppc_pte *pte, bool data,
204 				     bool primary)
205 {
206 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
207 	u32 sre;
208 	hva_t ptegp;
209 	u32 pteg[16];
210 	u32 ptem = 0;
211 	int i;
212 	int found = 0;
213 
214 	sre = find_sr(vcpu, eaddr);
215 
216 	dprintk_pte("SR 0x%lx: vsid=0x%x, raw=0x%x\n", eaddr >> 28,
217 		    sr_vsid(sre), sre);
218 
219 	pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
220 
221 	ptegp = kvmppc_mmu_book3s_32_get_pteg(vcpu_book3s, sre, eaddr, primary);
222 	if (kvm_is_error_hva(ptegp)) {
223 		printk(KERN_INFO "KVM: Invalid PTEG!\n");
224 		goto no_page_found;
225 	}
226 
227 	ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
228 
229 	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
230 		printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", ptegp);
231 		goto no_page_found;
232 	}
233 
234 	for (i=0; i<16; i+=2) {
235 		if (ptem == pteg[i]) {
236 			u8 pp;
237 
238 			pte->raddr = (pteg[i+1] & ~(0xFFFULL)) | (eaddr & 0xFFF);
239 			pp = pteg[i+1] & 3;
240 
241 			if ((sr_kp(sre) &&  (vcpu->arch.shared->msr & MSR_PR)) ||
242 			    (sr_ks(sre) && !(vcpu->arch.shared->msr & MSR_PR)))
243 				pp |= 4;
244 
245 			pte->may_write = false;
246 			pte->may_read = false;
247 			pte->may_execute = true;
248 			switch (pp) {
249 				case 0:
250 				case 1:
251 				case 2:
252 				case 6:
253 					pte->may_write = true;
254 				case 3:
255 				case 5:
256 				case 7:
257 					pte->may_read = true;
258 					break;
259 			}
260 
261 			if ( !pte->may_read )
262 				continue;
263 
264 			dprintk_pte("MMU: Found PTE -> %x %x - %x\n",
265 				    pteg[i], pteg[i+1], pp);
266 			found = 1;
267 			break;
268 		}
269 	}
270 
271 	/* Update PTE C and A bits, so the guest's swapper knows we used the
272 	   page */
273 	if (found) {
274 		u32 oldpte = pteg[i+1];
275 
276 		if (pte->may_read)
277 			pteg[i+1] |= PTEG_FLAG_ACCESSED;
278 		if (pte->may_write)
279 			pteg[i+1] |= PTEG_FLAG_DIRTY;
280 		else
281 			dprintk_pte("KVM: Mapping read-only page!\n");
282 
283 		/* Write back into the PTEG */
284 		if (pteg[i+1] != oldpte)
285 			copy_to_user((void __user *)ptegp, pteg, sizeof(pteg));
286 
287 		return 0;
288 	}
289 
290 no_page_found:
291 
292 	if (check_debug_ip(vcpu)) {
293 		dprintk_pte("KVM MMU: No PTE found (sdr1=0x%llx ptegp=0x%lx)\n",
294 			    to_book3s(vcpu)->sdr1, ptegp);
295 		for (i=0; i<16; i+=2) {
296 			dprintk_pte("   %02d: 0x%x - 0x%x (0x%x)\n",
297 				    i, pteg[i], pteg[i+1], ptem);
298 		}
299 	}
300 
301 	return -ENOENT;
302 }
303 
304 static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
305 				      struct kvmppc_pte *pte, bool data)
306 {
307 	int r;
308 	ulong mp_ea = vcpu->arch.magic_page_ea;
309 
310 	pte->eaddr = eaddr;
311 
312 	/* Magic page override */
313 	if (unlikely(mp_ea) &&
314 	    unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
315 	    !(vcpu->arch.shared->msr & MSR_PR)) {
316 		pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
317 		pte->raddr = vcpu->arch.magic_page_pa | (pte->raddr & 0xfff);
318 		pte->raddr &= KVM_PAM;
319 		pte->may_execute = true;
320 		pte->may_read = true;
321 		pte->may_write = true;
322 
323 		return 0;
324 	}
325 
326 	r = kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, pte, data);
327 	if (r < 0)
328 	       r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte, data, true);
329 	if (r < 0)
330 	       r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte, data, false);
331 
332 	return r;
333 }
334 
335 
336 static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
337 {
338 	return vcpu->arch.shared->sr[srnum];
339 }
340 
341 static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
342 					ulong value)
343 {
344 	vcpu->arch.shared->sr[srnum] = value;
345 	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
346 }
347 
348 static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool large)
349 {
350 	kvmppc_mmu_pte_flush(vcpu, 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 
360 	if (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
361 		sr = find_sr(vcpu, ea);
362 		if (sr_valid(sr))
363 			gvsid = sr_vsid(sr);
364 	}
365 
366 	/* In case we only have one of MSR_IR or MSR_DR set, let's put
367 	   that in the real-mode context (and hope RM doesn't access
368 	   high memory) */
369 	switch (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
370 	case 0:
371 		*vsid = VSID_REAL | esid;
372 		break;
373 	case MSR_IR:
374 		*vsid = VSID_REAL_IR | gvsid;
375 		break;
376 	case MSR_DR:
377 		*vsid = VSID_REAL_DR | gvsid;
378 		break;
379 	case MSR_DR|MSR_IR:
380 		if (sr_valid(sr))
381 			*vsid = sr_vsid(sr);
382 		else
383 			*vsid = VSID_BAT | gvsid;
384 		break;
385 	default:
386 		BUG();
387 	}
388 
389 	if (vcpu->arch.shared->msr & MSR_PR)
390 		*vsid |= VSID_PR;
391 
392 	return 0;
393 }
394 
395 static bool kvmppc_mmu_book3s_32_is_dcbz32(struct kvm_vcpu *vcpu)
396 {
397 	return true;
398 }
399 
400 
401 void kvmppc_mmu_book3s_32_init(struct kvm_vcpu *vcpu)
402 {
403 	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
404 
405 	mmu->mtsrin = kvmppc_mmu_book3s_32_mtsrin;
406 	mmu->mfsrin = kvmppc_mmu_book3s_32_mfsrin;
407 	mmu->xlate = kvmppc_mmu_book3s_32_xlate;
408 	mmu->reset_msr = kvmppc_mmu_book3s_32_reset_msr;
409 	mmu->tlbie = kvmppc_mmu_book3s_32_tlbie;
410 	mmu->esid_to_vsid = kvmppc_mmu_book3s_32_esid_to_vsid;
411 	mmu->ea_to_vp = kvmppc_mmu_book3s_32_ea_to_vp;
412 	mmu->is_dcbz32 = kvmppc_mmu_book3s_32_is_dcbz32;
413 
414 	mmu->slbmte = NULL;
415 	mmu->slbmfee = NULL;
416 	mmu->slbmfev = NULL;
417 	mmu->slbie = NULL;
418 	mmu->slbia = NULL;
419 }
420