xref: /openbmc/linux/arch/powerpc/kvm/book3s_64_mmu_radix.c (revision 1188f7f111c61394ec56beb8e30322305a8220b6)
1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   *
4   * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
5   */
6  
7  #include <linux/types.h>
8  #include <linux/string.h>
9  #include <linux/kvm.h>
10  #include <linux/kvm_host.h>
11  #include <linux/anon_inodes.h>
12  #include <linux/file.h>
13  #include <linux/debugfs.h>
14  #include <linux/pgtable.h>
15  
16  #include <asm/kvm_ppc.h>
17  #include <asm/kvm_book3s.h>
18  #include "book3s_hv.h"
19  #include <asm/page.h>
20  #include <asm/mmu.h>
21  #include <asm/pgalloc.h>
22  #include <asm/pte-walk.h>
23  #include <asm/ultravisor.h>
24  #include <asm/kvm_book3s_uvmem.h>
25  #include <asm/plpar_wrappers.h>
26  #include <asm/firmware.h>
27  
28  /*
29   * Supported radix tree geometry.
30   * Like p9, we support either 5 or 9 bits at the first (lowest) level,
31   * for a page size of 64k or 4k.
32   */
33  static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
34  
__kvmhv_copy_tofrom_guest_radix(int lpid,int pid,gva_t eaddr,void * to,void * from,unsigned long n)35  unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
36  					      gva_t eaddr, void *to, void *from,
37  					      unsigned long n)
38  {
39  	int old_pid, old_lpid;
40  	unsigned long quadrant, ret = n;
41  	bool is_load = !!to;
42  
43  	/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
44  	if (kvmhv_on_pseries())
45  		return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
46  					  (to != NULL) ? __pa(to): 0,
47  					  (from != NULL) ? __pa(from): 0, n);
48  
49  	if (eaddr & (0xFFFUL << 52))
50  		return ret;
51  
52  	quadrant = 1;
53  	if (!pid)
54  		quadrant = 2;
55  	if (is_load)
56  		from = (void *) (eaddr | (quadrant << 62));
57  	else
58  		to = (void *) (eaddr | (quadrant << 62));
59  
60  	preempt_disable();
61  
62  	asm volatile("hwsync" ::: "memory");
63  	isync();
64  	/* switch the lpid first to avoid running host with unallocated pid */
65  	old_lpid = mfspr(SPRN_LPID);
66  	if (old_lpid != lpid)
67  		mtspr(SPRN_LPID, lpid);
68  	if (quadrant == 1) {
69  		old_pid = mfspr(SPRN_PID);
70  		if (old_pid != pid)
71  			mtspr(SPRN_PID, pid);
72  	}
73  	isync();
74  
75  	pagefault_disable();
76  	if (is_load)
77  		ret = __copy_from_user_inatomic(to, (const void __user *)from, n);
78  	else
79  		ret = __copy_to_user_inatomic((void __user *)to, from, n);
80  	pagefault_enable();
81  
82  	asm volatile("hwsync" ::: "memory");
83  	isync();
84  	/* switch the pid first to avoid running host with unallocated pid */
85  	if (quadrant == 1 && pid != old_pid)
86  		mtspr(SPRN_PID, old_pid);
87  	if (lpid != old_lpid)
88  		mtspr(SPRN_LPID, old_lpid);
89  	isync();
90  
91  	preempt_enable();
92  
93  	return ret;
94  }
95  
kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,void * from,unsigned long n)96  static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
97  					  void *to, void *from, unsigned long n)
98  {
99  	int lpid = vcpu->kvm->arch.lpid;
100  	int pid = vcpu->arch.pid;
101  
102  	/* This would cause a data segment intr so don't allow the access */
103  	if (eaddr & (0x3FFUL << 52))
104  		return -EINVAL;
105  
106  	/* Should we be using the nested lpid */
107  	if (vcpu->arch.nested)
108  		lpid = vcpu->arch.nested->shadow_lpid;
109  
110  	/* If accessing quadrant 3 then pid is expected to be 0 */
111  	if (((eaddr >> 62) & 0x3) == 0x3)
112  		pid = 0;
113  
114  	eaddr &= ~(0xFFFUL << 52);
115  
116  	return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n);
117  }
118  
kvmhv_copy_from_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * to,unsigned long n)119  long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to,
120  				 unsigned long n)
121  {
122  	long ret;
123  
124  	ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n);
125  	if (ret > 0)
126  		memset(to + (n - ret), 0, ret);
127  
128  	return ret;
129  }
130  
kvmhv_copy_to_guest_radix(struct kvm_vcpu * vcpu,gva_t eaddr,void * from,unsigned long n)131  long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from,
132  			       unsigned long n)
133  {
134  	return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n);
135  }
136  
kvmppc_mmu_walk_radix_tree(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,u64 root,u64 * pte_ret_p)137  int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
138  			       struct kvmppc_pte *gpte, u64 root,
139  			       u64 *pte_ret_p)
140  {
141  	struct kvm *kvm = vcpu->kvm;
142  	int ret, level, ps;
143  	unsigned long rts, bits, offset, index;
144  	u64 pte, base, gpa;
145  	__be64 rpte;
146  
147  	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
148  		((root & RTS2_MASK) >> RTS2_SHIFT);
149  	bits = root & RPDS_MASK;
150  	base = root & RPDB_MASK;
151  
152  	offset = rts + 31;
153  
154  	/* Current implementations only support 52-bit space */
155  	if (offset != 52)
156  		return -EINVAL;
157  
158  	/* Walk each level of the radix tree */
159  	for (level = 3; level >= 0; --level) {
160  		u64 addr;
161  		/* Check a valid size */
162  		if (level && bits != p9_supported_radix_bits[level])
163  			return -EINVAL;
164  		if (level == 0 && !(bits == 5 || bits == 9))
165  			return -EINVAL;
166  		offset -= bits;
167  		index = (eaddr >> offset) & ((1UL << bits) - 1);
168  		/* Check that low bits of page table base are zero */
169  		if (base & ((1UL << (bits + 3)) - 1))
170  			return -EINVAL;
171  		/* Read the entry from guest memory */
172  		addr = base + (index * sizeof(rpte));
173  
174  		kvm_vcpu_srcu_read_lock(vcpu);
175  		ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
176  		kvm_vcpu_srcu_read_unlock(vcpu);
177  		if (ret) {
178  			if (pte_ret_p)
179  				*pte_ret_p = addr;
180  			return ret;
181  		}
182  		pte = __be64_to_cpu(rpte);
183  		if (!(pte & _PAGE_PRESENT))
184  			return -ENOENT;
185  		/* Check if a leaf entry */
186  		if (pte & _PAGE_PTE)
187  			break;
188  		/* Get ready to walk the next level */
189  		base = pte & RPDB_MASK;
190  		bits = pte & RPDS_MASK;
191  	}
192  
193  	/* Need a leaf at lowest level; 512GB pages not supported */
194  	if (level < 0 || level == 3)
195  		return -EINVAL;
196  
197  	/* We found a valid leaf PTE */
198  	/* Offset is now log base 2 of the page size */
199  	gpa = pte & 0x01fffffffffff000ul;
200  	if (gpa & ((1ul << offset) - 1))
201  		return -EINVAL;
202  	gpa |= eaddr & ((1ul << offset) - 1);
203  	for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
204  		if (offset == mmu_psize_defs[ps].shift)
205  			break;
206  	gpte->page_size = ps;
207  	gpte->page_shift = offset;
208  
209  	gpte->eaddr = eaddr;
210  	gpte->raddr = gpa;
211  
212  	/* Work out permissions */
213  	gpte->may_read = !!(pte & _PAGE_READ);
214  	gpte->may_write = !!(pte & _PAGE_WRITE);
215  	gpte->may_execute = !!(pte & _PAGE_EXEC);
216  
217  	gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
218  
219  	if (pte_ret_p)
220  		*pte_ret_p = pte;
221  
222  	return 0;
223  }
224  
225  /*
226   * Used to walk a partition or process table radix tree in guest memory
227   * Note: We exploit the fact that a partition table and a process
228   * table have the same layout, a partition-scoped page table and a
229   * process-scoped page table have the same layout, and the 2nd
230   * doubleword of a partition table entry has the same layout as
231   * the PTCR register.
232   */
kvmppc_mmu_radix_translate_table(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,u64 table,int table_index,u64 * pte_ret_p)233  int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
234  				     struct kvmppc_pte *gpte, u64 table,
235  				     int table_index, u64 *pte_ret_p)
236  {
237  	struct kvm *kvm = vcpu->kvm;
238  	int ret;
239  	unsigned long size, ptbl, root;
240  	struct prtb_entry entry;
241  
242  	if ((table & PRTS_MASK) > 24)
243  		return -EINVAL;
244  	size = 1ul << ((table & PRTS_MASK) + 12);
245  
246  	/* Is the table big enough to contain this entry? */
247  	if ((table_index * sizeof(entry)) >= size)
248  		return -EINVAL;
249  
250  	/* Read the table to find the root of the radix tree */
251  	ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
252  	kvm_vcpu_srcu_read_lock(vcpu);
253  	ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
254  	kvm_vcpu_srcu_read_unlock(vcpu);
255  	if (ret)
256  		return ret;
257  
258  	/* Root is stored in the first double word */
259  	root = be64_to_cpu(entry.prtb0);
260  
261  	return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
262  }
263  
kvmppc_mmu_radix_xlate(struct kvm_vcpu * vcpu,gva_t eaddr,struct kvmppc_pte * gpte,bool data,bool iswrite)264  int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
265  			   struct kvmppc_pte *gpte, bool data, bool iswrite)
266  {
267  	u32 pid;
268  	u64 pte;
269  	int ret;
270  
271  	/* Work out effective PID */
272  	switch (eaddr >> 62) {
273  	case 0:
274  		pid = vcpu->arch.pid;
275  		break;
276  	case 3:
277  		pid = 0;
278  		break;
279  	default:
280  		return -EINVAL;
281  	}
282  
283  	ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte,
284  				vcpu->kvm->arch.process_table, pid, &pte);
285  	if (ret)
286  		return ret;
287  
288  	/* Check privilege (applies only to process scoped translations) */
289  	if (kvmppc_get_msr(vcpu) & MSR_PR) {
290  		if (pte & _PAGE_PRIVILEGED) {
291  			gpte->may_read = 0;
292  			gpte->may_write = 0;
293  			gpte->may_execute = 0;
294  		}
295  	} else {
296  		if (!(pte & _PAGE_PRIVILEGED)) {
297  			/* Check AMR/IAMR to see if strict mode is in force */
298  			if (kvmppc_get_amr_hv(vcpu) & (1ul << 62))
299  				gpte->may_read = 0;
300  			if (kvmppc_get_amr_hv(vcpu) & (1ul << 63))
301  				gpte->may_write = 0;
302  			if (vcpu->arch.iamr & (1ul << 62))
303  				gpte->may_execute = 0;
304  		}
305  	}
306  
307  	return 0;
308  }
309  
kvmppc_radix_tlbie_page(struct kvm * kvm,unsigned long addr,unsigned int pshift,unsigned int lpid)310  void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
311  			     unsigned int pshift, unsigned int lpid)
312  {
313  	unsigned long psize = PAGE_SIZE;
314  	int psi;
315  	long rc;
316  	unsigned long rb;
317  
318  	if (pshift)
319  		psize = 1UL << pshift;
320  	else
321  		pshift = PAGE_SHIFT;
322  
323  	addr &= ~(psize - 1);
324  
325  	if (!kvmhv_on_pseries()) {
326  		radix__flush_tlb_lpid_page(lpid, addr, psize);
327  		return;
328  	}
329  
330  	psi = shift_to_mmu_psize(pshift);
331  
332  	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) {
333  		rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58));
334  		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1),
335  					lpid, rb);
336  	} else {
337  		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
338  					    H_RPTI_TYPE_NESTED |
339  					    H_RPTI_TYPE_TLB,
340  					    psize_to_rpti_pgsize(psi),
341  					    addr, addr + psize);
342  	}
343  
344  	if (rc)
345  		pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc);
346  }
347  
kvmppc_radix_flush_pwc(struct kvm * kvm,unsigned int lpid)348  static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
349  {
350  	long rc;
351  
352  	if (!kvmhv_on_pseries()) {
353  		radix__flush_pwc_lpid(lpid);
354  		return;
355  	}
356  
357  	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
358  		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1),
359  					lpid, TLBIEL_INVAL_SET_LPID);
360  	else
361  		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
362  					    H_RPTI_TYPE_NESTED |
363  					    H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL,
364  					    0, -1UL);
365  	if (rc)
366  		pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc);
367  }
368  
kvmppc_radix_update_pte(struct kvm * kvm,pte_t * ptep,unsigned long clr,unsigned long set,unsigned long addr,unsigned int shift)369  static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
370  				      unsigned long clr, unsigned long set,
371  				      unsigned long addr, unsigned int shift)
372  {
373  	return __radix_pte_update(ptep, clr, set);
374  }
375  
kvmppc_radix_set_pte_at(struct kvm * kvm,unsigned long addr,pte_t * ptep,pte_t pte)376  static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
377  			     pte_t *ptep, pte_t pte)
378  {
379  	radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
380  }
381  
382  static struct kmem_cache *kvm_pte_cache;
383  static struct kmem_cache *kvm_pmd_cache;
384  
kvmppc_pte_alloc(void)385  static pte_t *kvmppc_pte_alloc(void)
386  {
387  	pte_t *pte;
388  
389  	pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
390  	/* pmd_populate() will only reference _pa(pte). */
391  	kmemleak_ignore(pte);
392  
393  	return pte;
394  }
395  
kvmppc_pte_free(pte_t * ptep)396  static void kvmppc_pte_free(pte_t *ptep)
397  {
398  	kmem_cache_free(kvm_pte_cache, ptep);
399  }
400  
kvmppc_pmd_alloc(void)401  static pmd_t *kvmppc_pmd_alloc(void)
402  {
403  	pmd_t *pmd;
404  
405  	pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL);
406  	/* pud_populate() will only reference _pa(pmd). */
407  	kmemleak_ignore(pmd);
408  
409  	return pmd;
410  }
411  
kvmppc_pmd_free(pmd_t * pmdp)412  static void kvmppc_pmd_free(pmd_t *pmdp)
413  {
414  	kmem_cache_free(kvm_pmd_cache, pmdp);
415  }
416  
417  /* Called with kvm->mmu_lock held */
kvmppc_unmap_pte(struct kvm * kvm,pte_t * pte,unsigned long gpa,unsigned int shift,const struct kvm_memory_slot * memslot,unsigned int lpid)418  void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa,
419  		      unsigned int shift,
420  		      const struct kvm_memory_slot *memslot,
421  		      unsigned int lpid)
422  
423  {
424  	unsigned long old;
425  	unsigned long gfn = gpa >> PAGE_SHIFT;
426  	unsigned long page_size = PAGE_SIZE;
427  	unsigned long hpa;
428  
429  	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
430  	kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
431  
432  	/* The following only applies to L1 entries */
433  	if (lpid != kvm->arch.lpid)
434  		return;
435  
436  	if (!memslot) {
437  		memslot = gfn_to_memslot(kvm, gfn);
438  		if (!memslot)
439  			return;
440  	}
441  	if (shift) { /* 1GB or 2MB page */
442  		page_size = 1ul << shift;
443  		if (shift == PMD_SHIFT)
444  			kvm->stat.num_2M_pages--;
445  		else if (shift == PUD_SHIFT)
446  			kvm->stat.num_1G_pages--;
447  	}
448  
449  	gpa &= ~(page_size - 1);
450  	hpa = old & PTE_RPN_MASK;
451  	kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size);
452  
453  	if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap)
454  		kvmppc_update_dirty_map(memslot, gfn, page_size);
455  }
456  
457  /*
458   * kvmppc_free_p?d are used to free existing page tables, and recursively
459   * descend and clear and free children.
460   * Callers are responsible for flushing the PWC.
461   *
462   * When page tables are being unmapped/freed as part of page fault path
463   * (full == false), valid ptes are generally not expected; however, there
464   * is one situation where they arise, which is when dirty page logging is
465   * turned off for a memslot while the VM is running.  The new memslot
466   * becomes visible to page faults before the memslot commit function
467   * gets to flush the memslot, which can lead to a 2MB page mapping being
468   * installed for a guest physical address where there are already 64kB
469   * (or 4kB) mappings (of sub-pages of the same 2MB page).
470   */
kvmppc_unmap_free_pte(struct kvm * kvm,pte_t * pte,bool full,unsigned int lpid)471  static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
472  				  unsigned int lpid)
473  {
474  	if (full) {
475  		memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE);
476  	} else {
477  		pte_t *p = pte;
478  		unsigned long it;
479  
480  		for (it = 0; it < PTRS_PER_PTE; ++it, ++p) {
481  			if (pte_val(*p) == 0)
482  				continue;
483  			kvmppc_unmap_pte(kvm, p,
484  					 pte_pfn(*p) << PAGE_SHIFT,
485  					 PAGE_SHIFT, NULL, lpid);
486  		}
487  	}
488  
489  	kvmppc_pte_free(pte);
490  }
491  
kvmppc_unmap_free_pmd(struct kvm * kvm,pmd_t * pmd,bool full,unsigned int lpid)492  static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
493  				  unsigned int lpid)
494  {
495  	unsigned long im;
496  	pmd_t *p = pmd;
497  
498  	for (im = 0; im < PTRS_PER_PMD; ++im, ++p) {
499  		if (!pmd_present(*p))
500  			continue;
501  		if (pmd_is_leaf(*p)) {
502  			if (full) {
503  				pmd_clear(p);
504  			} else {
505  				WARN_ON_ONCE(1);
506  				kvmppc_unmap_pte(kvm, (pte_t *)p,
507  					 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
508  					 PMD_SHIFT, NULL, lpid);
509  			}
510  		} else {
511  			pte_t *pte;
512  
513  			pte = pte_offset_kernel(p, 0);
514  			kvmppc_unmap_free_pte(kvm, pte, full, lpid);
515  			pmd_clear(p);
516  		}
517  	}
518  	kvmppc_pmd_free(pmd);
519  }
520  
kvmppc_unmap_free_pud(struct kvm * kvm,pud_t * pud,unsigned int lpid)521  static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
522  				  unsigned int lpid)
523  {
524  	unsigned long iu;
525  	pud_t *p = pud;
526  
527  	for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) {
528  		if (!pud_present(*p))
529  			continue;
530  		if (pud_is_leaf(*p)) {
531  			pud_clear(p);
532  		} else {
533  			pmd_t *pmd;
534  
535  			pmd = pmd_offset(p, 0);
536  			kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
537  			pud_clear(p);
538  		}
539  	}
540  	pud_free(kvm->mm, pud);
541  }
542  
kvmppc_free_pgtable_radix(struct kvm * kvm,pgd_t * pgd,unsigned int lpid)543  void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
544  {
545  	unsigned long ig;
546  
547  	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
548  		p4d_t *p4d = p4d_offset(pgd, 0);
549  		pud_t *pud;
550  
551  		if (!p4d_present(*p4d))
552  			continue;
553  		pud = pud_offset(p4d, 0);
554  		kvmppc_unmap_free_pud(kvm, pud, lpid);
555  		p4d_clear(p4d);
556  	}
557  }
558  
kvmppc_free_radix(struct kvm * kvm)559  void kvmppc_free_radix(struct kvm *kvm)
560  {
561  	if (kvm->arch.pgtable) {
562  		kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
563  					  kvm->arch.lpid);
564  		pgd_free(kvm->mm, kvm->arch.pgtable);
565  		kvm->arch.pgtable = NULL;
566  	}
567  }
568  
kvmppc_unmap_free_pmd_entry_table(struct kvm * kvm,pmd_t * pmd,unsigned long gpa,unsigned int lpid)569  static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
570  					unsigned long gpa, unsigned int lpid)
571  {
572  	pte_t *pte = pte_offset_kernel(pmd, 0);
573  
574  	/*
575  	 * Clearing the pmd entry then flushing the PWC ensures that the pte
576  	 * page no longer be cached by the MMU, so can be freed without
577  	 * flushing the PWC again.
578  	 */
579  	pmd_clear(pmd);
580  	kvmppc_radix_flush_pwc(kvm, lpid);
581  
582  	kvmppc_unmap_free_pte(kvm, pte, false, lpid);
583  }
584  
kvmppc_unmap_free_pud_entry_table(struct kvm * kvm,pud_t * pud,unsigned long gpa,unsigned int lpid)585  static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
586  					unsigned long gpa, unsigned int lpid)
587  {
588  	pmd_t *pmd = pmd_offset(pud, 0);
589  
590  	/*
591  	 * Clearing the pud entry then flushing the PWC ensures that the pmd
592  	 * page and any children pte pages will no longer be cached by the MMU,
593  	 * so can be freed without flushing the PWC again.
594  	 */
595  	pud_clear(pud);
596  	kvmppc_radix_flush_pwc(kvm, lpid);
597  
598  	kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
599  }
600  
601  /*
602   * There are a number of bits which may differ between different faults to
603   * the same partition scope entry. RC bits, in the course of cleaning and
604   * aging. And the write bit can change, either the access could have been
605   * upgraded, or a read fault could happen concurrently with a write fault
606   * that sets those bits first.
607   */
608  #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
609  
kvmppc_create_pte(struct kvm * kvm,pgd_t * pgtable,pte_t pte,unsigned long gpa,unsigned int level,unsigned long mmu_seq,unsigned int lpid,unsigned long * rmapp,struct rmap_nested ** n_rmap)610  int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
611  		      unsigned long gpa, unsigned int level,
612  		      unsigned long mmu_seq, unsigned int lpid,
613  		      unsigned long *rmapp, struct rmap_nested **n_rmap)
614  {
615  	pgd_t *pgd;
616  	p4d_t *p4d;
617  	pud_t *pud, *new_pud = NULL;
618  	pmd_t *pmd, *new_pmd = NULL;
619  	pte_t *ptep, *new_ptep = NULL;
620  	int ret;
621  
622  	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
623  	pgd = pgtable + pgd_index(gpa);
624  	p4d = p4d_offset(pgd, gpa);
625  
626  	pud = NULL;
627  	if (p4d_present(*p4d))
628  		pud = pud_offset(p4d, gpa);
629  	else
630  		new_pud = pud_alloc_one(kvm->mm, gpa);
631  
632  	pmd = NULL;
633  	if (pud && pud_present(*pud) && !pud_is_leaf(*pud))
634  		pmd = pmd_offset(pud, gpa);
635  	else if (level <= 1)
636  		new_pmd = kvmppc_pmd_alloc();
637  
638  	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
639  		new_ptep = kvmppc_pte_alloc();
640  
641  	/* Check if we might have been invalidated; let the guest retry if so */
642  	spin_lock(&kvm->mmu_lock);
643  	ret = -EAGAIN;
644  	if (mmu_invalidate_retry(kvm, mmu_seq))
645  		goto out_unlock;
646  
647  	/* Now traverse again under the lock and change the tree */
648  	ret = -ENOMEM;
649  	if (p4d_none(*p4d)) {
650  		if (!new_pud)
651  			goto out_unlock;
652  		p4d_populate(kvm->mm, p4d, new_pud);
653  		new_pud = NULL;
654  	}
655  	pud = pud_offset(p4d, gpa);
656  	if (pud_is_leaf(*pud)) {
657  		unsigned long hgpa = gpa & PUD_MASK;
658  
659  		/* Check if we raced and someone else has set the same thing */
660  		if (level == 2) {
661  			if (pud_raw(*pud) == pte_raw(pte)) {
662  				ret = 0;
663  				goto out_unlock;
664  			}
665  			/* Valid 1GB page here already, add our extra bits */
666  			WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
667  							PTE_BITS_MUST_MATCH);
668  			kvmppc_radix_update_pte(kvm, (pte_t *)pud,
669  					      0, pte_val(pte), hgpa, PUD_SHIFT);
670  			ret = 0;
671  			goto out_unlock;
672  		}
673  		/*
674  		 * If we raced with another CPU which has just put
675  		 * a 1GB pte in after we saw a pmd page, try again.
676  		 */
677  		if (!new_pmd) {
678  			ret = -EAGAIN;
679  			goto out_unlock;
680  		}
681  		/* Valid 1GB page here already, remove it */
682  		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
683  				 lpid);
684  	}
685  	if (level == 2) {
686  		if (!pud_none(*pud)) {
687  			/*
688  			 * There's a page table page here, but we wanted to
689  			 * install a large page, so remove and free the page
690  			 * table page.
691  			 */
692  			kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
693  		}
694  		kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
695  		if (rmapp && n_rmap)
696  			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
697  		ret = 0;
698  		goto out_unlock;
699  	}
700  	if (pud_none(*pud)) {
701  		if (!new_pmd)
702  			goto out_unlock;
703  		pud_populate(kvm->mm, pud, new_pmd);
704  		new_pmd = NULL;
705  	}
706  	pmd = pmd_offset(pud, gpa);
707  	if (pmd_is_leaf(*pmd)) {
708  		unsigned long lgpa = gpa & PMD_MASK;
709  
710  		/* Check if we raced and someone else has set the same thing */
711  		if (level == 1) {
712  			if (pmd_raw(*pmd) == pte_raw(pte)) {
713  				ret = 0;
714  				goto out_unlock;
715  			}
716  			/* Valid 2MB page here already, add our extra bits */
717  			WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
718  							PTE_BITS_MUST_MATCH);
719  			kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
720  					0, pte_val(pte), lgpa, PMD_SHIFT);
721  			ret = 0;
722  			goto out_unlock;
723  		}
724  
725  		/*
726  		 * If we raced with another CPU which has just put
727  		 * a 2MB pte in after we saw a pte page, try again.
728  		 */
729  		if (!new_ptep) {
730  			ret = -EAGAIN;
731  			goto out_unlock;
732  		}
733  		/* Valid 2MB page here already, remove it */
734  		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
735  				 lpid);
736  	}
737  	if (level == 1) {
738  		if (!pmd_none(*pmd)) {
739  			/*
740  			 * There's a page table page here, but we wanted to
741  			 * install a large page, so remove and free the page
742  			 * table page.
743  			 */
744  			kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
745  		}
746  		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
747  		if (rmapp && n_rmap)
748  			kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
749  		ret = 0;
750  		goto out_unlock;
751  	}
752  	if (pmd_none(*pmd)) {
753  		if (!new_ptep)
754  			goto out_unlock;
755  		pmd_populate(kvm->mm, pmd, new_ptep);
756  		new_ptep = NULL;
757  	}
758  	ptep = pte_offset_kernel(pmd, gpa);
759  	if (pte_present(*ptep)) {
760  		/* Check if someone else set the same thing */
761  		if (pte_raw(*ptep) == pte_raw(pte)) {
762  			ret = 0;
763  			goto out_unlock;
764  		}
765  		/* Valid page here already, add our extra bits */
766  		WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) &
767  							PTE_BITS_MUST_MATCH);
768  		kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0);
769  		ret = 0;
770  		goto out_unlock;
771  	}
772  	kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
773  	if (rmapp && n_rmap)
774  		kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap);
775  	ret = 0;
776  
777   out_unlock:
778  	spin_unlock(&kvm->mmu_lock);
779  	if (new_pud)
780  		pud_free(kvm->mm, new_pud);
781  	if (new_pmd)
782  		kvmppc_pmd_free(new_pmd);
783  	if (new_ptep)
784  		kvmppc_pte_free(new_ptep);
785  	return ret;
786  }
787  
kvmppc_hv_handle_set_rc(struct kvm * kvm,bool nested,bool writing,unsigned long gpa,unsigned int lpid)788  bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing,
789  			     unsigned long gpa, unsigned int lpid)
790  {
791  	unsigned long pgflags;
792  	unsigned int shift;
793  	pte_t *ptep;
794  
795  	/*
796  	 * Need to set an R or C bit in the 2nd-level tables;
797  	 * since we are just helping out the hardware here,
798  	 * it is sufficient to do what the hardware does.
799  	 */
800  	pgflags = _PAGE_ACCESSED;
801  	if (writing)
802  		pgflags |= _PAGE_DIRTY;
803  
804  	if (nested)
805  		ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
806  	else
807  		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
808  
809  	if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
810  		kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
811  		return true;
812  	}
813  	return false;
814  }
815  
kvmppc_book3s_instantiate_page(struct kvm_vcpu * vcpu,unsigned long gpa,struct kvm_memory_slot * memslot,bool writing,bool kvm_ro,pte_t * inserted_pte,unsigned int * levelp)816  int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
817  				   unsigned long gpa,
818  				   struct kvm_memory_slot *memslot,
819  				   bool writing, bool kvm_ro,
820  				   pte_t *inserted_pte, unsigned int *levelp)
821  {
822  	struct kvm *kvm = vcpu->kvm;
823  	struct page *page = NULL;
824  	unsigned long mmu_seq;
825  	unsigned long hva, gfn = gpa >> PAGE_SHIFT;
826  	bool upgrade_write = false;
827  	bool *upgrade_p = &upgrade_write;
828  	pte_t pte, *ptep;
829  	unsigned int shift, level;
830  	int ret;
831  	bool large_enable;
832  
833  	/* used to check for invalidations in progress */
834  	mmu_seq = kvm->mmu_invalidate_seq;
835  	smp_rmb();
836  
837  	/*
838  	 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
839  	 * do it with !atomic && !async, which is how we call it.
840  	 * We always ask for write permission since the common case
841  	 * is that the page is writable.
842  	 */
843  	hva = gfn_to_hva_memslot(memslot, gfn);
844  	if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {
845  		upgrade_write = true;
846  	} else {
847  		unsigned long pfn;
848  
849  		/* Call KVM generic code to do the slow-path check */
850  		pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
851  					   writing, upgrade_p, NULL);
852  		if (is_error_noslot_pfn(pfn))
853  			return -EFAULT;
854  		page = NULL;
855  		if (pfn_valid(pfn)) {
856  			page = pfn_to_page(pfn);
857  			if (PageReserved(page))
858  				page = NULL;
859  		}
860  	}
861  
862  	/*
863  	 * Read the PTE from the process' radix tree and use that
864  	 * so we get the shift and attribute bits.
865  	 */
866  	spin_lock(&kvm->mmu_lock);
867  	ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift);
868  	pte = __pte(0);
869  	if (ptep)
870  		pte = READ_ONCE(*ptep);
871  	spin_unlock(&kvm->mmu_lock);
872  	/*
873  	 * If the PTE disappeared temporarily due to a THP
874  	 * collapse, just return and let the guest try again.
875  	 */
876  	if (!pte_present(pte)) {
877  		if (page)
878  			put_page(page);
879  		return RESUME_GUEST;
880  	}
881  
882  	/* If we're logging dirty pages, always map single pages */
883  	large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES);
884  
885  	/* Get pte level from shift/size */
886  	if (large_enable && shift == PUD_SHIFT &&
887  	    (gpa & (PUD_SIZE - PAGE_SIZE)) ==
888  	    (hva & (PUD_SIZE - PAGE_SIZE))) {
889  		level = 2;
890  	} else if (large_enable && shift == PMD_SHIFT &&
891  		   (gpa & (PMD_SIZE - PAGE_SIZE)) ==
892  		   (hva & (PMD_SIZE - PAGE_SIZE))) {
893  		level = 1;
894  	} else {
895  		level = 0;
896  		if (shift > PAGE_SHIFT) {
897  			/*
898  			 * If the pte maps more than one page, bring over
899  			 * bits from the virtual address to get the real
900  			 * address of the specific single page we want.
901  			 */
902  			unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;
903  			pte = __pte(pte_val(pte) | (hva & rpnmask));
904  		}
905  	}
906  
907  	pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
908  	if (writing || upgrade_write) {
909  		if (pte_val(pte) & _PAGE_WRITE)
910  			pte = __pte(pte_val(pte) | _PAGE_DIRTY);
911  	} else {
912  		pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
913  	}
914  
915  	/* Allocate space in the tree and write the PTE */
916  	ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
917  				mmu_seq, kvm->arch.lpid, NULL, NULL);
918  	if (inserted_pte)
919  		*inserted_pte = pte;
920  	if (levelp)
921  		*levelp = level;
922  
923  	if (page) {
924  		if (!ret && (pte_val(pte) & _PAGE_WRITE))
925  			set_page_dirty_lock(page);
926  		put_page(page);
927  	}
928  
929  	/* Increment number of large pages if we (successfully) inserted one */
930  	if (!ret) {
931  		if (level == 1)
932  			kvm->stat.num_2M_pages++;
933  		else if (level == 2)
934  			kvm->stat.num_1G_pages++;
935  	}
936  
937  	return ret;
938  }
939  
kvmppc_book3s_radix_page_fault(struct kvm_vcpu * vcpu,unsigned long ea,unsigned long dsisr)940  int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu,
941  				   unsigned long ea, unsigned long dsisr)
942  {
943  	struct kvm *kvm = vcpu->kvm;
944  	unsigned long gpa, gfn;
945  	struct kvm_memory_slot *memslot;
946  	long ret;
947  	bool writing = !!(dsisr & DSISR_ISSTORE);
948  	bool kvm_ro = false;
949  
950  	/* Check for unusual errors */
951  	if (dsisr & DSISR_UNSUPP_MMU) {
952  		pr_err("KVM: Got unsupported MMU fault\n");
953  		return -EFAULT;
954  	}
955  	if (dsisr & DSISR_BADACCESS) {
956  		/* Reflect to the guest as DSI */
957  		pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
958  		kvmppc_core_queue_data_storage(vcpu,
959  				kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
960  				ea, dsisr);
961  		return RESUME_GUEST;
962  	}
963  
964  	/* Translate the logical address */
965  	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
966  	gpa &= ~0xF000000000000000ul;
967  	gfn = gpa >> PAGE_SHIFT;
968  	if (!(dsisr & DSISR_PRTABLE_FAULT))
969  		gpa |= ea & 0xfff;
970  
971  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
972  		return kvmppc_send_page_to_uv(kvm, gfn);
973  
974  	/* Get the corresponding memslot */
975  	memslot = gfn_to_memslot(kvm, gfn);
976  
977  	/* No memslot means it's an emulated MMIO region */
978  	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
979  		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
980  			     DSISR_SET_RC)) {
981  			/*
982  			 * Bad address in guest page table tree, or other
983  			 * unusual error - reflect it to the guest as DSI.
984  			 */
985  			kvmppc_core_queue_data_storage(vcpu,
986  					kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
987  					ea, dsisr);
988  			return RESUME_GUEST;
989  		}
990  		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
991  	}
992  
993  	if (memslot->flags & KVM_MEM_READONLY) {
994  		if (writing) {
995  			/* give the guest a DSI */
996  			kvmppc_core_queue_data_storage(vcpu,
997  					kvmppc_get_msr(vcpu) & SRR1_PREFIXED,
998  					ea, DSISR_ISSTORE | DSISR_PROTFAULT);
999  			return RESUME_GUEST;
1000  		}
1001  		kvm_ro = true;
1002  	}
1003  
1004  	/* Failed to set the reference/change bits */
1005  	if (dsisr & DSISR_SET_RC) {
1006  		spin_lock(&kvm->mmu_lock);
1007  		if (kvmppc_hv_handle_set_rc(kvm, false, writing,
1008  					    gpa, kvm->arch.lpid))
1009  			dsisr &= ~DSISR_SET_RC;
1010  		spin_unlock(&kvm->mmu_lock);
1011  
1012  		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1013  			       DSISR_PROTFAULT | DSISR_SET_RC)))
1014  			return RESUME_GUEST;
1015  	}
1016  
1017  	/* Try to insert a pte */
1018  	ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
1019  					     kvm_ro, NULL, NULL);
1020  
1021  	if (ret == 0 || ret == -EAGAIN)
1022  		ret = RESUME_GUEST;
1023  	return ret;
1024  }
1025  
1026  /* Called with kvm->mmu_lock held */
kvm_unmap_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1027  void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1028  		     unsigned long gfn)
1029  {
1030  	pte_t *ptep;
1031  	unsigned long gpa = gfn << PAGE_SHIFT;
1032  	unsigned int shift;
1033  
1034  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
1035  		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
1036  		return;
1037  	}
1038  
1039  	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1040  	if (ptep && pte_present(*ptep))
1041  		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1042  				 kvm->arch.lpid);
1043  }
1044  
1045  /* Called with kvm->mmu_lock held */
kvm_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1046  bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1047  		   unsigned long gfn)
1048  {
1049  	pte_t *ptep;
1050  	unsigned long gpa = gfn << PAGE_SHIFT;
1051  	unsigned int shift;
1052  	bool ref = false;
1053  	unsigned long old, *rmapp;
1054  
1055  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1056  		return ref;
1057  
1058  	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1059  	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
1060  		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
1061  					      gpa, shift);
1062  		/* XXX need to flush tlb here? */
1063  		/* Also clear bit in ptes in shadow pgtable for nested guests */
1064  		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1065  		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0,
1066  					       old & PTE_RPN_MASK,
1067  					       1UL << shift);
1068  		ref = true;
1069  	}
1070  	return ref;
1071  }
1072  
1073  /* Called with kvm->mmu_lock held */
kvm_test_age_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long gfn)1074  bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
1075  			unsigned long gfn)
1076  
1077  {
1078  	pte_t *ptep;
1079  	unsigned long gpa = gfn << PAGE_SHIFT;
1080  	unsigned int shift;
1081  	bool ref = false;
1082  
1083  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1084  		return ref;
1085  
1086  	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1087  	if (ptep && pte_present(*ptep) && pte_young(*ptep))
1088  		ref = true;
1089  	return ref;
1090  }
1091  
1092  /* Returns the number of PAGE_SIZE pages that are dirty */
kvm_radix_test_clear_dirty(struct kvm * kvm,struct kvm_memory_slot * memslot,int pagenum)1093  static int kvm_radix_test_clear_dirty(struct kvm *kvm,
1094  				struct kvm_memory_slot *memslot, int pagenum)
1095  {
1096  	unsigned long gfn = memslot->base_gfn + pagenum;
1097  	unsigned long gpa = gfn << PAGE_SHIFT;
1098  	pte_t *ptep, pte;
1099  	unsigned int shift;
1100  	int ret = 0;
1101  	unsigned long old, *rmapp;
1102  
1103  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1104  		return ret;
1105  
1106  	/*
1107  	 * For performance reasons we don't hold kvm->mmu_lock while walking the
1108  	 * partition scoped table.
1109  	 */
1110  	ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);
1111  	if (!ptep)
1112  		return 0;
1113  
1114  	pte = READ_ONCE(*ptep);
1115  	if (pte_present(pte) && pte_dirty(pte)) {
1116  		spin_lock(&kvm->mmu_lock);
1117  		/*
1118  		 * Recheck the pte again
1119  		 */
1120  		if (pte_val(pte) != pte_val(*ptep)) {
1121  			/*
1122  			 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
1123  			 * only find PAGE_SIZE pte entries here. We can continue
1124  			 * to use the pte addr returned by above page table
1125  			 * walk.
1126  			 */
1127  			if (!pte_present(*ptep) || !pte_dirty(*ptep)) {
1128  				spin_unlock(&kvm->mmu_lock);
1129  				return 0;
1130  			}
1131  		}
1132  
1133  		ret = 1;
1134  		VM_BUG_ON(shift);
1135  		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
1136  					      gpa, shift);
1137  		kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
1138  		/* Also clear bit in ptes in shadow pgtable for nested guests */
1139  		rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1140  		kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0,
1141  					       old & PTE_RPN_MASK,
1142  					       1UL << shift);
1143  		spin_unlock(&kvm->mmu_lock);
1144  	}
1145  	return ret;
1146  }
1147  
kvmppc_hv_get_dirty_log_radix(struct kvm * kvm,struct kvm_memory_slot * memslot,unsigned long * map)1148  long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
1149  			struct kvm_memory_slot *memslot, unsigned long *map)
1150  {
1151  	unsigned long i, j;
1152  	int npages;
1153  
1154  	for (i = 0; i < memslot->npages; i = j) {
1155  		npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
1156  
1157  		/*
1158  		 * Note that if npages > 0 then i must be a multiple of npages,
1159  		 * since huge pages are only used to back the guest at guest
1160  		 * real addresses that are a multiple of their size.
1161  		 * Since we have at most one PTE covering any given guest
1162  		 * real address, if npages > 1 we can skip to i + npages.
1163  		 */
1164  		j = i + 1;
1165  		if (npages) {
1166  			set_dirty_bits(map, i, npages);
1167  			j = i + npages;
1168  		}
1169  	}
1170  	return 0;
1171  }
1172  
kvmppc_radix_flush_memslot(struct kvm * kvm,const struct kvm_memory_slot * memslot)1173  void kvmppc_radix_flush_memslot(struct kvm *kvm,
1174  				const struct kvm_memory_slot *memslot)
1175  {
1176  	unsigned long n;
1177  	pte_t *ptep;
1178  	unsigned long gpa;
1179  	unsigned int shift;
1180  
1181  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
1182  		kvmppc_uvmem_drop_pages(memslot, kvm, true);
1183  
1184  	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
1185  		return;
1186  
1187  	gpa = memslot->base_gfn << PAGE_SHIFT;
1188  	spin_lock(&kvm->mmu_lock);
1189  	for (n = memslot->npages; n; --n) {
1190  		ptep = find_kvm_secondary_pte(kvm, gpa, &shift);
1191  		if (ptep && pte_present(*ptep))
1192  			kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
1193  					 kvm->arch.lpid);
1194  		gpa += PAGE_SIZE;
1195  	}
1196  	/*
1197  	 * Increase the mmu notifier sequence number to prevent any page
1198  	 * fault that read the memslot earlier from writing a PTE.
1199  	 */
1200  	kvm->mmu_invalidate_seq++;
1201  	spin_unlock(&kvm->mmu_lock);
1202  }
1203  
add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info * info,int psize,int * indexp)1204  static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
1205  				 int psize, int *indexp)
1206  {
1207  	if (!mmu_psize_defs[psize].shift)
1208  		return;
1209  	info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
1210  		(mmu_psize_defs[psize].ap << 29);
1211  	++(*indexp);
1212  }
1213  
kvmhv_get_rmmu_info(struct kvm * kvm,struct kvm_ppc_rmmu_info * info)1214  int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
1215  {
1216  	int i;
1217  
1218  	if (!radix_enabled())
1219  		return -EINVAL;
1220  	memset(info, 0, sizeof(*info));
1221  
1222  	/* 4k page size */
1223  	info->geometries[0].page_shift = 12;
1224  	info->geometries[0].level_bits[0] = 9;
1225  	for (i = 1; i < 4; ++i)
1226  		info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
1227  	/* 64k page size */
1228  	info->geometries[1].page_shift = 16;
1229  	for (i = 0; i < 4; ++i)
1230  		info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
1231  
1232  	i = 0;
1233  	add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
1234  	add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
1235  	add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
1236  	add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
1237  
1238  	return 0;
1239  }
1240  
kvmppc_init_vm_radix(struct kvm * kvm)1241  int kvmppc_init_vm_radix(struct kvm *kvm)
1242  {
1243  	kvm->arch.pgtable = pgd_alloc(kvm->mm);
1244  	if (!kvm->arch.pgtable)
1245  		return -ENOMEM;
1246  	return 0;
1247  }
1248  
pte_ctor(void * addr)1249  static void pte_ctor(void *addr)
1250  {
1251  	memset(addr, 0, RADIX_PTE_TABLE_SIZE);
1252  }
1253  
pmd_ctor(void * addr)1254  static void pmd_ctor(void *addr)
1255  {
1256  	memset(addr, 0, RADIX_PMD_TABLE_SIZE);
1257  }
1258  
1259  struct debugfs_radix_state {
1260  	struct kvm	*kvm;
1261  	struct mutex	mutex;
1262  	unsigned long	gpa;
1263  	int		lpid;
1264  	int		chars_left;
1265  	int		buf_index;
1266  	char		buf[128];
1267  	u8		hdr;
1268  };
1269  
debugfs_radix_open(struct inode * inode,struct file * file)1270  static int debugfs_radix_open(struct inode *inode, struct file *file)
1271  {
1272  	struct kvm *kvm = inode->i_private;
1273  	struct debugfs_radix_state *p;
1274  
1275  	p = kzalloc(sizeof(*p), GFP_KERNEL);
1276  	if (!p)
1277  		return -ENOMEM;
1278  
1279  	kvm_get_kvm(kvm);
1280  	p->kvm = kvm;
1281  	mutex_init(&p->mutex);
1282  	file->private_data = p;
1283  
1284  	return nonseekable_open(inode, file);
1285  }
1286  
debugfs_radix_release(struct inode * inode,struct file * file)1287  static int debugfs_radix_release(struct inode *inode, struct file *file)
1288  {
1289  	struct debugfs_radix_state *p = file->private_data;
1290  
1291  	kvm_put_kvm(p->kvm);
1292  	kfree(p);
1293  	return 0;
1294  }
1295  
debugfs_radix_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)1296  static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
1297  				 size_t len, loff_t *ppos)
1298  {
1299  	struct debugfs_radix_state *p = file->private_data;
1300  	ssize_t ret, r;
1301  	unsigned long n;
1302  	struct kvm *kvm;
1303  	unsigned long gpa;
1304  	pgd_t *pgt;
1305  	struct kvm_nested_guest *nested;
1306  	pgd_t *pgdp;
1307  	p4d_t p4d, *p4dp;
1308  	pud_t pud, *pudp;
1309  	pmd_t pmd, *pmdp;
1310  	pte_t *ptep;
1311  	int shift;
1312  	unsigned long pte;
1313  
1314  	kvm = p->kvm;
1315  	if (!kvm_is_radix(kvm))
1316  		return 0;
1317  
1318  	ret = mutex_lock_interruptible(&p->mutex);
1319  	if (ret)
1320  		return ret;
1321  
1322  	if (p->chars_left) {
1323  		n = p->chars_left;
1324  		if (n > len)
1325  			n = len;
1326  		r = copy_to_user(buf, p->buf + p->buf_index, n);
1327  		n -= r;
1328  		p->chars_left -= n;
1329  		p->buf_index += n;
1330  		buf += n;
1331  		len -= n;
1332  		ret = n;
1333  		if (r) {
1334  			if (!n)
1335  				ret = -EFAULT;
1336  			goto out;
1337  		}
1338  	}
1339  
1340  	gpa = p->gpa;
1341  	nested = NULL;
1342  	pgt = NULL;
1343  	while (len != 0 && p->lpid >= 0) {
1344  		if (gpa >= RADIX_PGTABLE_RANGE) {
1345  			gpa = 0;
1346  			pgt = NULL;
1347  			if (nested) {
1348  				kvmhv_put_nested(nested);
1349  				nested = NULL;
1350  			}
1351  			p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid);
1352  			p->hdr = 0;
1353  			if (p->lpid < 0)
1354  				break;
1355  		}
1356  		if (!pgt) {
1357  			if (p->lpid == 0) {
1358  				pgt = kvm->arch.pgtable;
1359  			} else {
1360  				nested = kvmhv_get_nested(kvm, p->lpid, false);
1361  				if (!nested) {
1362  					gpa = RADIX_PGTABLE_RANGE;
1363  					continue;
1364  				}
1365  				pgt = nested->shadow_pgtable;
1366  			}
1367  		}
1368  		n = 0;
1369  		if (!p->hdr) {
1370  			if (p->lpid > 0)
1371  				n = scnprintf(p->buf, sizeof(p->buf),
1372  					      "\nNested LPID %d: ", p->lpid);
1373  			n += scnprintf(p->buf + n, sizeof(p->buf) - n,
1374  				      "pgdir: %lx\n", (unsigned long)pgt);
1375  			p->hdr = 1;
1376  			goto copy;
1377  		}
1378  
1379  		pgdp = pgt + pgd_index(gpa);
1380  		p4dp = p4d_offset(pgdp, gpa);
1381  		p4d = READ_ONCE(*p4dp);
1382  		if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
1383  			gpa = (gpa & P4D_MASK) + P4D_SIZE;
1384  			continue;
1385  		}
1386  
1387  		pudp = pud_offset(&p4d, gpa);
1388  		pud = READ_ONCE(*pudp);
1389  		if (!(pud_val(pud) & _PAGE_PRESENT)) {
1390  			gpa = (gpa & PUD_MASK) + PUD_SIZE;
1391  			continue;
1392  		}
1393  		if (pud_val(pud) & _PAGE_PTE) {
1394  			pte = pud_val(pud);
1395  			shift = PUD_SHIFT;
1396  			goto leaf;
1397  		}
1398  
1399  		pmdp = pmd_offset(&pud, gpa);
1400  		pmd = READ_ONCE(*pmdp);
1401  		if (!(pmd_val(pmd) & _PAGE_PRESENT)) {
1402  			gpa = (gpa & PMD_MASK) + PMD_SIZE;
1403  			continue;
1404  		}
1405  		if (pmd_val(pmd) & _PAGE_PTE) {
1406  			pte = pmd_val(pmd);
1407  			shift = PMD_SHIFT;
1408  			goto leaf;
1409  		}
1410  
1411  		ptep = pte_offset_kernel(&pmd, gpa);
1412  		pte = pte_val(READ_ONCE(*ptep));
1413  		if (!(pte & _PAGE_PRESENT)) {
1414  			gpa += PAGE_SIZE;
1415  			continue;
1416  		}
1417  		shift = PAGE_SHIFT;
1418  	leaf:
1419  		n = scnprintf(p->buf, sizeof(p->buf),
1420  			      " %lx: %lx %d\n", gpa, pte, shift);
1421  		gpa += 1ul << shift;
1422  	copy:
1423  		p->chars_left = n;
1424  		if (n > len)
1425  			n = len;
1426  		r = copy_to_user(buf, p->buf, n);
1427  		n -= r;
1428  		p->chars_left -= n;
1429  		p->buf_index = n;
1430  		buf += n;
1431  		len -= n;
1432  		ret += n;
1433  		if (r) {
1434  			if (!ret)
1435  				ret = -EFAULT;
1436  			break;
1437  		}
1438  	}
1439  	p->gpa = gpa;
1440  	if (nested)
1441  		kvmhv_put_nested(nested);
1442  
1443   out:
1444  	mutex_unlock(&p->mutex);
1445  	return ret;
1446  }
1447  
debugfs_radix_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)1448  static ssize_t debugfs_radix_write(struct file *file, const char __user *buf,
1449  			   size_t len, loff_t *ppos)
1450  {
1451  	return -EACCES;
1452  }
1453  
1454  static const struct file_operations debugfs_radix_fops = {
1455  	.owner	 = THIS_MODULE,
1456  	.open	 = debugfs_radix_open,
1457  	.release = debugfs_radix_release,
1458  	.read	 = debugfs_radix_read,
1459  	.write	 = debugfs_radix_write,
1460  	.llseek	 = generic_file_llseek,
1461  };
1462  
kvmhv_radix_debugfs_init(struct kvm * kvm)1463  void kvmhv_radix_debugfs_init(struct kvm *kvm)
1464  {
1465  	debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm,
1466  			    &debugfs_radix_fops);
1467  }
1468  
kvmppc_radix_init(void)1469  int kvmppc_radix_init(void)
1470  {
1471  	unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE;
1472  
1473  	kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
1474  	if (!kvm_pte_cache)
1475  		return -ENOMEM;
1476  
1477  	size = sizeof(void *) << RADIX_PMD_INDEX_SIZE;
1478  
1479  	kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, 0, pmd_ctor);
1480  	if (!kvm_pmd_cache) {
1481  		kmem_cache_destroy(kvm_pte_cache);
1482  		return -ENOMEM;
1483  	}
1484  
1485  	return 0;
1486  }
1487  
kvmppc_radix_exit(void)1488  void kvmppc_radix_exit(void)
1489  {
1490  	kmem_cache_destroy(kvm_pte_cache);
1491  	kmem_cache_destroy(kvm_pmd_cache);
1492  }
1493