1 // SPDX-License-Identifier: GPL-2.0-only
4 * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
7 #include <linux/types.h>
8 #include <linux/string.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>
16 #include <asm/kvm_ppc.h>
17 #include <asm/kvm_book3s.h>
20 #include <asm/pgalloc.h>
21 #include <asm/pte-walk.h>
22 #include <asm/ultravisor.h>
23 #include <asm/kvm_book3s_uvmem.h>
26 * Supported radix tree geometry.
27 * Like p9, we support either 5 or 9 bits at the first (lowest) level,
28 * for a page size of 64k or 4k.
30 static int p9_supported_radix_bits
[4] = { 5, 9, 9, 13 };
32 unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid
, int pid
,
33 gva_t eaddr
, void *to
, void *from
,
36 int old_pid
, old_lpid
;
37 unsigned long quadrant
, ret
= n
;
40 /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
41 if (kvmhv_on_pseries())
42 return plpar_hcall_norets(H_COPY_TOFROM_GUEST
, lpid
, pid
, eaddr
,
43 (to
!= NULL
) ? __pa(to
): 0,
44 (from
!= NULL
) ? __pa(from
): 0, n
);
50 from
= (void *) (eaddr
| (quadrant
<< 62));
52 to
= (void *) (eaddr
| (quadrant
<< 62));
56 /* switch the lpid first to avoid running host with unallocated pid */
57 old_lpid
= mfspr(SPRN_LPID
);
59 mtspr(SPRN_LPID
, lpid
);
61 old_pid
= mfspr(SPRN_PID
);
68 ret
= copy_from_user_nofault(to
, (const void __user
*)from
, n
);
70 ret
= copy_to_user_nofault((void __user
*)to
, from
, n
);
72 /* switch the pid first to avoid running host with unallocated pid */
73 if (quadrant
== 1 && pid
!= old_pid
)
74 mtspr(SPRN_PID
, old_pid
);
76 mtspr(SPRN_LPID
, old_lpid
);
83 EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix
);
85 static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu
*vcpu
, gva_t eaddr
,
86 void *to
, void *from
, unsigned long n
)
88 int lpid
= vcpu
->kvm
->arch
.lpid
;
89 int pid
= vcpu
->arch
.pid
;
91 /* This would cause a data segment intr so don't allow the access */
92 if (eaddr
& (0x3FFUL
<< 52))
95 /* Should we be using the nested lpid */
96 if (vcpu
->arch
.nested
)
97 lpid
= vcpu
->arch
.nested
->shadow_lpid
;
99 /* If accessing quadrant 3 then pid is expected to be 0 */
100 if (((eaddr
>> 62) & 0x3) == 0x3)
103 eaddr
&= ~(0xFFFUL
<< 52);
105 return __kvmhv_copy_tofrom_guest_radix(lpid
, pid
, eaddr
, to
, from
, n
);
108 long kvmhv_copy_from_guest_radix(struct kvm_vcpu
*vcpu
, gva_t eaddr
, void *to
,
113 ret
= kvmhv_copy_tofrom_guest_radix(vcpu
, eaddr
, to
, NULL
, n
);
115 memset(to
+ (n
- ret
), 0, ret
);
119 EXPORT_SYMBOL_GPL(kvmhv_copy_from_guest_radix
);
121 long kvmhv_copy_to_guest_radix(struct kvm_vcpu
*vcpu
, gva_t eaddr
, void *from
,
124 return kvmhv_copy_tofrom_guest_radix(vcpu
, eaddr
, NULL
, from
, n
);
126 EXPORT_SYMBOL_GPL(kvmhv_copy_to_guest_radix
);
128 int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu
*vcpu
, gva_t eaddr
,
129 struct kvmppc_pte
*gpte
, u64 root
,
132 struct kvm
*kvm
= vcpu
->kvm
;
134 unsigned long rts
, bits
, offset
, index
;
138 rts
= ((root
& RTS1_MASK
) >> (RTS1_SHIFT
- 3)) |
139 ((root
& RTS2_MASK
) >> RTS2_SHIFT
);
140 bits
= root
& RPDS_MASK
;
141 base
= root
& RPDB_MASK
;
145 /* Current implementations only support 52-bit space */
149 /* Walk each level of the radix tree */
150 for (level
= 3; level
>= 0; --level
) {
152 /* Check a valid size */
153 if (level
&& bits
!= p9_supported_radix_bits
[level
])
155 if (level
== 0 && !(bits
== 5 || bits
== 9))
158 index
= (eaddr
>> offset
) & ((1UL << bits
) - 1);
159 /* Check that low bits of page table base are zero */
160 if (base
& ((1UL << (bits
+ 3)) - 1))
162 /* Read the entry from guest memory */
163 addr
= base
+ (index
* sizeof(rpte
));
164 ret
= kvm_read_guest(kvm
, addr
, &rpte
, sizeof(rpte
));
170 pte
= __be64_to_cpu(rpte
);
171 if (!(pte
& _PAGE_PRESENT
))
173 /* Check if a leaf entry */
176 /* Get ready to walk the next level */
177 base
= pte
& RPDB_MASK
;
178 bits
= pte
& RPDS_MASK
;
181 /* Need a leaf at lowest level; 512GB pages not supported */
182 if (level
< 0 || level
== 3)
185 /* We found a valid leaf PTE */
186 /* Offset is now log base 2 of the page size */
187 gpa
= pte
& 0x01fffffffffff000ul
;
188 if (gpa
& ((1ul << offset
) - 1))
190 gpa
|= eaddr
& ((1ul << offset
) - 1);
191 for (ps
= MMU_PAGE_4K
; ps
< MMU_PAGE_COUNT
; ++ps
)
192 if (offset
== mmu_psize_defs
[ps
].shift
)
194 gpte
->page_size
= ps
;
195 gpte
->page_shift
= offset
;
200 /* Work out permissions */
201 gpte
->may_read
= !!(pte
& _PAGE_READ
);
202 gpte
->may_write
= !!(pte
& _PAGE_WRITE
);
203 gpte
->may_execute
= !!(pte
& _PAGE_EXEC
);
205 gpte
->rc
= pte
& (_PAGE_ACCESSED
| _PAGE_DIRTY
);
214 * Used to walk a partition or process table radix tree in guest memory
215 * Note: We exploit the fact that a partition table and a process
216 * table have the same layout, a partition-scoped page table and a
217 * process-scoped page table have the same layout, and the 2nd
218 * doubleword of a partition table entry has the same layout as
221 int kvmppc_mmu_radix_translate_table(struct kvm_vcpu
*vcpu
, gva_t eaddr
,
222 struct kvmppc_pte
*gpte
, u64 table
,
223 int table_index
, u64
*pte_ret_p
)
225 struct kvm
*kvm
= vcpu
->kvm
;
227 unsigned long size
, ptbl
, root
;
228 struct prtb_entry entry
;
230 if ((table
& PRTS_MASK
) > 24)
232 size
= 1ul << ((table
& PRTS_MASK
) + 12);
234 /* Is the table big enough to contain this entry? */
235 if ((table_index
* sizeof(entry
)) >= size
)
238 /* Read the table to find the root of the radix tree */
239 ptbl
= (table
& PRTB_MASK
) + (table_index
* sizeof(entry
));
240 ret
= kvm_read_guest(kvm
, ptbl
, &entry
, sizeof(entry
));
244 /* Root is stored in the first double word */
245 root
= be64_to_cpu(entry
.prtb0
);
247 return kvmppc_mmu_walk_radix_tree(vcpu
, eaddr
, gpte
, root
, pte_ret_p
);
250 int kvmppc_mmu_radix_xlate(struct kvm_vcpu
*vcpu
, gva_t eaddr
,
251 struct kvmppc_pte
*gpte
, bool data
, bool iswrite
)
257 /* Work out effective PID */
258 switch (eaddr
>> 62) {
260 pid
= vcpu
->arch
.pid
;
269 ret
= kvmppc_mmu_radix_translate_table(vcpu
, eaddr
, gpte
,
270 vcpu
->kvm
->arch
.process_table
, pid
, &pte
);
274 /* Check privilege (applies only to process scoped translations) */
275 if (kvmppc_get_msr(vcpu
) & MSR_PR
) {
276 if (pte
& _PAGE_PRIVILEGED
) {
279 gpte
->may_execute
= 0;
282 if (!(pte
& _PAGE_PRIVILEGED
)) {
283 /* Check AMR/IAMR to see if strict mode is in force */
284 if (vcpu
->arch
.amr
& (1ul << 62))
286 if (vcpu
->arch
.amr
& (1ul << 63))
288 if (vcpu
->arch
.iamr
& (1ul << 62))
289 gpte
->may_execute
= 0;
296 void kvmppc_radix_tlbie_page(struct kvm
*kvm
, unsigned long addr
,
297 unsigned int pshift
, unsigned int lpid
)
299 unsigned long psize
= PAGE_SIZE
;
305 psize
= 1UL << pshift
;
309 addr
&= ~(psize
- 1);
311 if (!kvmhv_on_pseries()) {
312 radix__flush_tlb_lpid_page(lpid
, addr
, psize
);
316 psi
= shift_to_mmu_psize(pshift
);
317 rb
= addr
| (mmu_get_ap(psi
) << PPC_BITLSHIFT(58));
318 rc
= plpar_hcall_norets(H_TLB_INVALIDATE
, H_TLBIE_P1_ENC(0, 0, 1),
321 pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc
);
324 static void kvmppc_radix_flush_pwc(struct kvm
*kvm
, unsigned int lpid
)
328 if (!kvmhv_on_pseries()) {
329 radix__flush_pwc_lpid(lpid
);
333 rc
= plpar_hcall_norets(H_TLB_INVALIDATE
, H_TLBIE_P1_ENC(1, 0, 1),
334 lpid
, TLBIEL_INVAL_SET_LPID
);
336 pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc
);
339 static unsigned long kvmppc_radix_update_pte(struct kvm
*kvm
, pte_t
*ptep
,
340 unsigned long clr
, unsigned long set
,
341 unsigned long addr
, unsigned int shift
)
343 return __radix_pte_update(ptep
, clr
, set
);
346 void kvmppc_radix_set_pte_at(struct kvm
*kvm
, unsigned long addr
,
347 pte_t
*ptep
, pte_t pte
)
349 radix__set_pte_at(kvm
->mm
, addr
, ptep
, pte
, 0);
352 static struct kmem_cache
*kvm_pte_cache
;
353 static struct kmem_cache
*kvm_pmd_cache
;
355 static pte_t
*kvmppc_pte_alloc(void)
359 pte
= kmem_cache_alloc(kvm_pte_cache
, GFP_KERNEL
);
360 /* pmd_populate() will only reference _pa(pte). */
361 kmemleak_ignore(pte
);
366 static void kvmppc_pte_free(pte_t
*ptep
)
368 kmem_cache_free(kvm_pte_cache
, ptep
);
371 static pmd_t
*kvmppc_pmd_alloc(void)
375 pmd
= kmem_cache_alloc(kvm_pmd_cache
, GFP_KERNEL
);
376 /* pud_populate() will only reference _pa(pmd). */
377 kmemleak_ignore(pmd
);
382 static void kvmppc_pmd_free(pmd_t
*pmdp
)
384 kmem_cache_free(kvm_pmd_cache
, pmdp
);
387 /* Called with kvm->mmu_lock held */
388 void kvmppc_unmap_pte(struct kvm
*kvm
, pte_t
*pte
, unsigned long gpa
,
390 const struct kvm_memory_slot
*memslot
,
395 unsigned long gfn
= gpa
>> PAGE_SHIFT
;
396 unsigned long page_size
= PAGE_SIZE
;
399 old
= kvmppc_radix_update_pte(kvm
, pte
, ~0UL, 0, gpa
, shift
);
400 kvmppc_radix_tlbie_page(kvm
, gpa
, shift
, lpid
);
402 /* The following only applies to L1 entries */
403 if (lpid
!= kvm
->arch
.lpid
)
407 memslot
= gfn_to_memslot(kvm
, gfn
);
411 if (shift
) { /* 1GB or 2MB page */
412 page_size
= 1ul << shift
;
413 if (shift
== PMD_SHIFT
)
414 kvm
->stat
.num_2M_pages
--;
415 else if (shift
== PUD_SHIFT
)
416 kvm
->stat
.num_1G_pages
--;
419 gpa
&= ~(page_size
- 1);
420 hpa
= old
& PTE_RPN_MASK
;
421 kvmhv_remove_nest_rmap_range(kvm
, memslot
, gpa
, hpa
, page_size
);
423 if ((old
& _PAGE_DIRTY
) && memslot
->dirty_bitmap
)
424 kvmppc_update_dirty_map(memslot
, gfn
, page_size
);
428 * kvmppc_free_p?d are used to free existing page tables, and recursively
429 * descend and clear and free children.
430 * Callers are responsible for flushing the PWC.
432 * When page tables are being unmapped/freed as part of page fault path
433 * (full == false), valid ptes are generally not expected; however, there
434 * is one situation where they arise, which is when dirty page logging is
435 * turned off for a memslot while the VM is running. The new memslot
436 * becomes visible to page faults before the memslot commit function
437 * gets to flush the memslot, which can lead to a 2MB page mapping being
438 * installed for a guest physical address where there are already 64kB
439 * (or 4kB) mappings (of sub-pages of the same 2MB page).
441 static void kvmppc_unmap_free_pte(struct kvm
*kvm
, pte_t
*pte
, bool full
,
445 memset(pte
, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE
);
450 for (it
= 0; it
< PTRS_PER_PTE
; ++it
, ++p
) {
451 if (pte_val(*p
) == 0)
453 kvmppc_unmap_pte(kvm
, p
,
454 pte_pfn(*p
) << PAGE_SHIFT
,
455 PAGE_SHIFT
, NULL
, lpid
);
459 kvmppc_pte_free(pte
);
462 static void kvmppc_unmap_free_pmd(struct kvm
*kvm
, pmd_t
*pmd
, bool full
,
468 for (im
= 0; im
< PTRS_PER_PMD
; ++im
, ++p
) {
469 if (!pmd_present(*p
))
471 if (pmd_is_leaf(*p
)) {
476 kvmppc_unmap_pte(kvm
, (pte_t
*)p
,
477 pte_pfn(*(pte_t
*)p
) << PAGE_SHIFT
,
478 PMD_SHIFT
, NULL
, lpid
);
483 pte
= pte_offset_map(p
, 0);
484 kvmppc_unmap_free_pte(kvm
, pte
, full
, lpid
);
488 kvmppc_pmd_free(pmd
);
491 static void kvmppc_unmap_free_pud(struct kvm
*kvm
, pud_t
*pud
,
497 for (iu
= 0; iu
< PTRS_PER_PUD
; ++iu
, ++p
) {
498 if (!pud_present(*p
))
500 if (pud_is_leaf(*p
)) {
505 pmd
= pmd_offset(p
, 0);
506 kvmppc_unmap_free_pmd(kvm
, pmd
, true, lpid
);
510 pud_free(kvm
->mm
, pud
);
513 void kvmppc_free_pgtable_radix(struct kvm
*kvm
, pgd_t
*pgd
, unsigned int lpid
)
517 for (ig
= 0; ig
< PTRS_PER_PGD
; ++ig
, ++pgd
) {
518 p4d_t
*p4d
= p4d_offset(pgd
, 0);
521 if (!p4d_present(*p4d
))
523 pud
= pud_offset(p4d
, 0);
524 kvmppc_unmap_free_pud(kvm
, pud
, lpid
);
529 void kvmppc_free_radix(struct kvm
*kvm
)
531 if (kvm
->arch
.pgtable
) {
532 kvmppc_free_pgtable_radix(kvm
, kvm
->arch
.pgtable
,
534 pgd_free(kvm
->mm
, kvm
->arch
.pgtable
);
535 kvm
->arch
.pgtable
= NULL
;
539 static void kvmppc_unmap_free_pmd_entry_table(struct kvm
*kvm
, pmd_t
*pmd
,
540 unsigned long gpa
, unsigned int lpid
)
542 pte_t
*pte
= pte_offset_kernel(pmd
, 0);
545 * Clearing the pmd entry then flushing the PWC ensures that the pte
546 * page no longer be cached by the MMU, so can be freed without
547 * flushing the PWC again.
550 kvmppc_radix_flush_pwc(kvm
, lpid
);
552 kvmppc_unmap_free_pte(kvm
, pte
, false, lpid
);
555 static void kvmppc_unmap_free_pud_entry_table(struct kvm
*kvm
, pud_t
*pud
,
556 unsigned long gpa
, unsigned int lpid
)
558 pmd_t
*pmd
= pmd_offset(pud
, 0);
561 * Clearing the pud entry then flushing the PWC ensures that the pmd
562 * page and any children pte pages will no longer be cached by the MMU,
563 * so can be freed without flushing the PWC again.
566 kvmppc_radix_flush_pwc(kvm
, lpid
);
568 kvmppc_unmap_free_pmd(kvm
, pmd
, false, lpid
);
572 * There are a number of bits which may differ between different faults to
573 * the same partition scope entry. RC bits, in the course of cleaning and
574 * aging. And the write bit can change, either the access could have been
575 * upgraded, or a read fault could happen concurrently with a write fault
576 * that sets those bits first.
578 #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
580 int kvmppc_create_pte(struct kvm
*kvm
, pgd_t
*pgtable
, pte_t pte
,
581 unsigned long gpa
, unsigned int level
,
582 unsigned long mmu_seq
, unsigned int lpid
,
583 unsigned long *rmapp
, struct rmap_nested
**n_rmap
)
587 pud_t
*pud
, *new_pud
= NULL
;
588 pmd_t
*pmd
, *new_pmd
= NULL
;
589 pte_t
*ptep
, *new_ptep
= NULL
;
592 /* Traverse the guest's 2nd-level tree, allocate new levels needed */
593 pgd
= pgtable
+ pgd_index(gpa
);
594 p4d
= p4d_offset(pgd
, gpa
);
597 if (p4d_present(*p4d
))
598 pud
= pud_offset(p4d
, gpa
);
600 new_pud
= pud_alloc_one(kvm
->mm
, gpa
);
603 if (pud
&& pud_present(*pud
) && !pud_is_leaf(*pud
))
604 pmd
= pmd_offset(pud
, gpa
);
606 new_pmd
= kvmppc_pmd_alloc();
608 if (level
== 0 && !(pmd
&& pmd_present(*pmd
) && !pmd_is_leaf(*pmd
)))
609 new_ptep
= kvmppc_pte_alloc();
611 /* Check if we might have been invalidated; let the guest retry if so */
612 spin_lock(&kvm
->mmu_lock
);
614 if (mmu_notifier_retry(kvm
, mmu_seq
))
617 /* Now traverse again under the lock and change the tree */
619 if (p4d_none(*p4d
)) {
622 p4d_populate(kvm
->mm
, p4d
, new_pud
);
625 pud
= pud_offset(p4d
, gpa
);
626 if (pud_is_leaf(*pud
)) {
627 unsigned long hgpa
= gpa
& PUD_MASK
;
629 /* Check if we raced and someone else has set the same thing */
631 if (pud_raw(*pud
) == pte_raw(pte
)) {
635 /* Valid 1GB page here already, add our extra bits */
636 WARN_ON_ONCE((pud_val(*pud
) ^ pte_val(pte
)) &
637 PTE_BITS_MUST_MATCH
);
638 kvmppc_radix_update_pte(kvm
, (pte_t
*)pud
,
639 0, pte_val(pte
), hgpa
, PUD_SHIFT
);
644 * If we raced with another CPU which has just put
645 * a 1GB pte in after we saw a pmd page, try again.
651 /* Valid 1GB page here already, remove it */
652 kvmppc_unmap_pte(kvm
, (pte_t
*)pud
, hgpa
, PUD_SHIFT
, NULL
,
656 if (!pud_none(*pud
)) {
658 * There's a page table page here, but we wanted to
659 * install a large page, so remove and free the page
662 kvmppc_unmap_free_pud_entry_table(kvm
, pud
, gpa
, lpid
);
664 kvmppc_radix_set_pte_at(kvm
, gpa
, (pte_t
*)pud
, pte
);
666 kvmhv_insert_nest_rmap(kvm
, rmapp
, n_rmap
);
670 if (pud_none(*pud
)) {
673 pud_populate(kvm
->mm
, pud
, new_pmd
);
676 pmd
= pmd_offset(pud
, gpa
);
677 if (pmd_is_leaf(*pmd
)) {
678 unsigned long lgpa
= gpa
& PMD_MASK
;
680 /* Check if we raced and someone else has set the same thing */
682 if (pmd_raw(*pmd
) == pte_raw(pte
)) {
686 /* Valid 2MB page here already, add our extra bits */
687 WARN_ON_ONCE((pmd_val(*pmd
) ^ pte_val(pte
)) &
688 PTE_BITS_MUST_MATCH
);
689 kvmppc_radix_update_pte(kvm
, pmdp_ptep(pmd
),
690 0, pte_val(pte
), lgpa
, PMD_SHIFT
);
696 * If we raced with another CPU which has just put
697 * a 2MB pte in after we saw a pte page, try again.
703 /* Valid 2MB page here already, remove it */
704 kvmppc_unmap_pte(kvm
, pmdp_ptep(pmd
), lgpa
, PMD_SHIFT
, NULL
,
708 if (!pmd_none(*pmd
)) {
710 * There's a page table page here, but we wanted to
711 * install a large page, so remove and free the page
714 kvmppc_unmap_free_pmd_entry_table(kvm
, pmd
, gpa
, lpid
);
716 kvmppc_radix_set_pte_at(kvm
, gpa
, pmdp_ptep(pmd
), pte
);
718 kvmhv_insert_nest_rmap(kvm
, rmapp
, n_rmap
);
722 if (pmd_none(*pmd
)) {
725 pmd_populate(kvm
->mm
, pmd
, new_ptep
);
728 ptep
= pte_offset_kernel(pmd
, gpa
);
729 if (pte_present(*ptep
)) {
730 /* Check if someone else set the same thing */
731 if (pte_raw(*ptep
) == pte_raw(pte
)) {
735 /* Valid page here already, add our extra bits */
736 WARN_ON_ONCE((pte_val(*ptep
) ^ pte_val(pte
)) &
737 PTE_BITS_MUST_MATCH
);
738 kvmppc_radix_update_pte(kvm
, ptep
, 0, pte_val(pte
), gpa
, 0);
742 kvmppc_radix_set_pte_at(kvm
, gpa
, ptep
, pte
);
744 kvmhv_insert_nest_rmap(kvm
, rmapp
, n_rmap
);
748 spin_unlock(&kvm
->mmu_lock
);
750 pud_free(kvm
->mm
, new_pud
);
752 kvmppc_pmd_free(new_pmd
);
754 kvmppc_pte_free(new_ptep
);
758 bool kvmppc_hv_handle_set_rc(struct kvm
*kvm
, bool nested
, bool writing
,
759 unsigned long gpa
, unsigned int lpid
)
761 unsigned long pgflags
;
766 * Need to set an R or C bit in the 2nd-level tables;
767 * since we are just helping out the hardware here,
768 * it is sufficient to do what the hardware does.
770 pgflags
= _PAGE_ACCESSED
;
772 pgflags
|= _PAGE_DIRTY
;
775 ptep
= find_kvm_nested_guest_pte(kvm
, lpid
, gpa
, &shift
);
777 ptep
= find_kvm_secondary_pte(kvm
, gpa
, &shift
);
779 if (ptep
&& pte_present(*ptep
) && (!writing
|| pte_write(*ptep
))) {
780 kvmppc_radix_update_pte(kvm
, ptep
, 0, pgflags
, gpa
, shift
);
786 int kvmppc_book3s_instantiate_page(struct kvm_vcpu
*vcpu
,
788 struct kvm_memory_slot
*memslot
,
789 bool writing
, bool kvm_ro
,
790 pte_t
*inserted_pte
, unsigned int *levelp
)
792 struct kvm
*kvm
= vcpu
->kvm
;
793 struct page
*page
= NULL
;
794 unsigned long mmu_seq
;
795 unsigned long hva
, gfn
= gpa
>> PAGE_SHIFT
;
796 bool upgrade_write
= false;
797 bool *upgrade_p
= &upgrade_write
;
799 unsigned int shift
, level
;
803 /* used to check for invalidations in progress */
804 mmu_seq
= kvm
->mmu_notifier_seq
;
808 * Do a fast check first, since __gfn_to_pfn_memslot doesn't
809 * do it with !atomic && !async, which is how we call it.
810 * We always ask for write permission since the common case
811 * is that the page is writable.
813 hva
= gfn_to_hva_memslot(memslot
, gfn
);
814 if (!kvm_ro
&& get_user_page_fast_only(hva
, FOLL_WRITE
, &page
)) {
815 upgrade_write
= true;
819 /* Call KVM generic code to do the slow-path check */
820 pfn
= __gfn_to_pfn_memslot(memslot
, gfn
, false, NULL
,
822 if (is_error_noslot_pfn(pfn
))
825 if (pfn_valid(pfn
)) {
826 page
= pfn_to_page(pfn
);
827 if (PageReserved(page
))
833 * Read the PTE from the process' radix tree and use that
834 * so we get the shift and attribute bits.
836 spin_lock(&kvm
->mmu_lock
);
837 ptep
= find_kvm_host_pte(kvm
, mmu_seq
, hva
, &shift
);
840 pte
= READ_ONCE(*ptep
);
841 spin_unlock(&kvm
->mmu_lock
);
843 * If the PTE disappeared temporarily due to a THP
844 * collapse, just return and let the guest try again.
846 if (!pte_present(pte
)) {
852 /* If we're logging dirty pages, always map single pages */
853 large_enable
= !(memslot
->flags
& KVM_MEM_LOG_DIRTY_PAGES
);
855 /* Get pte level from shift/size */
856 if (large_enable
&& shift
== PUD_SHIFT
&&
857 (gpa
& (PUD_SIZE
- PAGE_SIZE
)) ==
858 (hva
& (PUD_SIZE
- PAGE_SIZE
))) {
860 } else if (large_enable
&& shift
== PMD_SHIFT
&&
861 (gpa
& (PMD_SIZE
- PAGE_SIZE
)) ==
862 (hva
& (PMD_SIZE
- PAGE_SIZE
))) {
866 if (shift
> PAGE_SHIFT
) {
868 * If the pte maps more than one page, bring over
869 * bits from the virtual address to get the real
870 * address of the specific single page we want.
872 unsigned long rpnmask
= (1ul << shift
) - PAGE_SIZE
;
873 pte
= __pte(pte_val(pte
) | (hva
& rpnmask
));
877 pte
= __pte(pte_val(pte
) | _PAGE_EXEC
| _PAGE_ACCESSED
);
878 if (writing
|| upgrade_write
) {
879 if (pte_val(pte
) & _PAGE_WRITE
)
880 pte
= __pte(pte_val(pte
) | _PAGE_DIRTY
);
882 pte
= __pte(pte_val(pte
) & ~(_PAGE_WRITE
| _PAGE_DIRTY
));
885 /* Allocate space in the tree and write the PTE */
886 ret
= kvmppc_create_pte(kvm
, kvm
->arch
.pgtable
, pte
, gpa
, level
,
887 mmu_seq
, kvm
->arch
.lpid
, NULL
, NULL
);
894 if (!ret
&& (pte_val(pte
) & _PAGE_WRITE
))
895 set_page_dirty_lock(page
);
899 /* Increment number of large pages if we (successfully) inserted one */
902 kvm
->stat
.num_2M_pages
++;
904 kvm
->stat
.num_1G_pages
++;
910 int kvmppc_book3s_radix_page_fault(struct kvm_vcpu
*vcpu
,
911 unsigned long ea
, unsigned long dsisr
)
913 struct kvm
*kvm
= vcpu
->kvm
;
914 unsigned long gpa
, gfn
;
915 struct kvm_memory_slot
*memslot
;
917 bool writing
= !!(dsisr
& DSISR_ISSTORE
);
920 /* Check for unusual errors */
921 if (dsisr
& DSISR_UNSUPP_MMU
) {
922 pr_err("KVM: Got unsupported MMU fault\n");
925 if (dsisr
& DSISR_BADACCESS
) {
926 /* Reflect to the guest as DSI */
927 pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr
);
928 kvmppc_core_queue_data_storage(vcpu
, ea
, dsisr
);
932 /* Translate the logical address */
933 gpa
= vcpu
->arch
.fault_gpa
& ~0xfffUL
;
934 gpa
&= ~0xF000000000000000ul
;
935 gfn
= gpa
>> PAGE_SHIFT
;
936 if (!(dsisr
& DSISR_PRTABLE_FAULT
))
939 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
)
940 return kvmppc_send_page_to_uv(kvm
, gfn
);
942 /* Get the corresponding memslot */
943 memslot
= gfn_to_memslot(kvm
, gfn
);
945 /* No memslot means it's an emulated MMIO region */
946 if (!memslot
|| (memslot
->flags
& KVM_MEMSLOT_INVALID
)) {
947 if (dsisr
& (DSISR_PRTABLE_FAULT
| DSISR_BADACCESS
|
950 * Bad address in guest page table tree, or other
951 * unusual error - reflect it to the guest as DSI.
953 kvmppc_core_queue_data_storage(vcpu
, ea
, dsisr
);
956 return kvmppc_hv_emulate_mmio(vcpu
, gpa
, ea
, writing
);
959 if (memslot
->flags
& KVM_MEM_READONLY
) {
961 /* give the guest a DSI */
962 kvmppc_core_queue_data_storage(vcpu
, ea
, DSISR_ISSTORE
|
969 /* Failed to set the reference/change bits */
970 if (dsisr
& DSISR_SET_RC
) {
971 spin_lock(&kvm
->mmu_lock
);
972 if (kvmppc_hv_handle_set_rc(kvm
, false, writing
,
973 gpa
, kvm
->arch
.lpid
))
974 dsisr
&= ~DSISR_SET_RC
;
975 spin_unlock(&kvm
->mmu_lock
);
977 if (!(dsisr
& (DSISR_BAD_FAULT_64S
| DSISR_NOHPTE
|
978 DSISR_PROTFAULT
| DSISR_SET_RC
)))
982 /* Try to insert a pte */
983 ret
= kvmppc_book3s_instantiate_page(vcpu
, gpa
, memslot
, writing
,
986 if (ret
== 0 || ret
== -EAGAIN
)
991 /* Called with kvm->mmu_lock held */
992 int kvm_unmap_radix(struct kvm
*kvm
, struct kvm_memory_slot
*memslot
,
996 unsigned long gpa
= gfn
<< PAGE_SHIFT
;
999 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
) {
1000 uv_page_inval(kvm
->arch
.lpid
, gpa
, PAGE_SHIFT
);
1004 ptep
= find_kvm_secondary_pte(kvm
, gpa
, &shift
);
1005 if (ptep
&& pte_present(*ptep
))
1006 kvmppc_unmap_pte(kvm
, ptep
, gpa
, shift
, memslot
,
1011 /* Called with kvm->mmu_lock held */
1012 int kvm_age_radix(struct kvm
*kvm
, struct kvm_memory_slot
*memslot
,
1016 unsigned long gpa
= gfn
<< PAGE_SHIFT
;
1019 unsigned long old
, *rmapp
;
1021 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
)
1024 ptep
= find_kvm_secondary_pte(kvm
, gpa
, &shift
);
1025 if (ptep
&& pte_present(*ptep
) && pte_young(*ptep
)) {
1026 old
= kvmppc_radix_update_pte(kvm
, ptep
, _PAGE_ACCESSED
, 0,
1028 /* XXX need to flush tlb here? */
1029 /* Also clear bit in ptes in shadow pgtable for nested guests */
1030 rmapp
= &memslot
->arch
.rmap
[gfn
- memslot
->base_gfn
];
1031 kvmhv_update_nest_rmap_rc_list(kvm
, rmapp
, _PAGE_ACCESSED
, 0,
1039 /* Called with kvm->mmu_lock held */
1040 int kvm_test_age_radix(struct kvm
*kvm
, struct kvm_memory_slot
*memslot
,
1044 unsigned long gpa
= gfn
<< PAGE_SHIFT
;
1048 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
)
1051 ptep
= find_kvm_secondary_pte(kvm
, gpa
, &shift
);
1052 if (ptep
&& pte_present(*ptep
) && pte_young(*ptep
))
1057 /* Returns the number of PAGE_SIZE pages that are dirty */
1058 static int kvm_radix_test_clear_dirty(struct kvm
*kvm
,
1059 struct kvm_memory_slot
*memslot
, int pagenum
)
1061 unsigned long gfn
= memslot
->base_gfn
+ pagenum
;
1062 unsigned long gpa
= gfn
<< PAGE_SHIFT
;
1066 unsigned long old
, *rmapp
;
1068 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
)
1072 * For performance reasons we don't hold kvm->mmu_lock while walking the
1073 * partition scoped table.
1075 ptep
= find_kvm_secondary_pte_unlocked(kvm
, gpa
, &shift
);
1079 pte
= READ_ONCE(*ptep
);
1080 if (pte_present(pte
) && pte_dirty(pte
)) {
1081 spin_lock(&kvm
->mmu_lock
);
1083 * Recheck the pte again
1085 if (pte_val(pte
) != pte_val(*ptep
)) {
1087 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can
1088 * only find PAGE_SIZE pte entries here. We can continue
1089 * to use the pte addr returned by above page table
1092 if (!pte_present(*ptep
) || !pte_dirty(*ptep
)) {
1093 spin_unlock(&kvm
->mmu_lock
);
1100 old
= kvmppc_radix_update_pte(kvm
, ptep
, _PAGE_DIRTY
, 0,
1102 kvmppc_radix_tlbie_page(kvm
, gpa
, shift
, kvm
->arch
.lpid
);
1103 /* Also clear bit in ptes in shadow pgtable for nested guests */
1104 rmapp
= &memslot
->arch
.rmap
[gfn
- memslot
->base_gfn
];
1105 kvmhv_update_nest_rmap_rc_list(kvm
, rmapp
, _PAGE_DIRTY
, 0,
1108 spin_unlock(&kvm
->mmu_lock
);
1113 long kvmppc_hv_get_dirty_log_radix(struct kvm
*kvm
,
1114 struct kvm_memory_slot
*memslot
, unsigned long *map
)
1119 for (i
= 0; i
< memslot
->npages
; i
= j
) {
1120 npages
= kvm_radix_test_clear_dirty(kvm
, memslot
, i
);
1123 * Note that if npages > 0 then i must be a multiple of npages,
1124 * since huge pages are only used to back the guest at guest
1125 * real addresses that are a multiple of their size.
1126 * Since we have at most one PTE covering any given guest
1127 * real address, if npages > 1 we can skip to i + npages.
1131 set_dirty_bits(map
, i
, npages
);
1138 void kvmppc_radix_flush_memslot(struct kvm
*kvm
,
1139 const struct kvm_memory_slot
*memslot
)
1146 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_START
)
1147 kvmppc_uvmem_drop_pages(memslot
, kvm
, true);
1149 if (kvm
->arch
.secure_guest
& KVMPPC_SECURE_INIT_DONE
)
1152 gpa
= memslot
->base_gfn
<< PAGE_SHIFT
;
1153 spin_lock(&kvm
->mmu_lock
);
1154 for (n
= memslot
->npages
; n
; --n
) {
1155 ptep
= find_kvm_secondary_pte(kvm
, gpa
, &shift
);
1156 if (ptep
&& pte_present(*ptep
))
1157 kvmppc_unmap_pte(kvm
, ptep
, gpa
, shift
, memslot
,
1162 * Increase the mmu notifier sequence number to prevent any page
1163 * fault that read the memslot earlier from writing a PTE.
1165 kvm
->mmu_notifier_seq
++;
1166 spin_unlock(&kvm
->mmu_lock
);
1169 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info
*info
,
1170 int psize
, int *indexp
)
1172 if (!mmu_psize_defs
[psize
].shift
)
1174 info
->ap_encodings
[*indexp
] = mmu_psize_defs
[psize
].shift
|
1175 (mmu_psize_defs
[psize
].ap
<< 29);
1179 int kvmhv_get_rmmu_info(struct kvm
*kvm
, struct kvm_ppc_rmmu_info
*info
)
1183 if (!radix_enabled())
1185 memset(info
, 0, sizeof(*info
));
1188 info
->geometries
[0].page_shift
= 12;
1189 info
->geometries
[0].level_bits
[0] = 9;
1190 for (i
= 1; i
< 4; ++i
)
1191 info
->geometries
[0].level_bits
[i
] = p9_supported_radix_bits
[i
];
1193 info
->geometries
[1].page_shift
= 16;
1194 for (i
= 0; i
< 4; ++i
)
1195 info
->geometries
[1].level_bits
[i
] = p9_supported_radix_bits
[i
];
1198 add_rmmu_ap_encoding(info
, MMU_PAGE_4K
, &i
);
1199 add_rmmu_ap_encoding(info
, MMU_PAGE_64K
, &i
);
1200 add_rmmu_ap_encoding(info
, MMU_PAGE_2M
, &i
);
1201 add_rmmu_ap_encoding(info
, MMU_PAGE_1G
, &i
);
1206 int kvmppc_init_vm_radix(struct kvm
*kvm
)
1208 kvm
->arch
.pgtable
= pgd_alloc(kvm
->mm
);
1209 if (!kvm
->arch
.pgtable
)
1214 static void pte_ctor(void *addr
)
1216 memset(addr
, 0, RADIX_PTE_TABLE_SIZE
);
1219 static void pmd_ctor(void *addr
)
1221 memset(addr
, 0, RADIX_PMD_TABLE_SIZE
);
1224 struct debugfs_radix_state
{
1235 static int debugfs_radix_open(struct inode
*inode
, struct file
*file
)
1237 struct kvm
*kvm
= inode
->i_private
;
1238 struct debugfs_radix_state
*p
;
1240 p
= kzalloc(sizeof(*p
), GFP_KERNEL
);
1246 mutex_init(&p
->mutex
);
1247 file
->private_data
= p
;
1249 return nonseekable_open(inode
, file
);
1252 static int debugfs_radix_release(struct inode
*inode
, struct file
*file
)
1254 struct debugfs_radix_state
*p
= file
->private_data
;
1256 kvm_put_kvm(p
->kvm
);
1261 static ssize_t
debugfs_radix_read(struct file
*file
, char __user
*buf
,
1262 size_t len
, loff_t
*ppos
)
1264 struct debugfs_radix_state
*p
= file
->private_data
;
1270 struct kvm_nested_guest
*nested
;
1280 if (!kvm_is_radix(kvm
))
1283 ret
= mutex_lock_interruptible(&p
->mutex
);
1287 if (p
->chars_left
) {
1291 r
= copy_to_user(buf
, p
->buf
+ p
->buf_index
, n
);
1308 while (len
!= 0 && p
->lpid
>= 0) {
1309 if (gpa
>= RADIX_PGTABLE_RANGE
) {
1313 kvmhv_put_nested(nested
);
1316 p
->lpid
= kvmhv_nested_next_lpid(kvm
, p
->lpid
);
1323 pgt
= kvm
->arch
.pgtable
;
1325 nested
= kvmhv_get_nested(kvm
, p
->lpid
, false);
1327 gpa
= RADIX_PGTABLE_RANGE
;
1330 pgt
= nested
->shadow_pgtable
;
1336 n
= scnprintf(p
->buf
, sizeof(p
->buf
),
1337 "\nNested LPID %d: ", p
->lpid
);
1338 n
+= scnprintf(p
->buf
+ n
, sizeof(p
->buf
) - n
,
1339 "pgdir: %lx\n", (unsigned long)pgt
);
1344 pgdp
= pgt
+ pgd_index(gpa
);
1345 p4dp
= p4d_offset(pgdp
, gpa
);
1346 p4d
= READ_ONCE(*p4dp
);
1347 if (!(p4d_val(p4d
) & _PAGE_PRESENT
)) {
1348 gpa
= (gpa
& P4D_MASK
) + P4D_SIZE
;
1352 pudp
= pud_offset(&p4d
, gpa
);
1353 pud
= READ_ONCE(*pudp
);
1354 if (!(pud_val(pud
) & _PAGE_PRESENT
)) {
1355 gpa
= (gpa
& PUD_MASK
) + PUD_SIZE
;
1358 if (pud_val(pud
) & _PAGE_PTE
) {
1364 pmdp
= pmd_offset(&pud
, gpa
);
1365 pmd
= READ_ONCE(*pmdp
);
1366 if (!(pmd_val(pmd
) & _PAGE_PRESENT
)) {
1367 gpa
= (gpa
& PMD_MASK
) + PMD_SIZE
;
1370 if (pmd_val(pmd
) & _PAGE_PTE
) {
1376 ptep
= pte_offset_kernel(&pmd
, gpa
);
1377 pte
= pte_val(READ_ONCE(*ptep
));
1378 if (!(pte
& _PAGE_PRESENT
)) {
1384 n
= scnprintf(p
->buf
, sizeof(p
->buf
),
1385 " %lx: %lx %d\n", gpa
, pte
, shift
);
1386 gpa
+= 1ul << shift
;
1391 r
= copy_to_user(buf
, p
->buf
, n
);
1406 kvmhv_put_nested(nested
);
1409 mutex_unlock(&p
->mutex
);
1413 static ssize_t
debugfs_radix_write(struct file
*file
, const char __user
*buf
,
1414 size_t len
, loff_t
*ppos
)
1419 static const struct file_operations debugfs_radix_fops
= {
1420 .owner
= THIS_MODULE
,
1421 .open
= debugfs_radix_open
,
1422 .release
= debugfs_radix_release
,
1423 .read
= debugfs_radix_read
,
1424 .write
= debugfs_radix_write
,
1425 .llseek
= generic_file_llseek
,
1428 void kvmhv_radix_debugfs_init(struct kvm
*kvm
)
1430 debugfs_create_file("radix", 0400, kvm
->arch
.debugfs_dir
, kvm
,
1431 &debugfs_radix_fops
);
1434 int kvmppc_radix_init(void)
1436 unsigned long size
= sizeof(void *) << RADIX_PTE_INDEX_SIZE
;
1438 kvm_pte_cache
= kmem_cache_create("kvm-pte", size
, size
, 0, pte_ctor
);
1442 size
= sizeof(void *) << RADIX_PMD_INDEX_SIZE
;
1444 kvm_pmd_cache
= kmem_cache_create("kvm-pmd", size
, size
, 0, pmd_ctor
);
1445 if (!kvm_pmd_cache
) {
1446 kmem_cache_destroy(kvm_pte_cache
);
1453 void kvmppc_radix_exit(void)
1455 kmem_cache_destroy(kvm_pte_cache
);
1456 kmem_cache_destroy(kvm_pmd_cache
);