2 * guest access functions
4 * Copyright IBM Corp. 2014
8 #include <linux/vmalloc.h>
10 #include <asm/pgtable.h>
17 unsigned long origin
: 52; /* Region- or Segment-Table Origin */
19 unsigned long g
: 1; /* Subspace Group Control */
20 unsigned long p
: 1; /* Private Space Control */
21 unsigned long s
: 1; /* Storage-Alteration-Event Control */
22 unsigned long x
: 1; /* Space-Switch-Event Control */
23 unsigned long r
: 1; /* Real-Space Control */
25 unsigned long dt
: 2; /* Designation-Type Control */
26 unsigned long tl
: 2; /* Region- or Segment-Table Length */
31 ASCE_TYPE_SEGMENT
= 0,
32 ASCE_TYPE_REGION3
= 1,
33 ASCE_TYPE_REGION2
= 2,
37 union region1_table_entry
{
40 unsigned long rto
: 52;/* Region-Table Origin */
42 unsigned long p
: 1; /* DAT-Protection Bit */
44 unsigned long tf
: 2; /* Region-Second-Table Offset */
45 unsigned long i
: 1; /* Region-Invalid Bit */
47 unsigned long tt
: 2; /* Table-Type Bits */
48 unsigned long tl
: 2; /* Region-Second-Table Length */
52 union region2_table_entry
{
55 unsigned long rto
: 52;/* Region-Table Origin */
57 unsigned long p
: 1; /* DAT-Protection Bit */
59 unsigned long tf
: 2; /* Region-Third-Table Offset */
60 unsigned long i
: 1; /* Region-Invalid Bit */
62 unsigned long tt
: 2; /* Table-Type Bits */
63 unsigned long tl
: 2; /* Region-Third-Table Length */
67 struct region3_table_entry_fc0
{
68 unsigned long sto
: 52;/* Segment-Table Origin */
70 unsigned long fc
: 1; /* Format-Control */
71 unsigned long p
: 1; /* DAT-Protection Bit */
73 unsigned long tf
: 2; /* Segment-Table Offset */
74 unsigned long i
: 1; /* Region-Invalid Bit */
75 unsigned long cr
: 1; /* Common-Region Bit */
76 unsigned long tt
: 2; /* Table-Type Bits */
77 unsigned long tl
: 2; /* Segment-Table Length */
80 struct region3_table_entry_fc1
{
81 unsigned long rfaa
: 33; /* Region-Frame Absolute Address */
83 unsigned long av
: 1; /* ACCF-Validity Control */
84 unsigned long acc
: 4; /* Access-Control Bits */
85 unsigned long f
: 1; /* Fetch-Protection Bit */
86 unsigned long fc
: 1; /* Format-Control */
87 unsigned long p
: 1; /* DAT-Protection Bit */
88 unsigned long co
: 1; /* Change-Recording Override */
90 unsigned long i
: 1; /* Region-Invalid Bit */
91 unsigned long cr
: 1; /* Common-Region Bit */
92 unsigned long tt
: 2; /* Table-Type Bits */
96 union region3_table_entry
{
98 struct region3_table_entry_fc0 fc0
;
99 struct region3_table_entry_fc1 fc1
;
102 unsigned long fc
: 1; /* Format-Control */
104 unsigned long i
: 1; /* Region-Invalid Bit */
105 unsigned long cr
: 1; /* Common-Region Bit */
106 unsigned long tt
: 2; /* Table-Type Bits */
111 struct segment_entry_fc0
{
112 unsigned long pto
: 53;/* Page-Table Origin */
113 unsigned long fc
: 1; /* Format-Control */
114 unsigned long p
: 1; /* DAT-Protection Bit */
116 unsigned long i
: 1; /* Segment-Invalid Bit */
117 unsigned long cs
: 1; /* Common-Segment Bit */
118 unsigned long tt
: 2; /* Table-Type Bits */
122 struct segment_entry_fc1
{
123 unsigned long sfaa
: 44; /* Segment-Frame Absolute Address */
125 unsigned long av
: 1; /* ACCF-Validity Control */
126 unsigned long acc
: 4; /* Access-Control Bits */
127 unsigned long f
: 1; /* Fetch-Protection Bit */
128 unsigned long fc
: 1; /* Format-Control */
129 unsigned long p
: 1; /* DAT-Protection Bit */
130 unsigned long co
: 1; /* Change-Recording Override */
132 unsigned long i
: 1; /* Segment-Invalid Bit */
133 unsigned long cs
: 1; /* Common-Segment Bit */
134 unsigned long tt
: 2; /* Table-Type Bits */
138 union segment_table_entry
{
140 struct segment_entry_fc0 fc0
;
141 struct segment_entry_fc1 fc1
;
144 unsigned long fc
: 1; /* Format-Control */
146 unsigned long i
: 1; /* Segment-Invalid Bit */
147 unsigned long cs
: 1; /* Common-Segment Bit */
148 unsigned long tt
: 2; /* Table-Type Bits */
154 TABLE_TYPE_SEGMENT
= 0,
155 TABLE_TYPE_REGION3
= 1,
156 TABLE_TYPE_REGION2
= 2,
157 TABLE_TYPE_REGION1
= 3
160 union page_table_entry
{
163 unsigned long pfra
: 52; /* Page-Frame Real Address */
164 unsigned long z
: 1; /* Zero Bit */
165 unsigned long i
: 1; /* Page-Invalid Bit */
166 unsigned long p
: 1; /* DAT-Protection Bit */
167 unsigned long co
: 1; /* Change-Recording Override */
173 * vaddress union in order to easily decode a virtual address into its
174 * region first index, region second index etc. parts.
179 unsigned long rfx
: 11;
180 unsigned long rsx
: 11;
181 unsigned long rtx
: 11;
182 unsigned long sx
: 11;
183 unsigned long px
: 8;
184 unsigned long bx
: 12;
187 unsigned long rfx01
: 2;
189 unsigned long rsx01
: 2;
191 unsigned long rtx01
: 2;
193 unsigned long sx01
: 2;
199 * raddress union which will contain the result (real or absolute address)
200 * after a page table walk. The rfaa, sfaa and pfra members are used to
201 * simply assign them the value of a region, segment or page table entry.
205 unsigned long rfaa
: 33; /* Region-Frame Absolute Address */
206 unsigned long sfaa
: 44; /* Segment-Frame Absolute Address */
207 unsigned long pfra
: 52; /* Page-Frame Real Address */
210 static unsigned long get_vcpu_asce(struct kvm_vcpu
*vcpu
)
212 switch (psw_bits(vcpu
->arch
.sie_block
->gpsw
).as
) {
214 return vcpu
->arch
.sie_block
->gcr
[1];
215 case PSW_AS_SECONDARY
:
216 return vcpu
->arch
.sie_block
->gcr
[7];
218 return vcpu
->arch
.sie_block
->gcr
[13];
223 static int deref_table(struct kvm
*kvm
, unsigned long gpa
, unsigned long *val
)
225 return kvm_read_guest(kvm
, gpa
, val
, sizeof(*val
));
229 * guest_translate - translate a guest virtual into a guest absolute address
231 * @gva: guest virtual address
232 * @gpa: points to where guest physical (absolute) address should be stored
233 * @write: indicates if access is a write access
235 * Translate a guest virtual address into a guest absolute address by means
236 * of dynamic address translation as specified by the architecuture.
237 * If the resulting absolute address is not available in the configuration
238 * an addressing exception is indicated and @gpa will not be changed.
240 * Returns: - zero on success; @gpa contains the resulting absolute address
241 * - a negative value if guest access failed due to e.g. broken
243 * - a positve value if an access exception happened. In this case
244 * the returned value is the program interruption code as defined
245 * by the architecture
247 static unsigned long guest_translate(struct kvm_vcpu
*vcpu
, unsigned long gva
,
248 unsigned long *gpa
, int write
)
250 union vaddress vaddr
= {.addr
= gva
};
251 union raddress raddr
= {.addr
= gva
};
252 union page_table_entry pte
;
253 int dat_protection
= 0;
254 union ctlreg0 ctlreg0
;
259 ctlreg0
.val
= vcpu
->arch
.sie_block
->gcr
[0];
260 edat1
= ctlreg0
.edat
&& test_vfacility(8);
261 edat2
= edat1
&& test_vfacility(78);
262 asce
.val
= get_vcpu_asce(vcpu
);
265 ptr
= asce
.origin
* 4096;
267 case ASCE_TYPE_REGION1
:
268 if (vaddr
.rfx01
> asce
.tl
)
269 return PGM_REGION_FIRST_TRANS
;
270 ptr
+= vaddr
.rfx
* 8;
272 case ASCE_TYPE_REGION2
:
274 return PGM_ASCE_TYPE
;
275 if (vaddr
.rsx01
> asce
.tl
)
276 return PGM_REGION_SECOND_TRANS
;
277 ptr
+= vaddr
.rsx
* 8;
279 case ASCE_TYPE_REGION3
:
280 if (vaddr
.rfx
|| vaddr
.rsx
)
281 return PGM_ASCE_TYPE
;
282 if (vaddr
.rtx01
> asce
.tl
)
283 return PGM_REGION_THIRD_TRANS
;
284 ptr
+= vaddr
.rtx
* 8;
286 case ASCE_TYPE_SEGMENT
:
287 if (vaddr
.rfx
|| vaddr
.rsx
|| vaddr
.rtx
)
288 return PGM_ASCE_TYPE
;
289 if (vaddr
.sx01
> asce
.tl
)
290 return PGM_SEGMENT_TRANSLATION
;
295 case ASCE_TYPE_REGION1
: {
296 union region1_table_entry rfte
;
298 if (kvm_is_error_gpa(vcpu
->kvm
, ptr
))
299 return PGM_ADDRESSING
;
300 if (deref_table(vcpu
->kvm
, ptr
, &rfte
.val
))
303 return PGM_REGION_FIRST_TRANS
;
304 if (rfte
.tt
!= TABLE_TYPE_REGION1
)
305 return PGM_TRANSLATION_SPEC
;
306 if (vaddr
.rsx01
< rfte
.tf
|| vaddr
.rsx01
> rfte
.tl
)
307 return PGM_REGION_SECOND_TRANS
;
309 dat_protection
|= rfte
.p
;
310 ptr
= rfte
.rto
* 4096 + vaddr
.rsx
* 8;
313 case ASCE_TYPE_REGION2
: {
314 union region2_table_entry rste
;
316 if (kvm_is_error_gpa(vcpu
->kvm
, ptr
))
317 return PGM_ADDRESSING
;
318 if (deref_table(vcpu
->kvm
, ptr
, &rste
.val
))
321 return PGM_REGION_SECOND_TRANS
;
322 if (rste
.tt
!= TABLE_TYPE_REGION2
)
323 return PGM_TRANSLATION_SPEC
;
324 if (vaddr
.rtx01
< rste
.tf
|| vaddr
.rtx01
> rste
.tl
)
325 return PGM_REGION_THIRD_TRANS
;
327 dat_protection
|= rste
.p
;
328 ptr
= rste
.rto
* 4096 + vaddr
.rtx
* 8;
331 case ASCE_TYPE_REGION3
: {
332 union region3_table_entry rtte
;
334 if (kvm_is_error_gpa(vcpu
->kvm
, ptr
))
335 return PGM_ADDRESSING
;
336 if (deref_table(vcpu
->kvm
, ptr
, &rtte
.val
))
339 return PGM_REGION_THIRD_TRANS
;
340 if (rtte
.tt
!= TABLE_TYPE_REGION3
)
341 return PGM_TRANSLATION_SPEC
;
342 if (rtte
.cr
&& asce
.p
&& edat2
)
343 return PGM_TRANSLATION_SPEC
;
344 if (rtte
.fc
&& edat2
) {
345 dat_protection
|= rtte
.fc1
.p
;
346 raddr
.rfaa
= rtte
.fc1
.rfaa
;
347 goto absolute_address
;
349 if (vaddr
.sx01
< rtte
.fc0
.tf
)
350 return PGM_SEGMENT_TRANSLATION
;
351 if (vaddr
.sx01
> rtte
.fc0
.tl
)
352 return PGM_SEGMENT_TRANSLATION
;
354 dat_protection
|= rtte
.fc0
.p
;
355 ptr
= rtte
.fc0
.sto
* 4096 + vaddr
.sx
* 8;
358 case ASCE_TYPE_SEGMENT
: {
359 union segment_table_entry ste
;
361 if (kvm_is_error_gpa(vcpu
->kvm
, ptr
))
362 return PGM_ADDRESSING
;
363 if (deref_table(vcpu
->kvm
, ptr
, &ste
.val
))
366 return PGM_SEGMENT_TRANSLATION
;
367 if (ste
.tt
!= TABLE_TYPE_SEGMENT
)
368 return PGM_TRANSLATION_SPEC
;
369 if (ste
.cs
&& asce
.p
)
370 return PGM_TRANSLATION_SPEC
;
371 if (ste
.fc
&& edat1
) {
372 dat_protection
|= ste
.fc1
.p
;
373 raddr
.sfaa
= ste
.fc1
.sfaa
;
374 goto absolute_address
;
376 dat_protection
|= ste
.fc0
.p
;
377 ptr
= ste
.fc0
.pto
* 2048 + vaddr
.px
* 8;
380 if (kvm_is_error_gpa(vcpu
->kvm
, ptr
))
381 return PGM_ADDRESSING
;
382 if (deref_table(vcpu
->kvm
, ptr
, &pte
.val
))
385 return PGM_PAGE_TRANSLATION
;
387 return PGM_TRANSLATION_SPEC
;
388 if (pte
.co
&& !edat1
)
389 return PGM_TRANSLATION_SPEC
;
390 dat_protection
|= pte
.p
;
391 raddr
.pfra
= pte
.pfra
;
393 raddr
.addr
= kvm_s390_real_to_abs(vcpu
, raddr
.addr
);
395 if (write
&& dat_protection
)
396 return PGM_PROTECTION
;
397 if (kvm_is_error_gpa(vcpu
->kvm
, raddr
.addr
))
398 return PGM_ADDRESSING
;
403 static inline int is_low_address(unsigned long ga
)
405 /* Check for address ranges 0..511 and 4096..4607 */
406 return (ga
& ~0x11fful
) == 0;
409 static int low_address_protection_enabled(struct kvm_vcpu
*vcpu
)
411 union ctlreg0 ctlreg0
= {.val
= vcpu
->arch
.sie_block
->gcr
[0]};
412 psw_t
*psw
= &vcpu
->arch
.sie_block
->gpsw
;
417 asce
.val
= get_vcpu_asce(vcpu
);
418 if (psw_bits(*psw
).t
&& asce
.p
)
423 struct trans_exc_code_bits
{
424 unsigned long addr
: 52; /* Translation-exception Address */
425 unsigned long fsi
: 2; /* Access Exception Fetch/Store Indication */
427 unsigned long b61
: 1;
428 unsigned long as
: 2; /* ASCE Identifier */
432 FSI_UNKNOWN
= 0, /* Unknown wether fetch or store */
433 FSI_STORE
= 1, /* Exception was due to store operation */
434 FSI_FETCH
= 2 /* Exception was due to fetch operation */
437 static int guest_page_range(struct kvm_vcpu
*vcpu
, unsigned long ga
,
438 unsigned long *pages
, unsigned long nr_pages
,
441 struct kvm_s390_pgm_info
*pgm
= &vcpu
->arch
.pgm
;
442 psw_t
*psw
= &vcpu
->arch
.sie_block
->gpsw
;
443 struct trans_exc_code_bits
*tec_bits
;
446 memset(pgm
, 0, sizeof(*pgm
));
447 tec_bits
= (struct trans_exc_code_bits
*)&pgm
->trans_exc_code
;
448 tec_bits
->fsi
= write
? FSI_STORE
: FSI_FETCH
;
449 tec_bits
->as
= psw_bits(*psw
).as
;
450 lap_enabled
= low_address_protection_enabled(vcpu
);
452 ga
= kvm_s390_logical_to_effective(vcpu
, ga
);
453 tec_bits
->addr
= ga
>> PAGE_SHIFT
;
454 if (write
&& lap_enabled
&& is_low_address(ga
)) {
455 pgm
->code
= PGM_PROTECTION
;
459 if (psw_bits(*psw
).t
) {
460 rc
= guest_translate(vcpu
, ga
, pages
, write
);
463 if (rc
== PGM_PROTECTION
)
468 *pages
= kvm_s390_real_to_abs(vcpu
, ga
);
469 if (kvm_is_error_gpa(vcpu
->kvm
, *pages
))
470 pgm
->code
= PGM_ADDRESSING
;
481 int access_guest(struct kvm_vcpu
*vcpu
, unsigned long ga
, void *data
,
482 unsigned long len
, int write
)
484 psw_t
*psw
= &vcpu
->arch
.sie_block
->gpsw
;
485 unsigned long _len
, nr_pages
, gpa
, idx
;
486 unsigned long pages_array
[2];
487 unsigned long *pages
;
492 /* Access register mode is not supported yet. */
493 if (psw_bits(*psw
).t
&& psw_bits(*psw
).as
== PSW_AS_ACCREG
)
495 nr_pages
= (((ga
& ~PAGE_MASK
) + len
- 1) >> PAGE_SHIFT
) + 1;
497 if (nr_pages
> ARRAY_SIZE(pages_array
))
498 pages
= vmalloc(nr_pages
* sizeof(unsigned long));
501 rc
= guest_page_range(vcpu
, ga
, pages
, nr_pages
, write
);
502 for (idx
= 0; idx
< nr_pages
&& !rc
; idx
++) {
503 gpa
= *(pages
+ idx
) + (ga
& ~PAGE_MASK
);
504 _len
= min(PAGE_SIZE
- (gpa
& ~PAGE_MASK
), len
);
506 rc
= kvm_write_guest(vcpu
->kvm
, gpa
, data
, _len
);
508 rc
= kvm_read_guest(vcpu
->kvm
, gpa
, data
, _len
);
513 if (nr_pages
> ARRAY_SIZE(pages_array
))
518 int access_guest_real(struct kvm_vcpu
*vcpu
, unsigned long gra
,
519 void *data
, unsigned long len
, int write
)
521 unsigned long _len
, gpa
;
525 gpa
= kvm_s390_real_to_abs(vcpu
, gra
);
526 _len
= min(PAGE_SIZE
- (gpa
& ~PAGE_MASK
), len
);
528 rc
= write_guest_abs(vcpu
, gpa
, data
, _len
);
530 rc
= read_guest_abs(vcpu
, gpa
, data
, _len
);