Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
KVM: arm64: Introduce standalone FGU computing primitive
Computing the FGU bits is made oddly complicated, as we use the RES0
helper instead of using a specific abstraction.
Introduce such an abstraction, which is going to make things significantly
simpler in the future.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260202184329.2724080-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
+25
-32
+25
-32
arch/arm64/kvm/config.c
+25
-32
arch/arm64/kvm/config.c
···
1335
1335
static u64 compute_reg_res0_bits(struct kvm *kvm,
1336
1336
const struct reg_feat_map_desc *r,
1337
1337
unsigned long require, unsigned long exclude)
1338
-
1339
1338
{
1340
1339
u64 res0;
1341
1340
1342
1341
res0 = compute_res0_bits(kvm, r->bit_feat_map, r->bit_feat_map_sz,
1343
1342
require, exclude);
1344
1343
1345
-
/*
1346
-
* If computing FGUs, don't take RES0 or register existence
1347
-
* into account -- we're not computing bits for the register
1348
-
* itself.
1349
-
*/
1350
-
if (!(exclude & NEVER_FGU)) {
1351
-
res0 |= compute_res0_bits(kvm, &r->feat_map, 1, require, exclude);
1352
-
res0 |= ~reg_feat_map_bits(&r->feat_map);
1353
-
}
1344
+
res0 |= compute_res0_bits(kvm, &r->feat_map, 1, require, exclude);
1345
+
res0 |= ~reg_feat_map_bits(&r->feat_map);
1354
1346
1355
1347
return res0;
1348
+
}
1349
+
1350
+
static u64 compute_fgu_bits(struct kvm *kvm, const struct reg_feat_map_desc *r)
1351
+
{
1352
+
/*
1353
+
* If computing FGUs, we collect the unsupported feature bits as
1354
+
* RES0 bits, but don't take the actual RES0 bits or register
1355
+
* existence into account -- we're not computing bits for the
1356
+
* register itself.
1357
+
*/
1358
+
return compute_res0_bits(kvm, r->bit_feat_map, r->bit_feat_map_sz,
1359
+
0, NEVER_FGU);
1356
1360
}
1357
1361
1358
1362
static u64 compute_reg_fixed_bits(struct kvm *kvm,
···
1374
1370
1375
1371
switch (fgt) {
1376
1372
case HFGRTR_GROUP:
1377
-
val |= compute_reg_res0_bits(kvm, &hfgrtr_desc,
1378
-
0, NEVER_FGU);
1379
-
val |= compute_reg_res0_bits(kvm, &hfgwtr_desc,
1380
-
0, NEVER_FGU);
1373
+
val |= compute_fgu_bits(kvm, &hfgrtr_desc);
1374
+
val |= compute_fgu_bits(kvm, &hfgwtr_desc);
1381
1375
break;
1382
1376
case HFGITR_GROUP:
1383
-
val |= compute_reg_res0_bits(kvm, &hfgitr_desc,
1384
-
0, NEVER_FGU);
1377
+
val |= compute_fgu_bits(kvm, &hfgitr_desc);
1385
1378
break;
1386
1379
case HDFGRTR_GROUP:
1387
-
val |= compute_reg_res0_bits(kvm, &hdfgrtr_desc,
1388
-
0, NEVER_FGU);
1389
-
val |= compute_reg_res0_bits(kvm, &hdfgwtr_desc,
1390
-
0, NEVER_FGU);
1380
+
val |= compute_fgu_bits(kvm, &hdfgrtr_desc);
1381
+
val |= compute_fgu_bits(kvm, &hdfgwtr_desc);
1391
1382
break;
1392
1383
case HAFGRTR_GROUP:
1393
-
val |= compute_reg_res0_bits(kvm, &hafgrtr_desc,
1394
-
0, NEVER_FGU);
1384
+
val |= compute_fgu_bits(kvm, &hafgrtr_desc);
1395
1385
break;
1396
1386
case HFGRTR2_GROUP:
1397
-
val |= compute_reg_res0_bits(kvm, &hfgrtr2_desc,
1398
-
0, NEVER_FGU);
1399
-
val |= compute_reg_res0_bits(kvm, &hfgwtr2_desc,
1400
-
0, NEVER_FGU);
1387
+
val |= compute_fgu_bits(kvm, &hfgrtr2_desc);
1388
+
val |= compute_fgu_bits(kvm, &hfgwtr2_desc);
1401
1389
break;
1402
1390
case HFGITR2_GROUP:
1403
-
val |= compute_reg_res0_bits(kvm, &hfgitr2_desc,
1404
-
0, NEVER_FGU);
1391
+
val |= compute_fgu_bits(kvm, &hfgitr2_desc);
1405
1392
break;
1406
1393
case HDFGRTR2_GROUP:
1407
-
val |= compute_reg_res0_bits(kvm, &hdfgrtr2_desc,
1408
-
0, NEVER_FGU);
1409
-
val |= compute_reg_res0_bits(kvm, &hdfgwtr2_desc,
1410
-
0, NEVER_FGU);
1394
+
val |= compute_fgu_bits(kvm, &hdfgrtr2_desc);
1395
+
val |= compute_fgu_bits(kvm, &hdfgwtr2_desc);
1411
1396
break;
1412
1397
default:
1413
1398
BUG();