tree: https://github.com/agraf/linux-2.6.git snp-host-v10 head: 689d7ab69df8f6bff29bd1dbefe7c07bba52a9ac commit: e57dbd72a4490baee2e82f45835580ac5c2d44bf [68/108] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20231109/202311092313.6740yf0y-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231109/202311092313.6740yf0y-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202311092313.6740yf0y-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): arch/x86/virt/svm/sev.c:280:5: warning: no previous prototype for 'snp_lookup_rmpentry' [-Wmissing-prototypes] 280 | int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) | ^~~~~~~~~~~~~~~~~~~ arch/x86/virt/svm/sev.c:352:6: warning: no previous prototype for 'sev_dump_hva_rmpentry' [-Wmissing-prototypes] 352 | void sev_dump_hva_rmpentry(unsigned long hva) | ^~~~~~~~~~~~~~~~~~~~~ >> arch/x86/virt/svm/sev.c:375:5: warning: no previous prototype for 'psmash' [-Wmissing-prototypes] 375 | int psmash(u64 pfn) | ^~~~~~ >> arch/x86/virt/svm/sev.c:431:5: warning: no previous prototype for 'rmp_make_private' [-Wmissing-prototypes] 431 | int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, int asid, bool immutable) | ^~~~~~~~~~~~~~~~ >> arch/x86/virt/svm/sev.c:449:5: warning: no previous prototype for 'rmp_make_shared' [-Wmissing-prototypes] 449 | int rmp_make_shared(u64 pfn, enum pg_level level) | ^~~~~~~~~~~~~~~ vim +/psmash +375 arch/x86/virt/svm/sev.c 279 > 280 int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) 281 { 282 struct rmpentry e; 283 int ret; 284 285 ret = __snp_lookup_rmpentry(pfn, &e, level); 286 if (ret) 287 return ret; 288 289 *assigned = !!e.assigned; 290 return 0; 291 } 292 EXPORT_SYMBOL_GPL(snp_lookup_rmpentry); 293 294 /* 295 * Dump the raw RMP entry for a particular PFN. These bits are documented in the 296 * PPR for a particular CPU model and provide useful information about how a 297 * particular PFN is being utilized by the kernel/firmware at the time certain 298 * unexpected events occur, such as RMP faults. 299 */ 300 static void sev_dump_rmpentry(u64 dumped_pfn) 301 { 302 struct rmpentry e; 303 u64 pfn, pfn_end; 304 int level, ret; 305 u64 *e_data; 306 307 ret = __snp_lookup_rmpentry(dumped_pfn, &e, &level); 308 if (ret) { 309 pr_info("Failed to read RMP entry for PFN 0x%llx, error %d\n", 310 dumped_pfn, ret); 311 return; 312 } 313 314 e_data = (u64 *)&e; 315 if (e.assigned) { 316 pr_info("RMP entry for PFN 0x%llx: [high=0x%016llx low=0x%016llx]\n", 317 dumped_pfn, e_data[1], e_data[0]); 318 return; 319 } 320 321 /* 322 * If the RMP entry for a particular PFN is not in an assigned state, 323 * then it is sometimes useful to get an idea of whether or not any RMP 324 * entries for other PFNs within the same 2MB region are assigned, since 325 * those too can affect the ability to access a particular PFN in 326 * certain situations, such as when the PFN is being accessed via a 2MB 327 * mapping in the host page table. 328 */ 329 pfn = ALIGN(dumped_pfn, PTRS_PER_PMD); 330 pfn_end = pfn + PTRS_PER_PMD; 331 332 while (pfn < pfn_end) { 333 ret = __snp_lookup_rmpentry(pfn, &e, &level); 334 if (ret) { 335 pr_info_ratelimited("Failed to read RMP entry for PFN 0x%llx\n", pfn); 336 pfn++; 337 continue; 338 } 339 340 if (e_data[0] || e_data[1]) { 341 pr_info("No assigned RMP entry for PFN 0x%llx, but the 2MB region contains populated RMP entries, e.g.: PFN 0x%llx: [high=0x%016llx low=0x%016llx]\n", 342 dumped_pfn, pfn, e_data[1], e_data[0]); 343 return; 344 } 345 pfn++; 346 } 347 348 pr_info("No populated RMP entries in the 2MB region containing PFN 0x%llx\n", 349 dumped_pfn); 350 } 351 > 352 void sev_dump_hva_rmpentry(unsigned long hva) 353 { 354 unsigned int level; 355 pgd_t *pgd; 356 pte_t *pte; 357 358 pgd = __va(read_cr3_pa()); 359 pgd += pgd_index(hva); 360 pte = lookup_address_in_pgd(pgd, hva, &level); 361 362 if (pte) { 363 pr_info("Can't dump RMP entry for HVA %lx: no PTE/PFN found\n", hva); 364 return; 365 } 366 367 sev_dump_rmpentry(pte_pfn(*pte)); 368 } 369 EXPORT_SYMBOL_GPL(sev_dump_hva_rmpentry); 370 371 /* 372 * PSMASH a 2MB aligned page into 4K pages in the RMP table while preserving the 373 * Validated bit. 374 */ > 375 int psmash(u64 pfn) 376 { 377 unsigned long paddr = pfn << PAGE_SHIFT; 378 int ret; 379 380 pr_debug("%s: PFN: 0x%llx\n", __func__, pfn); 381 382 if (!pfn_valid(pfn)) 383 return -EINVAL; 384 385 if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) 386 return -ENXIO; 387 388 /* Binutils version 2.36 supports the PSMASH mnemonic. */ 389 asm volatile(".byte 0xF3, 0x0F, 0x01, 0xFF" 390 : "=a"(ret) 391 : "a"(paddr) 392 : "memory", "cc"); 393 394 return ret; 395 } 396 EXPORT_SYMBOL_GPL(psmash); 397 398 static int rmpupdate(u64 pfn, struct rmp_state *val) 399 { 400 unsigned long paddr = pfn << PAGE_SHIFT; 401 int ret, level, npages; 402 int attempts = 0; 403 404 if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) 405 return -ENXIO; 406 407 do { 408 /* Binutils version 2.36 supports the RMPUPDATE mnemonic. */ 409 asm volatile(".byte 0xF2, 0x0F, 0x01, 0xFE" 410 : "=a"(ret) 411 : "a"(paddr), "c"((unsigned long)val) 412 : "memory", "cc"); 413 414 attempts++; 415 } while (ret == RMPUPDATE_FAIL_OVERLAP); 416 417 if (ret) { 418 pr_err("RMPUPDATE failed after %d attempts, ret: %d, pfn: %llx, npages: %d, level: %d\n", 419 attempts, ret, pfn, npages, level); 420 sev_dump_rmpentry(pfn); 421 dump_stack(); 422 return -EFAULT; 423 } 424 425 return 0; 426 } 427 428 /* 429 * Assign a page to guest using the RMPUPDATE instruction. 430 */ > 431 int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, int asid, bool immutable) 432 { 433 struct rmp_state val; 434 435 memset(&val, 0, sizeof(val)); 436 val.assigned = 1; 437 val.asid = asid; 438 val.immutable = immutable; 439 val.gpa = gpa; 440 val.pagesize = X86_TO_RMP_PG_LEVEL(level); 441 442 return rmpupdate(pfn, &val); 443 } 444 EXPORT_SYMBOL_GPL(rmp_make_private); 445 446 /* 447 * Transition a page to hypervisor/shared state using the RMPUPDATE instruction. 448 */ > 449 int rmp_make_shared(u64 pfn, enum pg_level level) -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
