target/ppc/mmu-radix64.c

   1 /*
   2  *  PowerPC Radix MMU mulation helpers for QEMU.
   3  *
   4  *  Copyright (c) 2016 Suraj Jitindar Singh, IBM Corporation
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "cpu.h"
  22 #include "exec/exec-all.h"
  23 #include "exec/helper-proto.h"
  24 #include "qemu/error-report.h"
  25 #include "sysemu/kvm.h"
  26 #include "kvm_ppc.h"
  27 #include "exec/log.h"
  28 #include "mmu-radix64.h"
  29 #include "mmu-book3s-v3.h"
  30
  31 static bool ppc_radix64_get_fully_qualified_addr(CPUPPCState *env, vaddr eaddr,
  32                                                  uint64_t *lpid, uint64_t *pid)
  33 {
  34     if (msr_hv) { /* MSR[HV] -> Hypervisor/bare metal */
  35         switch (eaddr & R_EADDR_QUADRANT) {
  36         case R_EADDR_QUADRANT0:
  37             *lpid = 0;
  38             *pid = env->spr[SPR_BOOKS_PID];
  39             break;
  40         case R_EADDR_QUADRANT1:
  41             *lpid = env->spr[SPR_LPIDR];
  42             *pid = env->spr[SPR_BOOKS_PID];
  43             break;
  44         case R_EADDR_QUADRANT2:
  45             *lpid = env->spr[SPR_LPIDR];
  46             *pid = 0;
  47             break;
  48         case R_EADDR_QUADRANT3:
  49             *lpid = 0;
  50             *pid = 0;
  51             break;
  52         }
  53     } else {  /* !MSR[HV] -> Guest */
  54         switch (eaddr & R_EADDR_QUADRANT) {
  55         case R_EADDR_QUADRANT0: /* Guest application */
  56             *lpid = env->spr[SPR_LPIDR];
  57             *pid = env->spr[SPR_BOOKS_PID];
  58             break;
  59         case R_EADDR_QUADRANT1: /* Illegal */
  60         case R_EADDR_QUADRANT2:
  61             return false;
  62         case R_EADDR_QUADRANT3: /* Guest OS */
  63             *lpid = env->spr[SPR_LPIDR];
  64             *pid = 0; /* pid set to 0 -> addresses guest operating system */
  65             break;
  66         }
  67     }
  68
  69     return true;
  70 }
  71
  72 static void ppc_radix64_raise_segi(PowerPCCPU *cpu, int rwx, vaddr eaddr)
  73 {
  74     CPUState *cs = CPU(cpu);
  75     CPUPPCState *env = &cpu->env;
  76
  77     if (rwx == 2) { /* Instruction Segment Interrupt */
  78         cs->exception_index = POWERPC_EXCP_ISEG;
  79     } else { /* Data Segment Interrupt */
  80         cs->exception_index = POWERPC_EXCP_DSEG;
  81         env->spr[SPR_DAR] = eaddr;
  82     }
  83     env->error_code = 0;
  84 }
  85
  86 static void ppc_radix64_raise_si(PowerPCCPU *cpu, int rwx, vaddr eaddr,
  87                                 uint32_t cause)
  88 {
  89     CPUState *cs = CPU(cpu);
  90     CPUPPCState *env = &cpu->env;
  91
  92     if (rwx == 2) { /* Instruction Storage Interrupt */
  93         cs->exception_index = POWERPC_EXCP_ISI;
  94         env->error_code = cause;
  95     } else { /* Data Storage Interrupt */
  96         cs->exception_index = POWERPC_EXCP_DSI;
  97         if (rwx == 1) { /* Write -> Store */
  98             cause |= DSISR_ISSTORE;
  99         }
 100         env->spr[SPR_DSISR] = cause;
 101         env->spr[SPR_DAR] = eaddr;
 102         env->error_code = 0;
 103     }
 104 }
 105
 106
 107 static bool ppc_radix64_check_prot(PowerPCCPU *cpu, int rwx, uint64_t pte,
 108                                    int *fault_cause, int *prot)
 109 {
 110     CPUPPCState *env = &cpu->env;
 111     const int need_prot[] = { PAGE_READ, PAGE_WRITE, PAGE_EXEC };
 112
 113     /* Check Page Attributes (pte58:59) */
 114     if (((pte & R_PTE_ATT) == R_PTE_ATT_NI_IO) && (rwx == 2)) {
 115         /*
 116          * Radix PTE entries with the non-idempotent I/O attribute are treated
 117          * as guarded storage
 118          */
 119         *fault_cause |= SRR1_NOEXEC_GUARD;
 120         return true;
 121     }
 122
 123     /* Determine permissions allowed by Encoded Access Authority */
 124     if ((pte & R_PTE_EAA_PRIV) && msr_pr) { /* Insufficient Privilege */
 125         *prot = 0;
 126     } else if (msr_pr || (pte & R_PTE_EAA_PRIV)) {
 127         *prot = ppc_radix64_get_prot_eaa(pte);
 128     } else { /* !msr_pr && !(pte & R_PTE_EAA_PRIV) */
 129         *prot = ppc_radix64_get_prot_eaa(pte);
 130         *prot &= ppc_radix64_get_prot_amr(cpu); /* Least combined permissions */
 131     }
 132
 133     /* Check if requested access type is allowed */
 134     if (need_prot[rwx] & ~(*prot)) { /* Page Protected for that Access */
 135         *fault_cause |= DSISR_PROTFAULT;
 136         return true;
 137     }
 138
 139     return false;
 140 }
 141
 142 static void ppc_radix64_set_rc(PowerPCCPU *cpu, int rwx, uint64_t pte,
 143                                hwaddr pte_addr, int *prot)
 144 {
 145     CPUState *cs = CPU(cpu);
 146     uint64_t npte;
 147
 148     npte = pte | R_PTE_R; /* Always set reference bit */
 149
 150     if (rwx == 1) { /* Store/Write */
 151         npte |= R_PTE_C; /* Set change bit */
 152     } else {
 153         /*
 154          * Treat the page as read-only for now, so that a later write
 155          * will pass through this function again to set the C bit.
 156          */
 157         *prot &= ~PAGE_WRITE;
 158     }
 159
 160     if (pte ^ npte) { /* If pte has changed then write it back */
 161         stq_phys(cs->as, pte_addr, npte);
 162     }
 163 }
 164
 165 static uint64_t ppc_radix64_walk_tree(PowerPCCPU *cpu, vaddr eaddr,
 166                                       uint64_t base_addr, uint64_t nls,
 167                                       hwaddr *raddr, int *psize,
 168                                       int *fault_cause, hwaddr *pte_addr)
 169 {
 170     CPUState *cs = CPU(cpu);
 171     uint64_t index, pde;
 172
 173     if (nls < 5) { /* Directory maps less than 2**5 entries */
 174         *fault_cause |= DSISR_R_BADCONFIG;
 175         return 0;
 176     }
 177
 178     /* Read page <directory/table> entry from guest address space */
 179     index = eaddr >> (*psize - nls); /* Shift */
 180     index &= ((1UL << nls) - 1); /* Mask */
 181     pde = ldq_phys(cs->as, base_addr + (index * sizeof(pde)));
 182     if (!(pde & R_PTE_VALID)) { /* Invalid Entry */
 183         *fault_cause |= DSISR_NOPTE;
 184         return 0;
 185     }
 186
 187     *psize -= nls;
 188
 189     /* Check if Leaf Entry -> Page Table Entry -> Stop the Search */
 190     if (pde & R_PTE_LEAF) {
 191         uint64_t rpn = pde & R_PTE_RPN;
 192         uint64_t mask = (1UL << *psize) - 1;
 193
 194         /* Or high bits of rpn and low bits to ea to form whole real addr */
 195         *raddr = (rpn & ~mask) | (eaddr & mask);
 196         *pte_addr = base_addr + (index * sizeof(pde));
 197         return pde;
 198     }
 199
 200     /* Next Level of Radix Tree */
 201     return ppc_radix64_walk_tree(cpu, eaddr, pde & R_PDE_NLB, pde & R_PDE_NLS,
 202                                  raddr, psize, fault_cause, pte_addr);
 203 }
 204
 205 static bool validate_pate(PowerPCCPU *cpu, uint64_t lpid, ppc_v3_pate_t *pate)
 206 {
 207     CPUPPCState *env = &cpu->env;
 208
 209     if (!(pate->dw0 & PATE0_HR)) {
 210         return false;
 211     }
 212     if (lpid == 0 && !msr_hv) {
 213         return false;
 214     }
 215     /* More checks ... */
 216     return true;
 217 }
 218
 219 int ppc_radix64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
 220                                  int mmu_idx)
 221 {
 222     CPUState *cs = CPU(cpu);
 223     CPUPPCState *env = &cpu->env;
 224     PPCVirtualHypervisorClass *vhc;
 225     hwaddr raddr, pte_addr;
 226     uint64_t lpid = 0, pid = 0, offset, size, prtbe0, pte;
 227     int page_size, prot, fault_cause = 0;
 228     ppc_v3_pate_t pate;
 229
 230     assert((rwx == 0) || (rwx == 1) || (rwx == 2));
 231     assert(ppc64_use_proc_tbl(cpu));
 232
 233     /* Real Mode Access */
 234     if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
 235         /* In real mode top 4 effective addr bits (mostly) ignored */
 236         raddr = eaddr & 0x0FFFFFFFFFFFFFFFULL;
 237
 238         tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
 239                      PAGE_READ | PAGE_WRITE | PAGE_EXEC, mmu_idx,
 240                      TARGET_PAGE_SIZE);
 241         return 0;
 242     }
 243
 244     /* Virtual Mode Access - get the fully qualified address */
 245     if (!ppc_radix64_get_fully_qualified_addr(env, eaddr, &lpid, &pid)) {
 246         ppc_radix64_raise_segi(cpu, rwx, eaddr);
 247         return 1;
 248     }
 249
 250     /* Get Process Table */
 251     if (cpu->vhyp) {
 252         vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
 253         vhc->get_pate(cpu->vhyp, &pate);
 254     } else {
 255         if (!ppc64_v3_get_pate(cpu, lpid, &pate)) {
 256             ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_NOPTE);
 257             return 1;
 258         }
 259         if (!validate_pate(cpu, lpid, &pate)) {
 260             ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_R_BADCONFIG);
 261         }
 262         /* We don't support guest mode yet */
 263         if (lpid != 0) {
 264             error_report("PowerNV guest support Unimplemented");
 265             exit(1);
 266        }
 267     }
 268
 269     /* Index Process Table by PID to Find Corresponding Process Table Entry */
 270     offset = pid * sizeof(struct prtb_entry);
 271     size = 1ULL << ((pate.dw1 & PATE1_R_PRTS) + 12);
 272     if (offset >= size) {
 273         /* offset exceeds size of the process table */
 274         ppc_radix64_raise_si(cpu, rwx, eaddr, DSISR_NOPTE);
 275         return 1;
 276     }
 277     prtbe0 = ldq_phys(cs->as, (pate.dw1 & PATE1_R_PRTB) + offset);
 278
 279     /* Walk Radix Tree from Process Table Entry to Convert EA to RA */
 280     page_size = PRTBE_R_GET_RTS(prtbe0);
 281     pte = ppc_radix64_walk_tree(cpu, eaddr & R_EADDR_MASK,
 282                                 prtbe0 & PRTBE_R_RPDB, prtbe0 & PRTBE_R_RPDS,
 283                                 &raddr, &page_size, &fault_cause, &pte_addr);
 284     if (!pte || ppc_radix64_check_prot(cpu, rwx, pte, &fault_cause, &prot)) {
 285         /* Couldn't get pte or access denied due to protection */
 286         ppc_radix64_raise_si(cpu, rwx, eaddr, fault_cause);
 287         return 1;
 288     }
 289
 290     /* Update Reference and Change Bits */
 291     ppc_radix64_set_rc(cpu, rwx, pte, pte_addr, &prot);
 292
 293     tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
 294                  prot, mmu_idx, 1UL << page_size);
 295     return 0;
 296 }
 297
 298 hwaddr ppc_radix64_get_phys_page_debug(PowerPCCPU *cpu, target_ulong eaddr)
 299 {
 300     CPUState *cs = CPU(cpu);
 301     CPUPPCState *env = &cpu->env;
 302     PPCVirtualHypervisorClass *vhc;
 303     hwaddr raddr, pte_addr;
 304     uint64_t lpid = 0, pid = 0, offset, size, prtbe0, pte;
 305     int page_size, fault_cause = 0;
 306     ppc_v3_pate_t pate;
 307
 308     /* Handle Real Mode */
 309     if (msr_dr == 0) {
 310         /* In real mode top 4 effective addr bits (mostly) ignored */
 311         return eaddr & 0x0FFFFFFFFFFFFFFFULL;
 312     }
 313
 314     /* Virtual Mode Access - get the fully qualified address */
 315     if (!ppc_radix64_get_fully_qualified_addr(env, eaddr, &lpid, &pid)) {
 316         return -1;
 317     }
 318
 319     /* Get Process Table */
 320     if (cpu->vhyp) {
 321         vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
 322         vhc->get_pate(cpu->vhyp, &pate);
 323     } else {
 324         if (!ppc64_v3_get_pate(cpu, lpid, &pate)) {
 325             return -1;
 326         }
 327         if (!validate_pate(cpu, lpid, &pate)) {
 328             return -1;
 329         }
 330         /* We don't support guest mode yet */
 331         if (lpid != 0) {
 332             error_report("PowerNV guest support Unimplemented");
 333             exit(1);
 334        }
 335     }
 336
 337     /* Index Process Table by PID to Find Corresponding Process Table Entry */
 338     offset = pid * sizeof(struct prtb_entry);
 339     size = 1ULL << ((pate.dw1 & PATE1_R_PRTS) + 12);
 340     if (offset >= size) {
 341         /* offset exceeds size of the process table */
 342         return -1;
 343     }
 344     prtbe0 = ldq_phys(cs->as, (pate.dw1 & PATE1_R_PRTB) + offset);
 345
 346     /* Walk Radix Tree from Process Table Entry to Convert EA to RA */
 347     page_size = PRTBE_R_GET_RTS(prtbe0);
 348     pte = ppc_radix64_walk_tree(cpu, eaddr & R_EADDR_MASK,
 349                                 prtbe0 & PRTBE_R_RPDB, prtbe0 & PRTBE_R_RPDS,
 350                                 &raddr, &page_size, &fault_cause, &pte_addr);
 351     if (!pte) {
 352         return -1;
 353     }
 354
 355     return raddr & TARGET_PAGE_MASK;
 356 }