| /* |
| * virtual page mapping and translated block handling |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <stdarg.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <unistd.h> |
| #include <inttypes.h> |
| #include <sys/mman.h> |
| |
| #include "cpu-i386.h" |
| #include "exec.h" |
| |
| //#define DEBUG_TB_INVALIDATE |
| #define DEBUG_FLUSH |
| |
| /* make various TB consistency checks */ |
| //#define DEBUG_TB_CHECK |
| |
| /* threshold to flush the translated code buffer */ |
| #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE) |
| |
| #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64) |
| |
| TranslationBlock tbs[CODE_GEN_MAX_BLOCKS]; |
| TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE]; |
| int nb_tbs; |
| /* any access to the tbs or the page table must use this lock */ |
| spinlock_t tb_lock = SPIN_LOCK_UNLOCKED; |
| |
| uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE]; |
| uint8_t *code_gen_ptr; |
| |
| /* XXX: pack the flags in the low bits of the pointer ? */ |
| typedef struct PageDesc { |
| unsigned long flags; |
| TranslationBlock *first_tb; |
| } PageDesc; |
| |
| #define L2_BITS 10 |
| #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS) |
| |
| #define L1_SIZE (1 << L1_BITS) |
| #define L2_SIZE (1 << L2_BITS) |
| |
| static void tb_invalidate_page(unsigned long address); |
| |
| unsigned long real_host_page_size; |
| unsigned long host_page_bits; |
| unsigned long host_page_size; |
| unsigned long host_page_mask; |
| |
| static PageDesc *l1_map[L1_SIZE]; |
| |
| void page_init(void) |
| { |
| /* NOTE: we can always suppose that host_page_size >= |
| TARGET_PAGE_SIZE */ |
| real_host_page_size = getpagesize(); |
| if (host_page_size == 0) |
| host_page_size = real_host_page_size; |
| if (host_page_size < TARGET_PAGE_SIZE) |
| host_page_size = TARGET_PAGE_SIZE; |
| host_page_bits = 0; |
| while ((1 << host_page_bits) < host_page_size) |
| host_page_bits++; |
| host_page_mask = ~(host_page_size - 1); |
| } |
| |
| /* dump memory mappings */ |
| void page_dump(FILE *f) |
| { |
| unsigned long start, end; |
| int i, j, prot, prot1; |
| PageDesc *p; |
| |
| fprintf(f, "%-8s %-8s %-8s %s\n", |
| "start", "end", "size", "prot"); |
| start = -1; |
| end = -1; |
| prot = 0; |
| for(i = 0; i <= L1_SIZE; i++) { |
| if (i < L1_SIZE) |
| p = l1_map[i]; |
| else |
| p = NULL; |
| for(j = 0;j < L2_SIZE; j++) { |
| if (!p) |
| prot1 = 0; |
| else |
| prot1 = p[j].flags; |
| if (prot1 != prot) { |
| end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS); |
| if (start != -1) { |
| fprintf(f, "%08lx-%08lx %08lx %c%c%c\n", |
| start, end, end - start, |
| prot & PAGE_READ ? 'r' : '-', |
| prot & PAGE_WRITE ? 'w' : '-', |
| prot & PAGE_EXEC ? 'x' : '-'); |
| } |
| if (prot1 != 0) |
| start = end; |
| else |
| start = -1; |
| prot = prot1; |
| } |
| if (!p) |
| break; |
| } |
| } |
| } |
| |
| static inline PageDesc *page_find_alloc(unsigned int index) |
| { |
| PageDesc **lp, *p; |
| |
| lp = &l1_map[index >> L2_BITS]; |
| p = *lp; |
| if (!p) { |
| /* allocate if not found */ |
| p = malloc(sizeof(PageDesc) * L2_SIZE); |
| memset(p, 0, sizeof(PageDesc) * L2_SIZE); |
| *lp = p; |
| } |
| return p + (index & (L2_SIZE - 1)); |
| } |
| |
| static inline PageDesc *page_find(unsigned int index) |
| { |
| PageDesc *p; |
| |
| p = l1_map[index >> L2_BITS]; |
| if (!p) |
| return 0; |
| return p + (index & (L2_SIZE - 1)); |
| } |
| |
| int page_get_flags(unsigned long address) |
| { |
| PageDesc *p; |
| |
| p = page_find(address >> TARGET_PAGE_BITS); |
| if (!p) |
| return 0; |
| return p->flags; |
| } |
| |
| /* modify the flags of a page and invalidate the code if |
| necessary. The flag PAGE_WRITE_ORG is positionned automatically |
| depending on PAGE_WRITE */ |
| void page_set_flags(unsigned long start, unsigned long end, int flags) |
| { |
| PageDesc *p; |
| unsigned long addr; |
| |
| start = start & TARGET_PAGE_MASK; |
| end = TARGET_PAGE_ALIGN(end); |
| if (flags & PAGE_WRITE) |
| flags |= PAGE_WRITE_ORG; |
| spin_lock(&tb_lock); |
| for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) { |
| p = page_find_alloc(addr >> TARGET_PAGE_BITS); |
| /* if the write protection is set, then we invalidate the code |
| inside */ |
| if (!(p->flags & PAGE_WRITE) && |
| (flags & PAGE_WRITE) && |
| p->first_tb) { |
| tb_invalidate_page(addr); |
| } |
| p->flags = flags; |
| } |
| spin_unlock(&tb_lock); |
| } |
| |
| void cpu_x86_tblocks_init(void) |
| { |
| if (!code_gen_ptr) { |
| code_gen_ptr = code_gen_buffer; |
| } |
| } |
| |
| /* set to NULL all the 'first_tb' fields in all PageDescs */ |
| static void page_flush_tb(void) |
| { |
| int i, j; |
| PageDesc *p; |
| |
| for(i = 0; i < L1_SIZE; i++) { |
| p = l1_map[i]; |
| if (p) { |
| for(j = 0; j < L2_SIZE; j++) |
| p[j].first_tb = NULL; |
| } |
| } |
| } |
| |
| /* flush all the translation blocks */ |
| /* XXX: tb_flush is currently not thread safe */ |
| void tb_flush(void) |
| { |
| int i; |
| #ifdef DEBUG_FLUSH |
| printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n", |
| code_gen_ptr - code_gen_buffer, |
| nb_tbs, |
| (code_gen_ptr - code_gen_buffer) / nb_tbs); |
| #endif |
| nb_tbs = 0; |
| for(i = 0;i < CODE_GEN_HASH_SIZE; i++) |
| tb_hash[i] = NULL; |
| page_flush_tb(); |
| code_gen_ptr = code_gen_buffer; |
| /* XXX: flush processor icache at this point if cache flush is |
| expensive */ |
| } |
| |
| #ifdef DEBUG_TB_CHECK |
| |
| static void tb_invalidate_check(unsigned long address) |
| { |
| TranslationBlock *tb; |
| int i; |
| address &= TARGET_PAGE_MASK; |
| for(i = 0;i < CODE_GEN_HASH_SIZE; i++) { |
| for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) { |
| if (!(address + TARGET_PAGE_SIZE <= tb->pc || |
| address >= tb->pc + tb->size)) { |
| printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n", |
| address, tb->pc, tb->size); |
| } |
| } |
| } |
| } |
| |
| /* verify that all the pages have correct rights for code */ |
| static void tb_page_check(void) |
| { |
| TranslationBlock *tb; |
| int i, flags1, flags2; |
| |
| for(i = 0;i < CODE_GEN_HASH_SIZE; i++) { |
| for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) { |
| flags1 = page_get_flags(tb->pc); |
| flags2 = page_get_flags(tb->pc + tb->size - 1); |
| if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) { |
| printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n", |
| tb->pc, tb->size, flags1, flags2); |
| } |
| } |
| } |
| } |
| |
| void tb_jmp_check(TranslationBlock *tb) |
| { |
| TranslationBlock *tb1; |
| unsigned int n1; |
| |
| /* suppress any remaining jumps to this TB */ |
| tb1 = tb->jmp_first; |
| for(;;) { |
| n1 = (long)tb1 & 3; |
| tb1 = (TranslationBlock *)((long)tb1 & ~3); |
| if (n1 == 2) |
| break; |
| tb1 = tb1->jmp_next[n1]; |
| } |
| /* check end of list */ |
| if (tb1 != tb) { |
| printf("ERROR: jmp_list from 0x%08lx\n", (long)tb); |
| } |
| } |
| |
| #endif |
| |
| /* invalidate one TB */ |
| static inline void tb_remove(TranslationBlock **ptb, TranslationBlock *tb, |
| int next_offset) |
| { |
| TranslationBlock *tb1; |
| for(;;) { |
| tb1 = *ptb; |
| if (tb1 == tb) { |
| *ptb = *(TranslationBlock **)((char *)tb1 + next_offset); |
| break; |
| } |
| ptb = (TranslationBlock **)((char *)tb1 + next_offset); |
| } |
| } |
| |
| static inline void tb_jmp_remove(TranslationBlock *tb, int n) |
| { |
| TranslationBlock *tb1, **ptb; |
| unsigned int n1; |
| |
| ptb = &tb->jmp_next[n]; |
| tb1 = *ptb; |
| if (tb1) { |
| /* find tb(n) in circular list */ |
| for(;;) { |
| tb1 = *ptb; |
| n1 = (long)tb1 & 3; |
| tb1 = (TranslationBlock *)((long)tb1 & ~3); |
| if (n1 == n && tb1 == tb) |
| break; |
| if (n1 == 2) { |
| ptb = &tb1->jmp_first; |
| } else { |
| ptb = &tb1->jmp_next[n1]; |
| } |
| } |
| /* now we can suppress tb(n) from the list */ |
| *ptb = tb->jmp_next[n]; |
| |
| tb->jmp_next[n] = NULL; |
| } |
| } |
| |
| /* reset the jump entry 'n' of a TB so that it is not chained to |
| another TB */ |
| static inline void tb_reset_jump(TranslationBlock *tb, int n) |
| { |
| tb_set_jmp_target(tb, n, (unsigned long)(tb->tc_ptr + tb->tb_next_offset[n])); |
| } |
| |
| static inline void tb_invalidate(TranslationBlock *tb, int parity) |
| { |
| PageDesc *p; |
| unsigned int page_index1, page_index2; |
| unsigned int h, n1; |
| TranslationBlock *tb1, *tb2; |
| |
| /* remove the TB from the hash list */ |
| h = tb_hash_func(tb->pc); |
| tb_remove(&tb_hash[h], tb, |
| offsetof(TranslationBlock, hash_next)); |
| /* remove the TB from the page list */ |
| page_index1 = tb->pc >> TARGET_PAGE_BITS; |
| if ((page_index1 & 1) == parity) { |
| p = page_find(page_index1); |
| tb_remove(&p->first_tb, tb, |
| offsetof(TranslationBlock, page_next[page_index1 & 1])); |
| } |
| page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS; |
| if ((page_index2 & 1) == parity) { |
| p = page_find(page_index2); |
| tb_remove(&p->first_tb, tb, |
| offsetof(TranslationBlock, page_next[page_index2 & 1])); |
| } |
| |
| /* suppress this TB from the two jump lists */ |
| tb_jmp_remove(tb, 0); |
| tb_jmp_remove(tb, 1); |
| |
| /* suppress any remaining jumps to this TB */ |
| tb1 = tb->jmp_first; |
| for(;;) { |
| n1 = (long)tb1 & 3; |
| if (n1 == 2) |
| break; |
| tb1 = (TranslationBlock *)((long)tb1 & ~3); |
| tb2 = tb1->jmp_next[n1]; |
| tb_reset_jump(tb1, n1); |
| tb1->jmp_next[n1] = NULL; |
| tb1 = tb2; |
| } |
| tb->jmp_first = (TranslationBlock *)((long)tb | 2); /* fail safe */ |
| } |
| |
| /* invalidate all TBs which intersect with the target page starting at addr */ |
| static void tb_invalidate_page(unsigned long address) |
| { |
| TranslationBlock *tb_next, *tb; |
| unsigned int page_index; |
| int parity1, parity2; |
| PageDesc *p; |
| #ifdef DEBUG_TB_INVALIDATE |
| printf("tb_invalidate_page: %lx\n", address); |
| #endif |
| |
| page_index = address >> TARGET_PAGE_BITS; |
| p = page_find(page_index); |
| if (!p) |
| return; |
| tb = p->first_tb; |
| parity1 = page_index & 1; |
| parity2 = parity1 ^ 1; |
| while (tb != NULL) { |
| tb_next = tb->page_next[parity1]; |
| tb_invalidate(tb, parity2); |
| tb = tb_next; |
| } |
| p->first_tb = NULL; |
| } |
| |
| /* add the tb in the target page and protect it if necessary */ |
| static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index) |
| { |
| PageDesc *p; |
| unsigned long host_start, host_end, addr, page_addr; |
| int prot; |
| |
| p = page_find_alloc(page_index); |
| tb->page_next[page_index & 1] = p->first_tb; |
| p->first_tb = tb; |
| if (p->flags & PAGE_WRITE) { |
| /* force the host page as non writable (writes will have a |
| page fault + mprotect overhead) */ |
| page_addr = (page_index << TARGET_PAGE_BITS); |
| host_start = page_addr & host_page_mask; |
| host_end = host_start + host_page_size; |
| prot = 0; |
| for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE) |
| prot |= page_get_flags(addr); |
| mprotect((void *)host_start, host_page_size, |
| (prot & PAGE_BITS) & ~PAGE_WRITE); |
| #ifdef DEBUG_TB_INVALIDATE |
| printf("protecting code page: 0x%08lx\n", |
| host_start); |
| #endif |
| p->flags &= ~PAGE_WRITE; |
| #ifdef DEBUG_TB_CHECK |
| tb_page_check(); |
| #endif |
| } |
| } |
| |
| /* Allocate a new translation block. Flush the translation buffer if |
| too many translation blocks or too much generated code. */ |
| TranslationBlock *tb_alloc(unsigned long pc) |
| { |
| TranslationBlock *tb; |
| |
| if (nb_tbs >= CODE_GEN_MAX_BLOCKS || |
| (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE) |
| return NULL; |
| tb = &tbs[nb_tbs++]; |
| tb->pc = pc; |
| return tb; |
| } |
| |
| /* link the tb with the other TBs */ |
| void tb_link(TranslationBlock *tb) |
| { |
| unsigned int page_index1, page_index2; |
| |
| /* add in the page list */ |
| page_index1 = tb->pc >> TARGET_PAGE_BITS; |
| tb_alloc_page(tb, page_index1); |
| page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS; |
| if (page_index2 != page_index1) { |
| tb_alloc_page(tb, page_index2); |
| } |
| tb->jmp_first = (TranslationBlock *)((long)tb | 2); |
| tb->jmp_next[0] = NULL; |
| tb->jmp_next[1] = NULL; |
| |
| /* init original jump addresses */ |
| if (tb->tb_next_offset[0] != 0xffff) |
| tb_reset_jump(tb, 0); |
| if (tb->tb_next_offset[1] != 0xffff) |
| tb_reset_jump(tb, 1); |
| } |
| |
| /* called from signal handler: invalidate the code and unprotect the |
| page. Return TRUE if the fault was succesfully handled. */ |
| int page_unprotect(unsigned long address) |
| { |
| unsigned int page_index, prot, pindex; |
| PageDesc *p, *p1; |
| unsigned long host_start, host_end, addr; |
| |
| host_start = address & host_page_mask; |
| page_index = host_start >> TARGET_PAGE_BITS; |
| p1 = page_find(page_index); |
| if (!p1) |
| return 0; |
| host_end = host_start + host_page_size; |
| p = p1; |
| prot = 0; |
| for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) { |
| prot |= p->flags; |
| p++; |
| } |
| /* if the page was really writable, then we change its |
| protection back to writable */ |
| if (prot & PAGE_WRITE_ORG) { |
| mprotect((void *)host_start, host_page_size, |
| (prot & PAGE_BITS) | PAGE_WRITE); |
| pindex = (address - host_start) >> TARGET_PAGE_BITS; |
| p1[pindex].flags |= PAGE_WRITE; |
| /* and since the content will be modified, we must invalidate |
| the corresponding translated code. */ |
| tb_invalidate_page(address); |
| #ifdef DEBUG_TB_CHECK |
| tb_invalidate_check(address); |
| #endif |
| return 1; |
| } else { |
| return 0; |
| } |
| } |
| |
| /* call this function when system calls directly modify a memory area */ |
| void page_unprotect_range(uint8_t *data, unsigned long data_size) |
| { |
| unsigned long start, end, addr; |
| |
| start = (unsigned long)data; |
| end = start + data_size; |
| start &= TARGET_PAGE_MASK; |
| end = TARGET_PAGE_ALIGN(end); |
| for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) { |
| page_unprotect(addr); |
| } |
| } |
| |
| /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr < |
| tb[1].tc_ptr. Return NULL if not found */ |
| TranslationBlock *tb_find_pc(unsigned long tc_ptr) |
| { |
| int m_min, m_max, m; |
| unsigned long v; |
| TranslationBlock *tb; |
| |
| if (nb_tbs <= 0) |
| return NULL; |
| if (tc_ptr < (unsigned long)code_gen_buffer || |
| tc_ptr >= (unsigned long)code_gen_ptr) |
| return NULL; |
| /* binary search (cf Knuth) */ |
| m_min = 0; |
| m_max = nb_tbs - 1; |
| while (m_min <= m_max) { |
| m = (m_min + m_max) >> 1; |
| tb = &tbs[m]; |
| v = (unsigned long)tb->tc_ptr; |
| if (v == tc_ptr) |
| return tb; |
| else if (tc_ptr < v) { |
| m_max = m - 1; |
| } else { |
| m_min = m + 1; |
| } |
| } |
| return &tbs[m_max]; |
| } |
