diff options
| -rw-r--r-- | translate-all.c | 210 |
1 files changed, 119 insertions, 91 deletions
diff --git a/translate-all.c b/translate-all.c index 0e8d176de0..b43bd03654 100644 --- a/translate-all.c +++ b/translate-all.c @@ -312,31 +312,6 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr) return false; } -#ifdef _WIN32 -static __attribute__((unused)) void map_exec(void *addr, long size) -{ - DWORD old_protect; - VirtualProtect(addr, size, - PAGE_EXECUTE_READWRITE, &old_protect); -} -#else -static __attribute__((unused)) void map_exec(void *addr, long size) -{ - unsigned long start, end, page_size; - - page_size = getpagesize(); - start = (unsigned long)addr; - start &= ~(page_size - 1); - - end = (unsigned long)addr + size; - end += page_size - 1; - end &= ~(page_size - 1); - - mprotect((void *)start, end - start, - PROT_READ | PROT_WRITE | PROT_EXEC); -} -#endif - void page_size_init(void) { /* NOTE: we can always suppose that qemu_host_page_size >= @@ -473,14 +448,6 @@ static inline PageDesc *page_find(tb_page_addr_t index) #define USE_STATIC_CODE_GEN_BUFFER #endif -/* ??? Should configure for this, not list operating systems here. */ -#if (defined(__linux__) \ - || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) \ - || defined(__DragonFly__) || defined(__OpenBSD__) \ - || defined(__NetBSD__)) -# define USE_MMAP -#endif - /* Minimum size of the code gen buffer. This number is randomly chosen, but not so small that we can't have a fair number of TB's live. */ #define MIN_CODE_GEN_BUFFER_SIZE (1024u * 1024) @@ -568,22 +535,102 @@ static inline void *split_cross_256mb(void *buf1, size_t size1) static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE] __attribute__((aligned(CODE_GEN_ALIGN))); +# ifdef _WIN32 +static inline void do_protect(void *addr, long size, int prot) +{ + DWORD old_protect; + VirtualProtect(addr, size, prot, &old_protect); +} + +static inline void map_exec(void *addr, long size) +{ + do_protect(addr, size, PAGE_EXECUTE_READWRITE); +} + +static inline void map_none(void *addr, long size) +{ + do_protect(addr, size, PAGE_NOACCESS); +} +# else +static inline void do_protect(void *addr, long size, int prot) +{ + uintptr_t start, end; + + start = (uintptr_t)addr; + start &= qemu_real_host_page_mask; + + end = (uintptr_t)addr + size; + end = ROUND_UP(end, qemu_real_host_page_size); + + mprotect((void *)start, end - start, prot); +} + +static inline void map_exec(void *addr, long size) +{ + do_protect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); +} + +static inline void map_none(void *addr, long size) +{ + do_protect(addr, size, PROT_NONE); +} +# endif /* WIN32 */ + static inline void *alloc_code_gen_buffer(void) { void *buf = static_code_gen_buffer; + size_t full_size, size; + + /* The size of the buffer, rounded down to end on a page boundary. */ + full_size = (((uintptr_t)buf + sizeof(static_code_gen_buffer)) + & qemu_real_host_page_mask) - (uintptr_t)buf; + + /* Reserve a guard page. */ + size = full_size - qemu_real_host_page_size; + + /* Honor a command-line option limiting the size of the buffer. */ + if (size > tcg_ctx.code_gen_buffer_size) { + size = (((uintptr_t)buf + tcg_ctx.code_gen_buffer_size) + & qemu_real_host_page_mask) - (uintptr_t)buf; + } + tcg_ctx.code_gen_buffer_size = size; + #ifdef __mips__ - if (cross_256mb(buf, tcg_ctx.code_gen_buffer_size)) { - buf = split_cross_256mb(buf, tcg_ctx.code_gen_buffer_size); + if (cross_256mb(buf, size)) { + buf = split_cross_256mb(buf, size); + size = tcg_ctx.code_gen_buffer_size; } #endif - map_exec(buf, tcg_ctx.code_gen_buffer_size); + + map_exec(buf, size); + map_none(buf + size, qemu_real_host_page_size); + qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE); + return buf; } -#elif defined(USE_MMAP) +#elif defined(_WIN32) +static inline void *alloc_code_gen_buffer(void) +{ + size_t size = tcg_ctx.code_gen_buffer_size; + void *buf1, *buf2; + + /* Perform the allocation in two steps, so that the guard page + is reserved but uncommitted. */ + buf1 = VirtualAlloc(NULL, size + qemu_real_host_page_size, + MEM_RESERVE, PAGE_NOACCESS); + if (buf1 != NULL) { + buf2 = VirtualAlloc(buf1, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE); + assert(buf1 == buf2); + } + + return buf1; +} +#else static inline void *alloc_code_gen_buffer(void) { int flags = MAP_PRIVATE | MAP_ANONYMOUS; uintptr_t start = 0; + size_t size = tcg_ctx.code_gen_buffer_size; void *buf; /* Constrain the position of the buffer based on the host cpu. @@ -599,86 +646,70 @@ static inline void *alloc_code_gen_buffer(void) Leave the choice of exact location with the kernel. */ flags |= MAP_32BIT; /* Cannot expect to map more than 800MB in low memory. */ - if (tcg_ctx.code_gen_buffer_size > 800u * 1024 * 1024) { - tcg_ctx.code_gen_buffer_size = 800u * 1024 * 1024; + if (size > 800u * 1024 * 1024) { + tcg_ctx.code_gen_buffer_size = size = 800u * 1024 * 1024; } # elif defined(__sparc__) start = 0x40000000ul; # elif defined(__s390x__) start = 0x90000000ul; # elif defined(__mips__) - /* ??? We ought to more explicitly manage layout for softmmu too. */ -# ifdef CONFIG_USER_ONLY - start = 0x68000000ul; -# elif _MIPS_SIM == _ABI64 +# if _MIPS_SIM == _ABI64 start = 0x128000000ul; # else start = 0x08000000ul; # endif # endif - buf = mmap((void *)start, tcg_ctx.code_gen_buffer_size, - PROT_WRITE | PROT_READ | PROT_EXEC, flags, -1, 0); + buf = mmap((void *)start, size + qemu_real_host_page_size, + PROT_NONE, flags, -1, 0); if (buf == MAP_FAILED) { return NULL; } #ifdef __mips__ - if (cross_256mb(buf, tcg_ctx.code_gen_buffer_size)) { + if (cross_256mb(buf, size)) { /* Try again, with the original still mapped, to avoid re-acquiring that 256mb crossing. This time don't specify an address. */ - size_t size2, size1 = tcg_ctx.code_gen_buffer_size; - void *buf2 = mmap(NULL, size1, PROT_WRITE | PROT_READ | PROT_EXEC, - flags, -1, 0); - if (buf2 != MAP_FAILED) { - if (!cross_256mb(buf2, size1)) { + size_t size2; + void *buf2 = mmap(NULL, size + qemu_real_host_page_size, + PROT_NONE, flags, -1, 0); + switch (buf2 != MAP_FAILED) { + case 1: + if (!cross_256mb(buf2, size)) { /* Success! Use the new buffer. */ - munmap(buf, size1); - return buf2; + munmap(buf, size); + break; } /* Failure. Work with what we had. */ - munmap(buf2, size1); + munmap(buf2, size); + /* fallthru */ + default: + /* Split the original buffer. Free the smaller half. */ + buf2 = split_cross_256mb(buf, size); + size2 = tcg_ctx.code_gen_buffer_size; + if (buf == buf2) { + munmap(buf + size2 + qemu_real_host_page_size, size - size2); + } else { + munmap(buf, size - size2); + } + size = size2; + break; } - - /* Split the original buffer. Free the smaller half. */ - buf2 = split_cross_256mb(buf, size1); - size2 = tcg_ctx.code_gen_buffer_size; - munmap(buf + (buf == buf2 ? size2 : 0), size1 - size2); - return buf2; + buf = buf2; } #endif - return buf; -} -#else -static inline void *alloc_code_gen_buffer(void) -{ - void *buf = g_try_malloc(tcg_ctx.code_gen_buffer_size); + /* Make the final buffer accessible. The guard page at the end + will remain inaccessible with PROT_NONE. */ + mprotect(buf, size, PROT_WRITE | PROT_READ | PROT_EXEC); - if (buf == NULL) { - return NULL; - } + /* Request large pages for the buffer. */ + qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE); -#ifdef __mips__ - if (cross_256mb(buf, tcg_ctx.code_gen_buffer_size)) { - void *buf2 = g_malloc(tcg_ctx.code_gen_buffer_size); - if (buf2 != NULL && !cross_256mb(buf2, size1)) { - /* Success! Use the new buffer. */ - free(buf); - buf = buf2; - } else { - /* Failure. Work with what we had. Since this is malloc - and not mmap, we can't free the other half. */ - free(buf2); - buf = split_cross_256mb(buf, tcg_ctx.code_gen_buffer_size); - } - } -#endif - - map_exec(buf, tcg_ctx.code_gen_buffer_size); return buf; } -#endif /* USE_STATIC_CODE_GEN_BUFFER, USE_MMAP */ +#endif /* USE_STATIC_CODE_GEN_BUFFER, WIN32, POSIX */ static inline void code_gen_alloc(size_t tb_size) { @@ -689,9 +720,6 @@ static inline void code_gen_alloc(size_t tb_size) exit(1); } - qemu_madvise(tcg_ctx.code_gen_buffer, tcg_ctx.code_gen_buffer_size, - QEMU_MADV_HUGEPAGE); - /* Estimate a good size for the number of TBs we can support. We still haven't deducted the prologue from the buffer size here, but that's minimal and won't affect the estimate much. */ @@ -708,8 +736,8 @@ static inline void code_gen_alloc(size_t tb_size) void tcg_exec_init(unsigned long tb_size) { cpu_gen_init(); - code_gen_alloc(tb_size); page_init(); + code_gen_alloc(tb_size); #if defined(CONFIG_SOFTMMU) /* There's no guest base to take into account, so go ahead and initialize the prologue now. */ |