diff options
Diffstat (limited to 'tcg/region.c')
| -rw-r--r-- | tcg/region.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/tcg/region.c b/tcg/region.c index 13087aa..7a34c96 100644 --- a/tcg/region.c +++ b/tcg/region.c @@ -48,10 +48,10 @@ struct tcg_region_state { /* fields set at init time */ void *start; void *start_aligned; - void *end; size_t n; size_t size; /* size of one region */ size_t stride; /* .size + guard size */ + size_t total_size; /* size of entire buffer, >= n * stride */ /* fields protected by the lock */ size_t current; /* current region index */ @@ -278,8 +278,9 @@ static void tcg_region_bounds(size_t curr_region, void **pstart, void **pend) if (curr_region == 0) { start = region.start; } + /* The final region may have a few extra pages due to earlier rounding. */ if (curr_region == region.n - 1) { - end = region.end; + end = region.start_aligned + region.total_size; } *pstart = start; @@ -817,8 +818,8 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx, Error **errp) */ void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus) { - void *buf, *aligned; - size_t size; + void *buf, *aligned, *end; + size_t total_size; size_t page_size; size_t region_size; size_t n_regions; @@ -830,19 +831,20 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus) assert(ok); buf = tcg_init_ctx.code_gen_buffer; - size = tcg_init_ctx.code_gen_buffer_size; + total_size = tcg_init_ctx.code_gen_buffer_size; page_size = qemu_real_host_page_size; n_regions = tcg_n_regions(max_cpus); /* The first region will be 'aligned - buf' bytes larger than the others */ aligned = QEMU_ALIGN_PTR_UP(buf, page_size); - g_assert(aligned < tcg_init_ctx.code_gen_buffer + size); + g_assert(aligned < tcg_init_ctx.code_gen_buffer + total_size); + /* * Make region_size a multiple of page_size, using aligned as the start. * As a result of this we might end up with a few extra pages at the end of * the buffer; we will assign those to the last region. */ - region_size = (size - (aligned - buf)) / n_regions; + region_size = (total_size - (aligned - buf)) / n_regions; region_size = QEMU_ALIGN_DOWN(region_size, page_size); /* A region must have at least 2 pages; one code, one guard */ @@ -856,9 +858,11 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus) region.start = buf; region.start_aligned = aligned; /* page-align the end, since its last page will be a guard page */ - region.end = QEMU_ALIGN_PTR_DOWN(buf + size, page_size); + end = QEMU_ALIGN_PTR_DOWN(buf + total_size, page_size); /* account for that last guard page */ - region.end -= page_size; + end -= page_size; + total_size = end - aligned; + region.total_size = total_size; /* * Set guard pages in the rw buffer, as that's the one into which @@ -899,7 +903,7 @@ void tcg_region_prologue_set(TCGContext *s) /* Register the balance of the buffer with gdb. */ tcg_register_jit(tcg_splitwx_to_rx(region.start), - region.end - region.start); + region.start_aligned + region.total_size - region.start); } /* @@ -940,8 +944,10 @@ size_t tcg_code_capacity(void) /* no need for synchronization; these variables are set at init time */ guard_size = region.stride - region.size; - capacity = region.end + guard_size - region.start; - capacity -= region.n * (guard_size + TCG_HIGHWATER); + capacity = region.total_size; + capacity -= (region.n - 1) * guard_size; + capacity -= region.n * TCG_HIGHWATER; + return capacity; } |