Add uc_ctl_get/set_tcg_buffer_size

We still need this API because the virtual memory address space of

32 bits os is only 4GB and we default need 1G per instance

Credits to @ZehMatt for original idea

Co-authored-by: ζeh Matt <5415177+ZehMatt@users.noreply.github.com>

include/uc_priv.h

@@ -90,7 +90,7 @@ typedef void (*uc_args_void_t)(void *);
 typedef void (*uc_args_uc_t)(struct uc_struct *);
 typedef void (*uc_args_int_uc_t)(struct uc_struct *);
 
-typedef void (*uc_args_uc_long_t)(struct uc_struct *, unsigned long);
+typedef void (*uc_args_uc_long_t)(struct uc_struct *, uint32_t);
 
 typedef void (*uc_args_uc_u64_t)(struct uc_struct *, uint64_t addr);
 
@@ -400,6 +400,7 @@ struct uc_struct {
 
     FlatView *empty_view; // Static function variable moved from flatviews_init
 
+    uint32_t tcg_buffer_size; // The buffer size we are going to use
 #ifdef WIN32
     PVOID seh_handle;
     void* seh_closure;

include/unicorn/unicorn.h

@@ -571,8 +571,12 @@ typedef enum uc_control_type {
     // Change the tlb implementation
     // see uc_tlb_type for current implemented types
     // Write: @args = (int)
-    UC_CTL_TLB_TYPE
+    UC_CTL_TLB_TYPE,
-
+    // Change the tcg translation buffer size, note that
+    // unicorn may adjust this value.
+    // Write: @args = (uint32_t)
+    // Read: @args = (uint32_t*)
+    UC_CTL_TCG_BUFFER_SIZE,
 } uc_control_type;
 
 /*

qemu/accel/tcg/translate-all.c

@@ -1209,7 +1209,7 @@ static uc_err uc_gen_tb(struct uc_struct *uc, uint64_t addr, uc_tb *out_tb)
 /* Must be called before using the QEMU cpus. 'tb_size' is the size
    (in bytes) allocated to the translation buffer. Zero means default
    size. */
-void tcg_exec_init(struct uc_struct *uc, unsigned long tb_size)
+void tcg_exec_init(struct uc_struct *uc, uint32_t tb_size)
 {
     /* remove tcg object. init here. */
     /* tcg class init: tcg-all.c:tcg_accel_class_init(), skip all. */

qemu/include/sysemu/tcg.h

@@ -14,6 +14,6 @@
 
 struct uc_struct;
 
-void tcg_exec_init(struct uc_struct *uc, unsigned long tb_size);
+void tcg_exec_init(struct uc_struct *uc, uint32_t tb_size);
 
 #endif

qemu/unicorn_common.h

@@ -10,7 +10,7 @@
 // codes for unicorns purposes.
 
 void vm_start(struct uc_struct*);
-void tcg_exec_init(struct uc_struct *uc, unsigned long tb_size);
+void tcg_exec_init(struct uc_struct *uc, uint32_t tb_size);
 bool unicorn_fill_tlb(CPUState *cs, vaddr address, int size,
                       MMUAccessType rw, int mmu_idx,
                       bool probe, uintptr_t retaddr);

uc.c

@@ -2374,6 +2374,20 @@ uc_err uc_ctl(uc_engine *uc, uc_control_type control, ...)
         break;
     }
 
+    case UC_CTL_TCG_BUFFER_SIZE: {
+        if (rw == UC_CTL_IO_WRITE) {
+            uint32_t size = va_arg(args, uint32_t);
+            uc->tcg_buffer_size = size;
+        } else {
+
+            UC_INIT(uc);
+
+            uint32_t *size = va_arg(args, uint32_t *);
+            *size = uc->tcg_buffer_size;
+        }
+        break;
+    }
+
     default:
         err = UC_ERR_ARG;
         break;