Re: [RFC v5 05/10] tcg: Add tcg opcodes and helpers for native library calls
On 8/25/23 03:45, Yeqi Fu wrote:
This commit implements tcg opcodes and helpers for native library
calls. A table is used to store the parameter types and return value
types for each native library function. In terms of types, only three
types are of real concern: the two base sizes int and intptr_t, and
if the value is a pointer, tcg_gen_g2h and tcg_gen_h2g are used for
address conversion.
Signed-off-by: Yeqi Fu
---
accel/tcg/tcg-runtime.h | 22
include/native/native-defs.h | 42
include/tcg/tcg-op-common.h | 11 ++
include/tcg/tcg.h| 9 ++
tcg/tcg-op.c | 193 ++-
5 files changed, 276 insertions(+), 1 deletion(-)
create mode 100644 include/native/native-defs.h
diff --git a/accel/tcg/tcg-runtime.h b/accel/tcg/tcg-runtime.h
index 39e68007f9..bda78b4489 100644
--- a/accel/tcg/tcg-runtime.h
+++ b/accel/tcg/tcg-runtime.h
@@ -37,6 +37,28 @@ DEF_HELPER_FLAGS_1(exit_atomic, TCG_CALL_NO_WG, noreturn,
env)
*/
#define helper_memset memset
DEF_HELPER_FLAGS_3(memset, TCG_CALL_NO_RWG, ptr, ptr, int, ptr)
+
+#define helper_memcpy memcpy
+DEF_HELPER_FLAGS_3(memcpy, TCG_CALL_NO_RWG, ptr, ptr, ptr, ptr)
+
+#define helper_strncpy strncpy
+DEF_HELPER_FLAGS_3(strncpy, TCG_CALL_NO_RWG, ptr, ptr, ptr, ptr)
+
+#define helper_memcmp memcmp
+DEF_HELPER_FLAGS_3(memcmp, TCG_CALL_NO_RWG, int, ptr, ptr, ptr)
+
+#define helper_strncmp strncmp
+DEF_HELPER_FLAGS_3(strncmp, TCG_CALL_NO_RWG, int, ptr, ptr, ptr)
+
+#define helper_strcpy strcpy
+DEF_HELPER_FLAGS_2(strcpy, TCG_CALL_NO_RWG, ptr, ptr, ptr)
+
+#define helper_strcat strcat
+DEF_HELPER_FLAGS_2(strcat, TCG_CALL_NO_RWG, ptr, ptr, ptr)
+
+#define helper_strcmp strcmp
+DEF_HELPER_FLAGS_2(strcmp, TCG_CALL_NO_RWG, int, ptr, ptr)
You cannot just call these directly. This will fail immediately whenever the guest does
something silly like
memcpy(NULL, "foo", 4);
This must raise SIGSEGV to the guest.
If we leave the bulk transform to tcg, the absolute minimum is
void * HELPER(memcpy)(void *dst, void *src, target_ulong len)
{
set_helper_retaddr(GETPC());
void *r = memcpy(dst, src, len);
clear_helper_retaddr();
return r;
}
There is no way to do this thread-local storage update from TCG.
But if we need to have a helper at all, we might as well do more and *not* leave the
transform to tcg. Something akin to
target_ulong HELPER(memcpy)(target_ulong dst, target_ulong src, target_ulong
len)
{
uintptr_t ra = GETPC();
CPUState *cpu = thread_cpu;
void *h_dst, *h_src;
if (!h2g_valid(src)) {
cpu_loop_exit_sigsegv(cpu, src, MMU_DATA_LOAD, 1, ra);
}
if (!h2g_valid(dst)) {
cpu_loop_exit_sigsegv(cpu, dst, MMU_DATA_STORE, 1, ra);
}
set_helper_retaddr(ra);
memcpy(g2h(cpu, dst), g2h(cpu, src), len);
clear_helper_retaddr(ra);
/* memcpy always returns its first argument */
return dst;
}
--- /dev/null
+++ b/include/native/native-defs.h
@@ -0,0 +1,42 @@
+/*
+ * Argument encoding. We only really care about 3 types. The two base
+ * sizes (int and intptr_t) and if the value is a pointer (in which
+ * case we need to adjust it g2h before passing to the native
+ * function).
+ */
+#define TYPE_NO_ARG 0x0
+#define TYPE_INT_ARG 0x1
+#define TYPE_IPTR_ARG 0x2
+#define TYPE_PTR_ARG 0x3
+
+#define ENCODE_TYPE(ret_value, arg1, arg2, arg3) \
+((ret_value) | (arg1 << 4) | (arg2 << 8) | (arg3 << 12))
Supposing we do the transform in tcg, this duplicates include/exec/helper-head.h, and
dh_typemask().
+static const FuncHelper func_helper_table[] = {
+{ .func = "memset",
+ .helper = (helper_func)gen_helper_memset,
+ .type = TYPE_AAIP },
+{ .func = "memcpy",
+ .helper = (helper_func)gen_helper_memcpy,
+ .type = TYPE_AAAP },
+{ .func = "strncpy",
+ .helper = (helper_func)gen_helper_strncpy,
+ .type = TYPE_AAAP },
+{ .func = "memcmp",
+ .helper = (helper_func)gen_helper_memcmp,
+ .type = TYPE_IAAP },
+{ .func = "strncmp",
+ .helper = (helper_func)gen_helper_strncmp,
+ .type = TYPE_IAAP },
+{ .func = "strcpy",
+ .helper = (helper_func)gen_helper_strcpy,
+ .type = TYPE_AAA },
+{ .func = "strcat",
+ .helper = (helper_func)gen_helper_strcat,
+ .type = TYPE_AAA },
+{ .func = "strcmp",
+ .helper = (helper_func)gen_helper_strcmp,
+ .type = TYPE_IAA },
+};
+/* p: iptr ; i: i32 ; a: ptr(address) */
+void gen_native_call_i32(const char *func_name, TCGv_i32 ret, TCGv_i32 arg1,
+ TCGv_i32 arg2, TCGv_i32 arg3)
+{
+TCGv_ptr arg1_ptr = tcg_temp_new_ptr();
+TCGv_ptr arg2_ptr = tcg_temp_new_ptr();
+TCGv_ptr arg3_ptr = tcg_temp_new_ptr();
+TCGv_ptr ret_ptr = tcg_temp_new_ptr();
+unsigned int i;
+for (i = 0; i < sizeof(func_helper_table) / sizeof(FuncHelper); i++) {
+if (strcmp(func_name, func_helper_table[i].func) == 0) {
+break;
+}
+}
+
[RFC v5 05/10] tcg: Add tcg opcodes and helpers for native library calls
This commit implements tcg opcodes and helpers for native library
calls. A table is used to store the parameter types and return value
types for each native library function. In terms of types, only three
types are of real concern: the two base sizes int and intptr_t, and
if the value is a pointer, tcg_gen_g2h and tcg_gen_h2g are used for
address conversion.
Signed-off-by: Yeqi Fu
---
accel/tcg/tcg-runtime.h | 22
include/native/native-defs.h | 42
include/tcg/tcg-op-common.h | 11 ++
include/tcg/tcg.h| 9 ++
tcg/tcg-op.c | 193 ++-
5 files changed, 276 insertions(+), 1 deletion(-)
create mode 100644 include/native/native-defs.h
diff --git a/accel/tcg/tcg-runtime.h b/accel/tcg/tcg-runtime.h
index 39e68007f9..bda78b4489 100644
--- a/accel/tcg/tcg-runtime.h
+++ b/accel/tcg/tcg-runtime.h
@@ -37,6 +37,28 @@ DEF_HELPER_FLAGS_1(exit_atomic, TCG_CALL_NO_WG, noreturn,
env)
*/
#define helper_memset memset
DEF_HELPER_FLAGS_3(memset, TCG_CALL_NO_RWG, ptr, ptr, int, ptr)
+
+#define helper_memcpy memcpy
+DEF_HELPER_FLAGS_3(memcpy, TCG_CALL_NO_RWG, ptr, ptr, ptr, ptr)
+
+#define helper_strncpy strncpy
+DEF_HELPER_FLAGS_3(strncpy, TCG_CALL_NO_RWG, ptr, ptr, ptr, ptr)
+
+#define helper_memcmp memcmp
+DEF_HELPER_FLAGS_3(memcmp, TCG_CALL_NO_RWG, int, ptr, ptr, ptr)
+
+#define helper_strncmp strncmp
+DEF_HELPER_FLAGS_3(strncmp, TCG_CALL_NO_RWG, int, ptr, ptr, ptr)
+
+#define helper_strcpy strcpy
+DEF_HELPER_FLAGS_2(strcpy, TCG_CALL_NO_RWG, ptr, ptr, ptr)
+
+#define helper_strcat strcat
+DEF_HELPER_FLAGS_2(strcat, TCG_CALL_NO_RWG, ptr, ptr, ptr)
+
+#define helper_strcmp strcmp
+DEF_HELPER_FLAGS_2(strcmp, TCG_CALL_NO_RWG, int, ptr, ptr)
+
#endif /* IN_HELPER_PROTO */
DEF_HELPER_FLAGS_3(ld_i128, TCG_CALL_NO_WG, i128, env, i64, i32)
diff --git a/include/native/native-defs.h b/include/native/native-defs.h
new file mode 100644
index 00..517bb86db0
--- /dev/null
+++ b/include/native/native-defs.h
@@ -0,0 +1,42 @@
+/*
+ * Argument encoding. We only really care about 3 types. The two base
+ * sizes (int and intptr_t) and if the value is a pointer (in which
+ * case we need to adjust it g2h before passing to the native
+ * function).
+ */
+#define TYPE_NO_ARG 0x0
+#define TYPE_INT_ARG 0x1
+#define TYPE_IPTR_ARG 0x2
+#define TYPE_PTR_ARG 0x3
+
+#define ENCODE_TYPE(ret_value, arg1, arg2, arg3) \
+((ret_value) | (arg1 << 4) | (arg2 << 8) | (arg3 << 12))
+
+#define TYPE_AAAP \
+ENCODE_TYPE(TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_IPTR_ARG)
+#define TYPE_IAAP \
+ENCODE_TYPE(TYPE_INT_ARG, TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_IPTR_ARG)
+#define TYPE_AAIP \
+ENCODE_TYPE(TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_INT_ARG, TYPE_IPTR_ARG)
+#define TYPE_AAA \
+ENCODE_TYPE(TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_NO_ARG)
+#define TYPE_IAA \
+ENCODE_TYPE(TYPE_INT_ARG, TYPE_PTR_ARG, TYPE_PTR_ARG, TYPE_NO_ARG)
+
+typedef void (*helper_)(struct TCGv_ptr_d *, struct TCGv_ptr_d *,
+struct TCGv_ptr_d *, struct TCGv_ptr_d *);
+typedef void (*helper_ippp)(struct TCGv_i32_d *, struct TCGv_ptr_d *,
+struct TCGv_ptr_d *, struct TCGv_ptr_d *);
+typedef void (*helper_ppip)(struct TCGv_ptr_d *, struct TCGv_ptr_d *,
+struct TCGv_i32_d *, struct TCGv_ptr_d *);
+typedef void (*helper_ppp)(struct TCGv_ptr_d *, struct TCGv_ptr_d *,
+ struct TCGv_ptr_d *);
+typedef void (*helper_ipp)(struct TCGv_i32_d *, struct TCGv_ptr_d *,
+ struct TCGv_ptr_d *);
+typedef void (*helper_func)(void *, ...);
+
+typedef struct {
+const char *func;
+helper_func helper;
+uint32_t type;
+} FuncHelper;
diff --git a/include/tcg/tcg-op-common.h b/include/tcg/tcg-op-common.h
index be382bbf77..2e712f1573 100644
--- a/include/tcg/tcg-op-common.h
+++ b/include/tcg/tcg-op-common.h
@@ -903,6 +903,12 @@ void tcg_gen_ld_vec(TCGv_vec r, TCGv_ptr base, TCGArg
offset);
void tcg_gen_st_vec(TCGv_vec r, TCGv_ptr base, TCGArg offset);
void tcg_gen_stl_vec(TCGv_vec r, TCGv_ptr base, TCGArg offset, TCGType t);
+/* Host <-> guest conversions */
+void tcg_gen_g2h_i32(TCGv_ptr ret, TCGv_i32 arg);
+void tcg_gen_g2h_i64(TCGv_ptr ret, TCGv_i64 arg);
+void tcg_gen_h2g_i32(TCGv_i32 ret, TCGv_ptr arg);
+void tcg_gen_h2g_i64(TCGv_i64 ret, TCGv_ptr arg);
+
/* Host pointer ops */
#if UINTPTR_MAX == UINT32_MAX
@@ -938,6 +944,11 @@ static inline void tcg_gen_addi_ptr(TCGv_ptr r, TCGv_ptr
a, intptr_t b)
glue(tcg_gen_addi_,PTR)((NAT)r, (NAT)a, b);
}
+static inline void tcg_gen_subi_ptr(TCGv_ptr r, TCGv_ptr a, intptr_t b)
+{
+glue(tcg_gen_subi_, PTR)((NAT)r, (NAT)a, b);
+}
+
static inline void tcg_gen_mov_ptr(TCGv_ptr d, TCGv_ptr s)
{
glue(tcg_gen_mov_,PTR)((NAT)d, (NAT)s);
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index 0875971719..a4c0f26dc4 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -35,6 +35,9
