qemu/include/tcg/tcg.h

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/*
* Tiny Code Generator for QEMU
*
* Copyright (c) 2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef TCG_H
#define TCG_H
#include "exec/memop.h"
#include "exec/memopidx.h"
#include "qemu/bitops.h"
#include "qemu/plugin.h"
#include "qemu/queue.h"
#include "tcg/tcg-mo.h"
#include "tcg-target-reg-bits.h"
#include "tcg-target.h"
#include "tcg/tcg-cond.h"
#include "tcg/debug-assert.h"
/* XXX: make safe guess about sizes */
#define MAX_OP_PER_INSTR 266
#define CPU_TEMP_BUF_NLONGS 128
#define TCG_STATIC_FRAME_SIZE (CPU_TEMP_BUF_NLONGS * sizeof(long))
#if TCG_TARGET_REG_BITS == 32
typedef int32_t tcg_target_long;
typedef uint32_t tcg_target_ulong;
#define TCG_PRIlx PRIx32
#define TCG_PRIld PRId32
#elif TCG_TARGET_REG_BITS == 64
typedef int64_t tcg_target_long;
typedef uint64_t tcg_target_ulong;
#define TCG_PRIlx PRIx64
#define TCG_PRIld PRId64
#else
#error unsupported
#endif
#if TCG_TARGET_NB_REGS <= 32
typedef uint32_t TCGRegSet;
#elif TCG_TARGET_NB_REGS <= 64
typedef uint64_t TCGRegSet;
#else
#error unsupported
#endif
#if TCG_TARGET_REG_BITS == 32
/* Turn some undef macros into false macros. */
#define TCG_TARGET_HAS_extr_i64_i32 0
#define TCG_TARGET_HAS_div_i64 0
#define TCG_TARGET_HAS_rem_i64 0
#define TCG_TARGET_HAS_div2_i64 0
#define TCG_TARGET_HAS_rot_i64 0
#define TCG_TARGET_HAS_ext8s_i64 0
#define TCG_TARGET_HAS_ext16s_i64 0
#define TCG_TARGET_HAS_ext32s_i64 0
#define TCG_TARGET_HAS_ext8u_i64 0
#define TCG_TARGET_HAS_ext16u_i64 0
#define TCG_TARGET_HAS_ext32u_i64 0
#define TCG_TARGET_HAS_bswap16_i64 0
#define TCG_TARGET_HAS_bswap32_i64 0
#define TCG_TARGET_HAS_bswap64_i64 0
#define TCG_TARGET_HAS_not_i64 0
#define TCG_TARGET_HAS_andc_i64 0
#define TCG_TARGET_HAS_orc_i64 0
#define TCG_TARGET_HAS_eqv_i64 0
#define TCG_TARGET_HAS_nand_i64 0
#define TCG_TARGET_HAS_nor_i64 0
#define TCG_TARGET_HAS_clz_i64 0
#define TCG_TARGET_HAS_ctz_i64 0
#define TCG_TARGET_HAS_ctpop_i64 0
#define TCG_TARGET_HAS_deposit_i64 0
#define TCG_TARGET_HAS_extract_i64 0
#define TCG_TARGET_HAS_sextract_i64 0
#define TCG_TARGET_HAS_extract2_i64 0
#define TCG_TARGET_HAS_negsetcond_i64 0
#define TCG_TARGET_HAS_add2_i64 0
#define TCG_TARGET_HAS_sub2_i64 0
#define TCG_TARGET_HAS_mulu2_i64 0
#define TCG_TARGET_HAS_muls2_i64 0
#define TCG_TARGET_HAS_muluh_i64 0
#define TCG_TARGET_HAS_mulsh_i64 0
/* Turn some undef macros into true macros. */
#define TCG_TARGET_HAS_add2_i32 1
#define TCG_TARGET_HAS_sub2_i32 1
#endif
#ifndef TCG_TARGET_deposit_i32_valid
#define TCG_TARGET_deposit_i32_valid(ofs, len) 1
#endif
#ifndef TCG_TARGET_deposit_i64_valid
#define TCG_TARGET_deposit_i64_valid(ofs, len) 1
#endif
#ifndef TCG_TARGET_extract_i32_valid
#define TCG_TARGET_extract_i32_valid(ofs, len) 1
#endif
#ifndef TCG_TARGET_extract_i64_valid
#define TCG_TARGET_extract_i64_valid(ofs, len) 1
#endif
/* Only one of DIV or DIV2 should be defined. */
#if defined(TCG_TARGET_HAS_div_i32)
#define TCG_TARGET_HAS_div2_i32 0
#elif defined(TCG_TARGET_HAS_div2_i32)
#define TCG_TARGET_HAS_div_i32 0
#define TCG_TARGET_HAS_rem_i32 0
#endif
#if defined(TCG_TARGET_HAS_div_i64)
#define TCG_TARGET_HAS_div2_i64 0
#elif defined(TCG_TARGET_HAS_div2_i64)
#define TCG_TARGET_HAS_div_i64 0
#define TCG_TARGET_HAS_rem_i64 0
#endif
#if !defined(TCG_TARGET_HAS_v64) \
&& !defined(TCG_TARGET_HAS_v128) \
&& !defined(TCG_TARGET_HAS_v256)
#define TCG_TARGET_MAYBE_vec 0
#define TCG_TARGET_HAS_abs_vec 0
#define TCG_TARGET_HAS_neg_vec 0
#define TCG_TARGET_HAS_not_vec 0
#define TCG_TARGET_HAS_andc_vec 0
#define TCG_TARGET_HAS_orc_vec 0
#define TCG_TARGET_HAS_nand_vec 0
#define TCG_TARGET_HAS_nor_vec 0
#define TCG_TARGET_HAS_eqv_vec 0
#define TCG_TARGET_HAS_roti_vec 0
#define TCG_TARGET_HAS_rots_vec 0
#define TCG_TARGET_HAS_rotv_vec 0
#define TCG_TARGET_HAS_shi_vec 0
#define TCG_TARGET_HAS_shs_vec 0
#define TCG_TARGET_HAS_shv_vec 0
#define TCG_TARGET_HAS_mul_vec 0
#define TCG_TARGET_HAS_sat_vec 0
#define TCG_TARGET_HAS_minmax_vec 0
#define TCG_TARGET_HAS_bitsel_vec 0
#define TCG_TARGET_HAS_cmpsel_vec 0
#define TCG_TARGET_HAS_tst_vec 0
#else
#define TCG_TARGET_MAYBE_vec 1
#endif
#ifndef TCG_TARGET_HAS_v64
#define TCG_TARGET_HAS_v64 0
#endif
#ifndef TCG_TARGET_HAS_v128
#define TCG_TARGET_HAS_v128 0
#endif
#ifndef TCG_TARGET_HAS_v256
#define TCG_TARGET_HAS_v256 0
#endif
typedef enum TCGOpcode {
#define DEF(name, oargs, iargs, cargs, flags) INDEX_op_ ## name,
#include "tcg/tcg-opc.h"
#undef DEF
NB_OPS,
} TCGOpcode;
#define tcg_regset_set_reg(d, r) ((d) |= (TCGRegSet)1 << (r))
#define tcg_regset_reset_reg(d, r) ((d) &= ~((TCGRegSet)1 << (r)))
#define tcg_regset_test_reg(d, r) (((d) >> (r)) & 1)
#ifndef TCG_TARGET_INSN_UNIT_SIZE
# error "Missing TCG_TARGET_INSN_UNIT_SIZE"
#elif TCG_TARGET_INSN_UNIT_SIZE == 1
typedef uint8_t tcg_insn_unit;
#elif TCG_TARGET_INSN_UNIT_SIZE == 2
typedef uint16_t tcg_insn_unit;
#elif TCG_TARGET_INSN_UNIT_SIZE == 4
typedef uint32_t tcg_insn_unit;
#elif TCG_TARGET_INSN_UNIT_SIZE == 8
typedef uint64_t tcg_insn_unit;
#else
/* The port better have done this. */
#endif
typedef struct TCGRelocation TCGRelocation;
struct TCGRelocation {
QSIMPLEQ_ENTRY(TCGRelocation) next;
tcg_insn_unit *ptr;
intptr_t addend;
int type;
};
typedef struct TCGOp TCGOp;
typedef struct TCGLabelUse TCGLabelUse;
struct TCGLabelUse {
QSIMPLEQ_ENTRY(TCGLabelUse) next;
TCGOp *op;
};
typedef struct TCGLabel TCGLabel;
struct TCGLabel {
bool present;
bool has_value;
uint16_t id;
union {
uintptr_t value;
const tcg_insn_unit *value_ptr;
} u;
QSIMPLEQ_HEAD(, TCGLabelUse) branches;
QSIMPLEQ_HEAD(, TCGRelocation) relocs;
QSIMPLEQ_ENTRY(TCGLabel) next;
};
typedef struct TCGPool {
struct TCGPool *next;
int size;
misc: Replace zero-length arrays with flexible array member (automatic) Description copied from Linux kernel commit from Gustavo A. R. Silva (see [3]): --v-- description start --v-- The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member [1], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being unadvertenly introduced [2] to the Linux codebase from now on. --^-- description end --^-- Do the similar housekeeping in the QEMU codebase (which uses C99 since commit 7be41675f7cb). All these instances of code were found with the help of the following Coccinelle script: @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; }; @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; } QEMU_PACKED; [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f [3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1 Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-04 18:38:15 +03:00
uint8_t data[] __attribute__ ((aligned));
} TCGPool;
#define TCG_POOL_CHUNK_SIZE 32768
#define TCG_MAX_TEMPS 512
#define TCG_MAX_INSNS 512
/* when the size of the arguments of a called function is smaller than
this value, they are statically allocated in the TB stack frame */
#define TCG_STATIC_CALL_ARGS_SIZE 128
typedef enum TCGType {
TCG_TYPE_I32,
TCG_TYPE_I64,
TCG_TYPE_I128,
TCG_TYPE_V64,
TCG_TYPE_V128,
TCG_TYPE_V256,
/* Number of different types (integer not enum) */
#define TCG_TYPE_COUNT (TCG_TYPE_V256 + 1)
/* An alias for the size of the host register. */
#if TCG_TARGET_REG_BITS == 32
TCG_TYPE_REG = TCG_TYPE_I32,
#else
TCG_TYPE_REG = TCG_TYPE_I64,
#endif
/* An alias for the size of the native pointer. */
#if UINTPTR_MAX == UINT32_MAX
TCG_TYPE_PTR = TCG_TYPE_I32,
#else
TCG_TYPE_PTR = TCG_TYPE_I64,
#endif
} TCGType;
/**
* tcg_type_size
* @t: type
*
* Return the size of the type in bytes.
*/
static inline int tcg_type_size(TCGType t)
{
unsigned i = t;
if (i >= TCG_TYPE_V64) {
tcg_debug_assert(i < TCG_TYPE_COUNT);
i -= TCG_TYPE_V64 - 1;
}
return 4 << i;
}
/**
* get_alignment_bits
* @memop: MemOp value
*
* Extract the alignment size from the memop.
*/
static inline unsigned get_alignment_bits(MemOp memop)
{
unsigned a = memop & MO_AMASK;
if (a == MO_UNALN) {
/* No alignment required. */
a = 0;
} else if (a == MO_ALIGN) {
/* A natural alignment requirement. */
a = memop & MO_SIZE;
} else {
/* A specific alignment requirement. */
a = a >> MO_ASHIFT;
}
return a;
}
typedef tcg_target_ulong TCGArg;
/* Define type and accessor macros for TCG variables.
TCG variables are the inputs and outputs of TCG ops, as described
in tcg/README. Target CPU front-end code uses these types to deal
with TCG variables as it emits TCG code via the tcg_gen_* functions.
They come in several flavours:
* TCGv_i32 : 32 bit integer type
* TCGv_i64 : 64 bit integer type
* TCGv_i128 : 128 bit integer type
* TCGv_ptr : a host pointer type
* TCGv_vec : a host vector type; the exact size is not exposed
to the CPU front-end code.
* TCGv : an integer type the same size as target_ulong
(an alias for either TCGv_i32 or TCGv_i64)
The compiler's type checking will complain if you mix them
up and pass the wrong sized TCGv to a function.
Users of tcg_gen_* don't need to know about any of the internal
details of these, and should treat them as opaque types.
You won't be able to look inside them in a debugger either.
Internal implementation details follow:
Note that there is no definition of the structs TCGv_i32_d etc anywhere.
This is deliberate, because the values we store in variables of type
TCGv_i32 are not really pointers-to-structures. They're just small
integers, but keeping them in pointer types like this means that the
compiler will complain if you accidentally pass a TCGv_i32 to a
function which takes a TCGv_i64, and so on. Only the internals of
TCG need to care about the actual contents of the types. */
typedef struct TCGv_i32_d *TCGv_i32;
typedef struct TCGv_i64_d *TCGv_i64;
typedef struct TCGv_i128_d *TCGv_i128;
typedef struct TCGv_ptr_d *TCGv_ptr;
typedef struct TCGv_vec_d *TCGv_vec;
typedef TCGv_ptr TCGv_env;
/* call flags */
/* Helper does not read globals (either directly or through an exception). It
implies TCG_CALL_NO_WRITE_GLOBALS. */
#define TCG_CALL_NO_READ_GLOBALS 0x0001
/* Helper does not write globals */
#define TCG_CALL_NO_WRITE_GLOBALS 0x0002
/* Helper can be safely suppressed if the return value is not used. */
#define TCG_CALL_NO_SIDE_EFFECTS 0x0004
/* Helper is G_NORETURN. */
#define TCG_CALL_NO_RETURN 0x0008
/* convenience version of most used call flags */
#define TCG_CALL_NO_RWG TCG_CALL_NO_READ_GLOBALS
#define TCG_CALL_NO_WG TCG_CALL_NO_WRITE_GLOBALS
#define TCG_CALL_NO_SE TCG_CALL_NO_SIDE_EFFECTS
#define TCG_CALL_NO_RWG_SE (TCG_CALL_NO_RWG | TCG_CALL_NO_SE)
#define TCG_CALL_NO_WG_SE (TCG_CALL_NO_WG | TCG_CALL_NO_SE)
/*
* Flags for the bswap opcodes.
* If IZ, the input is zero-extended, otherwise unknown.
* If OZ or OS, the output is zero- or sign-extended respectively,
* otherwise the high bits are undefined.
*/
enum {
TCG_BSWAP_IZ = 1,
TCG_BSWAP_OZ = 2,
TCG_BSWAP_OS = 4,
};
tcg: optimise memory layout of TCGTemp This brings down the size of the struct from 56 to 32 bytes on 64-bit, and to 20 bytes on 32-bit. This leads to memory savings: Before: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 41131 29800 88 71019 1156b ./aarch64-softmmu/tcg/tcg.o 37969 29416 96 67481 10799 ./x86_64-linux-user/tcg/tcg.o 39354 28816 96 68266 10aaa ./arm-linux-user/tcg/tcg.o 40802 29096 88 69986 11162 ./arm-softmmu/tcg/tcg.o 39417 29672 88 69177 10e39 ./x86_64-softmmu/tcg/tcg.o After: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 40883 29800 88 70771 11473 ./aarch64-softmmu/tcg/tcg.o 37473 29416 96 66985 105a9 ./x86_64-linux-user/tcg/tcg.o 38858 28816 96 67770 108ba ./arm-linux-user/tcg/tcg.o 40554 29096 88 69738 1106a ./arm-softmmu/tcg/tcg.o 39169 29672 88 68929 10d41 ./x86_64-softmmu/tcg/tcg.o Note that using an entire byte for some enums that need less than that wastes a few bits (noticeable in 32 bits, where we use 20 bytes instead of 16) but avoids extraction code, which overall is a win--I've tested several variations of the patch, and the appended is the best performer for OpenSSL's bntest by a very small margin: Before: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null [...] Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10538.479833 task-clock (msec) # 0.999 CPUs utilized ( +- 0.38% ) 772 context-switches # 0.073 K/sec ( +- 2.03% ) 0 cpu-migrations # 0.000 K/sec ( +-100.00% ) 2,207 page-faults # 0.209 K/sec ( +- 0.08% ) 10.552871687 seconds time elapsed ( +- 0.39% ) After: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10459.968847 task-clock (msec) # 0.999 CPUs utilized ( +- 0.30% ) 739 context-switches # 0.071 K/sec ( +- 1.71% ) 0 cpu-migrations # 0.000 K/sec ( +- 68.14% ) 2,204 page-faults # 0.211 K/sec ( +- 0.10% ) 10.473900411 seconds time elapsed ( +- 0.30% ) Suggested-by: Stefan Weil <sw@weilnetz.de> Suggested-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-04-03 03:07:53 +03:00
typedef enum TCGTempVal {
TEMP_VAL_DEAD,
TEMP_VAL_REG,
TEMP_VAL_MEM,
TEMP_VAL_CONST,
} TCGTempVal;
typedef enum TCGTempKind {
/*
* Temp is dead at the end of the extended basic block (EBB),
* the single-entry multiple-exit region that falls through
* conditional branches.
*/
TEMP_EBB,
/* Temp is live across the entire translation block, but dead at end. */
TEMP_TB,
/* Temp is live across the entire translation block, and between them. */
TEMP_GLOBAL,
/* Temp is in a fixed register. */
TEMP_FIXED,
/* Temp is a fixed constant. */
TEMP_CONST,
} TCGTempKind;
typedef struct TCGTemp {
TCGReg reg:8;
tcg: optimise memory layout of TCGTemp This brings down the size of the struct from 56 to 32 bytes on 64-bit, and to 20 bytes on 32-bit. This leads to memory savings: Before: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 41131 29800 88 71019 1156b ./aarch64-softmmu/tcg/tcg.o 37969 29416 96 67481 10799 ./x86_64-linux-user/tcg/tcg.o 39354 28816 96 68266 10aaa ./arm-linux-user/tcg/tcg.o 40802 29096 88 69986 11162 ./arm-softmmu/tcg/tcg.o 39417 29672 88 69177 10e39 ./x86_64-softmmu/tcg/tcg.o After: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 40883 29800 88 70771 11473 ./aarch64-softmmu/tcg/tcg.o 37473 29416 96 66985 105a9 ./x86_64-linux-user/tcg/tcg.o 38858 28816 96 67770 108ba ./arm-linux-user/tcg/tcg.o 40554 29096 88 69738 1106a ./arm-softmmu/tcg/tcg.o 39169 29672 88 68929 10d41 ./x86_64-softmmu/tcg/tcg.o Note that using an entire byte for some enums that need less than that wastes a few bits (noticeable in 32 bits, where we use 20 bytes instead of 16) but avoids extraction code, which overall is a win--I've tested several variations of the patch, and the appended is the best performer for OpenSSL's bntest by a very small margin: Before: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null [...] Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10538.479833 task-clock (msec) # 0.999 CPUs utilized ( +- 0.38% ) 772 context-switches # 0.073 K/sec ( +- 2.03% ) 0 cpu-migrations # 0.000 K/sec ( +-100.00% ) 2,207 page-faults # 0.209 K/sec ( +- 0.08% ) 10.552871687 seconds time elapsed ( +- 0.39% ) After: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10459.968847 task-clock (msec) # 0.999 CPUs utilized ( +- 0.30% ) 739 context-switches # 0.071 K/sec ( +- 1.71% ) 0 cpu-migrations # 0.000 K/sec ( +- 68.14% ) 2,204 page-faults # 0.211 K/sec ( +- 0.10% ) 10.473900411 seconds time elapsed ( +- 0.30% ) Suggested-by: Stefan Weil <sw@weilnetz.de> Suggested-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-04-03 03:07:53 +03:00
TCGTempVal val_type:8;
TCGType base_type:8;
TCGType type:8;
TCGTempKind kind:3;
unsigned int indirect_reg:1;
unsigned int indirect_base:1;
unsigned int mem_coherent:1;
unsigned int mem_allocated:1;
unsigned int temp_allocated:1;
unsigned int temp_subindex:2;
tcg: optimise memory layout of TCGTemp This brings down the size of the struct from 56 to 32 bytes on 64-bit, and to 20 bytes on 32-bit. This leads to memory savings: Before: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 41131 29800 88 71019 1156b ./aarch64-softmmu/tcg/tcg.o 37969 29416 96 67481 10799 ./x86_64-linux-user/tcg/tcg.o 39354 28816 96 68266 10aaa ./arm-linux-user/tcg/tcg.o 40802 29096 88 69986 11162 ./arm-softmmu/tcg/tcg.o 39417 29672 88 69177 10e39 ./x86_64-softmmu/tcg/tcg.o After: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 40883 29800 88 70771 11473 ./aarch64-softmmu/tcg/tcg.o 37473 29416 96 66985 105a9 ./x86_64-linux-user/tcg/tcg.o 38858 28816 96 67770 108ba ./arm-linux-user/tcg/tcg.o 40554 29096 88 69738 1106a ./arm-softmmu/tcg/tcg.o 39169 29672 88 68929 10d41 ./x86_64-softmmu/tcg/tcg.o Note that using an entire byte for some enums that need less than that wastes a few bits (noticeable in 32 bits, where we use 20 bytes instead of 16) but avoids extraction code, which overall is a win--I've tested several variations of the patch, and the appended is the best performer for OpenSSL's bntest by a very small margin: Before: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null [...] Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10538.479833 task-clock (msec) # 0.999 CPUs utilized ( +- 0.38% ) 772 context-switches # 0.073 K/sec ( +- 2.03% ) 0 cpu-migrations # 0.000 K/sec ( +-100.00% ) 2,207 page-faults # 0.209 K/sec ( +- 0.08% ) 10.552871687 seconds time elapsed ( +- 0.39% ) After: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10459.968847 task-clock (msec) # 0.999 CPUs utilized ( +- 0.30% ) 739 context-switches # 0.071 K/sec ( +- 1.71% ) 0 cpu-migrations # 0.000 K/sec ( +- 68.14% ) 2,204 page-faults # 0.211 K/sec ( +- 0.10% ) 10.473900411 seconds time elapsed ( +- 0.30% ) Suggested-by: Stefan Weil <sw@weilnetz.de> Suggested-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-04-03 03:07:53 +03:00
int64_t val;
struct TCGTemp *mem_base;
tcg: optimise memory layout of TCGTemp This brings down the size of the struct from 56 to 32 bytes on 64-bit, and to 20 bytes on 32-bit. This leads to memory savings: Before: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 41131 29800 88 71019 1156b ./aarch64-softmmu/tcg/tcg.o 37969 29416 96 67481 10799 ./x86_64-linux-user/tcg/tcg.o 39354 28816 96 68266 10aaa ./arm-linux-user/tcg/tcg.o 40802 29096 88 69986 11162 ./arm-softmmu/tcg/tcg.o 39417 29672 88 69177 10e39 ./x86_64-softmmu/tcg/tcg.o After: $ find . -name 'tcg.o' | xargs size text data bss dec hex filename 40883 29800 88 70771 11473 ./aarch64-softmmu/tcg/tcg.o 37473 29416 96 66985 105a9 ./x86_64-linux-user/tcg/tcg.o 38858 28816 96 67770 108ba ./arm-linux-user/tcg/tcg.o 40554 29096 88 69738 1106a ./arm-softmmu/tcg/tcg.o 39169 29672 88 68929 10d41 ./x86_64-softmmu/tcg/tcg.o Note that using an entire byte for some enums that need less than that wastes a few bits (noticeable in 32 bits, where we use 20 bytes instead of 16) but avoids extraction code, which overall is a win--I've tested several variations of the patch, and the appended is the best performer for OpenSSL's bntest by a very small margin: Before: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null [...] Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10538.479833 task-clock (msec) # 0.999 CPUs utilized ( +- 0.38% ) 772 context-switches # 0.073 K/sec ( +- 2.03% ) 0 cpu-migrations # 0.000 K/sec ( +-100.00% ) 2,207 page-faults # 0.209 K/sec ( +- 0.08% ) 10.552871687 seconds time elapsed ( +- 0.39% ) After: $ taskset -c 0 perf stat -r 15 -- x86_64-linux-user/qemu-x86_64 img/bntest-x86_64 >/dev/null Performance counter stats for 'x86_64-linux-user/qemu-x86_64 img/bntest-x86_64' (15 runs): 10459.968847 task-clock (msec) # 0.999 CPUs utilized ( +- 0.30% ) 739 context-switches # 0.071 K/sec ( +- 1.71% ) 0 cpu-migrations # 0.000 K/sec ( +- 68.14% ) 2,204 page-faults # 0.211 K/sec ( +- 0.10% ) 10.473900411 seconds time elapsed ( +- 0.30% ) Suggested-by: Stefan Weil <sw@weilnetz.de> Suggested-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-04-03 03:07:53 +03:00
intptr_t mem_offset;
const char *name;
/* Pass-specific information that can be stored for a temporary.
One word worth of integer data, and one pointer to data
allocated separately. */
uintptr_t state;
void *state_ptr;
} TCGTemp;
typedef struct TCGContext TCGContext;
typedef struct TCGTempSet {
unsigned long l[BITS_TO_LONGS(TCG_MAX_TEMPS)];
} TCGTempSet;
/*
* With 1 128-bit output, a 32-bit host requires 4 output parameters,
* which leaves a maximum of 28 other slots. Which is enough for 7
* 128-bit operands.
*/
#define DEAD_ARG (1 << 4)
#define SYNC_ARG (1 << 0)
typedef uint32_t TCGLifeData;
struct TCGOp {
TCGOpcode opc : 8;
unsigned nargs : 8;
/* Parameters for this opcode. See below. */
unsigned param1 : 8;
unsigned param2 : 8;
/* Lifetime data of the operands. */
TCGLifeData life;
/* Next and previous opcodes. */
QTAILQ_ENTRY(TCGOp) link;
/* Register preferences for the output(s). */
TCGRegSet output_pref[2];
/* Arguments for the opcode. */
TCGArg args[];
};
#define TCGOP_CALLI(X) (X)->param1
#define TCGOP_CALLO(X) (X)->param2
#define TCGOP_VECL(X) (X)->param1
#define TCGOP_VECE(X) (X)->param2
/* Make sure operands fit in the bitfields above. */
QEMU_BUILD_BUG_ON(NB_OPS > (1 << 8));
static inline TCGRegSet output_pref(const TCGOp *op, unsigned i)
{
return i < ARRAY_SIZE(op->output_pref) ? op->output_pref[i] : 0;
}
struct TCGContext {
uint8_t *pool_cur, *pool_end;
TCGPool *pool_first, *pool_current, *pool_first_large;
int nb_labels;
int nb_globals;
int nb_temps;
int nb_indirects;
int nb_ops;
TCGType addr_type; /* TCG_TYPE_I32 or TCG_TYPE_I64 */
int page_mask;
uint8_t page_bits;
uint8_t tlb_dyn_max_bits;
uint8_t insn_start_words;
TCGBar guest_mo;
TCGRegSet reserved_regs;
intptr_t current_frame_offset;
intptr_t frame_start;
intptr_t frame_end;
TCGTemp *frame_temp;
TranslationBlock *gen_tb; /* tb for which code is being generated */
tcg_insn_unit *code_buf; /* pointer for start of tb */
tcg_insn_unit *code_ptr; /* pointer for running end of tb */
#ifdef CONFIG_DEBUG_TCG
int goto_tb_issue_mask;
const TCGOpcode *vecop_list;
#endif
/* Code generation. Note that we specifically do not use tcg_insn_unit
here, because there's too much arithmetic throughout that relies
on addition and subtraction working on bytes. Rely on the GCC
extension that allows arithmetic on void*. */
void *code_gen_buffer;
size_t code_gen_buffer_size;
void *code_gen_ptr;
void *data_gen_ptr;
/* Threshold to flush the translated code buffer. */
void *code_gen_highwater;
/* Track which vCPU triggers events */
CPUState *cpu; /* *_trans */
/* These structures are private to tcg-target.c.inc. */
#ifdef TCG_TARGET_NEED_LDST_LABELS
QSIMPLEQ_HEAD(, TCGLabelQemuLdst) ldst_labels;
#endif
#ifdef TCG_TARGET_NEED_POOL_LABELS
struct TCGLabelPoolData *pool_labels;
#endif
TCGLabel *exitreq_label;
#ifdef CONFIG_PLUGIN
/*
* We keep one plugin_tb struct per TCGContext. Note that on every TB
* translation we clear but do not free its contents; this way we
* avoid a lot of malloc/free churn, since after a few TB's it's
* unlikely that we'll need to allocate either more instructions or more
* space for instructions (for variable-instruction-length ISAs).
*/
struct qemu_plugin_tb *plugin_tb;
const struct DisasContextBase *plugin_db;
/* descriptor of the instruction being translated */
struct qemu_plugin_insn *plugin_insn;
#endif
GHashTable *const_table[TCG_TYPE_COUNT];
TCGTempSet free_temps[TCG_TYPE_COUNT];
TCGTemp temps[TCG_MAX_TEMPS]; /* globals first, temps after */
QTAILQ_HEAD(, TCGOp) ops, free_ops;
QSIMPLEQ_HEAD(, TCGLabel) labels;
/*
* When clear, new ops are added to the tail of @ops.
* When set, new ops are added in front of @emit_before_op.
*/
TCGOp *emit_before_op;
/* Tells which temporary holds a given register.
It does not take into account fixed registers */
TCGTemp *reg_to_temp[TCG_TARGET_NB_REGS];
uint16_t gen_insn_end_off[TCG_MAX_INSNS];
uint64_t *gen_insn_data;
/* Exit to translator on overflow. */
sigjmp_buf jmp_trans;
};
static inline bool temp_readonly(TCGTemp *ts)
{
return ts->kind >= TEMP_FIXED;
}
#ifdef CONFIG_USER_ONLY
extern bool tcg_use_softmmu;
#else
#define tcg_use_softmmu true
#endif
tcg: enable multiple TCG contexts in softmmu This enables parallel TCG code generation. However, we do not take advantage of it yet since tb_lock is still held during tb_gen_code. In user-mode we use a single TCG context; see the documentation added to tcg_region_init for the rationale. Note that targets do not need any conversion: targets initialize a TCGContext (e.g. defining TCG globals), and after this initialization has finished, the context is cloned by the vCPU threads, each of them keeping a separate copy. TCG threads claim one entry in tcg_ctxs[] by atomically increasing n_tcg_ctxs. Do not be too annoyed by the subsequent atomic_read's of that variable and tcg_ctxs; they are there just to play nice with analysis tools such as thread sanitizer. Note that we do not allocate an array of contexts (we allocate an array of pointers instead) because when tcg_context_init is called, we do not know yet how many contexts we'll use since the bool behind qemu_tcg_mttcg_enabled() isn't set yet. Previous patches folded some TCG globals into TCGContext. The non-const globals remaining are only set at init time, i.e. before the TCG threads are spawned. Here is a list of these set-at-init-time globals under tcg/: Only written by tcg_context_init: - indirect_reg_alloc_order - tcg_op_defs Only written by tcg_target_init (called from tcg_context_init): - tcg_target_available_regs - tcg_target_call_clobber_regs - arm: arm_arch, use_idiv_instructions - i386: have_cmov, have_bmi1, have_bmi2, have_lzcnt, have_movbe, have_popcnt - mips: use_movnz_instructions, use_mips32_instructions, use_mips32r2_instructions, got_sigill (tcg_target_detect_isa) - ppc: have_isa_2_06, have_isa_3_00, tb_ret_addr - s390: tb_ret_addr, s390_facilities - sparc: qemu_ld_trampoline, qemu_st_trampoline (build_trampolines), use_vis3_instructions Only written by tcg_prologue_init: - 'struct jit_code_entry one_entry' - aarch64: tb_ret_addr - arm: tb_ret_addr - i386: tb_ret_addr, guest_base_flags - ia64: tb_ret_addr - mips: tb_ret_addr, bswap32_addr, bswap32u_addr, bswap64_addr Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-07-20 01:57:58 +03:00
extern __thread TCGContext *tcg_ctx;
extern const void *tcg_code_gen_epilogue;
extern uintptr_t tcg_splitwx_diff;
extern TCGv_env tcg_env;
bool in_code_gen_buffer(const void *p);
#ifdef CONFIG_DEBUG_TCG
const void *tcg_splitwx_to_rx(void *rw);
void *tcg_splitwx_to_rw(const void *rx);
#else
static inline const void *tcg_splitwx_to_rx(void *rw)
{
return rw ? rw + tcg_splitwx_diff : NULL;
}
static inline void *tcg_splitwx_to_rw(const void *rx)
{
return rx ? (void *)rx - tcg_splitwx_diff : NULL;
}
#endif
static inline TCGArg temp_arg(TCGTemp *ts)
{
return (uintptr_t)ts;
}
static inline TCGTemp *arg_temp(TCGArg a)
{
return (TCGTemp *)(uintptr_t)a;
}
#ifdef CONFIG_DEBUG_TCG
size_t temp_idx(TCGTemp *ts);
TCGTemp *tcgv_i32_temp(TCGv_i32 v);
#else
static inline size_t temp_idx(TCGTemp *ts)
{
return ts - tcg_ctx->temps;
}
/*
* Using the offset of a temporary, relative to TCGContext, rather than
* its index means that we don't use 0. That leaves offset 0 free for
* a NULL representation without having to leave index 0 unused.
*/
static inline TCGTemp *tcgv_i32_temp(TCGv_i32 v)
{
return (void *)tcg_ctx + (uintptr_t)v;
}
#endif
static inline TCGTemp *tcgv_i64_temp(TCGv_i64 v)
{
return tcgv_i32_temp((TCGv_i32)v);
}
static inline TCGTemp *tcgv_i128_temp(TCGv_i128 v)
{
return tcgv_i32_temp((TCGv_i32)v);
}
static inline TCGTemp *tcgv_ptr_temp(TCGv_ptr v)
{
return tcgv_i32_temp((TCGv_i32)v);
}
static inline TCGTemp *tcgv_vec_temp(TCGv_vec v)
{
return tcgv_i32_temp((TCGv_i32)v);
}
static inline TCGArg tcgv_i32_arg(TCGv_i32 v)
{
return temp_arg(tcgv_i32_temp(v));
}
static inline TCGArg tcgv_i64_arg(TCGv_i64 v)
{
return temp_arg(tcgv_i64_temp(v));
}
static inline TCGArg tcgv_i128_arg(TCGv_i128 v)
{
return temp_arg(tcgv_i128_temp(v));
}
static inline TCGArg tcgv_ptr_arg(TCGv_ptr v)
{
return temp_arg(tcgv_ptr_temp(v));
}
static inline TCGArg tcgv_vec_arg(TCGv_vec v)
{
return temp_arg(tcgv_vec_temp(v));
}
static inline TCGv_i32 temp_tcgv_i32(TCGTemp *t)
{
(void)temp_idx(t); /* trigger embedded assert */
return (TCGv_i32)((void *)t - (void *)tcg_ctx);
}
static inline TCGv_i64 temp_tcgv_i64(TCGTemp *t)
{
return (TCGv_i64)temp_tcgv_i32(t);
}
static inline TCGv_i128 temp_tcgv_i128(TCGTemp *t)
{
return (TCGv_i128)temp_tcgv_i32(t);
}
static inline TCGv_ptr temp_tcgv_ptr(TCGTemp *t)
{
return (TCGv_ptr)temp_tcgv_i32(t);
}
static inline TCGv_vec temp_tcgv_vec(TCGTemp *t)
{
return (TCGv_vec)temp_tcgv_i32(t);
}
static inline TCGArg tcg_get_insn_param(TCGOp *op, int arg)
{
return op->args[arg];
}
static inline void tcg_set_insn_param(TCGOp *op, int arg, TCGArg v)
{
op->args[arg] = v;
}
static inline uint64_t tcg_get_insn_start_param(TCGOp *op, int arg)
{
if (TCG_TARGET_REG_BITS == 64) {
return tcg_get_insn_param(op, arg);
} else {
return deposit64(tcg_get_insn_param(op, arg * 2), 32, 32,
tcg_get_insn_param(op, arg * 2 + 1));
}
}
static inline void tcg_set_insn_start_param(TCGOp *op, int arg, uint64_t v)
{
if (TCG_TARGET_REG_BITS == 64) {
tcg_set_insn_param(op, arg, v);
} else {
tcg_set_insn_param(op, arg * 2, v);
tcg_set_insn_param(op, arg * 2 + 1, v >> 32);
}
}
/* The last op that was emitted. */
static inline TCGOp *tcg_last_op(void)
{
return QTAILQ_LAST(&tcg_ctx->ops);
}
/* Test for whether to terminate the TB for using too many opcodes. */
static inline bool tcg_op_buf_full(void)
{
/* This is not a hard limit, it merely stops translation when
* we have produced "enough" opcodes. We want to limit TB size
* such that a RISC host can reasonably use a 16-bit signed
* branch within the TB. We also need to be mindful of the
* 16-bit unsigned offsets, TranslationBlock.jmp_reset_offset[]
* and TCGContext.gen_insn_end_off[].
*/
return tcg_ctx->nb_ops >= 4000;
}
/* pool based memory allocation */
tcg: remove tb_lock Use mmap_lock in user-mode to protect TCG state and the page descriptors. In !user-mode, each vCPU has its own TCG state, so no locks needed. Per-page locks are used to protect the page descriptors. Per-TB locks are used in both modes to protect TB jumps. Some notes: - tb_lock is removed from notdirty_mem_write by passing a locked page_collection to tb_invalidate_phys_page_fast. - tcg_tb_lookup/remove/insert/etc have their own internal lock(s), so there is no need to further serialize access to them. - do_tb_flush is run in a safe async context, meaning no other vCPU threads are running. Therefore acquiring mmap_lock there is just to please tools such as thread sanitizer. - Not visible in the diff, but tb_invalidate_phys_page already has an assert_memory_lock. - cpu_io_recompile is !user-only, so no mmap_lock there. - Added mmap_unlock()'s before all siglongjmp's that could be called in user-mode while mmap_lock is held. + Added an assert for !have_mmap_lock() after returning from the longjmp in cpu_exec, just like we do in cpu_exec_step_atomic. Performance numbers before/after: Host: AMD Opteron(tm) Processor 6376 ubuntu 17.04 ppc64 bootup+shutdown time 700 +-+--+----+------+------------+-----------+------------*--+-+ | + + + + + *B | | before ***B*** ** * | |tb lock removal ###D### *** | 600 +-+ *** +-+ | ** # | | *B* #D | | *** * ## | 500 +-+ *** ### +-+ | * *** ### | | *B* # ## | | ** * #D# | 400 +-+ ** ## +-+ | ** ### | | ** ## | | ** # ## | 300 +-+ * B* #D# +-+ | B *** ### | | * ** #### | | * *** ### | 200 +-+ B *B #D# +-+ | #B* * ## # | | #* ## | | + D##D# + + + + | 100 +-+--+----+------+------------+-----------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/HwmBHXe debian jessie aarch64 bootup+shutdown time 90 +-+--+-----+-----+------------+------------+------------+--+-+ | + + + + + + | | before ***B*** B | 80 +tb lock removal ###D### **D +-+ | **### | | **## | 70 +-+ ** # +-+ | ** ## | | ** # | 60 +-+ *B ## +-+ | ** ## | | *** #D | 50 +-+ *** ## +-+ | * ** ### | | **B* ### | 40 +-+ **** # ## +-+ | **** #D# | | ***B** ### | 30 +-+ B***B** #### +-+ | B * * # ### | | B ###D# | 20 +-+ D ##D## +-+ | D# | | + + + + + + | 10 +-+--+-----+-----+------------+------------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/iGpGFtv The gains are high for 4-8 CPUs. Beyond that point, however, unrelated lock contention significantly hurts scalability. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-08-05 06:46:31 +03:00
/* user-mode: mmap_lock must be held for tcg_malloc_internal. */
void *tcg_malloc_internal(TCGContext *s, int size);
void tcg_pool_reset(TCGContext *s);
tcg: allocate TB structs before the corresponding translated code Allocating an arbitrarily-sized array of tbs results in either (a) a lot of memory wasted or (b) unnecessary flushes of the code cache when we run out of TB structs in the array. An obvious solution would be to just malloc a TB struct when needed, and keep the TB array as an array of pointers (recall that tb_find_pc() needs the TB array to run in O(log n)). Perhaps a better solution, which is implemented in this patch, is to allocate TB's right before the translated code they describe. This results in some memory waste due to padding to have code and TBs in separate cache lines--for instance, I measured 4.7% of padding in the used portion of code_gen_buffer when booting aarch64 Linux on a host with 64-byte cache lines. However, it can allow for optimizations in some host architectures, since TCG backends could safely assume that the TB and the corresponding translated code are very close to each other in memory. See this message by rth for a detailed explanation: https://lists.gnu.org/archive/html/qemu-devel/2017-03/msg05172.html Subject: Re: GSoC 2017 Proposal: TCG performance enhancements Message-ID: <1e67644b-4b30-887e-d329-1848e94c9484@twiddle.net> Suggested-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Emilio G. Cota <cota@braap.org> Message-Id: <1496790745-314-3-git-send-email-cota@braap.org> [rth: Simplify the arithmetic in tcg_tb_alloc] Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-07 02:12:25 +03:00
TranslationBlock *tcg_tb_alloc(TCGContext *s);
tcg: introduce regions to split code_gen_buffer This is groundwork for supporting multiple TCG contexts. The naive solution here is to split code_gen_buffer statically among the TCG threads; this however results in poor utilization if translation needs are different across TCG threads. What we do here is to add an extra layer of indirection, assigning regions that act just like pages do in virtual memory allocation. (BTW if you are wondering about the chosen naming, I did not want to use blocks or pages because those are already heavily used in QEMU). We use a global lock to serialize allocations as well as statistics reporting (we now export the size of the used code_gen_buffer with tcg_code_size()). Note that for the allocator we could just use a counter and atomic_inc; however, that would complicate the gathering of tcg_code_size()-like stats. So given that the region operations are not a fast path, a lock seems the most reasonable choice. The effectiveness of this approach is clear after seeing some numbers. I used the bootup+shutdown of debian-arm with '-tb-size 80' as a benchmark. Note that I'm evaluating this after enabling per-thread TCG (which is done by a subsequent commit). * -smp 1, 1 region (entire buffer): qemu: flush code_size=83885014 nb_tbs=154739 avg_tb_size=357 qemu: flush code_size=83884902 nb_tbs=153136 avg_tb_size=363 qemu: flush code_size=83885014 nb_tbs=152777 avg_tb_size=364 qemu: flush code_size=83884950 nb_tbs=150057 avg_tb_size=373 qemu: flush code_size=83884998 nb_tbs=150234 avg_tb_size=373 qemu: flush code_size=83885014 nb_tbs=154009 avg_tb_size=360 qemu: flush code_size=83885014 nb_tbs=151007 avg_tb_size=370 qemu: flush code_size=83885014 nb_tbs=151816 avg_tb_size=367 That is, 8 flushes. * -smp 8, 32 regions (80/32 MB per region) [i.e. this patch]: qemu: flush code_size=76328008 nb_tbs=141040 avg_tb_size=356 qemu: flush code_size=75366534 nb_tbs=138000 avg_tb_size=361 qemu: flush code_size=76864546 nb_tbs=140653 avg_tb_size=361 qemu: flush code_size=76309084 nb_tbs=135945 avg_tb_size=375 qemu: flush code_size=74581856 nb_tbs=132909 avg_tb_size=375 qemu: flush code_size=73927256 nb_tbs=135616 avg_tb_size=360 qemu: flush code_size=78629426 nb_tbs=142896 avg_tb_size=365 qemu: flush code_size=76667052 nb_tbs=138508 avg_tb_size=368 Again, 8 flushes. Note how buffer utilization is not 100%, but it is close. Smaller region sizes would yield higher utilization, but we want region allocation to be rare (it acquires a lock), so we do not want to go too small. * -smp 8, static partitioning of 8 regions (10 MB per region): qemu: flush code_size=21936504 nb_tbs=40570 avg_tb_size=354 qemu: flush code_size=11472174 nb_tbs=20633 avg_tb_size=370 qemu: flush code_size=11603976 nb_tbs=21059 avg_tb_size=365 qemu: flush code_size=23254872 nb_tbs=41243 avg_tb_size=377 qemu: flush code_size=28289496 nb_tbs=52057 avg_tb_size=358 qemu: flush code_size=43605160 nb_tbs=78896 avg_tb_size=367 qemu: flush code_size=45166552 nb_tbs=82158 avg_tb_size=364 qemu: flush code_size=63289640 nb_tbs=116494 avg_tb_size=358 qemu: flush code_size=51389960 nb_tbs=93937 avg_tb_size=362 qemu: flush code_size=59665928 nb_tbs=107063 avg_tb_size=372 qemu: flush code_size=38380824 nb_tbs=68597 avg_tb_size=374 qemu: flush code_size=44884568 nb_tbs=79901 avg_tb_size=376 qemu: flush code_size=50782632 nb_tbs=90681 avg_tb_size=374 qemu: flush code_size=39848888 nb_tbs=71433 avg_tb_size=372 qemu: flush code_size=64708840 nb_tbs=119052 avg_tb_size=359 qemu: flush code_size=49830008 nb_tbs=90992 avg_tb_size=362 qemu: flush code_size=68372408 nb_tbs=123442 avg_tb_size=368 qemu: flush code_size=33555560 nb_tbs=59514 avg_tb_size=378 qemu: flush code_size=44748344 nb_tbs=80974 avg_tb_size=367 qemu: flush code_size=37104248 nb_tbs=67609 avg_tb_size=364 That is, 20 flushes. Note how a static partitioning approach uses the code buffer poorly, leading to many unnecessary flushes. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-07-08 02:24:20 +03:00
void tcg_region_reset_all(void);
size_t tcg_code_size(void);
size_t tcg_code_capacity(void);
tcg: track TBs with per-region BST's This paves the way for enabling scalable parallel generation of TCG code. Instead of tracking TBs with a single binary search tree (BST), use a BST for each TCG region, protecting it with a lock. This is as scalable as it gets, since each TCG thread operates on a separate region. The core of this change is the introduction of struct tcg_region_tree, which contains a pointer to a GTree and an associated lock to serialize accesses to it. We then allocate an array of tcg_region_tree's, adding the appropriate padding to avoid false sharing based on qemu_dcache_linesize. Given a tc_ptr, we first find the corresponding region_tree. This is done by special-casing the first and last regions first, since they might be of size != region.size; otherwise we just divide the offset by region.stride. I was worried about this division (several dozen cycles of latency), but profiling shows that this is not a fast path. Note that region.stride is not required to be a power of two; it is only required to be a multiple of the host's page size. Note that with this design we can also provide consistent snapshots about all region trees at once; for instance, tcg_tb_foreach acquires/releases all region_tree locks before/after iterating over them. For this reason we now drop tb_lock in dump_exec_info(). As an alternative I considered implementing a concurrent BST, but this can be tricky to get right, offers no consistent snapshots of the BST, and performance and scalability-wise I don't think it could ever beat having separate GTrees, given that our workload is insert-mostly (all concurrent BST designs I've seen focus, understandably, on making lookups fast, which comes at the expense of convoluted, non-wait-free insertions/removals). Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-07-26 23:58:05 +03:00
void tcg_tb_insert(TranslationBlock *tb);
void tcg_tb_remove(TranslationBlock *tb);
TranslationBlock *tcg_tb_lookup(uintptr_t tc_ptr);
void tcg_tb_foreach(GTraverseFunc func, gpointer user_data);
size_t tcg_nb_tbs(void);
tcg: remove tb_lock Use mmap_lock in user-mode to protect TCG state and the page descriptors. In !user-mode, each vCPU has its own TCG state, so no locks needed. Per-page locks are used to protect the page descriptors. Per-TB locks are used in both modes to protect TB jumps. Some notes: - tb_lock is removed from notdirty_mem_write by passing a locked page_collection to tb_invalidate_phys_page_fast. - tcg_tb_lookup/remove/insert/etc have their own internal lock(s), so there is no need to further serialize access to them. - do_tb_flush is run in a safe async context, meaning no other vCPU threads are running. Therefore acquiring mmap_lock there is just to please tools such as thread sanitizer. - Not visible in the diff, but tb_invalidate_phys_page already has an assert_memory_lock. - cpu_io_recompile is !user-only, so no mmap_lock there. - Added mmap_unlock()'s before all siglongjmp's that could be called in user-mode while mmap_lock is held. + Added an assert for !have_mmap_lock() after returning from the longjmp in cpu_exec, just like we do in cpu_exec_step_atomic. Performance numbers before/after: Host: AMD Opteron(tm) Processor 6376 ubuntu 17.04 ppc64 bootup+shutdown time 700 +-+--+----+------+------------+-----------+------------*--+-+ | + + + + + *B | | before ***B*** ** * | |tb lock removal ###D### *** | 600 +-+ *** +-+ | ** # | | *B* #D | | *** * ## | 500 +-+ *** ### +-+ | * *** ### | | *B* # ## | | ** * #D# | 400 +-+ ** ## +-+ | ** ### | | ** ## | | ** # ## | 300 +-+ * B* #D# +-+ | B *** ### | | * ** #### | | * *** ### | 200 +-+ B *B #D# +-+ | #B* * ## # | | #* ## | | + D##D# + + + + | 100 +-+--+----+------+------------+-----------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/HwmBHXe debian jessie aarch64 bootup+shutdown time 90 +-+--+-----+-----+------------+------------+------------+--+-+ | + + + + + + | | before ***B*** B | 80 +tb lock removal ###D### **D +-+ | **### | | **## | 70 +-+ ** # +-+ | ** ## | | ** # | 60 +-+ *B ## +-+ | ** ## | | *** #D | 50 +-+ *** ## +-+ | * ** ### | | **B* ### | 40 +-+ **** # ## +-+ | **** #D# | | ***B** ### | 30 +-+ B***B** #### +-+ | B * * # ### | | B ###D# | 20 +-+ D ##D## +-+ | D# | | + + + + + + | 10 +-+--+-----+-----+------------+------------+------------+--+-+ 1 8 16 Guest CPUs 48 64 png: https://imgur.com/iGpGFtv The gains are high for 4-8 CPUs. Beyond that point, however, unrelated lock contention significantly hurts scalability. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-08-05 06:46:31 +03:00
/* user-mode: Called with mmap_lock held. */
static inline void *tcg_malloc(int size)
{
TCGContext *s = tcg_ctx;
uint8_t *ptr, *ptr_end;
/* ??? This is a weak placeholder for minimum malloc alignment. */
size = QEMU_ALIGN_UP(size, 8);
ptr = s->pool_cur;
ptr_end = ptr + size;
if (unlikely(ptr_end > s->pool_end)) {
return tcg_malloc_internal(tcg_ctx, size);
} else {
s->pool_cur = ptr_end;
return ptr;
}
}
void tcg_func_start(TCGContext *s);
int tcg_gen_code(TCGContext *s, TranslationBlock *tb, uint64_t pc_start);
void tb_target_set_jmp_target(const TranslationBlock *, int,
uintptr_t, uintptr_t);
void tcg_set_frame(TCGContext *s, TCGReg reg, intptr_t start, intptr_t size);
#define TCG_CT_CONST 1 /* any constant of register size */
typedef struct TCGArgConstraint {
unsigned ct : 16;
unsigned alias_index : 4;
unsigned sort_index : 4;
unsigned pair_index : 4;
unsigned pair : 2; /* 0: none, 1: first, 2: second, 3: second alias */
bool oalias : 1;
bool ialias : 1;
bool newreg : 1;
TCGRegSet regs;
} TCGArgConstraint;
#define TCG_MAX_OP_ARGS 16
/* Bits for TCGOpDef->flags, 8 bits available, all used. */
enum {
/* Instruction exits the translation block. */
TCG_OPF_BB_EXIT = 0x01,
/* Instruction defines the end of a basic block. */
TCG_OPF_BB_END = 0x02,
/* Instruction clobbers call registers and potentially update globals. */
TCG_OPF_CALL_CLOBBER = 0x04,
/* Instruction has side effects: it cannot be removed if its outputs
are not used, and might trigger exceptions. */
TCG_OPF_SIDE_EFFECTS = 0x08,
/* Instruction operands are 64-bits (otherwise 32-bits). */
TCG_OPF_64BIT = 0x10,
/* Instruction is optional and not implemented by the host, or insn
is generic and should not be implemented by the host. */
TCG_OPF_NOT_PRESENT = 0x20,
/* Instruction operands are vectors. */
TCG_OPF_VECTOR = 0x40,
/* Instruction is a conditional branch. */
TCG_OPF_COND_BRANCH = 0x80
};
typedef struct TCGOpDef {
const char *name;
uint8_t nb_oargs, nb_iargs, nb_cargs, nb_args;
uint8_t flags;
TCGArgConstraint *args_ct;
} TCGOpDef;
extern TCGOpDef tcg_op_defs[];
extern const size_t tcg_op_defs_max;
typedef struct TCGTargetOpDef {
TCGOpcode op;
const char *args_ct_str[TCG_MAX_OP_ARGS];
} TCGTargetOpDef;
bool tcg_op_supported(TCGOpcode op);
void tcg_gen_call0(void *func, TCGHelperInfo *, TCGTemp *ret);
void tcg_gen_call1(void *func, TCGHelperInfo *, TCGTemp *ret, TCGTemp *);
void tcg_gen_call2(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *);
void tcg_gen_call3(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *, TCGTemp *);
void tcg_gen_call4(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *, TCGTemp *, TCGTemp *);
void tcg_gen_call5(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *, TCGTemp *, TCGTemp *, TCGTemp *);
void tcg_gen_call6(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *, TCGTemp *, TCGTemp *,
TCGTemp *, TCGTemp *);
void tcg_gen_call7(void *func, TCGHelperInfo *, TCGTemp *ret,
TCGTemp *, TCGTemp *, TCGTemp *, TCGTemp *,
TCGTemp *, TCGTemp *, TCGTemp *);
TCGOp *tcg_emit_op(TCGOpcode opc, unsigned nargs);
void tcg_op_remove(TCGContext *s, TCGOp *op);
TCGOp *tcg_op_insert_before(TCGContext *s, TCGOp *op,
TCGOpcode opc, unsigned nargs);
TCGOp *tcg_op_insert_after(TCGContext *s, TCGOp *op,
TCGOpcode opc, unsigned nargs);
/**
* tcg_remove_ops_after:
* @op: target operation
*
* Discard any opcodes emitted since @op. Expected usage is to save
* a starting point with tcg_last_op(), speculatively emit opcodes,
* then decide whether or not to keep those opcodes after the fact.
*/
void tcg_remove_ops_after(TCGOp *op);
void tcg_optimize(TCGContext *s);
TCGLabel *gen_new_label(void);
/**
* label_arg
* @l: label
*
* Encode a label for storage in the TCG opcode stream.
*/
static inline TCGArg label_arg(TCGLabel *l)
{
return (uintptr_t)l;
}
/**
* arg_label
* @i: value
*
* The opposite of label_arg. Retrieve a label from the
* encoding of the TCG opcode stream.
*/
static inline TCGLabel *arg_label(TCGArg i)
{
return (TCGLabel *)(uintptr_t)i;
}
/**
* tcg_ptr_byte_diff
* @a, @b: addresses to be differenced
*
* There are many places within the TCG backends where we need a byte
* difference between two pointers. While this can be accomplished
* with local casting, it's easy to get wrong -- especially if one is
* concerned with the signedness of the result.
*
* This version relies on GCC's void pointer arithmetic to get the
* correct result.
*/
static inline ptrdiff_t tcg_ptr_byte_diff(const void *a, const void *b)
{
return a - b;
}
/**
* tcg_pcrel_diff
* @s: the tcg context
* @target: address of the target
*
* Produce a pc-relative difference, from the current code_ptr
* to the destination address.
*/
static inline ptrdiff_t tcg_pcrel_diff(TCGContext *s, const void *target)
{
return tcg_ptr_byte_diff(target, tcg_splitwx_to_rx(s->code_ptr));
}
/**
* tcg_tbrel_diff
* @s: the tcg context
* @target: address of the target
*
* Produce a difference, from the beginning of the current TB code
* to the destination address.
*/
static inline ptrdiff_t tcg_tbrel_diff(TCGContext *s, const void *target)
{
return tcg_ptr_byte_diff(target, tcg_splitwx_to_rx(s->code_buf));
}
/**
* tcg_current_code_size
* @s: the tcg context
*
* Compute the current code size within the translation block.
* This is used to fill in qemu's data structures for goto_tb.
*/
static inline size_t tcg_current_code_size(TCGContext *s)
{
return tcg_ptr_byte_diff(s->code_ptr, s->code_buf);
}
/**
* tcg_qemu_tb_exec:
* @env: pointer to CPUArchState for the CPU
* @tb_ptr: address of generated code for the TB to execute
*
* Start executing code from a given translation block.
* Where translation blocks have been linked, execution
* may proceed from the given TB into successive ones.
* Control eventually returns only when some action is needed
* from the top-level loop: either control must pass to a TB
* which has not yet been directly linked, or an asynchronous
* event such as an interrupt needs handling.
*
* Return: The return value is the value passed to the corresponding
* tcg_gen_exit_tb() at translation time of the last TB attempted to execute.
* The value is either zero or a 4-byte aligned pointer to that TB combined
* with additional information in its two least significant bits. The
* additional information is encoded as follows:
* 0, 1: the link between this TB and the next is via the specified
* TB index (0 or 1). That is, we left the TB via (the equivalent
* of) "goto_tb <index>". The main loop uses this to determine
* how to link the TB just executed to the next.
* 2: we are using instruction counting code generation, and we
* did not start executing this TB because the instruction counter
* would hit zero midway through it. In this case the pointer
* returned is the TB we were about to execute, and the caller must
* arrange to execute the remaining count of instructions.
* 3: we stopped because the CPU's exit_request flag was set
* (usually meaning that there is an interrupt that needs to be
* handled). The pointer returned is the TB we were about to execute
* when we noticed the pending exit request.
*
* If the bottom two bits indicate an exit-via-index then the CPU
* state is correctly synchronised and ready for execution of the next
* TB (and in particular the guest PC is the address to execute next).
* Otherwise, we gave up on execution of this TB before it started, and
* the caller must fix up the CPU state by calling the CPU's
* synchronize_from_tb() method with the TB pointer we return (falling
* back to calling the CPU's set_pc method with tb->pb if no
* synchronize_from_tb() method exists).
*
* Note that TCG targets may use a different definition of tcg_qemu_tb_exec
* to this default (which just calls the prologue.code emitted by
* tcg_target_qemu_prologue()).
*/
#define TB_EXIT_MASK 3
#define TB_EXIT_IDX0 0
#define TB_EXIT_IDX1 1
#define TB_EXIT_IDXMAX 1
#define TB_EXIT_REQUESTED 3
#ifdef CONFIG_TCG_INTERPRETER
uintptr_t tcg_qemu_tb_exec(CPUArchState *env, const void *tb_ptr);
#else
typedef uintptr_t tcg_prologue_fn(CPUArchState *env, const void *tb_ptr);
extern tcg_prologue_fn *tcg_qemu_tb_exec;
#endif
void tcg_register_jit(const void *buf, size_t buf_size);
#if TCG_TARGET_MAYBE_vec
/* Return zero if the tuple (opc, type, vece) is unsupportable;
return > 0 if it is directly supportable;
return < 0 if we must call tcg_expand_vec_op. */
int tcg_can_emit_vec_op(TCGOpcode, TCGType, unsigned);
#else
static inline int tcg_can_emit_vec_op(TCGOpcode o, TCGType t, unsigned ve)
{
return 0;
}
#endif
/* Expand the tuple (opc, type, vece) on the given arguments. */
void tcg_expand_vec_op(TCGOpcode, TCGType, unsigned, TCGArg, ...);
/* Replicate a constant C according to the log2 of the element size. */
uint64_t dup_const(unsigned vece, uint64_t c);
#define dup_const(VECE, C) \
(__builtin_constant_p(VECE) \
? ( (VECE) == MO_8 ? 0x0101010101010101ull * (uint8_t)(C) \
: (VECE) == MO_16 ? 0x0001000100010001ull * (uint16_t)(C) \
: (VECE) == MO_32 ? 0x0000000100000001ull * (uint32_t)(C) \
: (VECE) == MO_64 ? (uint64_t)(C) \
: (qemu_build_not_reached_always(), 0)) \
: dup_const(VECE, C))
static inline const TCGOpcode *tcg_swap_vecop_list(const TCGOpcode *n)
{
#ifdef CONFIG_DEBUG_TCG
const TCGOpcode *o = tcg_ctx->vecop_list;
tcg_ctx->vecop_list = n;
return o;
#else
return NULL;
#endif
}
bool tcg_can_emit_vecop_list(const TCGOpcode *, TCGType, unsigned);
void tcg_dump_ops(TCGContext *s, FILE *f, bool have_prefs);
#endif /* TCG_H */