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2018-05-11Merge remote-tracking branch ↵Peter Maydell3-0/+106
'remotes/pmaydell/tags/pull-target-arm-20180510' into staging target-arm queue: * hw/arm/iotkit.c: fix minor memory leak * softfloat: fix wrong-exception-flags bug for multiply-add corner case * arm: isolate and clean up DTB generation * implement Arm v8.1-Atomics extension * Fix some bugs and missing instructions in the v8.2-FP16 extension # gpg: Signature made Thu 10 May 2018 18:44:34 BST # gpg: using RSA key 3C2525ED14360CDE # gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" # gpg: aka "Peter Maydell <pmaydell@gmail.com>" # gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" # Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE * remotes/pmaydell/tags/pull-target-arm-20180510: (21 commits) target/arm: Clear SVE high bits for FMOV target/arm: Fix float16 to/from int16 target/arm: Implement vector shifted FCVT for fp16 target/arm: Implement vector shifted SCVF/UCVF for fp16 target/arm: Enable ARM_FEATURE_V8_ATOMICS for user-only target/arm: Implement CAS and CASP target/arm: Fill in disas_ldst_atomic target/arm: Introduce ARM_FEATURE_V8_ATOMICS and initial decode target/riscv: Use new atomic min/max expanders tcg: Use GEN_ATOMIC_HELPER_FN for opposite endian atomic add tcg: Introduce atomic helpers for integer min/max target/xtensa: Use new min/max expanders target/arm: Use new min/max expanders tcg: Introduce helpers for integer min/max atomic.h: Work around gcc spurious "unused value" warning make sure that we aren't overwriting mc->get_hotplug_handler by accident arm/boot: split load_dtb() from arm_load_kernel() platform-bus-device: use device plug callback instead of machine_done notifier pc: simplify MachineClass::get_hotplug_handler handling softfloat: Handle default NaN mode after pickNaNMulAdd, not before ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> # Conflicts: # target/riscv/translate.c
2018-05-10tcg: Introduce atomic helpers for integer min/maxRichard Henderson3-0/+50
Given that this atomic operation will be used by both risc-v and aarch64, let's not duplicate code across the two targets. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180508151437.4232-5-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-05-10tcg: Introduce helpers for integer min/maxRichard Henderson2-0/+56
These operations are re-invented by several targets so far. Several supported hosts have insns for these, so place the expanders out-of-line for a future introduction of tcg opcodes. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180508151437.4232-2-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-05-09tcg: Limit the number of ops in a TBRichard Henderson2-1/+10
In 6001f7729e12 we partially attempt to address the branch displacement overflow caused by 15fa08f845. However, gcc/testsuite/gcc.target/aarch64/advsimd-intrinsics/vqtbX.c is a testcase that contains a TB so large as to overflow anyway. The limit here of 8000 ops produces a maximum output TB size of 24112 bytes on a ppc64le host with that test case. This is still much less than the maximum forward branch distance of 32764 bytes. Cc: qemu-stable@nongnu.org Fixes: 15fa08f845 ("tcg: Dynamically allocate TCGOps") Reviewed-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-09tcg/i386: Fix dup_vec in non-AVX2 codepathPeter Maydell1-3/+3
The VPUNPCKLD* instructions are all "non-destructive source", indicated by "NDS" in the encoding string in the x86 ISA manual. This means that they take two source operands, one of which is encoded in the VEX.vvvv field. We were incorrectly treating them as if they were destructive-source and passing 0 as the 'v' argument of tcg_out_vex_modrm(). This meant we were always using %xmm0 as one of the source operands, causing incorrect results if the register allocator happened to want to use something else. For instance the input AArch64 insn: DUP v26.16b, w21 which becomes TCG IR ops: dup_vec v128,e8,tmp2,x21 st_vec v128,e8,tmp2,env,$0xa40 was assembled to: 0x607c568c: c4 c1 7a 7e 86 e8 00 00 vmovq 0xe8(%r14), %xmm0 0x607c5694: 00 0x607c5695: c5 f9 60 c8 vpunpcklbw %xmm0, %xmm0, %xmm1 0x607c5699: c5 f9 61 c9 vpunpcklwd %xmm1, %xmm0, %xmm1 0x607c569d: c5 f9 70 c9 00 vpshufd $0, %xmm1, %xmm1 0x607c56a2: c4 c1 7a 7f 8e 40 0a 00 vmovdqu %xmm1, 0xa40(%r14) 0x607c56aa: 00 when the vpunpcklwd insn should be "%xmm1, %xmm1, %xmm1". This resulted in our incorrectly setting the output vector to q26=0000320000003200:0000320000003200 when given an input of x21 == 0000000002803200 rather than the expected all-zeroes. Pass the correct source register number to tcg_out_vex_modrm() for these insns. Fixes: 770c2fc7bb70804a Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20180504153431.5169-1-peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-01tcg: workaround branch instruction overflow in tcg_out_qemu_ld/stLaurent Vivier3-6/+6
ppc64 uses a BC instruction to call the tcg_out_qemu_ld/st slow path. BC instruction uses a relative address encoded on 14 bits. The slow path functions are added at the end of the generated instructions buffer, in the reverse order of the callers. So more we have slow path functions more the distance between the caller (BC) and the function increases. This patch changes the behavior to generate the functions in the same order of the callers. Cc: qemu-stable@nongnu.org Fixes: 15fa08f845 ("tcg: Dynamically allocate TCGOps") Signed-off-by: Laurent Vivier <lvivier@redhat.com> Message-Id: <20180429235840.16659-1-lvivier@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-01tcg: Improve TCGv_ptr supportRichard Henderson3-80/+128
Drop TCGV_PTR_TO_NAT and TCGV_NAT_TO_PTR internal macros. Add tcg_temp_local_new_ptr, tcg_gen_brcondi_ptr, tcg_gen_ext_i32_ptr, tcg_gen_trunc_i64_ptr, tcg_gen_extu_ptr_i64, tcg_gen_trunc_ptr_i32. Use inlines instead of macros where possible. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-01tcg: Allow wider vectors for cmp and mulRichard Henderson1-4/+4
In db432672, we allow wide inputs for operations such as add. However, in 212be173 and 3774030a we didn't do the same for compare and multiply. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-01tcg/arm: Fix memory barrier encodingHenry Wertz1-2/+2
I found with qemu 2.11.x or newer that I would get an illegal instruction error running some Intel binaries on my ARM chromebook. On investigation, I found it was quitting on memory barriers. qemu instruction: mb $0x31 was translating as: 0x604050cc: 5bf07ff5 blpl #0x600250a8 After patch it gives: 0x604050cc: f57ff05b dmb ish In short, I found INSN_DMB_ISH (memory barrier for ARMv7) appeared to be correct based on online docs, but due to some endian-related shenanigans it had to be byte-swapped to suit qemu; it appears INSN_DMB_MCR (memory barrier for ARMv6) also should be byte swapped (and this patch does so). I have not checked for correctness of aarch64's barrier instruction. Cc: qemu-stable@nongnu.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Henry Wertz <hwertz10@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-05-01tcg: Document INDEX_mul[us]h_*Richard Henderson1-0/+8
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-04-16tcg/mips: Handle large offsets from target env to tlb_tablePeter Maydell1-7/+4
The MIPS TCG target makes the assumption that the offset from the target env pointer to the tlb_table is less than about 64K. This used to be true, but gradual addition of features to the Arm target means that it's no longer true there. This results in the build-time assertion failing: In file included from /home/pm215/qemu/include/qemu/osdep.h:36:0, from /home/pm215/qemu/tcg/tcg.c:28: /home/pm215/qemu/tcg/mips/tcg-target.inc.c: In function ‘tcg_out_tlb_load’: /home/pm215/qemu/include/qemu/compiler.h:90:36: error: static assertion failed: "not expecting: offsetof(CPUArchState, tlb_table[NB_MMU_MODES - 1][1]) > 0x7ff0 + 0x7fff" #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg) ^ /home/pm215/qemu/include/qemu/compiler.h:98:30: note: in expansion of macro ‘QEMU_BUILD_BUG_MSG’ #define QEMU_BUILD_BUG_ON(x) QEMU_BUILD_BUG_MSG(x, "not expecting: " #x) ^ /home/pm215/qemu/tcg/mips/tcg-target.inc.c:1236:9: note: in expansion of macro ‘QEMU_BUILD_BUG_ON’ QEMU_BUILD_BUG_ON(offsetof(CPUArchState, ^ /home/pm215/qemu/rules.mak:66: recipe for target 'tcg/tcg.o' failed An ideal long term approach would be to rearrange the CPU state so that the tlb_table was not so far along it, but this is tricky because it would move it from the "not cleared on CPU reset" part of the struct to the "cleared on CPU reset" part. As a simple fix for the 2.12 release, make the MIPS TCG target handle an arbitrary offset by emitting more add instructions. This will mean an extra instruction in the fastpath for TCG loads and stores for the affected guests (currently just aarch64-softmmu). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Message-id: 20180413142336.32163-1-peter.maydell@linaro.org
2018-04-10tcg: Introduce tcg_set_insn_start_paramRichard Henderson1-0/+10
The parameters for tcg_gen_insn_start are target_ulong, which may be split into two TCGArg parameters for storage in the opcode on 32-bit hosts. Fixes the ARM target and its direct use of tcg_set_insn_param, which would set the wrong argument in the 64-on-32 case. Cc: qemu-stable@nongnu.org Reported-by: alarson@ddci.com Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20180410003558.2470-1-richard.henderson@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-03-28tcg: Mark muluh_i64 and mulsh_i64 as 64-bit opsRichard Henderson1-2/+2
Failure to do so results in the tcg optimizer sign-extending any constant fold from 32-bits. This turns out to be visible in the RISC-V testsuite using a host that emits these opcodes (e.g. any non-x86_64). Reported-by: Michael Clark <mjc@sifive.com> Reviewed-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-03-16tcg: Add choose_vector_sizeRichard Henderson1-180/+260
This unifies 5 copies of checks for supported vector size, and in the process fixes a missing check in tcg_gen_gvec_2s. This lead to an assertion failure for 64-bit vector multiply, which is not available in the AVX instruction set. Suggested-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-03-16tcg/i386: Support INDEX_op_dup2_vec for -m32Richard Henderson1-0/+9
Unknown why -m32 was passing with gcc but not clang; it should have failed for both. This would be used for tcg_gen_dup_i64_vec, and visible with the right TB and an aarch64 guest. Reported-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-03-16tcg: Improve tcg_gen_muli_i32/i64Richard Henderson1-6/+18
Convert multiplication by power of two to left shift. Reviewed-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg/aarch64: Add vector operationsRichard Henderson3-47/+569
Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg/i386: Add vector operationsRichard Henderson3-54/+987
The x86 vector instruction set is extremely irregular. With newer editions, Intel has filled in some of the blanks. However, we don't get many 64-bit operations until SSE4.2, introduced in 2009. The subsequent edition was for AVX1, introduced in 2011, which added three-operand addressing, and adjusts how all instructions should be encoded. Given the relatively narrow 2 year window between possible to support and desirable to support, and to vastly simplify code maintainence, I am only planning to support AVX1 and later cpus. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg/optimize: Handle vector opcodes during optimizeRichard Henderson1-73/+77
Trivial move and constant propagation. Some identity and constant function folding, but nothing that requires knowledge of the size of the vector element. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic vector helpers with a scalar operandRichard Henderson2-2/+418
Use dup to convert a non-constant scalar to a third vector. Add addition, multiplication, and logical operations with an immediate. Add addition, subtraction, multiplication, and logical operations with a non-constant scalar. Allow for the front-end to build operations in which the scalar operand comes first. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic helpers for saturating arithmeticRichard Henderson2-0/+102
No vector ops as yet. SSE only has direct support for 8- and 16-bit saturation; handling 32- and 64-bit saturation is much more expensive. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic vector ops for multiplicationRichard Henderson8-0/+62
Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic vector ops for comparisonsRichard Henderson7-0/+189
Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic vector ops for constant shiftsRichard Henderson8-0/+416
Opcodes are added for scalar and vector shifts, but considering the varied semantics of these do not expose them to the front ends. Do go ahead and provide them in case they are needed for backend expansion. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add generic vector expandersRichard Henderson8-16/+1620
Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Standardize integral arguments to expandersRichard Henderson2-29/+29
Some functions use intN_t arguments, some use uintN_t, some just used "unsigned". To aid putting function pointers in tables, we need consistency. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Add types and basic operations for host vectorsRichard Henderson6-4/+541
Nothing uses or enables them yet. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-02-08tcg: Allow multiple word entries into the constant poolRichard Henderson1-21/+92
This will be required for storing vector constants. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-01-16tcg/ppc: Allow a 32-bit offset to the constant poolRichard Henderson1-28/+39
We recently relaxed the limit of the number of opcodes that can appear in a TranslationBlock. In certain cases this has resulted in relocation overflow. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-01-16tcg/ppc: Support tlb offsets larger than 64kRichard Henderson1-9/+8
AArch64 with SVE has an offset of 80k to the 8th TLB. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-01-16tcg/arm: Support tlb offsets larger than 64kRichard Henderson1-13/+17
AArch64 with SVE has an offset of 80k to the 8th TLB. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-01-16tcg/arm: Fix double-word comparisonsRichard Henderson1-26/+60
The code sequence we were generating was only good for unsigned comparisons. For signed comparisions, use the sequence from gcc. Fixes booting of ppc64 firmware, with a patch changing the code sequence for ppc comparisons. Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-12-29tcg: Allow 6 arguments to TCG helpersRichard Henderson3-7/+13
We already handle this in the backends, and the lifetime datum for the TCGOp is already large enough. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-12-29tcg: Add tcg_signed_condRichard Henderson1-0/+6
Complimenting the existing tcg_unsigned_cond. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-12-29tcg: Generalize TCGOp parametersRichard Henderson3-17/+19
We had two fields specific to INDEX_op_call. Rename these and add some macros so that the fields may be reused for other opcodes. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-12-29tcg: Dynamically allocate TCGOpsRichard Henderson4-136/+62
With no fixed array allocation, we can't overflow a buffer. This will be important as optimizations related to host vectors may expand the number of ops used. Use QTAILQ to link the ops together. Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-12-29tcg: Remove TCGV_UNUSED* and TCGV_IS_UNUSED*Richard Henderson3-15/+2
These are now trivial sets and tests against NULL. Unwrap. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-11-03tcg/s390x: Use constant pool for prologueRichard Henderson1-32/+12
Rather than have separate code only used for guest_base, rely on a recent change to handle constant pool entries. Cc: qemu-s390x@nongnu.org Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-11-03tcg: Allow constant pool entries in the prologueRichard Henderson1-7/+42
Both ARMv6 and AArch64 currently may drop complex guest_base values into the constant pool. But generic code wasn't expecting that, and the pool is not emitted. Correct that. Tested-by: Emilio G. Cota <cota@braap.org> Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com> Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-24tcg: Initialize cpu_env genericallyRichard Henderson3-47/+24
This is identical for each target. So, move the initialization to common code. Move the variable itself out of tcg_ctx and name it cpu_env to minimize changes within targets. This also means we can remove tcg_global_reg_new_{ptr,i32,i64}, since there are no longer global-register temps created by targets. Reviewed-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-24tcg: enable multiple TCG contexts in softmmuEmilio G. Cota2-12/+141
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>
2017-10-24tcg: introduce regions to split code_gen_bufferEmilio G. Cota2-2/+226
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>
2017-10-24tcg: allocate optimizer temps with tcg_mallocEmilio G. Cota1-23/+19
Groundwork for supporting multiple TCG contexts. While at it, also allocate temps_used directly as a bitmap of the required size, instead of using a bitmap of TCG_MAX_TEMPS via TCGTempSet. Performance-wise we lose about 1.12% in a translation-heavy workload such as booting+shutting down debian-arm: Performance counter stats for 'taskset -c 0 arm-softmmu/qemu-system-arm \ -machine type=virt -nographic -smp 1 -m 4096 \ -netdev user,id=unet,hostfwd=tcp::2222-:22 \ -device virtio-net-device,netdev=unet \ -drive file=die-on-boot.qcow2,id=myblock,index=0,if=none \ -device virtio-blk-device,drive=myblock \ -kernel kernel.img -append console=ttyAMA0 root=/dev/vda1 \ -name arm,debug-threads=on -smp 1' (10 runs): exec time (s) Relative slowdown wrt original (%) --------------------------------------------------------------- original 20.213321616 0. tcg_malloc 20.441130078 1.1270214 TCGContext 20.477846517 1.3086662 g_malloc 20.780527895 2.8061013 The other two alternatives shown in the table are: - TCGContext: embed temps[TCG_MAX_TEMPS] and TCGTempSet used_temps in TCGContext. This is simple enough but it isn't faster than using tcg_malloc; moreover, it wastes memory. - g_malloc: allocate/deallocate both temps and used_temps every time tcg_optimize is executed. Suggested-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-24tcg: distribute profiling counters across TCGContext'sEmilio G. Cota2-35/+113
This is groundwork for supporting multiple TCG contexts. To avoid scalability issues when profiling info is enabled, this patch makes the profiling info counters distributed via the following changes: 1) Consolidate profile info into its own struct, TCGProfile, which TCGContext also includes. Note that tcg_table_op_count is brought into TCGProfile after dropping the tcg_ prefix. 2) Iterate over the TCG contexts in the system to obtain the total counts. This change also requires updating the accessors to TCGProfile fields to use atomic_read/set whenever there may be conflicting accesses (as defined in C11) to them. 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>
2017-10-24tcg: introduce **tcg_ctxs to keep track of all TCGContext'sEmilio G. Cota1-0/+5
Groundwork for supporting multiple TCG contexts. Note that having n_tcg_ctxs is unnecessary. However, it is convenient to have it, since it will simplify iterating over the array: we'll have just a for loop instead of having to iterate over a NULL-terminated array (which would require n+1 elems) or having to check with ifdef's for usermode/softmmu. 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>
2017-10-24gen-icount: fold exitreq_label into TCGContextEmilio G. Cota1-0/+2
Groundwork for supporting multiple TCG contexts. Reviewed-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 <richard.henderson@linaro.org>
2017-10-24tcg: define tcg_init_ctx and make tcg_ctx a pointerEmilio G. Cota3-43/+46
Groundwork for supporting multiple TCG contexts. The core of this patch is this change to tcg/tcg.h: > -extern TCGContext tcg_ctx; > +extern TCGContext tcg_init_ctx; > +extern TCGContext *tcg_ctx; Note that for now we set *tcg_ctx to whatever TCGContext is passed to tcg_context_init -- in this case &tcg_init_ctx. 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>
2017-10-24tcg: take tb_ctx out of TCGContextEmilio G. Cota1-2/+0
Groundwork for supporting multiple TCG contexts. Reviewed-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 <richard.henderson@linaro.org>
2017-10-24tcg: check CF_PARALLEL instead of parallel_cpusEmilio G. Cota2-5/+6
Thereby decoupling the resulting translated code from the current state of the system. The tb->cflags field is not passed to tcg generation functions. So we add a field to TCGContext, storing there a copy of tb->cflags. Most architectures have <= 32 registers, which results in a 4-byte hole in TCGContext. Use this hole for the new field. 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>
2017-10-24tcg: define CF_PARALLEL and use it for TB hashing along with CF_COUNT_MASKEmilio G. Cota1-1/+0
This will enable us to decouple code translation from the value of parallel_cpus at any given time. It will also help us minimize TB flushes when generating code via EXCP_ATOMIC. Note that the declaration of parallel_cpus is brought to exec-all.h to be able to define there the "curr_cflags" inline. Signed-off-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
generated by cgit v1.1 at 2024-12-27 13:18:51 +0000