| Message ID | 20240628175030.595936-1-debug@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] target/riscv: zimop and zcmop extension for riscv | expand |
Please ignore this one. Wrong command and all patches came out as one. Sorry about that. On Fri, Jun 28, 2024 at 10:50 AM Deepak Gupta <debug@rivosinc.com> wrote: > > `zimop` stands for `may be operations`. `zcmop` stands for compressed > `may be operations`. For some RISC-V CPU extension, once compiled into > the binary are part of generated code which can't be gated behind a probe > of whether an instruction set is supported or not. One such example is > `zicfiss` [1] extension where `shadow stack push` and `shadow stack pop > and check` will be part of every function body. Thus binaries compiled > with such extensions need to run in following scenarios > > - On machines where extension is present and enabled > - On machines where extension is present and disabled > - On machines where extension is not present/implemented. > > `zimop` (for 32bit instructions) and `zcmop` (for compressed) were devised > and defined [2] to support such future (like zicfiss) CPU extensions > where zimops and zcmops provide a base non-faulting behavior for > codepoints that may claimed by future ISA extensions. Minimally, any > CPU implementation wanting to have binary compatibility with such > binaries only has to implement `zimop and zcmop`. Furthermore, this > allows per-task optin for software where user has the option to enable > the feature on per-task basis. > > `zimop` are defined to write zero to `rd`. `zcmop` are defined to *not* write > to any register. > > [1] - https://github.com/riscv/riscv-cfi/blob/main/src/cfi_backward.adoc > [2] - https://github.com/riscv/riscv-isa-manual/blob/main/src/zimop.adoc > > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > target/riscv/cpu.c | 2 ++ > target/riscv/cpu_cfg.h | 1 + > 2 files changed, 3 insertions(+) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index eb1a2e7d6d..3caf8553d1 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -113,6 +113,7 @@ const RISCVIsaExtData isa_edata_arr[] = { > ISA_EXT_DATA_ENTRY(zihintntl, PRIV_VERSION_1_10_0, ext_zihintntl), > ISA_EXT_DATA_ENTRY(zihintpause, PRIV_VERSION_1_10_0, ext_zihintpause), > ISA_EXT_DATA_ENTRY(zihpm, PRIV_VERSION_1_12_0, ext_zihpm), > + ISA_EXT_DATA_ENTRY(zimops, PRIV_VERSION_1_12_0, ext_zimops), > ISA_EXT_DATA_ENTRY(zmmul, PRIV_VERSION_1_12_0, ext_zmmul), > ISA_EXT_DATA_ENTRY(za64rs, PRIV_VERSION_1_12_0, has_priv_1_11), > ISA_EXT_DATA_ENTRY(zaamo, PRIV_VERSION_1_12_0, ext_zaamo), > @@ -2273,6 +2274,7 @@ static Property riscv_cpu_properties[] = { > * it with -x and default to 'false'. > */ > DEFINE_PROP_BOOL("x-misa-w", RISCVCPU, cfg.misa_w, false), > + DEFINE_PROP_BOOL("zimops", RISCVCPU, cfg.ext_zimops, true), > DEFINE_PROP_END_OF_LIST(), > }; > > diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h > index cb750154bd..5c42ff8cdf 100644 > --- a/target/riscv/cpu_cfg.h > +++ b/target/riscv/cpu_cfg.h > @@ -124,6 +124,7 @@ struct RISCVCPUConfig { > uint32_t mvendorid; > uint64_t marchid; > uint64_t mimpid; > + bool ext_zimops; > > /* Named features */ > bool ext_svade; > -- > 2.34.1 > > > From 4d15b0e0037f444eb75e60b398e19dcf476f07d4 Mon Sep 17 00:00:00 2001 > From: Deepak Gupta <debug@rivosinc.com> > Date: Fri, 28 Jun 2024 00:13:58 -0700 > Subject: [PATCH 2/3] target/riscv: zimop instruction encoding and its > implementation > > This patch adds assigned codepoints for decoder for 32bit instructions > and provide implementation for instruction. If extension is present, > then moves 0 to `rd`. > > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > target/riscv/insn32.decode | 15 +++++++ > target/riscv/insn_trans/trans_zimops.c.inc | 50 ++++++++++++++++++++++ > target/riscv/translate.c | 3 ++ > 3 files changed, 68 insertions(+) > create mode 100644 target/riscv/insn_trans/trans_zimops.c.inc > > diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode > index f22df04cfd..fca3838a9f 100644 > --- a/target/riscv/insn32.decode > +++ b/target/riscv/insn32.decode > @@ -167,6 +167,21 @@ csrrwi ............ ..... 101 ..... 1110011 @csr > csrrsi ............ ..... 110 ..... 1110011 @csr > csrrci ............ ..... 111 ..... 1110011 @csr > > +# zimops (unpriv integer may be operations) instructions with system opcode > +# zimops_r and zimops_rr are two code points assigned to zimops > +# Any new extension that claims zimops encoding should be placed above mop.r > +# and mop.rr > + > +# mop.r > +{ > + zimops_r 1-00--0 111-- ----- 100 ..... 1110011 %rd > +} > + > +# mop.rr > +{ > + zimops_rr 1-00--1 ----- ----- 100 ..... 1110011 %rd > +} > + > # *** RV64I Base Instruction Set (in addition to RV32I) *** > lwu ............ ..... 110 ..... 0000011 @i > ld ............ ..... 011 ..... 0000011 @i > diff --git a/target/riscv/insn_trans/trans_zimops.c.inc b/target/riscv/insn_trans/trans_zimops.c.inc > new file mode 100644 > index 0000000000..b5ad7bded8 > --- /dev/null > +++ b/target/riscv/insn_trans/trans_zimops.c.inc > @@ -0,0 +1,50 @@ > +/* > + * RISC-V translation routines for the Control-Flow Integrity Extension > + * > + * Copyright (c) 2024 Rivos Inc. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2 or later, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +static bool trans_zimops_r(DisasContext *ctx, arg_zimops_r * a) > +{ > + /* zimops not implemented, raise illegal instruction & return true */ > + if (!ctx->cfg_ptr->ext_zimops) { > + gen_exception_illegal(ctx); > + return true; > + } > + /* > + * zimops implemented, simply grab destination and mov zero. > + * return true > + */ > + TCGv dest = dest_gpr(ctx, a->rd); > + dest = tcg_constant_tl(0); > + gen_set_gpr(ctx, a->rd, dest); > + return true; > +} > + > +static bool trans_zimops_rr(DisasContext *ctx, arg_zimops_r * a) > +{ > + /* zimops not implemented, raise illegal instruction & return true */ > + if (!ctx->cfg_ptr->ext_zimops) { > + gen_exception_illegal(ctx); > + return true; > + } > + /* > + * zimops implemented, simply grab destination and mov zero. > + * return true > + */ > + TCGv dest = dest_gpr(ctx, a->rd); > + dest = tcg_constant_tl(0); > + gen_set_gpr(ctx, a->rd, dest); > + return true; > +} > diff --git a/target/riscv/translate.c b/target/riscv/translate.c > index 2c27fd4ce1..b7fd3456c8 100644 > --- a/target/riscv/translate.c > +++ b/target/riscv/translate.c > @@ -1115,6 +1115,9 @@ static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc) > /* Include decoders for factored-out extensions */ > #include "decode-XVentanaCondOps.c.inc" > > +/* Include decoder for zimop */ > +#include "insn_trans/trans_zimops.c.inc" > + > /* The specification allows for longer insns, but not supported by qemu. */ > #define MAX_INSN_LEN 4 > > -- > 2.34.1 > > > From dc5d2c62475ac7a9cf42b9ed1398961505b8b91d Mon Sep 17 00:00:00 2001 > From: Deepak Gupta <debug@rivosinc.com> > Date: Tue, 2 Jan 2024 15:46:13 -0800 > Subject: [PATCH 3/3] target/riscv: Introduce `compressed zimop` aka `zcmop` > > Analogous to zimop, there are 8 encodings carved out of illegal space > encodings (c.lui xn, 0) in compressed instructions which are defined > to be zcmops short for compressed may be operations. > > Unlike zimops (which write 0 to rd), zcmops don't actually write anything > to any register. Their encodings allow future extensions to define them to > read register x[n]. > > Signed-off-by: Deepak Gupta <debug@rivosinc.com> > --- > target/riscv/insn16.decode | 6 ++++++ > target/riscv/insn_trans/trans_zimops.c.inc | 11 +++++++++++ > 2 files changed, 17 insertions(+) > > diff --git a/target/riscv/insn16.decode b/target/riscv/insn16.decode > index b96c534e73..d24b54d319 100644 > --- a/target/riscv/insn16.decode > +++ b/target/riscv/insn16.decode > @@ -32,6 +32,7 @@ > %uimm_cl_w 5:1 10:3 6:1 !function=ex_shift_2 > %imm_cb 12:s1 5:2 2:1 10:2 3:2 !function=ex_shift_1 > %imm_cj 12:s1 8:1 9:2 6:1 7:1 2:1 11:1 3:3 !function=ex_shift_1 > +%zcmop_n 8:3 > > %shlimm_6bit 12:1 2:5 !function=ex_rvc_shiftli > %shrimm_6bit 12:1 2:5 !function=ex_rvc_shiftri > @@ -66,6 +67,8 @@ > &cmpp urlist spimm > &cmjt index > > +&cmop zcmop_n > + > # Formats 16: > @cr .... ..... ..... .. &r rs2=%rs2_5 rs1=%rd %rd > @ci ... . ..... ..... .. &i imm=%imm_ci rs1=%rd %rd > @@ -109,6 +112,8 @@ > @cm_mv ... ... ... .. ... .. &r2_s rs2=%r2s rs1=%r1s > @cm_jt ... ... ........ .. &cmjt %index > > +@c_mop ... . ..... ..... .. &cmop %zcmop_n > + > # *** RV32/64C Standard Extension (Quadrant 0) *** > { > # Opcode of all zeros is illegal; rd != 0, nzuimm == 0 is reserved. > @@ -140,6 +145,7 @@ sw 110 ... ... .. ... 00 @cs_w > addi 000 . ..... ..... 01 @ci > addi 010 . ..... ..... 01 @c_li > { > + zcmops 011 0 0...1 00000 01 @c_mop # zcmop carving out of illegal c.lui xn,0 space > illegal 011 0 ----- 00000 01 # c.addi16sp and c.lui, RES nzimm=0 > addi 011 . 00010 ..... 01 @c_addi16sp > lui 011 . ..... ..... 01 @c_lui > diff --git a/target/riscv/insn_trans/trans_zimops.c.inc b/target/riscv/insn_trans/trans_zimops.c.inc > index b5ad7bded8..99f25bd9ea 100644 > --- a/target/riscv/insn_trans/trans_zimops.c.inc > +++ b/target/riscv/insn_trans/trans_zimops.c.inc > @@ -48,3 +48,14 @@ static bool trans_zimops_rr(DisasContext *ctx, arg_zimops_r * a) > gen_set_gpr(ctx, a->rd, dest); > return true; > } > + > +static bool trans_zcmops(DisasContext *ctx, arg_zcmops * a) > +{ > + /* zimops not implemented, return false */ > + if (!ctx->cfg_ptr->ext_zimops) { > + gen_exception_illegal(ctx); > + return false; > + } > + > + return true; > +} > -- > 2.34.1 >
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index eb1a2e7d6d..3caf8553d1 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -113,6 +113,7 @@ const RISCVIsaExtData isa_edata_arr[] = { ISA_EXT_DATA_ENTRY(zihintntl, PRIV_VERSION_1_10_0, ext_zihintntl), ISA_EXT_DATA_ENTRY(zihintpause, PRIV_VERSION_1_10_0, ext_zihintpause), ISA_EXT_DATA_ENTRY(zihpm, PRIV_VERSION_1_12_0, ext_zihpm), + ISA_EXT_DATA_ENTRY(zimops, PRIV_VERSION_1_12_0, ext_zimops), ISA_EXT_DATA_ENTRY(zmmul, PRIV_VERSION_1_12_0, ext_zmmul), ISA_EXT_DATA_ENTRY(za64rs, PRIV_VERSION_1_12_0, has_priv_1_11), ISA_EXT_DATA_ENTRY(zaamo, PRIV_VERSION_1_12_0, ext_zaamo), @@ -2273,6 +2274,7 @@ static Property riscv_cpu_properties[] = { * it with -x and default to 'false'. */ DEFINE_PROP_BOOL("x-misa-w", RISCVCPU, cfg.misa_w, false), + DEFINE_PROP_BOOL("zimops", RISCVCPU, cfg.ext_zimops, true), DEFINE_PROP_END_OF_LIST(), }; diff --git a/target/riscv/cpu_cfg.h b/target/riscv/cpu_cfg.h index cb750154bd..5c42ff8cdf 100644 --- a/target/riscv/cpu_cfg.h +++ b/target/riscv/cpu_cfg.h @@ -124,6 +124,7 @@ struct RISCVCPUConfig { uint32_t mvendorid; uint64_t marchid; uint64_t mimpid; + bool ext_zimops; /* Named features */ bool ext_svade; -- 2.34.1 From 4d15b0e0037f444eb75e60b398e19dcf476f07d4 Mon Sep 17 00:00:00 2001 From: Deepak Gupta <debug@rivosinc.com> Date: Fri, 28 Jun 2024 00:13:58 -0700 Subject: [PATCH 2/3] target/riscv: zimop instruction encoding and its implementation This patch adds assigned codepoints for decoder for 32bit instructions and provide implementation for instruction. If extension is present, then moves 0 to `rd`. Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- target/riscv/insn32.decode | 15 +++++++ target/riscv/insn_trans/trans_zimops.c.inc | 50 ++++++++++++++++++++++ target/riscv/translate.c | 3 ++ 3 files changed, 68 insertions(+) create mode 100644 target/riscv/insn_trans/trans_zimops.c.inc diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode index f22df04cfd..fca3838a9f 100644 --- a/target/riscv/insn32.decode +++ b/target/riscv/insn32.decode @@ -167,6 +167,21 @@ csrrwi ............ ..... 101 ..... 1110011 @csr csrrsi ............ ..... 110 ..... 1110011 @csr csrrci ............ ..... 111 ..... 1110011 @csr +# zimops (unpriv integer may be operations) instructions with system opcode +# zimops_r and zimops_rr are two code points assigned to zimops +# Any new extension that claims zimops encoding should be placed above mop.r +# and mop.rr + +# mop.r +{ + zimops_r 1-00--0 111-- ----- 100 ..... 1110011 %rd +} + +# mop.rr +{ + zimops_rr 1-00--1 ----- ----- 100 ..... 1110011 %rd +} + # *** RV64I Base Instruction Set (in addition to RV32I) *** lwu ............ ..... 110 ..... 0000011 @i ld ............ ..... 011 ..... 0000011 @i diff --git a/target/riscv/insn_trans/trans_zimops.c.inc b/target/riscv/insn_trans/trans_zimops.c.inc new file mode 100644 index 0000000000..b5ad7bded8 --- /dev/null +++ b/target/riscv/insn_trans/trans_zimops.c.inc @@ -0,0 +1,50 @@ +/* + * RISC-V translation routines for the Control-Flow Integrity Extension + * + * Copyright (c) 2024 Rivos Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ +static bool trans_zimops_r(DisasContext *ctx, arg_zimops_r * a) +{ + /* zimops not implemented, raise illegal instruction & return true */ + if (!ctx->cfg_ptr->ext_zimops) { + gen_exception_illegal(ctx); + return true; + } + /* + * zimops implemented, simply grab destination and mov zero. + * return true + */ + TCGv dest = dest_gpr(ctx, a->rd); + dest = tcg_constant_tl(0); + gen_set_gpr(ctx, a->rd, dest); + return true; +} + +static bool trans_zimops_rr(DisasContext *ctx, arg_zimops_r * a) +{ + /* zimops not implemented, raise illegal instruction & return true */ + if (!ctx->cfg_ptr->ext_zimops) { + gen_exception_illegal(ctx); + return true; + } + /* + * zimops implemented, simply grab destination and mov zero. + * return true + */ + TCGv dest = dest_gpr(ctx, a->rd); + dest = tcg_constant_tl(0); + gen_set_gpr(ctx, a->rd, dest); + return true; +} diff --git a/target/riscv/translate.c b/target/riscv/translate.c index 2c27fd4ce1..b7fd3456c8 100644 --- a/target/riscv/translate.c +++ b/target/riscv/translate.c @@ -1115,6 +1115,9 @@ static uint32_t opcode_at(DisasContextBase *dcbase, target_ulong pc) /* Include decoders for factored-out extensions */ #include "decode-XVentanaCondOps.c.inc" +/* Include decoder for zimop */ +#include "insn_trans/trans_zimops.c.inc" + /* The specification allows for longer insns, but not supported by qemu. */ #define MAX_INSN_LEN 4 -- 2.34.1 From dc5d2c62475ac7a9cf42b9ed1398961505b8b91d Mon Sep 17 00:00:00 2001 From: Deepak Gupta <debug@rivosinc.com> Date: Tue, 2 Jan 2024 15:46:13 -0800 Subject: [PATCH 3/3] target/riscv: Introduce `compressed zimop` aka `zcmop` Analogous to zimop, there are 8 encodings carved out of illegal space encodings (c.lui xn, 0) in compressed instructions which are defined to be zcmops short for compressed may be operations. Unlike zimops (which write 0 to rd), zcmops don't actually write anything to any register. Their encodings allow future extensions to define them to read register x[n]. Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- target/riscv/insn16.decode | 6 ++++++ target/riscv/insn_trans/trans_zimops.c.inc | 11 +++++++++++ 2 files changed, 17 insertions(+) diff --git a/target/riscv/insn16.decode b/target/riscv/insn16.decode index b96c534e73..d24b54d319 100644 --- a/target/riscv/insn16.decode +++ b/target/riscv/insn16.decode @@ -32,6 +32,7 @@ %uimm_cl_w 5:1 10:3 6:1 !function=ex_shift_2 %imm_cb 12:s1 5:2 2:1 10:2 3:2 !function=ex_shift_1 %imm_cj 12:s1 8:1 9:2 6:1 7:1 2:1 11:1 3:3 !function=ex_shift_1 +%zcmop_n 8:3 %shlimm_6bit 12:1 2:5 !function=ex_rvc_shiftli %shrimm_6bit 12:1 2:5 !function=ex_rvc_shiftri @@ -66,6 +67,8 @@ &cmpp urlist spimm &cmjt index +&cmop zcmop_n + # Formats 16: @cr .... ..... ..... .. &r rs2=%rs2_5 rs1=%rd %rd @ci ... . ..... ..... .. &i imm=%imm_ci rs1=%rd %rd @@ -109,6 +112,8 @@ @cm_mv ... ... ... .. ... .. &r2_s rs2=%r2s rs1=%r1s @cm_jt ... ... ........ .. &cmjt %index +@c_mop ... . ..... ..... .. &cmop %zcmop_n + # *** RV32/64C Standard Extension (Quadrant 0) *** { # Opcode of all zeros is illegal; rd != 0, nzuimm == 0 is reserved. @@ -140,6 +145,7 @@ sw 110 ... ... .. ... 00 @cs_w addi 000 . ..... ..... 01 @ci addi 010 . ..... ..... 01 @c_li { + zcmops 011 0 0...1 00000 01 @c_mop # zcmop carving out of illegal c.lui xn,0 space illegal 011 0 ----- 00000 01 # c.addi16sp and c.lui, RES nzimm=0 addi 011 . 00010 ..... 01 @c_addi16sp lui 011 . ..... ..... 01 @c_lui diff --git a/target/riscv/insn_trans/trans_zimops.c.inc b/target/riscv/insn_trans/trans_zimops.c.inc index b5ad7bded8..99f25bd9ea 100644 --- a/target/riscv/insn_trans/trans_zimops.c.inc +++ b/target/riscv/insn_trans/trans_zimops.c.inc @@ -48,3 +48,14 @@ static bool trans_zimops_rr(DisasContext *ctx, arg_zimops_r * a) gen_set_gpr(ctx, a->rd, dest); return true; } + +static bool trans_zcmops(DisasContext *ctx, arg_zcmops * a) +{ + /* zimops not implemented, return false */ + if (!ctx->cfg_ptr->ext_zimops) { + gen_exception_illegal(ctx); + return false; + } + + return true; +}
`zimop` stands for `may be operations`. `zcmop` stands for compressed `may be operations`. For some RISC-V CPU extension, once compiled into the binary are part of generated code which can't be gated behind a probe of whether an instruction set is supported or not. One such example is `zicfiss` [1] extension where `shadow stack push` and `shadow stack pop and check` will be part of every function body. Thus binaries compiled with such extensions need to run in following scenarios - On machines where extension is present and enabled - On machines where extension is present and disabled - On machines where extension is not present/implemented. `zimop` (for 32bit instructions) and `zcmop` (for compressed) were devised and defined [2] to support such future (like zicfiss) CPU extensions where zimops and zcmops provide a base non-faulting behavior for codepoints that may claimed by future ISA extensions. Minimally, any CPU implementation wanting to have binary compatibility with such binaries only has to implement `zimop and zcmop`. Furthermore, this allows per-task optin for software where user has the option to enable the feature on per-task basis. `zimop` are defined to write zero to `rd`. `zcmop` are defined to *not* write to any register. [1] - https://github.com/riscv/riscv-cfi/blob/main/src/cfi_backward.adoc [2] - https://github.com/riscv/riscv-isa-manual/blob/main/src/zimop.adoc Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- target/riscv/cpu.c | 2 ++ target/riscv/cpu_cfg.h | 1 + 2 files changed, 3 insertions(+)