| Message ID | 20240514023910.301766-1-alistair.francis@wdc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | target/riscv: rvzicbo: Fixup CBO extension register calculation | expand |
On 5/14/24 04:39, Alistair Francis wrote: > When running the instruction > > ``` > cbo.flush 0(x0) > ``` > > QEMU would segfault. > > The issue was in cpu_gpr[a->rs1] as QEMU does not have cpu_gpr[0] > allocated. > > In order to fix this let's use the existing get_address() > helper. This also has the benefit of performing pointer mask > calculations on the address specified in rs1. > > The pointer masking specificiation specifically states: > > """ > Cache Management Operations: All instructions in Zicbom, Zicbop and Zicboz > """ > > So this is the correct behaviour and we previously have been incorrectly > not masking the address. > > Signed-off-by: Alistair Francis<alistair.francis@wdc.com> > Reported-by: Fabian Thomas<fabian.thomas@cispa.de> > Fixes: e05da09b7cfd ("target/riscv: implement Zicbom extension") > --- > target/riscv/insn_trans/trans_rvzicbo.c.inc | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
On 5/13/24 23:39, Alistair Francis wrote: > When running the instruction > > ``` > cbo.flush 0(x0) > ``` > > QEMU would segfault. > > The issue was in cpu_gpr[a->rs1] as QEMU does not have cpu_gpr[0] > allocated. > > In order to fix this let's use the existing get_address() > helper. This also has the benefit of performing pointer mask > calculations on the address specified in rs1. > > The pointer masking specificiation specifically states: > > """ > Cache Management Operations: All instructions in Zicbom, Zicbop and Zicboz > """ > > So this is the correct behaviour and we previously have been incorrectly > not masking the address. > > Signed-off-by: Alistair Francis <alistair.francis@wdc.com> > Reported-by: Fabian Thomas <fabian.thomas@cispa.de> > Fixes: e05da09b7cfd ("target/riscv: implement Zicbom extension") > --- LGTM but I wonder if this is the same fix as this one sent by Phil a month ago or so: https://lore.kernel.org/qemu-riscv/20240419110514.69697-1-philmd@linaro.org/ ("[PATCH] target/riscv: Use get_address() to get address with Zicbom extensions") Thanks, Daniel > target/riscv/insn_trans/trans_rvzicbo.c.inc | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/target/riscv/insn_trans/trans_rvzicbo.c.inc b/target/riscv/insn_trans/trans_rvzicbo.c.inc > index d5d7095903..15711c3140 100644 > --- a/target/riscv/insn_trans/trans_rvzicbo.c.inc > +++ b/target/riscv/insn_trans/trans_rvzicbo.c.inc > @@ -31,27 +31,35 @@ > static bool trans_cbo_clean(DisasContext *ctx, arg_cbo_clean *a) > { > REQUIRE_ZICBOM(ctx); > - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); > + TCGv src = get_address(ctx, a->rs1, 0); > + > + gen_helper_cbo_clean_flush(tcg_env, src); > return true; > } > > static bool trans_cbo_flush(DisasContext *ctx, arg_cbo_flush *a) > { > REQUIRE_ZICBOM(ctx); > - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); > + TCGv src = get_address(ctx, a->rs1, 0); > + > + gen_helper_cbo_clean_flush(tcg_env, src); > return true; > } > > static bool trans_cbo_inval(DisasContext *ctx, arg_cbo_inval *a) > { > REQUIRE_ZICBOM(ctx); > - gen_helper_cbo_inval(tcg_env, cpu_gpr[a->rs1]); > + TCGv src = get_address(ctx, a->rs1, 0); > + > + gen_helper_cbo_inval(tcg_env, src); > return true; > } > > static bool trans_cbo_zero(DisasContext *ctx, arg_cbo_zero *a) > { > REQUIRE_ZICBOZ(ctx); > - gen_helper_cbo_zero(tcg_env, cpu_gpr[a->rs1]); > + TCGv src = get_address(ctx, a->rs1, 0); > + > + gen_helper_cbo_zero(tcg_env, src); > return true; > }
On Tue, May 14, 2024 at 7:11 PM Daniel Henrique Barboza <dbarboza@ventanamicro.com> wrote: > > > > On 5/13/24 23:39, Alistair Francis wrote: > > When running the instruction > > > > ``` > > cbo.flush 0(x0) > > ``` > > > > QEMU would segfault. > > > > The issue was in cpu_gpr[a->rs1] as QEMU does not have cpu_gpr[0] > > allocated. > > > > In order to fix this let's use the existing get_address() > > helper. This also has the benefit of performing pointer mask > > calculations on the address specified in rs1. > > > > The pointer masking specificiation specifically states: > > > > """ > > Cache Management Operations: All instructions in Zicbom, Zicbop and Zicboz > > """ > > > > So this is the correct behaviour and we previously have been incorrectly > > not masking the address. > > > > Signed-off-by: Alistair Francis <alistair.francis@wdc.com> > > Reported-by: Fabian Thomas <fabian.thomas@cispa.de> > > Fixes: e05da09b7cfd ("target/riscv: implement Zicbom extension") > > --- > > LGTM but I wonder if this is the same fix as this one sent by Phil a month > ago or so: > > https://lore.kernel.org/qemu-riscv/20240419110514.69697-1-philmd@linaro.org/ > ("[PATCH] target/riscv: Use get_address() to get address with Zicbom extensions") It is the same fix! I somehow missed that patch at the time. Sorry Philippe! I'm going to merge this one as it includes the details about pointer masking, which I think is useful as that's why we are using get_address() instead of get_gpr() Alistair > > > Thanks, > > Daniel > > > target/riscv/insn_trans/trans_rvzicbo.c.inc | 16 ++++++++++++---- > > 1 file changed, 12 insertions(+), 4 deletions(-) > > > > diff --git a/target/riscv/insn_trans/trans_rvzicbo.c.inc b/target/riscv/insn_trans/trans_rvzicbo.c.inc > > index d5d7095903..15711c3140 100644 > > --- a/target/riscv/insn_trans/trans_rvzicbo.c.inc > > +++ b/target/riscv/insn_trans/trans_rvzicbo.c.inc > > @@ -31,27 +31,35 @@ > > static bool trans_cbo_clean(DisasContext *ctx, arg_cbo_clean *a) > > { > > REQUIRE_ZICBOM(ctx); > > - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); > > + TCGv src = get_address(ctx, a->rs1, 0); > > + > > + gen_helper_cbo_clean_flush(tcg_env, src); > > return true; > > } > > > > static bool trans_cbo_flush(DisasContext *ctx, arg_cbo_flush *a) > > { > > REQUIRE_ZICBOM(ctx); > > - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); > > + TCGv src = get_address(ctx, a->rs1, 0); > > + > > + gen_helper_cbo_clean_flush(tcg_env, src); > > return true; > > } > > > > static bool trans_cbo_inval(DisasContext *ctx, arg_cbo_inval *a) > > { > > REQUIRE_ZICBOM(ctx); > > - gen_helper_cbo_inval(tcg_env, cpu_gpr[a->rs1]); > > + TCGv src = get_address(ctx, a->rs1, 0); > > + > > + gen_helper_cbo_inval(tcg_env, src); > > return true; > > } > > > > static bool trans_cbo_zero(DisasContext *ctx, arg_cbo_zero *a) > > { > > REQUIRE_ZICBOZ(ctx); > > - gen_helper_cbo_zero(tcg_env, cpu_gpr[a->rs1]); > > + TCGv src = get_address(ctx, a->rs1, 0); > > + > > + gen_helper_cbo_zero(tcg_env, src); > > return true; > > }
diff --git a/target/riscv/insn_trans/trans_rvzicbo.c.inc b/target/riscv/insn_trans/trans_rvzicbo.c.inc index d5d7095903..15711c3140 100644 --- a/target/riscv/insn_trans/trans_rvzicbo.c.inc +++ b/target/riscv/insn_trans/trans_rvzicbo.c.inc @@ -31,27 +31,35 @@ static bool trans_cbo_clean(DisasContext *ctx, arg_cbo_clean *a) { REQUIRE_ZICBOM(ctx); - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); + TCGv src = get_address(ctx, a->rs1, 0); + + gen_helper_cbo_clean_flush(tcg_env, src); return true; } static bool trans_cbo_flush(DisasContext *ctx, arg_cbo_flush *a) { REQUIRE_ZICBOM(ctx); - gen_helper_cbo_clean_flush(tcg_env, cpu_gpr[a->rs1]); + TCGv src = get_address(ctx, a->rs1, 0); + + gen_helper_cbo_clean_flush(tcg_env, src); return true; } static bool trans_cbo_inval(DisasContext *ctx, arg_cbo_inval *a) { REQUIRE_ZICBOM(ctx); - gen_helper_cbo_inval(tcg_env, cpu_gpr[a->rs1]); + TCGv src = get_address(ctx, a->rs1, 0); + + gen_helper_cbo_inval(tcg_env, src); return true; } static bool trans_cbo_zero(DisasContext *ctx, arg_cbo_zero *a) { REQUIRE_ZICBOZ(ctx); - gen_helper_cbo_zero(tcg_env, cpu_gpr[a->rs1]); + TCGv src = get_address(ctx, a->rs1, 0); + + gen_helper_cbo_zero(tcg_env, src); return true; }
When running the instruction ``` cbo.flush 0(x0) ``` QEMU would segfault. The issue was in cpu_gpr[a->rs1] as QEMU does not have cpu_gpr[0] allocated. In order to fix this let's use the existing get_address() helper. This also has the benefit of performing pointer mask calculations on the address specified in rs1. The pointer masking specificiation specifically states: """ Cache Management Operations: All instructions in Zicbom, Zicbop and Zicboz """ So this is the correct behaviour and we previously have been incorrectly not masking the address. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reported-by: Fabian Thomas <fabian.thomas@cispa.de> Fixes: e05da09b7cfd ("target/riscv: implement Zicbom extension") --- target/riscv/insn_trans/trans_rvzicbo.c.inc | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)