| Message ID | 20200811153235.4527-1-gromero@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] target/ppc: Integrate icount to purr, vtb, and tbu40 | expand |
On 8/11/20 8:32 AM, Gustavo Romero wrote: > Currently if option '-icount auto' is passed to the QEMU TCG to enable > counting instructions the VM crashes with the following error report when > Linux runs on it: > > qemu-system-ppc64: Bad icount read > > This happens because read/write access to the SPRs PURR, VTB, and TBU40 > is not integrated to the icount framework. > > This commit fixes that issue by making the read/write access of these > SPRs aware of icount framework, adding the proper gen_io_start() calls > before calling the helpers to load/store these SPRs in TCG and ensuring > that the associated TBs end immediately after, accordingly to what's in > docs/devel/tcg-icount.rst. > > Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> > --- > target/ppc/translate_init.inc.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
On Wed, Aug 12, 2020 at 02:33:33PM -0700, Richard Henderson wrote: > On 8/11/20 8:32 AM, Gustavo Romero wrote: > > Currently if option '-icount auto' is passed to the QEMU TCG to enable > > counting instructions the VM crashes with the following error report when > > Linux runs on it: > > > > qemu-system-ppc64: Bad icount read > > > > This happens because read/write access to the SPRs PURR, VTB, and TBU40 > > is not integrated to the icount framework. > > > > This commit fixes that issue by making the read/write access of these > > SPRs aware of icount framework, adding the proper gen_io_start() calls > > before calling the helpers to load/store these SPRs in TCG and ensuring > > that the associated TBs end immediately after, accordingly to what's in > > docs/devel/tcg-icount.rst. > > > > Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> > > --- > > target/ppc/translate_init.inc.c | 30 ++++++++++++++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Applied to ppc-for-5.2, thanks.
On 8/12/20 9:03 PM, David Gibson wrote: > On Wed, Aug 12, 2020 at 02:33:33PM -0700, Richard Henderson wrote: >> On 8/11/20 8:32 AM, Gustavo Romero wrote: >>> Currently if option '-icount auto' is passed to the QEMU TCG to enable >>> counting instructions the VM crashes with the following error report when >>> Linux runs on it: >>> >>> qemu-system-ppc64: Bad icount read >>> >>> This happens because read/write access to the SPRs PURR, VTB, and TBU40 >>> is not integrated to the icount framework. >>> >>> This commit fixes that issue by making the read/write access of these >>> SPRs aware of icount framework, adding the proper gen_io_start() calls >>> before calling the helpers to load/store these SPRs in TCG and ensuring >>> that the associated TBs end immediately after, accordingly to what's in >>> docs/devel/tcg-icount.rst. >>> >>> Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> >>> --- >>> target/ppc/translate_init.inc.c | 30 ++++++++++++++++++++++++++++++ >>> 1 file changed, 30 insertions(+) >> >> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> > > Applied to ppc-for-5.2, thanks. Thanks Peter, Richard and David. Best regards, Gustavo
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c index 7e66822b5d..ccf9ce3441 100644 --- a/target/ppc/translate_init.inc.c +++ b/target/ppc/translate_init.inc.c @@ -284,12 +284,24 @@ static void spr_write_atbu(DisasContext *ctx, int sprn, int gprn) ATTRIBUTE_UNUSED static void spr_read_purr(DisasContext *ctx, int gprn, int sprn) { + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_load_purr(cpu_gpr[gprn], cpu_env); + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_stop_exception(ctx); + } } static void spr_write_purr(DisasContext *ctx, int sprn, int gprn) { + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_store_purr(cpu_env, cpu_gpr[gprn]); + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_stop_exception(ctx); + } } /* HDECR */ @@ -319,17 +331,35 @@ static void spr_write_hdecr(DisasContext *ctx, int sprn, int gprn) static void spr_read_vtb(DisasContext *ctx, int gprn, int sprn) { + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_load_vtb(cpu_gpr[gprn], cpu_env); + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_stop_exception(ctx); + } } static void spr_write_vtb(DisasContext *ctx, int sprn, int gprn) { + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_store_vtb(cpu_env, cpu_gpr[gprn]); + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_stop_exception(ctx); + } } static void spr_write_tbu40(DisasContext *ctx, int sprn, int gprn) { + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_store_tbu40(cpu_env, cpu_gpr[gprn]); + if (tb_cflags(ctx->base.tb) & CF_USE_ICOUNT) { + gen_stop_exception(ctx); + } } #endif
Currently if option '-icount auto' is passed to the QEMU TCG to enable counting instructions the VM crashes with the following error report when Linux runs on it: qemu-system-ppc64: Bad icount read This happens because read/write access to the SPRs PURR, VTB, and TBU40 is not integrated to the icount framework. This commit fixes that issue by making the read/write access of these SPRs aware of icount framework, adding the proper gen_io_start() calls before calling the helpers to load/store these SPRs in TCG and ensuring that the associated TBs end immediately after, accordingly to what's in docs/devel/tcg-icount.rst. Signed-off-by: Gustavo Romero <gromero@linux.ibm.com> --- target/ppc/translate_init.inc.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)