Re: [PATCH] target/nios2: Use gen_io_start/end around wrctl instruction.

2020-06-19 Thread Peter Maydell 
On Thu, 18 Jun 2020 at 18:31, Peter Maydell  wrote:
>
> On Thu, 18 Jun 2020 at 04:50, wentongw  wrote:
> >
> > From: Wentong Wu 
> >
> > wrctl instruction on nios2 target will cause checking cpu interrupt,
> > but tcg_handle_interrupt() will call cpu_abort() if the CPU gets an
> > interrupt while it's not in a 'can do IO' state, so around wrctl
> > instruction add gen_io_start/end.
> >
> > Signed-off-by: Wentong Wu 
> > ---
> >  target/nios2/translate.c | 7 +++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/target/nios2/translate.c b/target/nios2/translate.c
> > index e17656e6..deaefcaf 100644
> > --- a/target/nios2/translate.c
> > +++ b/target/nios2/translate.c
> > @@ -32,6 +32,7 @@
> >  #include "exec/cpu_ldst.h"
> >  #include "exec/translator.h"
> >  #include "qemu/qemu-print.h"
> > +#include "exec/gen-icount.h"
> >
> >  /* is_jmp field values */
> >  #define DISAS_JUMPDISAS_TARGET_0 /* only pc was modified dynamically */
> > @@ -518,7 +519,13 @@ static void wrctl(DisasContext *dc, uint32_t code, 
> > uint32_t flags)
> >  /* If interrupts were enabled using WRCTL, trigger them. */
> >  #if !defined(CONFIG_USER_ONLY)
> >  if ((instr.imm5 + CR_BASE) == CR_STATUS) {
> > +if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
> > +gen_io_start();
> > +}
> >  gen_helper_check_interrupts(dc->cpu_env);
> > +if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
> > +gen_io_end();
> > +}
>
> You also need to end the TB, which we should do whether
> we're using icount or not. This is awkward because nios2 has
> not correctly implemented the DISAS_UPDATE that is the right
> way to do that.

After some further discussion with other maintainers abotu
the gen_io_start/gen_io_end semantics, it turns out that
I was wrong about the need for gen_io_end -- if you are
going to end the TB after the I/O instruction (which you are
in this case) then you do not need the gen_io_end() call,
it is handled automatically for you by common code. So
you can drop that bit from the next version of this patch.

Sorry for the confusion.

thanks
-- PMM

Re: [PATCH] target/nios2: Use gen_io_start/end around wrctl instruction.

2020-06-18 Thread Peter Maydell 
On Thu, 18 Jun 2020 at 04:50, wentongw  wrote:
>
> From: Wentong Wu 
>
> wrctl instruction on nios2 target will cause checking cpu interrupt,
> but tcg_handle_interrupt() will call cpu_abort() if the CPU gets an
> interrupt while it's not in a 'can do IO' state, so around wrctl
> instruction add gen_io_start/end.
>
> Signed-off-by: Wentong Wu 
> ---
>  target/nios2/translate.c | 7 +++
>  1 file changed, 7 insertions(+)
>
> diff --git a/target/nios2/translate.c b/target/nios2/translate.c
> index e17656e6..deaefcaf 100644
> --- a/target/nios2/translate.c
> +++ b/target/nios2/translate.c
> @@ -32,6 +32,7 @@
>  #include "exec/cpu_ldst.h"
>  #include "exec/translator.h"
>  #include "qemu/qemu-print.h"
> +#include "exec/gen-icount.h"
>
>  /* is_jmp field values */
>  #define DISAS_JUMPDISAS_TARGET_0 /* only pc was modified dynamically */
> @@ -518,7 +519,13 @@ static void wrctl(DisasContext *dc, uint32_t code, 
> uint32_t flags)
>  /* If interrupts were enabled using WRCTL, trigger them. */
>  #if !defined(CONFIG_USER_ONLY)
>  if ((instr.imm5 + CR_BASE) == CR_STATUS) {
> +if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
> +gen_io_start();
> +}
>  gen_helper_check_interrupts(dc->cpu_env);
> +if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
> +gen_io_end();
> +}

You also need to end the TB, which we should do whether
we're using icount or not. This is awkward because nios2 has
not correctly implemented the DISAS_UPDATE that is the right
way to do that. So you'll need some preliminary patches:

Patch 1: Implement and use DISAS_NORETURN
 + the current places in t_gen_helper_raise_exception() and
   gen_exception() that set dc->is_jmp = DISAS_UPDATE
   should instead set it to DISAS_NORETURN. (This is because
   they both call gen_helper_raise_exception() and at runtime
   execution will never return from that helper call.)
 + In gen_intermediate_code(), in the "switch (dc->is_jmp)"
   you need a new "case DISAS_NORETURN:" which goes with
   DISAS_TB_JUMP as another kind of "nothing more to generate".

Patch 2: Make DISAS_UPDATE write PC back to CPU state
 + Move the "case DISAS_UPDATE:" from being like DISAS_JUMP
   up so it does the same thing as DISAS_NEXT (ie explicitly
   writes the PC back into the cpu state before doing a
   tcg_gen_exit_tb()). This is OK because patch 1 removed
   the only two previous users of it, so we don't break
   anything by bringing its semantics into line with how
   most targets use it.

Patch 3: this patch to use gen_io_start/end
 + You can now put "dc->is_jmp = DISAS_UPDATE;" inside the
   "is this a CR_STATUS write" if() block, which should
   cause the wrctl to always end the TB.

thanks
-- PMM

Re: [PATCH] target/nios2: Use gen_io_start/end around wrctl instruction.

2020-06-17 Thread no-reply 
Patchew URL: 
https://patchew.org/QEMU/20200618114129.5636-1-wentong...@intel.com/



Hi,

This series failed the asan build test. Please find the testing commands and
their output below. If you have Docker installed, you can probably reproduce it
locally.

=== TEST SCRIPT BEGIN ===
#!/bin/bash
export ARCH=x86_64
make docker-image-fedora V=1 NETWORK=1
time make docker-test-debug@fedora TARGET_LIST=x86_64-softmmu J=14 NETWORK=1
=== TEST SCRIPT END ===

  CC  qga/qapi-generated/qga-qapi-visit.o
  CC  qga/qapi-generated/qga-qapi-commands.o
  CC  qga/qapi-generated/qga-qapi-init-commands.o
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  AR  libqemuutil.a
  LINKelf2dmp
  CC  qemu-img.o
---
  GEN docs/interop/qemu-ga-ref.html
  GEN docs/interop/qemu-ga-ref.txt
  GEN docs/interop/qemu-ga-ref.7
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKqemu-keymap
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKivshmem-client
  LINKivshmem-server
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKqemu-nbd
  AS  pc-bios/optionrom/multiboot.o
  AS  pc-bios/optionrom/linuxboot.o
  CC  pc-bios/optionrom/linuxboot_dma.o
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKqemu-storage-daemon
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  AS  pc-bios/optionrom/kvmvapic.o
  AS  pc-bios/optionrom/pvh.o
  CC  pc-bios/optionrom/pvh_main.o
---
  BUILD   pc-bios/optionrom/multiboot.raw
  BUILD   pc-bios/optionrom/linuxboot.raw
  SIGNpc-bios/optionrom/linuxboot_dma.bin
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKqemu-edid
  SIGNpc-bios/optionrom/multiboot.bin
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKfsdev/virtfs-proxy-helper
  SIGNpc-bios/optionrom/linuxboot.bin
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  BUILD   pc-bios/optionrom/kvmvapic.img
  BUILD   pc-bios/optionrom/pvh.img
  LINKscsi/qemu-pr-helper
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  BUILD   pc-bios/optionrom/kvmvapic.raw
  BUILD   pc-bios/optionrom/pvh.raw
  SIGNpc-bios/optionrom/kvmvapic.bin
  SIGNpc-bios/optionrom/pvh.bin
  LINKqemu-bridge-helper
/usr/bin/ld: 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors_vfork.S.o):
 warning: common of `__interception::real_vfork' overridden by definition from 
/usr/lib64/clang/10.0.0/lib/linux/libclang_rt.asan-x86_64.a(asan_interceptors.cpp.o)
  LINKvirtiofsd
/usr/bin/ld:

[PATCH] target/nios2: Use gen_io_start/end around wrctl instruction.

2020-06-17 Thread wentongw 
From: Wentong Wu 

wrctl instruction on nios2 target will cause checking cpu interrupt,
but tcg_handle_interrupt() will call cpu_abort() if the CPU gets an
interrupt while it's not in a 'can do IO' state, so around wrctl
instruction add gen_io_start/end.

Signed-off-by: Wentong Wu 
---
 target/nios2/translate.c | 7 +++
 1 file changed, 7 insertions(+)

diff --git a/target/nios2/translate.c b/target/nios2/translate.c
index e17656e6..deaefcaf 100644
--- a/target/nios2/translate.c
+++ b/target/nios2/translate.c
@@ -32,6 +32,7 @@
 #include "exec/cpu_ldst.h"
 #include "exec/translator.h"
 #include "qemu/qemu-print.h"
+#include "exec/gen-icount.h"
 
 /* is_jmp field values */
 #define DISAS_JUMPDISAS_TARGET_0 /* only pc was modified dynamically */
@@ -518,7 +519,13 @@ static void wrctl(DisasContext *dc, uint32_t code, 
uint32_t flags)
 /* If interrupts were enabled using WRCTL, trigger them. */
 #if !defined(CONFIG_USER_ONLY)
 if ((instr.imm5 + CR_BASE) == CR_STATUS) {
+if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
+gen_io_start();
+}
 gen_helper_check_interrupts(dc->cpu_env);
+if (tb_cflags(dc->tb) & CF_USE_ICOUNT) {
+gen_io_end();
+}
 }
 #endif
 }
-- 
2.21.3