Re: [Qemu-devel] [PATCH RFC v5 3/7] qemu_init_vcpu: add a new Error parameter to propagate

[Markus Armbruster]

Fei Li <address@hidden> writes:

> The caller of qemu_init_vcpu() already passed the **errp to handle

Which caller?  There are many.  Or do you mean "The callers"?

> errors. In view of this, add a new Error parameter to the following
> call trace to propagate the error and let the further caller check it.

Which "call trace"?

> Besides, make qemu_init_vcpu() return a Boolean value to let its
> callers know whether it succeeds.
>
> Signed-off-by: Fei Li <address@hidden>
> Reviewed-by: Fam Zheng <address@hidden>
> ---
>  accel/tcg/user-exec-stub.c      |  2 +-
>  cpus.c                          | 34 +++++++++++++++++++++-------------
>  include/qom/cpu.h               |  2 +-
>  target/alpha/cpu.c              |  4 +++-
>  target/arm/cpu.c                |  4 +++-
>  target/cris/cpu.c               |  4 +++-
>  target/hppa/cpu.c               |  4 +++-
>  target/i386/cpu.c               |  4 +++-
>  target/lm32/cpu.c               |  4 +++-
>  target/m68k/cpu.c               |  4 +++-
>  target/microblaze/cpu.c         |  4 +++-
>  target/mips/cpu.c               |  4 +++-
>  target/moxie/cpu.c              |  4 +++-
>  target/nios2/cpu.c              |  4 +++-
>  target/openrisc/cpu.c           |  4 +++-
>  target/ppc/translate_init.inc.c |  4 +++-
>  target/riscv/cpu.c              |  4 +++-
>  target/s390x/cpu.c              |  4 +++-
>  target/sh4/cpu.c                |  4 +++-
>  target/sparc/cpu.c              |  4 +++-
>  target/tilegx/cpu.c             |  4 +++-
>  target/tricore/cpu.c            |  4 +++-
>  target/unicore32/cpu.c          |  4 +++-
>  target/xtensa/cpu.c             |  4 +++-
>  24 files changed, 86 insertions(+), 36 deletions(-)
>
> diff --git a/accel/tcg/user-exec-stub.c b/accel/tcg/user-exec-stub.c
> index a32b4496af..38f6b928d4 100644
> --- a/accel/tcg/user-exec-stub.c
> +++ b/accel/tcg/user-exec-stub.c
> @@ -10,7 +10,7 @@ void cpu_resume(CPUState *cpu)
>  {
>  }
>  
> -void qemu_init_vcpu(CPUState *cpu)
> +bool qemu_init_vcpu(CPUState *cpu, Error **errp)
>  {

You need to return a value here.  Sure you compile-tested this?

>  }
>  
> diff --git a/cpus.c b/cpus.c
> index 361678e459..c4db70607e 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -1918,7 +1918,7 @@ void cpu_remove_sync(CPUState *cpu)
>  /* For temporary buffers for forming a name */
>  #define VCPU_THREAD_NAME_SIZE 16
>  
> -static void qemu_tcg_init_vcpu(CPUState *cpu)
> +static void qemu_tcg_init_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>      static QemuCond *single_tcg_halt_cond;
> @@ -1974,7 +1974,7 @@ static void qemu_tcg_init_vcpu(CPUState *cpu)
>      }
>  }
>  
> -static void qemu_hax_start_vcpu(CPUState *cpu)
> +static void qemu_hax_start_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>  
> @@ -1991,7 +1991,7 @@ static void qemu_hax_start_vcpu(CPUState *cpu)
>  #endif
>  }
>  
> -static void qemu_kvm_start_vcpu(CPUState *cpu)
> +static void qemu_kvm_start_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>  
> @@ -2004,7 +2004,7 @@ static void qemu_kvm_start_vcpu(CPUState *cpu)
>                         cpu, QEMU_THREAD_JOINABLE);
>  }
>  
> -static void qemu_hvf_start_vcpu(CPUState *cpu)
> +static void qemu_hvf_start_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>  
> @@ -2022,7 +2022,7 @@ static void qemu_hvf_start_vcpu(CPUState *cpu)
>                         cpu, QEMU_THREAD_JOINABLE);
>  }
>  
> -static void qemu_whpx_start_vcpu(CPUState *cpu)
> +static void qemu_whpx_start_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>  
> @@ -2038,7 +2038,7 @@ static void qemu_whpx_start_vcpu(CPUState *cpu)
>  #endif
>  }
>  
> -static void qemu_dummy_start_vcpu(CPUState *cpu)
> +static void qemu_dummy_start_vcpu(CPUState *cpu, Error **errp)
>  {
>      char thread_name[VCPU_THREAD_NAME_SIZE];
>  
> @@ -2051,11 +2051,12 @@ static void qemu_dummy_start_vcpu(CPUState *cpu)
>                         QEMU_THREAD_JOINABLE);
>  }
>  
> -void qemu_init_vcpu(CPUState *cpu)
> +bool qemu_init_vcpu(CPUState *cpu, Error **errp)
>  {
>      cpu->nr_cores = smp_cores;
>      cpu->nr_threads = smp_threads;
>      cpu->stopped = true;
> +    Error *local_err = NULL;
>  
>      if (!cpu->as) {
>          /* If the target cpu hasn't set up any address spaces itself,
> @@ -2066,22 +2067,29 @@ void qemu_init_vcpu(CPUState *cpu)
>      }
>  
>      if (kvm_enabled()) {
> -        qemu_kvm_start_vcpu(cpu);
> +        qemu_kvm_start_vcpu(cpu, &local_err);
>      } else if (hax_enabled()) {
> -        qemu_hax_start_vcpu(cpu);
> +        qemu_hax_start_vcpu(cpu, &local_err);
>      } else if (hvf_enabled()) {
> -        qemu_hvf_start_vcpu(cpu);
> +        qemu_hvf_start_vcpu(cpu, &local_err);
>      } else if (tcg_enabled()) {
> -        qemu_tcg_init_vcpu(cpu);
> +        qemu_tcg_init_vcpu(cpu, &local_err);
>      } else if (whpx_enabled()) {
> -        qemu_whpx_start_vcpu(cpu);
> +        qemu_whpx_start_vcpu(cpu, &local_err);
>      } else {
> -        qemu_dummy_start_vcpu(cpu);
> +        qemu_dummy_start_vcpu(cpu, &local_err);
> +    }
> +
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return false;
>      }
>  
>      while (!cpu->created) {
>          qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
>      }
> +
> +    return true;
>  }
>  
>  void cpu_stop_current(void)
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index dc130cd307..4d85dda175 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -1012,7 +1012,7 @@ void end_exclusive(void);
>   *
>   * Initializes a vCPU.
>   */
> -void qemu_init_vcpu(CPUState *cpu);
> +bool qemu_init_vcpu(CPUState *cpu, Error **errp);
>  
>  #define SSTEP_ENABLE  0x1  /* Enable simulated HW single stepping */
>  #define SSTEP_NOIRQ   0x2  /* Do not use IRQ while single stepping */
> diff --git a/target/alpha/cpu.c b/target/alpha/cpu.c
> index b08078e7fc..d531bd4f7e 100644
> --- a/target/alpha/cpu.c
> +++ b/target/alpha/cpu.c
> @@ -66,7 +66,9 @@ static void alpha_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      acc->parent_realize(dev, errp);
>  }
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index b5e61cc177..40f300174d 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1038,7 +1038,9 @@ static void arm_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      }
>  #endif
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      cpu_reset(cs);
>  
>      acc->parent_realize(dev, errp);
> diff --git a/target/cris/cpu.c b/target/cris/cpu.c
> index a23aba2688..ec92d69781 100644
> --- a/target/cris/cpu.c
> +++ b/target/cris/cpu.c
> @@ -140,7 +140,9 @@ static void cris_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      }
>  
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      ccc->parent_realize(dev, errp);
>  }
> diff --git a/target/hppa/cpu.c b/target/hppa/cpu.c
> index 00bf444620..08f600ced9 100644
> --- a/target/hppa/cpu.c
> +++ b/target/hppa/cpu.c
> @@ -98,7 +98,9 @@ static void hppa_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      acc->parent_realize(dev, errp);
>  
>  #ifndef CONFIG_USER_ONLY
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index c88876dfe3..d199f91258 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5112,7 +5112,9 @@ static void x86_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      }
>  #endif
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      /*
>       * Most Intel and certain AMD CPUs support hyperthreading. Even though 
> QEMU
> diff --git a/target/lm32/cpu.c b/target/lm32/cpu.c
> index b7499cb627..d50b1e4a43 100644
> --- a/target/lm32/cpu.c
> +++ b/target/lm32/cpu.c
> @@ -139,7 +139,9 @@ static void lm32_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>  
>      cpu_reset(cs);
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      lcc->parent_realize(dev, errp);
>  }
> diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
> index 582e3a73b3..4ab53f2d58 100644
> --- a/target/m68k/cpu.c
> +++ b/target/m68k/cpu.c
> @@ -231,7 +231,9 @@ static void m68k_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      m68k_cpu_init_gdb(cpu);
>  
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      mcc->parent_realize(dev, errp);
>  }
> diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
> index 9b546a2c18..3906c864a3 100644
> --- a/target/microblaze/cpu.c
> +++ b/target/microblaze/cpu.c
> @@ -161,7 +161,9 @@ static void mb_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      env->pvr.regs[0] = PVR0_USE_EXC_MASK \
>                         | PVR0_USE_ICACHE_MASK \
> diff --git a/target/mips/cpu.c b/target/mips/cpu.c
> index 497706b669..62be84af76 100644
> --- a/target/mips/cpu.c
> +++ b/target/mips/cpu.c
> @@ -136,7 +136,9 @@ static void mips_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      cpu_mips_realize_env(&cpu->env);
>  
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      mcc->parent_realize(dev, errp);
>  }
> diff --git a/target/moxie/cpu.c b/target/moxie/cpu.c
> index 8d67eb6727..8581a6d922 100644
> --- a/target/moxie/cpu.c
> +++ b/target/moxie/cpu.c
> @@ -66,7 +66,9 @@ static void moxie_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      cpu_reset(cs);
>  
>      mcc->parent_realize(dev, errp);
> diff --git a/target/nios2/cpu.c b/target/nios2/cpu.c
> index fbfaa2ce26..5c7b4b486e 100644
> --- a/target/nios2/cpu.c
> +++ b/target/nios2/cpu.c
> @@ -94,7 +94,9 @@ static void nios2_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      cpu_reset(cs);
>  
>      ncc->parent_realize(dev, errp);
> diff --git a/target/openrisc/cpu.c b/target/openrisc/cpu.c
> index fb7cb5c507..a6dcdb9df9 100644
> --- a/target/openrisc/cpu.c
> +++ b/target/openrisc/cpu.c
> @@ -83,7 +83,9 @@ static void openrisc_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      cpu_reset(cs);
>  
>      occ->parent_realize(dev, errp);
> diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
> index 263e63cb03..a6dd2318a6 100644
> --- a/target/ppc/translate_init.inc.c
> +++ b/target/ppc/translate_init.inc.c
> @@ -9694,7 +9694,9 @@ static void ppc_cpu_realize(DeviceState *dev, Error 
> **errp)
>                                   32, "power-vsx.xml", 0);
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        goto unrealize;
> +    }
>  
>      pcc->parent_realize(dev, errp);
>  
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index d630e8fd6c..ef56215e92 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -303,7 +303,9 @@ static void riscv_cpu_realize(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>      cpu_reset(cs);
>  
>      mcc->parent_realize(dev, errp);
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 18ba7f85a5..2a3eac9761 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -222,7 +222,9 @@ static void s390_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      qemu_register_reset(s390_cpu_machine_reset_cb, cpu);
>  #endif
>      s390_cpu_gdb_init(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      /*
>       * KVM requires the initial CPU reset ioctl to be executed on the target
> diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c
> index b9f393b7c7..d32ef2e1cb 100644
> --- a/target/sh4/cpu.c
> +++ b/target/sh4/cpu.c
> @@ -196,7 +196,9 @@ static void superh_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      }
>  
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      scc->parent_realize(dev, errp);
>  }
> diff --git a/target/sparc/cpu.c b/target/sparc/cpu.c
> index 0f090ece54..9c22f6a7df 100644
> --- a/target/sparc/cpu.c
> +++ b/target/sparc/cpu.c
> @@ -773,7 +773,9 @@ static void sparc_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      scc->parent_realize(dev, errp);
>  }
> diff --git a/target/tilegx/cpu.c b/target/tilegx/cpu.c
> index bfe9be59b5..234148fabd 100644
> --- a/target/tilegx/cpu.c
> +++ b/target/tilegx/cpu.c
> @@ -92,7 +92,9 @@ static void tilegx_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>      }
>  
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      tcc->parent_realize(dev, errp);
>  }
> diff --git a/target/tricore/cpu.c b/target/tricore/cpu.c
> index 2edaef1aef..5482d6ea3f 100644
> --- a/target/tricore/cpu.c
> +++ b/target/tricore/cpu.c
> @@ -96,7 +96,9 @@ static void tricore_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          set_feature(env, TRICORE_FEATURE_13);
>      }
>      cpu_reset(cs);
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      tcc->parent_realize(dev, errp);
>  }
> diff --git a/target/unicore32/cpu.c b/target/unicore32/cpu.c
> index 68f978d80b..1f6a33b6f3 100644
> --- a/target/unicore32/cpu.c
> +++ b/target/unicore32/cpu.c
> @@ -96,7 +96,9 @@ static void uc32_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>          return;
>      }
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      ucc->parent_realize(dev, errp);
>  }
> diff --git a/target/xtensa/cpu.c b/target/xtensa/cpu.c
> index a54dbe4260..d2351c9b20 100644
> --- a/target/xtensa/cpu.c
> +++ b/target/xtensa/cpu.c
> @@ -131,7 +131,9 @@ static void xtensa_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>  
>      cs->gdb_num_regs = xcc->config->gdb_regmap.num_regs;
>  
> -    qemu_init_vcpu(cs);
> +    if (!qemu_init_vcpu(cs, errp)) {
> +        return;
> +    }
>  
>      xcc->parent_realize(dev, errp);
>  }

I see how you changed the code to pass an Error from the
qemu_FOO_start_vcpu() through qemu_init_vcpu() to its callers.  I can't
see how such errors can be created.  Without a way to create any, the
patch is pointless.  What am I missing?