[Qemu-devel] Re: [PATCH 1/4] move registering of cpu_reset to inside cpu_init

[Jan Kiszka <jan.kiszka@siemens.com>]

Glauber Costa wrote:
> This is not pc specific by any means. So we can be
> moved to inside cpu_x86_init().
> 
> This is part of an attempt to only initialize kvm state
> after everything is already properly initialized. If we don't
> do that, we can race against, for example, APIC state if kvm vcpus
> are ran in threads (happens in qemu-kvm.git, soon to happen here too)
> 
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  hw/pc.c              |    7 -------
>  target-i386/helper.c |    8 ++++++++
>  2 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/pc.c b/hw/pc.c
> index 61f6e7b..351de83 100644
> --- a/hw/pc.c
> +++ b/hw/pc.c
> @@ -725,12 +725,6 @@ static void load_linux(target_phys_addr_t option_rom,
>      generate_bootsect(option_rom, gpr, seg, 0);
>  }
>  
> -static void main_cpu_reset(void *opaque)
> -{
> -    CPUState *env = opaque;
> -    cpu_reset(env);
> -}
> -
>  static const int ide_iobase[2] = { 0x1f0, 0x170 };
>  static const int ide_iobase2[2] = { 0x3f6, 0x376 };
>  static const int ide_irq[2] = { 14, 15 };
> @@ -861,7 +855,6 @@ static void pc_init1(ram_addr_t ram_size, int vga_ram_size,
>              /* XXX: enable it in all cases */
>              env->cpuid_features |= CPUID_APIC;
>          }
> -        qemu_register_reset(main_cpu_reset, env);
>          if (pci_enabled) {
>              apic_init(env);
>          }
> diff --git a/target-i386/helper.c b/target-i386/helper.c
> index a070e08..2210412 100644
> --- a/target-i386/helper.c
> +++ b/target-i386/helper.c
> @@ -29,6 +29,7 @@
>  #include "exec-all.h"
>  #include "qemu-common.h"
>  #include "kvm.h"
> +#include "hw/hw.h"
>  
>  //#define DEBUG_MMU
>  
> @@ -507,6 +508,11 @@ void cpu_reset(CPUX86State *env)
>      cpu_watchpoint_remove_all(env, BP_CPU);
>  }
>  
> +static void main_cpu_reset(void *_env)
> +{
> +    cpu_reset((CPUState *)_env);
> +}
> +
>  void cpu_x86_close(CPUX86State *env)
>  {
>      qemu_free(env);
> @@ -1689,6 +1695,8 @@ CPUX86State *cpu_x86_init(const char *cpu_model)
>          return NULL;
>      }
>      cpu_reset(env);
> +    qemu_register_reset(main_cpu_reset, env);
> +
>  #ifdef CONFIG_KQEMU
>      kqemu_init(env);
>  #endif

After digging through the dependencies of apic and cpu again, this looks
safe (it reorders reset execution, but that should have no side effect).

Jan

-- 
Siemens AG, Corporate Technology, CT SE 2
Corporate Competence Center Embedded Linux