[12/16] qom/cpu: Add MemoryRegion property

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Add a MemoryRegion property, which if set is used to construct
the CPU's initial (default) AddressSpace.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
[PMM: code is moved from qom/cpu.c to exec.c to avoid having to
 make qom/cpu.o be a non-common object file; code to use the
 MemoryRegion and to default it to system_memory added.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 cpus.c            |  4 +++-
 exec.c            | 13 +++++++++++++
 include/qom/cpu.h |  1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

On Thu, Nov 05, 2015 at 06:15:54PM +0000, Peter Maydell wrote:
> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> 
> Add a MemoryRegion property, which if set is used to construct
> the CPU's initial (default) AddressSpace.
> 
> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> [PMM: code is moved from qom/cpu.c to exec.c to avoid having to
>  make qom/cpu.o be a non-common object file; code to use the
>  MemoryRegion and to default it to system_memory added.]
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>


Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>



> ---
>  cpus.c            |  4 +++-
>  exec.c            | 13 +++++++++++++
>  include/qom/cpu.h |  1 +
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/cpus.c b/cpus.c
> index 764ea75..b7c19e0 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -1356,7 +1356,9 @@ void qemu_init_vcpu(CPUState *cpu)
>          /* If the target cpu hasn't set up any address spaces itself,
>           * give it the default one.
>           */
> -        cpu_address_space_init(cpu, &address_space_memory, 0);
> +        AddressSpace *as = address_space_init_shareable(cpu->memory,
> +                                                        "cpu-memory");
> +        cpu_address_space_init(cpu, as, 0);
>      }
>  
>      if (kvm_enabled()) {
> diff --git a/exec.c b/exec.c
> index 9998fa0..21b1b57 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -637,6 +637,19 @@ void cpu_exec_init(CPUState *cpu, Error **errp)
>  
>  #ifndef CONFIG_USER_ONLY
>      cpu->thread_id = qemu_get_thread_id();
> +
> +    /* This is a softmmu CPU object, so create a property for it
> +     * so users can wire up its memory. (This can't go in qom/cpu.c
> +     * because that file is compiled only once for both user-mode
> +     * and system builds.) The default if no link is set up is to use
> +     * the system address space.
> +     */
> +    object_property_add_link(OBJECT(cpu), "memory", TYPE_MEMORY_REGION,
> +                             (Object **)&cpu->memory,
> +                             qdev_prop_allow_set_link_before_realize,
> +                             OBJ_PROP_LINK_UNREF_ON_RELEASE,
> +                             &error_abort);
> +    cpu->memory = system_memory;
>  #endif
>  
>  #if defined(CONFIG_USER_ONLY)
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index 10ef5cc..39a9a24 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -292,6 +292,7 @@ struct CPUState {
>      CPUAddressSpace *cpu_ases;
>      int num_ases;
>      AddressSpace *as;
> +    MemoryRegion *memory;
>  
>      void *env_ptr; /* CPUArchState */
>      struct TranslationBlock *current_tb;
> -- 
> 1.9.1
>

On 05/11/2015 19:15, Peter Maydell wrote:
> +
> +    /* This is a softmmu CPU object, so create a property for it
> +     * so users can wire up its memory. (This can't go in qom/cpu.c
> +     * because that file is compiled only once for both user-mode
> +     * and system builds.) The default if no link is set up is to use
> +     * the system address space.
> +     */
> +    object_property_add_link(OBJECT(cpu), "memory", TYPE_MEMORY_REGION,
> +                             (Object **)&cpu->memory,
> +                             qdev_prop_allow_set_link_before_realize,
> +                             OBJ_PROP_LINK_UNREF_ON_RELEASE,
> +                             &error_abort);
> +    cpu->memory = system_memory;

You need object_ref(cpu->memory) here, because setting cpu->memory will
drop a reference from the previously-set value.

Paolo

>  #endif