Re: [PATCH v2 1/6] target-arm: kvm: save/restore mp state

[Greg Bellows <greg.bellows@linaro.org>]

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On Wed, Mar 4, 2015 at 8:35 AM, Alex Bennée <alex.bennee@linaro.org> wrote:

> This adds the saving and restore of the current Multi-Processing state
> of the machine. While the KVM_GET/SET_MP_STATE API exposes a number of
> potential states for x86 we only use two for ARM. Either the process is
> running or not. We then save this state into the cpu_powered TCG state
> to avoid changing the serialisation format.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> ---
> v2
>   - make mpstate field runtime dependant (kvm_enabled())
>   - drop initial KVM_CAP_MP_STATE requirement
>   - re-use cpu_powered instead of new field
>
> diff --git a/target-arm/machine.c b/target-arm/machine.c
> index 9446e5a..185f9a2 100644
> --- a/target-arm/machine.c
> +++ b/target-arm/machine.c
> @@ -161,6 +161,7 @@ static const VMStateInfo vmstate_cpsr = {
>      .put = put_cpsr,
>  };
>
> +
>

remove ​extraneous space
​


>  static void cpu_pre_save(void *opaque)
>  {
>      ARMCPU *cpu = opaque;
> @@ -170,6 +171,20 @@ static void cpu_pre_save(void *opaque)
>              /* This should never fail */
>              abort();
>          }
> +#if defined CONFIG_KVM
>

​The convention for ifdefing KVMatures appears to be more around the
feature rather than KVM_CONFIG.  For instance ​loo fek at
kvm_check_extension in kvm-all.c.  I may be missing something but if you
follow this convention this should be

    #ifdef KVM_CAP_MP_STATE



> +        if (kvm_check_extension(CPU(cpu)->kvm_state, KVM_CAP_MP_STATE)) {
> +            struct kvm_mp_state mp_state;
> +            int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MP_STATE,
> &mp_state);
> +            if (ret) {
> +                fprintf(stderr, "%s: failed to get MP_STATE %d/%s\n",
> +                        __func__, ret, strerror(ret));
> +                abort();
> +            }
> +            cpu->powered_off =
> +                (mp_state.mp_state == KVM_MP_STATE_RUNNABLE)
> +                ? false : true;
> +        }
> +#endif
>      } else {
>          if (!write_cpustate_to_list(cpu)) {
>              /* This should never fail. */
> @@ -222,6 +237,20 @@ static int cpu_post_load(void *opaque, int version_id)
>           * we're using it.
>           */
>          write_list_to_cpustate(cpu);
> +#if defined CONFIG_KVM
> +        if (kvm_check_extension(CPU(cpu)->kvm_state, KVM_CAP_MP_STATE)) {
> +            struct kvm_mp_state mp_state = {
> +                .mp_state =
> +                cpu->powered_off ? KVM_MP_STATE_HALTED :
> KVM_MP_STATE_RUNNABLE
> +            };
> +            int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MP_STATE,
> &mp_state);
> +            if (ret) {
> +                fprintf(stderr, "%s: failed to set MP_STATE %d/%s\n",
> +                        __func__, ret, strerror(ret));
> +                return -1;
> +            }
> +        }
> +#endif
>      } else {
>          if (!write_list_to_cpustate(cpu)) {
>              return -1;
> --
> 2.3.1
>
>
> ​Besides these the above nits...

Reviewed-by: Greg Bellows <greg.bellows@linaro.org>​

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