[PATCH v2 1/2] KVM: Add KVM_EXIT_SYSTEM_EVENT to user space API header

[Christoffer Dall]

On Thu, Dec 12, 2013 at 09:42:26PM +0530, Anup Patel wrote:
> Currently, we don't have an exit reason to notify user space about
> a system-level event (for e.g. system reset or shutdown) triggered
> by the VCPU. This patch adds exit reason KVM_EXIT_SYSTEM_EVENT for
> this purpose. We can also inform user space about the 'type' and
> architecture specific 'flags' of a system-level event using the
> kvm_run structure.
> 
> This newly added KVM_EXIT_SYSTEM_EVENT will be used by KVM arm/arm64
> in-kernel PSCI support to reset/shutdown VMs.
> 
> Signed-off-by: Anup Patel <anup.patel at linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
> ---
>  Documentation/virtual/kvm/api.txt |   15 +++++++++++++++
>  include/uapi/linux/kvm.h          |    8 ++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index aad3244..4ef180e 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2699,6 +2699,21 @@ It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an
>  external interrupt has just been delivered into the guest. User space
>  should put the acknowledged interrupt vector into the 'epr' field.
>  
> +		/* KVM_EXIT_SYSTEM_EVENT */
> +		struct {
> +#define KVM_SYSTEM_EVENT_SHUTDOWN       1
> +#define KVM_SYSTEM_EVENT_RESET          2
> +			__u32 type;
> +			__u64 flags;
> +		} system_event;
> +
> +If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered
> +a system-level event using some architecture specific mechanism (hypercall
> +or some special instruction). In case of ARM/ARM64, this is triggered using
> +HVC instruction based PSCI call from the vcpu. The 'type' field describes
> +the system-level event type. The 'flags' field describes architecture
> +specific flags for the system-level event.
> +
>  		/* Fix the size of the union. */
>  		char padding[256];
>  	};
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 902f124..bb13faa 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -171,6 +171,7 @@ struct kvm_pit_config {
>  #define KVM_EXIT_WATCHDOG         21
>  #define KVM_EXIT_S390_TSCH        22
>  #define KVM_EXIT_EPR              23
> +#define KVM_EXIT_SYSTEM_EVENT     24
>  
>  /* For KVM_EXIT_INTERNAL_ERROR */
>  /* Emulate instruction failed. */
> @@ -301,6 +302,13 @@ struct kvm_run {
>  		struct {
>  			__u32 epr;
>  		} epr;
> +		/* KVM_EXIT_SYSTEM_EVENT */
> +		struct {
> +#define KVM_SYSTEM_EVENT_SHUTDOWN       1
> +#define KVM_SYSTEM_EVENT_RESET          2
> +			__u32 type;
> +			__u64 flags;
> +		} system_event;
>  		/* Fix the size of the union. */
>  		char padding[256];
>  	};
> -- 
> 1.7.9.5
> 

Looks good to me:

Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>