Re: [PATCH v7 2/5] arm64: KVM: encapsulate kvm_cpu_context in kvm_host_data

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 11/12/2018 12:13, Andrew Murray wrote:
> The virt/arm core allocates a percpu structure as per the kvm_cpu_context_t
> type, at present this is typedef'd to kvm_cpu_context and used to store
> host cpu context. The kvm_cpu_context structure is also used elsewhere to
> hold vcpu context. In order to use the percpu to hold additional future
> host information we encapsulate kvm_cpu_context in a new structure.
> 
> Signed-off-by: Andrew Murray <andrew.murray@arm.com>
> ---
>   arch/arm64/include/asm/kvm_host.h | 8 ++++++--
>   arch/arm64/kernel/asm-offsets.c   | 3 ++-
>   virt/kvm/arm/arm.c                | 4 +++-
>   3 files changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 1550192..bcf9d60 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -205,7 +205,11 @@ struct kvm_cpu_context {
>   	struct kvm_vcpu *__hyp_running_vcpu;
>   };
>   
> -typedef struct kvm_cpu_context kvm_cpu_context_t;
> +struct kvm_host_data {
> +	struct kvm_cpu_context __kvm_cpu_state;
> +};
> +
> +typedef struct kvm_host_data kvm_cpu_context_t;
>   
>   struct kvm_vcpu_arch {
>   	struct kvm_cpu_context ctxt;
> @@ -241,7 +245,7 @@ struct kvm_vcpu_arch {
>   	struct kvm_guest_debug_arch external_debug_state;
>   
>   	/* Pointer to host CPU context */
> -	kvm_cpu_context_t *host_cpu_context;
> +	struct kvm_cpu_context *host_cpu_context;
>   
>   	struct thread_info *host_thread_info;	/* hyp VA */
>   	struct user_fpsimd_state *host_fpsimd_state;	/* hyp VA */
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index 323aeb5..da34022 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -142,7 +142,8 @@ int main(void)
>     DEFINE(CPU_FP_REGS,		offsetof(struct kvm_regs, fp_regs));
>     DEFINE(VCPU_FPEXC32_EL2,	offsetof(struct kvm_vcpu, arch.ctxt.sys_regs[FPEXC32_EL2]));
>     DEFINE(VCPU_HOST_CONTEXT,	offsetof(struct kvm_vcpu, arch.host_cpu_context));
> -  DEFINE(HOST_CONTEXT_VCPU,	offsetof(struct kvm_cpu_context, __hyp_running_vcpu));
> +  DEFINE(HOST_CONTEXT_VCPU,	offsetof(struct kvm_cpu_context, __hyp_running_vcpu)
> +				+ offsetof(struct kvm_host_data, __kvm_cpu_state));

nit: You could fold the member field in the offsetof(). i.e,
      DEFINE(HOST_CONTEXT_VCPU, offsetof(struct kvm_host_data, 
__kvm_cpu_state.__hyp_running_vcpu)

like the VCPU_HOST_CONTEXT above ?

Cheers
Suzuki