Re: [PATCH v4 09/15] KVM: arm: redefine kvm_cpu_context_t to save the host cp14 states

[Christoffer Dall <christoffer.dall@linaro.org>]

On Mon, Aug 10, 2015 at 09:26:01PM +0800, Zhichao Huang wrote:
> Redefine kvm_cpu_context_t as a new struct that include the cp14 states,
> which we used to save the host cp14 states.
> 
> Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
> ---
>  arch/arm/include/asm/kvm_host.h | 6 +++++-
>  arch/arm/kernel/asm-offsets.c   | 4 +++-
>  arch/arm/kvm/interrupts.S       | 6 ++++--
>  3 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 63ac005..fc461ac 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -91,7 +91,11 @@ struct kvm_vcpu_fault_info {
>  	u32 hyp_pc;		/* PC when exception was taken from Hyp mode */
>  };
>  
> -typedef struct vfp_hard_struct kvm_cpu_context_t;
> +struct kvm_cpu_context {
> +	struct vfp_hard_struct vfp;
> +	u32 cp14[NR_CP14_REGS];
> +};
> +typedef struct kvm_cpu_context kvm_cpu_context_t;
>  
>  struct kvm_vcpu_arch {
>  	struct kvm_regs regs;
> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
> index 9158de0..cee4254 100644
> --- a/arch/arm/kernel/asm-offsets.c
> +++ b/arch/arm/kernel/asm-offsets.c
> @@ -175,7 +175,9 @@ int main(void)
>    DEFINE(VCPU_CP14,		offsetof(struct kvm_vcpu, arch.cp14));
>    DEFINE(VCPU_CP15,		offsetof(struct kvm_vcpu, arch.cp15));
>    DEFINE(VCPU_VFP_GUEST,	offsetof(struct kvm_vcpu, arch.vfp_guest));
> -  DEFINE(VCPU_VFP_HOST,		offsetof(struct kvm_vcpu, arch.host_cpu_context));
> +  DEFINE(VCPU_HOST_CONTEXT,	offsetof(struct kvm_vcpu, arch.host_cpu_context));
> +  DEFINE(VCPU_VFP_HOST,		offsetof(struct kvm_cpu_context, vfp));
> +  DEFINE(VCPU_CP14_HOST,	offsetof(struct kvm_cpu_context, cp14));

it's a bit weird to call these last two VCPU_ something when they're not
offsets of the vcpu struct...

>    DEFINE(VCPU_REGS,		offsetof(struct kvm_vcpu, arch.regs));
>    DEFINE(VCPU_USR_REGS,		offsetof(struct kvm_vcpu, arch.regs.usr_regs));
>    DEFINE(VCPU_SVC_REGS,		offsetof(struct kvm_vcpu, arch.regs.svc_regs));
> diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
> index 48333ff..d4ff22e 100644
> --- a/arch/arm/kvm/interrupts.S
> +++ b/arch/arm/kvm/interrupts.S
> @@ -176,8 +176,9 @@ __kvm_vcpu_return:
>  	@ Switch VFP/NEON hardware state to the host's
>  	add	r7, vcpu, #VCPU_VFP_GUEST
>  	store_vfp_state r7
> -	add	r7, vcpu, #VCPU_VFP_HOST
> +	add	r7, vcpu, #VCPU_HOST_CONTEXT
>  	ldr	r7, [r7]
> +	add	r7, r7, #VCPU_VFP_HOST
>  	restore_vfp_state r7
>  
>  after_vfp_restore:
> @@ -484,8 +485,9 @@ switch_to_guest_vfp:
>  	set_hcptr vmtrap, (HCPTR_TCP(10) | HCPTR_TCP(11))
>  
>  	@ Switch VFP/NEON hardware state to the guest's
> -	add	r7, r0, #VCPU_VFP_HOST
> +	add	r7, r0, #VCPU_HOST_CONTEXT
>  	ldr	r7, [r7]
> +	add	r7, r7, #VCPU_VFP_HOST
>  	store_vfp_state r7
>  	add	r7, r0, #VCPU_VFP_GUEST
>  	restore_vfp_state r7
> -- 
> 1.7.12.4
> 

Otherwise this look ok.

-Christoffer