Re: [PATCH 19/37] KVM: arm64: Introduce separate VHE/non-VHE sysreg save/restore functions

[Andrew Jones]

On Thu, Oct 12, 2017 at 12:41:23PM +0200, Christoffer Dall wrote:
> As we are about to handle system registers quite differently between VHE
> and non-VHE systems.  In preparation for that, we need to split some of
> the handling functions between VHE and non-VHE functionality.
> 
> For now, we simply copy the non-VHE functions, but we do change the use
> of static keys for VHE and non-VHE functionality now that we have
> separate functions.
> 
> Signed-off-by: Christoffer Dall 
> ---
>  arch/arm64/include/asm/kvm_hyp.h | 12 
>  arch/arm64/kvm/hyp/switch.c  | 20 ++--
>  arch/arm64/kvm/hyp/sysreg-sr.c   | 40 
> 
>  3 files changed, 50 insertions(+), 22 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_hyp.h 
> b/arch/arm64/include/asm/kvm_hyp.h
> index a0e5a70..998152d 100644
> --- a/arch/arm64/include/asm/kvm_hyp.h
> +++ b/arch/arm64/include/asm/kvm_hyp.h
> @@ -132,10 +132,14 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu 
> *vcpu);
>  void __timer_enable_traps(struct kvm_vcpu *vcpu);
>  void __timer_disable_traps(struct kvm_vcpu *vcpu);
>  
> -void __sysreg_save_host_state(struct kvm_cpu_context *ctxt);
> -void __sysreg_restore_host_state(struct kvm_cpu_context *ctxt);
> -void __sysreg_save_guest_state(struct kvm_cpu_context *ctxt);
> -void __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt);
> +void __sysreg_save_host_state_nvhe(struct kvm_cpu_context *ctxt);
> +void __sysreg_restore_host_state_nvhe(struct kvm_cpu_context *ctxt);
> +void __sysreg_save_guest_state_nvhe(struct kvm_cpu_context *ctxt);
> +void __sysreg_restore_guest_state_nvhe(struct kvm_cpu_context *ctxt);
> +void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt);
> +void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt);
> +void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt);
> +void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt);
>  void __sysreg32_save_state(struct kvm_vcpu *vcpu);
>  void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
>  
> diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
> index b98b73b..7c4d430 100644
> --- a/arch/arm64/kvm/hyp/switch.c
> +++ b/arch/arm64/kvm/hyp/switch.c
> @@ -330,7 +330,7 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
>   host_ctxt->__hyp_running_vcpu = vcpu;
>   guest_ctxt = &vcpu->arch.ctxt;
>  
> - __sysreg_save_host_state(host_ctxt);
> + sysreg_save_host_state_vhe(host_ctxt);
>  
>   __activate_traps(vcpu);
>   __activate_vm(vcpu);
> @@ -342,7 +342,7 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
>* to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
>*/
>   __sysreg32_restore_state(vcpu);
> - __sysreg_restore_guest_state(guest_ctxt);
> + sysreg_restore_guest_state_vhe(guest_ctxt);
>   __debug_switch_to_guest(vcpu);
>  
>   /* Jump in the fire! */
> @@ -353,13 +353,13 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
>   if (fixup_guest_exit(vcpu, &exit_code))
>   goto again;
>  
> - __sysreg_save_guest_state(guest_ctxt);
> + sysreg_save_guest_state_vhe(guest_ctxt);
>   __sysreg32_save_state(vcpu);
>   __vgic_save_state(vcpu);
>  
>   __deactivate_traps(vcpu);
>  
> - __sysreg_restore_host_state(host_ctxt);
> + sysreg_restore_host_state_vhe(host_ctxt);
>  
>   /*
>* This must come after restoring the host sysregs, since a non-VHE

This comment is a carry over from the non-VHE function. It's a bit
confusing in a VHE-only function, so it should probably be removed,
perhaps with its own patch though.


> @@ -383,7 +383,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>   host_ctxt->__hyp_running_vcpu = vcpu;
>   guest_ctxt = &vcpu->arch.ctxt;
>  
> - __sysreg_save_host_state(host_ctxt);
> + __sysreg_save_host_state_nvhe(host_ctxt);
>  
>   __activate_traps(vcpu);
>   __activate_vm(vcpu);
> @@ -396,7 +396,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>* to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
>*/
>   __sysreg32_restore_state(vcpu);
> - __sysreg_restore_guest_state(guest_ctxt);
> + __sysreg_restore_guest_state_nvhe(guest_ctxt);
>   __debug_switch_to_guest(vcpu);
>  
>   /* Jump in the fire! */
> @@ -407,7 +407,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>   if (fixup_guest_exit(vcpu, &exit_code))
>   goto again;
>  
> - __sysreg_save_guest_state(guest_ctxt);
> + __sysreg_save_guest_state_nvhe(guest_ctxt);
>   __sysreg32_save_state(vcpu);
>   __timer_disable_traps(vcpu);
>   __vgic_save_state(vcpu);
> @@ -415,7 +415,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
>   __deactivate_traps(vcpu);
>   __deactivate_vm(vcpu);
>  
> - __sysreg_restore_host_state(host_ctxt);
> + __sysreg_restore_host_state_nvhe(host_ctxt);
>  
>   /*
>* This must come after restoring

[PATCH 19/37] KVM: arm64: Introduce separate VHE/non-VHE sysreg save/restore functions

[Christoffer Dall]

As we are about to handle system registers quite differently between VHE
and non-VHE systems.  In preparation for that, we need to split some of
the handling functions between VHE and non-VHE functionality.

For now, we simply copy the non-VHE functions, but we do change the use
of static keys for VHE and non-VHE functionality now that we have
separate functions.

Signed-off-by: Christoffer Dall 
---
 arch/arm64/include/asm/kvm_hyp.h | 12 
 arch/arm64/kvm/hyp/switch.c  | 20 ++--
 arch/arm64/kvm/hyp/sysreg-sr.c   | 40 
 3 files changed, 50 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index a0e5a70..998152d 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -132,10 +132,14 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
 void __timer_enable_traps(struct kvm_vcpu *vcpu);
 void __timer_disable_traps(struct kvm_vcpu *vcpu);
 
-void __sysreg_save_host_state(struct kvm_cpu_context *ctxt);
-void __sysreg_restore_host_state(struct kvm_cpu_context *ctxt);
-void __sysreg_save_guest_state(struct kvm_cpu_context *ctxt);
-void __sysreg_restore_guest_state(struct kvm_cpu_context *ctxt);
+void __sysreg_save_host_state_nvhe(struct kvm_cpu_context *ctxt);
+void __sysreg_restore_host_state_nvhe(struct kvm_cpu_context *ctxt);
+void __sysreg_save_guest_state_nvhe(struct kvm_cpu_context *ctxt);
+void __sysreg_restore_guest_state_nvhe(struct kvm_cpu_context *ctxt);
+void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt);
+void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt);
+void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt);
+void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt);
 void __sysreg32_save_state(struct kvm_vcpu *vcpu);
 void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
 
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index b98b73b..7c4d430 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -330,7 +330,7 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
 
-   __sysreg_save_host_state(host_ctxt);
+   sysreg_save_host_state_vhe(host_ctxt);
 
__activate_traps(vcpu);
__activate_vm(vcpu);
@@ -342,7 +342,7 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
 */
__sysreg32_restore_state(vcpu);
-   __sysreg_restore_guest_state(guest_ctxt);
+   sysreg_restore_guest_state_vhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
 
/* Jump in the fire! */
@@ -353,13 +353,13 @@ int kvm_vcpu_run(struct kvm_vcpu *vcpu)
if (fixup_guest_exit(vcpu, &exit_code))
goto again;
 
-   __sysreg_save_guest_state(guest_ctxt);
+   sysreg_save_guest_state_vhe(guest_ctxt);
__sysreg32_save_state(vcpu);
__vgic_save_state(vcpu);
 
__deactivate_traps(vcpu);
 
-   __sysreg_restore_host_state(host_ctxt);
+   sysreg_restore_host_state_vhe(host_ctxt);
 
/*
 * This must come after restoring the host sysregs, since a non-VHE
@@ -383,7 +383,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
 
-   __sysreg_save_host_state(host_ctxt);
+   __sysreg_save_host_state_nvhe(host_ctxt);
 
__activate_traps(vcpu);
__activate_vm(vcpu);
@@ -396,7 +396,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
 */
__sysreg32_restore_state(vcpu);
-   __sysreg_restore_guest_state(guest_ctxt);
+   __sysreg_restore_guest_state_nvhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
 
/* Jump in the fire! */
@@ -407,7 +407,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
if (fixup_guest_exit(vcpu, &exit_code))
goto again;
 
-   __sysreg_save_guest_state(guest_ctxt);
+   __sysreg_save_guest_state_nvhe(guest_ctxt);
__sysreg32_save_state(vcpu);
__timer_disable_traps(vcpu);
__vgic_save_state(vcpu);
@@ -415,7 +415,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
 
-   __sysreg_restore_host_state(host_ctxt);
+   __sysreg_restore_host_state_nvhe(host_ctxt);
 
/*
 * This must come after restoring the host sysregs, since a non-VHE
@@ -440,7 +440,7 @@ static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 
elr, u64 par,
__timer_disable_traps(vcpu);
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
-   __sysreg_restore_host_state(__host_ctxt);
+   __sysreg_restore_host_state_nvhe(__host_ctx