[PATCH v4 13/40] KVM: arm64: Introduce VHE-specific kvm_vcpu_run

[Andrew Jones]

On Thu, Feb 15, 2018 at 10:03:05PM +0100, Christoffer Dall wrote:
> So far this is mostly (see below) a copy of the legacy non-VHE switch
> function, but we will start reworking these functions in separate
> directions to work on VHE and non-VHE in the most optimal way in later
> patches.
> 
> The only difference after this patch between the VHE and non-VHE run
> functions is that we omit the branch-predictor variant-2 hardening for
> QC Falkor CPUs, because this workaround is specific to a series of
> non-VHE ARMv8.0 CPUs.
> 
> Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
> Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
> ---
> 
> Notes:
>     Changes since v3:
>      - Added BUG() to 32-bit ARM VHE run function
>      - Omitted QC Falkor BP Hardening functionality from VHE-specific
>        function
>     
>     Changes since v2:
>      - Reworded commit message
>     
>     Changes since v1:
>      - Rename kvm_vcpu_run to kvm_vcpu_run_vhe and rename __kvm_vcpu_run to
>        __kvm_vcpu_run_nvhe
>      - Removed stray whitespace line
> 
>  arch/arm/include/asm/kvm_asm.h   |  5 ++-
>  arch/arm/kvm/hyp/switch.c        |  2 +-
>  arch/arm64/include/asm/kvm_asm.h |  4 ++-
>  arch/arm64/kvm/hyp/switch.c      | 66 +++++++++++++++++++++++++++++++++++++++-
>  virt/kvm/arm/arm.c               |  5 ++-
>  5 files changed, 77 insertions(+), 5 deletions(-)
> 

...

> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index 2062d9357971..5bd879c78951 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -736,7 +736,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  		if (has_vhe())
>  			kvm_arm_vhe_guest_enter();
>  
> -		ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);
> +		if (has_vhe())
> +			ret = kvm_vcpu_run_vhe(vcpu);
> +		else
> +			ret = kvm_call_hyp(__kvm_vcpu_run_nvhe, vcpu);
>  
>  		if (has_vhe())
>  			kvm_arm_vhe_guest_exit();

We can combine these has_vhe()'s

 if (has_vhe()) {
    kvm_arm_vhe_guest_enter();
    ret = kvm_vcpu_run_vhe(vcpu);
    kvm_arm_vhe_guest_exit();
 } else
    ret = kvm_call_hyp(__kvm_vcpu_run_nvhe, vcpu);

Thanks,
drew