Re: [PATCH v3 10/15] KVM: arm64: Guest exit handlers for nVHE hyp

[Will Deacon <will@kernel.org>]

On Mon, Jul 19, 2021 at 05:03:41PM +0100, Fuad Tabba wrote:
> Add an array of pointers to handlers for various trap reasons in
> nVHE code.
> 
> The current code selects how to fixup a guest on exit based on a
> series of if/else statements. Future patches will also require
> different handling for guest exists. Create an array of handlers
> to consolidate them.
> 
> No functional change intended as the array isn't populated yet.
> 
> Acked-by: Will Deacon <will@kernel.org>
> Signed-off-by: Fuad Tabba <tabba@google.com>
> ---
>  arch/arm64/kvm/hyp/include/hyp/switch.h | 43 +++++++++++++++++++++++++
>  arch/arm64/kvm/hyp/nvhe/switch.c        | 35 ++++++++++++++++++++
>  2 files changed, 78 insertions(+)

Definitely keep my Ack on this, but Clang just chucked out a warning due to:

> diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
> index a0e78a6027be..5a2b89b96c67 100644
> --- a/arch/arm64/kvm/hyp/include/hyp/switch.h
> +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
> @@ -409,6 +409,46 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu)
>  	return true;
>  }
>  
> +typedef int (*exit_handle_fn)(struct kvm_vcpu *);
> +
> +exit_handle_fn kvm_get_nvhe_exit_handler(struct kvm_vcpu *vcpu);

and:

> diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
> index 86f3d6482935..36da423006bd 100644
> --- a/arch/arm64/kvm/hyp/nvhe/switch.c
> +++ b/arch/arm64/kvm/hyp/nvhe/switch.c
> @@ -158,6 +158,41 @@ static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
>  		write_sysreg(pmu->events_host, pmcntenset_el0);
>  }
>  
> +typedef int (*exit_handle_fn)(struct kvm_vcpu *);

Which leads to:

arch/arm64/kvm/hyp/nvhe/switch.c:189:15: warning: redefinition of typedef 'exit_handle_fn' is a C11 feature [-Wtypedef-redefinition]
typedef int (*exit_handle_fn)(struct kvm_vcpu *);
              ^
./arch/arm64/kvm/hyp/include/hyp/switch.h:416:15: note: previous definition is here
typedef int (*exit_handle_fn)(struct kvm_vcpu *);
              ^
1 warning generated.

So I guess just pick your favourite?

Will