Subject: Re: [PATCH v4 06/15] KVM: arm64: Add paravirtualization header files
To:     Gavin Shan <gshan@redhat.com>, kvmarm@lists.cs.columbia.edu
Cc:     kvm@vger.kernel.org, maz@kernel.org, linux-kernel@vger.kernel.org,
        shan.gavin@gmail.com, Jonathan.Cameron@huawei.com,
        pbonzini@redhat.com, vkuznets@redhat.com, will@kernel.org
References: <20210815005947.83699-1-gshan@redhat.com>
 <20210815005947.83699-7-gshan@redhat.com>
From:   Eric Auger <eauger@redhat.com>
Message-ID: <82506a31-7b32-f8e2-c0cb-0f39d204ef3a@redhat.com>
Date:   Wed, 10 Nov 2021 19:06:22 +0100
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Hi Gavin,

On 8/15/21 2:59 AM, Gavin Shan wrote:
> We need put more stuff in the paravirtualization header files when
> the asynchronous page fault is supported. The generic header files
> can't meet the goal.
you need to explain why
 This duplicate the generic header files to be
s/This duplicate/Duplicate
> our platform specific header files. It's the preparatory work to
> support the asynchronous page fault in the subsequent patches:
why duplication and not move. Shouldn't it be squashed with another
subsequent patch?

Eric
> 
>    include/uapi/asm-generic/kvm_para.h
>    include/asm-generic/kvm_para.h
> 
>    arch/arm64/include/uapi/asm/kvm_para.h
>    arch/arm64/include/asm/kvm_para.h
> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> ---
>  arch/arm64/include/asm/kvm_para.h      | 27 ++++++++++++++++++++++++++
>  arch/arm64/include/uapi/asm/Kbuild     |  2 --
>  arch/arm64/include/uapi/asm/kvm_para.h |  5 +++++
>  3 files changed, 32 insertions(+), 2 deletions(-)
>  create mode 100644 arch/arm64/include/asm/kvm_para.h
>  create mode 100644 arch/arm64/include/uapi/asm/kvm_para.h
> 
> diff --git a/arch/arm64/include/asm/kvm_para.h b/arch/arm64/include/asm/kvm_para.h
> new file mode 100644
> index 000000000000..0ea481dd1c7a
> --- /dev/null
> +++ b/arch/arm64/include/asm/kvm_para.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_ARM_KVM_PARA_H
> +#define _ASM_ARM_KVM_PARA_H
> +
> +#include <uapi/asm/kvm_para.h>
> +
> +static inline bool kvm_check_and_clear_guest_paused(void)
> +{
> +	return false;
> +}
> +
> +static inline unsigned int kvm_arch_para_features(void)
> +{
> +	return 0;
> +}
> +
> +static inline unsigned int kvm_arch_para_hints(void)
> +{
> +	return 0;
> +}
> +
> +static inline bool kvm_para_available(void)
> +{
> +	return false;
> +}
> +
> +#endif /* _ASM_ARM_KVM_PARA_H */
> diff --git a/arch/arm64/include/uapi/asm/Kbuild b/arch/arm64/include/uapi/asm/Kbuild
> index 602d137932dc..f66554cd5c45 100644
> --- a/arch/arm64/include/uapi/asm/Kbuild
> +++ b/arch/arm64/include/uapi/asm/Kbuild
> @@ -1,3 +1 @@
>  # SPDX-License-Identifier: GPL-2.0
> -
> -generic-y += kvm_para.h
> diff --git a/arch/arm64/include/uapi/asm/kvm_para.h b/arch/arm64/include/uapi/asm/kvm_para.h
> new file mode 100644
> index 000000000000..cd212282b90c
> --- /dev/null
> +++ b/arch/arm64/include/uapi/asm/kvm_para.h
> @@ -0,0 +1,5 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_ASM_ARM_KVM_PARA_H
> +#define _UAPI_ASM_ARM_KVM_PARA_H
> +
> +#endif /* _UAPI_ASM_ARM_KVM_PARA_H */
>