Message-ID: <87268dce-1b5d-0556-7e65-2a75a7893cd1@redhat.com>
Date:   Tue, 21 Feb 2023 08:35:58 +0100
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Subject: Re: [PATCH v2 05/29] LoongArch: KVM: Add vcpu related header files
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To:     Xi Ruoyao <xry111@xry111.site>, maobibo <maobibo@loongson.cn>,
        Tianrui Zhao <zhaotianrui@loongson.cn>
Cc:     Huacai Chen <chenhuacai@kernel.org>,
        WANG Xuerui <kernel@xen0n.name>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
        Mark Brown <broonie@kernel.org>,
        Alex Deucher <alexander.deucher@amd.com>,
        Oliver Upton <oliver.upton@linux.dev>
References: <20230220065735.1282809-1-zhaotianrui@loongson.cn>
 <20230220065735.1282809-6-zhaotianrui@loongson.cn>
 <497693ca2cbc443c1d9f796c3aace6c9987bec72.camel@xry111.site>
 <7d6125dd-29e8-14d8-b1d7-d8c14d7bec80@loongson.cn>
 <4cd00b5cdc78da6357d2d326e607b169faee34a8.camel@xry111.site>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <4cd00b5cdc78da6357d2d326e607b169faee34a8.camel@xry111.site>
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On 2/21/23 08:12, Xi Ruoyao wrote:
>> We are preparing to submit these instruction support for binutils,
>> however it is still necessary. Supposing that it is supported in future
>> gcc version, we can not drop existing gcc 12/13 supporting to compiling
>> kernel with LoongArch architecture.
> You can drop the support for KVM with less capable Binutils versions,
> like:
> 
> config AS_HAS_LVZ
>      def_bool $(as-instr some_gcsr_insn \$r0, \$gcsr0)
> 
> config KVM
>      depends on AS_HAS_LVZ
> 

There are precedents in Linux for using .word when necessary.  There's 
no reason to prevent using KVM on old Binutils versions.

Paolo