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From:   =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn@kernel.org>
To:     Andy Chiu <andy.chiu@sifive.com>, linux-riscv@lists.infradead.org,
        palmer@dabbelt.com, anup@brainfault.org, atishp@atishpatra.org,
        kvm-riscv@lists.infradead.org, kvm@vger.kernel.org
Cc:     vineetg@rivosinc.com, greentime.hu@sifive.com,
        guoren@linux.alibaba.com, Andy Chiu <andy.chiu@sifive.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Andrew Jones <ajones@ventanamicro.com>,
        Heiko Stuebner <heiko.stuebner@vrull.eu>,
        Conor Dooley <conor.dooley@microchip.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Liao Chang <liaochang1@huawei.com>,
        Jisheng Zhang <jszhang@kernel.org>,
        Vincent Chen <vincent.chen@sifive.com>,
        Guo Ren <guoren@kernel.org>,
        =?utf-8?B?Qmo=?= =?utf-8?B?w7ZybiBUw7ZwZWw=?= 
        <bjorn@rivosinc.com>,
        Xianting Tian <xianting.tian@linux.alibaba.com>,
        Mattias Nissler <mnissler@rivosinc.com>,
        Richard Henderson <richard.henderson@linaro.org>
Subject: Re: [PATCH -next v15 10/19] riscv: Allocate user's vector context
 in the first-use trap
In-Reply-To: <20230317113538.10878-11-andy.chiu@sifive.com>
Date:   Thu, 23 Mar 2023 11:29:37 +0100
Message-ID: <87edpf4v72.fsf@all.your.base.are.belong.to.us>
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Andy Chiu <andy.chiu@sifive.com> writes:

> Vector unit is disabled by default for all user processes. Thus, a
> process will take a trap (illegal instruction) into kernel at the first
> time when it uses Vector. Only after then, the kernel allocates V
> context and starts take care of the context for that user process.
>
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@lina=
ro.org
> Signed-off-by: Andy Chiu <andy.chiu@sifive.com>

Reviewed-by: Bj=C3=B6rn T=C3=B6pel <bjorn@rivosinc.com>