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Mon, 18 Aug 2025 03:29:10 -0700 (PDT) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 18 Aug 2025 12:29:10 +0200 Message-Id: Subject: Re: [PATCH 0/6] ONE_REG interface for SBI FWFT extension Cc: "Palmer Dabbelt" , "Paul Walmsley" , "Alexandre Ghiti" , "Andrew Jones" , "Anup Patel" , "Paolo Bonzini" , "Shuah Khan" , , , , , , "linux-riscv" To: "Anup Patel" , "Atish Patra" From: =?utf-8?q?Radim_Kr=C4=8Dm=C3=A1=C5=99?= References: <20250814155548.457172-1-apatel@ventanamicro.com> In-Reply-To: <20250814155548.457172-1-apatel@ventanamicro.com> 2025-08-14T21:25:42+05:30, Anup Patel : > This series adds ONE_REG interface for SBI FWFT extension implemented > by KVM RISC-V. I think it would be better to ONE_REG the CSRs (medeleg/menvcfg), or at least expose their CSR fields (each sensible medeleg bit, PMM, ...) through kvm_riscv_config, than to couple this with SBI/FWFT. The controlled behavior is defined by the ISA, and userspace might want to configure the S-mode execution environment even when SBI/FWFT is not present, which is not possible with the current design. Is there a benefit in expressing the ISA model through SBI/FWFT? Thanks.