From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f52.google.com (mail-wm1-f52.google.com [209.85.128.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A31D7258EDA for ; Mon, 18 Aug 2025 10:29:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.52 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512954; cv=none; b=QNlfQ8jYh6OIjUrl5M/xIRZY0Cz/oab7HWVG1TvhmrKcMyOORBlxKJ8aGXAxYvqdxfm2lEMip4hY5jcjbs0VYyFHyiXKgTQnXXwWlwHr5O+DYjlPez1klew9+gsPvtdYg5BXEp62mwfrUMbkjzGFv7o5jmzFWn7unOa4rwtG9co= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755512954; c=relaxed/simple; bh=BhbysUcbAKjEA8/11kFRzX2E12IzlBavWPgZPsKEmYQ=; h=Mime-Version:Content-Type:Date:Message-Id:Subject:Cc:To:From: References:In-Reply-To; b=haEAuIVLcjs0+EqX19Ps+zNRc7Hjm0oJ4eI78UXUF3dHz+igkG/13jM6BxT2Z2MXAin+N7bcIPNYRuZbFImcvKzPgeLCMcldngNmOQ4CI1zPflmF8CGRk4FCcOXtGd2v4NEYf36hjbZnNJez4XFwevrTEoB87IxiuALlGAh+Fm8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ventanamicro.com; spf=pass smtp.mailfrom=ventanamicro.com; dkim=pass (2048-bit key) header.d=ventanamicro.com header.i=@ventanamicro.com header.b=H8UUTFuj; arc=none smtp.client-ip=209.85.128.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ventanamicro.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ventanamicro.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ventanamicro.com header.i=@ventanamicro.com header.b="H8UUTFuj" Received: by mail-wm1-f52.google.com with SMTP id 5b1f17b1804b1-45a1fc6996aso2677735e9.0 for ; Mon, 18 Aug 2025 03:29:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ventanamicro.com; s=google; t=1755512951; x=1756117751; darn=vger.kernel.org; h=in-reply-to:references:from:to:cc:subject:message-id:date :content-transfer-encoding:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=BhbysUcbAKjEA8/11kFRzX2E12IzlBavWPgZPsKEmYQ=; b=H8UUTFujZ5bOLN6tfCzFgID6wonxXrPF9cK8Z+ZS9fyfn7aGURLVqHXgqUfi0r1/vT Sn5ORcibCb9aNtRsE/3btDwWwqXJZGMUURJjuWMjBC4l7T9zXMjCDo1M57XWLJlakU+l i2xjswyTWWLeLqPI7PT19ZhfG/PayiG1TGLWAI9BpBnIVjtqe8FmsjaE4txXpr5y6qRM kBWo98qzE6NncAWo39DOGtkOl77CnZymx9LV6pX2e0hE0mXXBX6HaP2BTNIo18pCZ6r3 bWRWDQzCLZj6P8Nz4Dyj/0QiMOQ0SPrY+hnQXZVGLZR3tXU6mpsrcrBxprzPFe2GmO2b aSmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755512951; x=1756117751; h=in-reply-to:references:from:to:cc:subject:message-id:date :content-transfer-encoding:mime-version:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=BhbysUcbAKjEA8/11kFRzX2E12IzlBavWPgZPsKEmYQ=; b=m/DQ9X09MRrTikXvU0mlqM3zP5gqggbKufT6dhlhc7GxzVoAit6D0wjdAFu7/wHIjV MlIzTdiK+IKCE/mTMdmzT2bx59SnbYvoTagUWo3ZXQA1R+7ebkTYR8oKb+EVzvCwIJex /tv7IMSqhVZn9j491OCf8l7/oQoYQKZcIObZr2UyIUZe4obRcE4wz35FuWYfBpqNSxCQ VoW1MCdUgVvH7z7CiB/ft4hYZXoUQM3W9cu9CZUJAR65om8I67ME/fSg7i2skVToL2YA EW08LBlDSAaKb77A1KzMgJQmeS4LFZjzVD9s6Y2TcgmajNz81u85tpYdErOHaOt/DfyL ZyHw== X-Forwarded-Encrypted: i=1; AJvYcCXXVsK/69bimCwGPhkzoXFYn8QM7wGkmduZ8N3zPIDjF9l+hG0AsgfQeayvDOYt11Mu2mhvrrJXnjgLrcA=@vger.kernel.org X-Gm-Message-State: AOJu0YwpIyZXwzN7g7ebfS2LYpklXbyoS/T8ImR+HtC2dCVXubOpx1sS Ogbhly881HCjWVkH67L83zKgJn2Y62U0WCTuZveWUqcWQA2Zn1KZHaaxwt0DoaMZcFI= X-Gm-Gg: ASbGncvj/KYSGYU3ExYTv3FF0TgFNLSNqF6yK9fTQ4l04q4820ZEbeQf7Z2HlBItnRj N9vc+sWTxvixcWKX7YzOqM/bDyL3eVwNmBgjfEKx+kmpw3zDd6gn+FjUi9FBGGndkCp5qPoxoE7 NZbO/NOSm14hbgu7nwliZG6zj3hwnVbBMfMGgpAj+zJP76d/9vUQ3nfg4CtTVXhi6mrv1L39hUG rzEvJOVYA3VMRRLt4NvtTOvUEoohp5XC2m6PYihyNpXbK2Dp49wqjXvEKCLRyTUPCSDzqvqtZBv P9G9OIteVPqQs9WiwE1XDX6wK5yweWIl7wfNhOHEBX9fLJf5I9Kq5LuKR72aum4mutNDszM97oA MBcoBERX3Mv3ZFjABPoT8lJnAyS/eMA== X-Google-Smtp-Source: AGHT+IFey14ol9S6TtNaCL77HGtEmBhLvnjzcHSJ5a+JMC7yNb3b8k4bUmeKUn0yZJ7mbxDU1Gpejg== X-Received: by 2002:a05:600c:46cf:b0:459:ddd6:1cbf with SMTP id 5b1f17b1804b1-45a21781fb3mr36116495e9.0.1755512950889; Mon, 18 Aug 2025 03:29:10 -0700 (PDT) Received: from localhost ([2a02:8308:a00c:e200:faeb:f88c:9e29:5aa1]) by smtp.gmail.com with UTF8SMTPSA id 5b1f17b1804b1-45a2232de40sm125126805e9.26.2025.08.18.03.29.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Aug 2025 03:29:10 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@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.