From nobody Mon Nov 25 18:05:12 2024 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 4FDD61D4144 for ; Fri, 25 Oct 2024 09:33:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729848790; cv=none; b=nBD9gQAeVrRFO1+pYAizoLJ4jBwhJh+4Auajezuk0C2qO8tuJH4vDeQGZcA4GNGeYlqcTKo7E8xS5yS5Id9d/xeLAN6Ap6on/1LZn2atDTA1cpq0O9+pK1qim6Wn2n/gQbQVH8uwUk/DNMUthMU0iXTFhPZp3h+Ft9rqZhZcE6Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729848790; c=relaxed/simple; bh=JJ/e/Y7d5t82y7GqFYdBYuyUdcCxOpC4iH0/oGh9cWU=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=Xewr9Ow1PK+5910hQX9/Bl2WX6lvAVfkBWJJpPIz7DpjkoVC18JHn2xNZtrMtqEVQxJBKowFRczDwPcpc7i2NNMn66JsAnUjreN32MIe2W5W5EtiNZiHBOscxjlpP/1oc0tSs4aeIO54FHU50Ywggi7D4++biOnBc7qASD1aoiw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=3gOdNBYc; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="3gOdNBYc" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6e9ba43a9a0so19896127b3.3 for ; Fri, 25 Oct 2024 02:33:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1729848787; x=1730453587; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=tuqhWRYGgjjam9B7W2GUDM6P6BKsivvZeF6kAk9BsZY=; b=3gOdNBYcZFrMsMUQElNPHJAzaA06U27ZvdNf9pso3P5BGcqeXIhEDxBihCEUE+5NbF 7GWiT/FoYzguhEyiTgy+EM33N73oRx/z8/8jTSqN+n63K4ca7viccj/tk+OEP6WjE5dz tk1uoCYYhGgB/udEoq8UM2ZvGqBpIgJ0Rsi9WnE01pVMncq/EJQmXEJAZg6IqLo9atCE Cje6LwpcUEvrEaJUWcBnkIRbqOSc0qnbrRD580BUr1EbhqvDGKH8k+9oIcwiyvQZHNyE 9/lEM3yIqG3jgG6KQ0VwLv5tkU7zfvYPuKHHbkyYbLCNfGVtB9cZ19z6Cd7cCWC5DMWe tshg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729848787; x=1730453587; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=tuqhWRYGgjjam9B7W2GUDM6P6BKsivvZeF6kAk9BsZY=; b=WPrvXEdZiCo2spMvvzp9JSbpZf1gR4zyIeJ2vUOGk3lVSIbs1E5hStszWuj4UGdNVc JQ+qaTs4wFM0mhGHesc4PXIBrXBMRi4Dd94qiMyfM7qOGfjb80Po/goeiLlPxwtXlqo5 JfbnSlno79WQtNVlHclV8CcW9BY94YF2vueZzMmB8Ku2DY0GONb0h6uMN45w4VMX+HuI k8QlHZBLx7vgiVpiabKY9xQRt6AFPZ5EkDNdGPVdMHHti70KwgjclJzrfG8LeW19c9Lv PRF0hyS3ADd0h71CoWrji1jhqoyMAk5+SbeeuzaL2GEWUE4Fdlz7oy6L2i8QUBhmNgFy aqjQ== X-Gm-Message-State: AOJu0Yz08Ra81oqq5/b4njjXgiEeXTl62ITi4c2s9Xg3AtHYo0HCGi7P 9O4aeai6c6OsvSvmb+y3+ehA1vDZywwwZ/JI0d6TslQ/gpxOa6bipsZLA8zPDZ/7C5659ltNThW hTA+McH7y52oS3Dq5puc9LdI79PKylOXfQp14T0mgRpTVo5+95ngLW9JIsyy6bzot7kHMB3yOwk V8G9UggQ3Ajh/7EP+XEbJf1TIrwqIa2M57GdlIGcbJ7QDtBAjLStI= X-Google-Smtp-Source: AGHT+IECH9pM1rudCKXymTwKhtnM/AU69iz4LBnNjtGpR3vZzl1lATWUss0Na2UGHQecUxyzkYn2RvfW2Hppzw== X-Received: from mostafa.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:333c]) (user=smostafa job=sendgmr) by 2002:a05:690c:296:b0:68d:52a1:be9 with SMTP id 00721157ae682-6e858147b16mr1078977b3.1.1729848786167; Fri, 25 Oct 2024 02:33:06 -0700 (PDT) Date: Fri, 25 Oct 2024 09:32:59 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <20241025093259.2216093-1-smostafa@google.com> Subject: [PATCH v3] Documentation: Update the behaviour of "kvm-arm.mode" From: Mostafa Saleh To: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: corbet@lwn.net, Mostafa Saleh , Will Deacon , Marc Zyngier Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 5053c3f0519c ("KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support") modified the behaviour of "kvm-arm.mode=3Dprotected" without the updating the kernel parameters doc. Update it to match the current implementation. Also, update required architecture version for nested virtualization as suggested by Marc. Cc: Will Deacon Cc: Marc Zyngier Signed-off-by: Mostafa Saleh --- v3: Reword as Marc suggested. v2: Update nested value also --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 1518343bbe22..ed92e207e9a0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2740,17 +2740,21 @@ nvhe: Standard nVHE-based mode, without support for protected guests. =20 - protected: nVHE-based mode with support for guests whose - state is kept private from the host. + protected: Mode with support for guests whose state is + kept private from the host, using VHE or + nVHE depending on HW support. =20 nested: VHE-based mode with support for nested - virtualization. Requires at least ARMv8.3 - hardware. + virtualization. Requires at least ARMv8.4 + hardware (with FEAT_NV2). =20 Defaults to VHE/nVHE based on hardware support. Setting mode to "protected" will disable kexec and hibernation - for the host. "nested" is experimental and should be - used with extreme caution. + for the host. To force nVHE on VHE hardware, add + "arm64_sw.hvhe=3D0 id_aa64mmfr1.vh=3D0" to the + command-line. + "nested" is experimental and should be used with + extreme caution. =20 kvm-arm.vgic_v3_group0_trap=3D [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0 --=20 2.47.0.163.g1226f6d8fa-goog