From patchwork Sat Feb 3 12:25:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 769695 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EC6A5DF0B; Sat, 3 Feb 2024 12:28:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706963307; cv=none; b=n1OSAhuzFzMtej2VQaqRptWZtuxOdJFP0+7uKHGO7suYzektaL+xeL1ghimMw+zo1Gul2xSIZFW3DISiCXpKgnVZdkMeww3t7BStx1uxgScrBWSILFYXXgXNSoxAmof50kGeTa5Fj0q/u3L/ydDO924qxHvc8984gonS6CgBHbs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706963307; c=relaxed/simple; bh=Z3injfV8td0LqFLeGew+/6AX1Y4kpAJIpTs5MPlZTRs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=uouGEWXOKqb6zr0SeEAQ21KZBMkJlrCe9CrmJKoYAb0WARCH60yhI7O/VnO40DsVUY13pP9DSH22spyry2U62ij5k05R8bRYKvOebXTtR6HqERT90WSCP4yOZE8DM8JxldzmasCMWxqkGnoQ/iNizF9IZ7rvNNqUFdFWHQFcZJo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mqlIJ5g3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mqlIJ5g3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D8ABC43390; Sat, 3 Feb 2024 12:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706963306; bh=Z3injfV8td0LqFLeGew+/6AX1Y4kpAJIpTs5MPlZTRs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=mqlIJ5g3tl5q0vYK7ykUXUM8Tc+tv8rON+LlVXaOXLZkci6RbJ9fIy9D+0L3q7RZE LNE4wWCXSxPrW+6yc449KPyyth2xlowITE1wQPdj9VVu14q4p28fH6+Mr/dcOpooOb BbEVSpIijcUScCJRz0nwuXKIusgNuQtMB02ImSKBl+XJwLtQ3oHiZv0JTqosJnP+BW vVz3wocrNiQnKimT9yoE4DaY5NZfLqfpeiSu3Mb9VHmwvHRJOGxxextL0Vny9D7SQt gGZECkE2b9Lri6+3C5cMXoGpJNtp9oXBohTewFa3e/ub1biMSTSfmS2n0YRloz6YyT PQqWESBoDqKPA== From: Mark Brown Date: Sat, 03 Feb 2024 12:25:30 +0000 Subject: [PATCH v8 04/38] arm64: Document boot requirements for Guarded Control Stacks Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240203-arm64-gcs-v8-4-c9fec77673ef@kernel.org> References: <20240203-arm64-gcs-v8-0-c9fec77673ef@kernel.org> In-Reply-To: <20240203-arm64-gcs-v8-0-c9fec77673ef@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.13-dev-a684c X-Developer-Signature: v=1; a=openpgp-sha256; l=1640; i=broonie@kernel.org; h=from:subject:message-id; bh=Z3injfV8td0LqFLeGew+/6AX1Y4kpAJIpTs5MPlZTRs=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBlvjDUsly811JO8MY9VKwAyipGXg/WYYy7DrZJ9PfF WUTZtWCJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZb4w1AAKCRAk1otyXVSH0Cp2B/ 9ZbiDjwSsFZbMG4QBc+H/K8vKVC04W/sEbxEueoW6RvocX423DsgVKt7TW3y4gTB9CNsk3bfhBpSJy 6Ade2Y1WKbQ8UudQ6Q46T26n3UDyrCs+lO5Ity3TveBReAWASeqybFoYtghSJjhoomY3nitWgA805k L7UsEzNP/UsrMpJz13RSBlmn74EryWZcdDt0milhnxX9Vqz/uyKUjQnYUghRBg+gp4joxeRK9ZJH5A V7SJkdsQX6g3OWnLAUYwC5zljMqXzEGptSSf89vn4Fg8NoQPePUIgsU6RQ6Ebg2hlmb8qTSvHBEJ6p pwKlr8cYsYxj5L+KGlC1UFZ6mVJsri X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB FEAT_GCS introduces a number of new system registers, we require that access to these registers is not trapped when we identify that the feature is detected. Signed-off-by: Mark Brown --- Documentation/arch/arm64/booting.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index b57776a68f15..de3679770c64 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -411,6 +411,28 @@ Before jumping into the kernel, the following conditions must be met: - HFGRWR_EL2.nPIRE0_EL1 (bit 57) must be initialised to 0b1. + - For features with Guarded Control Stacks (FEAT_GCS): + + - If EL3 is present: + + - SCR_EL3.GCSEn (bit 39) must be initialised to 0b1. + + - If the kernel is entered at EL1 and EL2 is present: + + - HFGITR_EL2.nGCSEPP (bit 59) must be initialised to 0b1. + + - HFGITR_EL2.nGCSSTR_EL1 (bit 58) must be initialised to 0b1. + + - HFGITR_EL2.nGCSPUSHM_EL1 (bit 57) must be initialised to 0b1. + + - HFGRTR_EL2.nGCS_EL1 (bit 53) must be initialised to 0b1. + + - HFGRTR_EL2.nGCS_EL0 (bit 52) must be initialised to 0b1. + + - HFGWTR_EL2.nGCS_EL1 (bit 53) must be initialised to 0b1. + + - HFGWTR_EL2.nGCS_EL0 (bit 52) must be initialised to 0b1. + The requirements described above for CPU mode, caches, MMUs, architected timers, coherency and system registers apply to all CPUs. All CPUs must enter the kernel in the same exception level. Where the values documented