From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5CF3C1C84DE; Wed, 25 Mar 2026 00:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774399063; cv=none; b=vDED/PeLlFs2Lc98qIGw/iEQOD/saahg4tWIfakoZgYxpMnhBE4Sb4r/34u4Dz6TeZUTcOXUyZsLuwHbzkaR6f4xIvtpZjNNSYOlPoDiB6lf/7cCj3ye91g+pYeONnXIkmQApR4xP2iYJrkPRPSvnM9eXXphlnJ/RtMbO6JJHAI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774399063; c=relaxed/simple; bh=Epyy7iecwoAn93JWXH+OSMxoxwAIEDRTjD5ZKKL3pZw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=eOWn0PjlifY3OJ5Rnytp6uZb0zcXwOmEaaOWVlsn44s1iGOaAY4MGid+5yeVuuRpMysVBM3uU6uF2oWxhYGrbRoF6AwJ9lMtQ5W28/a1LrAF/7fsK53rQtmaJbZ5bYYsz10tVA+0MIf4F72TsHz0/08i8FangsrTlCZ0jMK93zs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=MnR3rorX; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="MnR3rorX" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3F5C516F2; Tue, 24 Mar 2026 17:37:27 -0700 (PDT) Received: from workstation-e142269.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 130513FB90; Tue, 24 Mar 2026 17:37:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1774399053; bh=Epyy7iecwoAn93JWXH+OSMxoxwAIEDRTjD5ZKKL3pZw=; h=From:To:Cc:Subject:Date:From; b=MnR3rorXkjxXLLNMQEvTUR+UbtwJDSGr3bzysj4xgUSLtTg7nEdk0wr7TiTqIHXe7 nczxlFPNVf7GrasIcAdzyGlaMf5PpGc1+5Vf0yTZe8PgA9TiJKtM83zQFnX0o0ZWgF 9CE6bxws/dv2PFOPeAnZzEWz6vAdHbu2gY1KFPuc= From: Wei-Lin Chang To: kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Paolo Bonzini , Shuah Khan , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon Subject: [PATCH 0/3] KVM: arm64: selftests: Basic nested guest support Date: Wed, 25 Mar 2026 00:36:17 +0000 Message-ID: <20260325003620.2214766-1-weilin.chang@arm.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi, This series adds basic support for running nested guests (L2) in kselftest. The first patch adds library functions. While designing the APIs for userspace, I referenced Joey's approach for kvm-unit-tests [1]. In summary, four preparatory functions are provided for userspace to set up state to run an L2 in EL1: - prepare_l2_stack() <- sets up stack for L2 - prepare_hyp_state() <- sets up vEL2 registers - prepare_eret_destination() <- userspace passes a function pointer for L2 to run - prepare_nested_sync_handler() <- sets up hvc handler in order to regain control after L2's hvc After calling those functions, userspace can vcpu_run(), and when run_l2() is called within the guest, the supplied function will be run in L2, with the control flow managed by the library code in nested.c and nested_asm.S. After running the L2 function, run_l2() will automatically return. Note that the L2 function supplied by the user does not have to call hvc. Patch 2 demonstrates usage of the APIs introduced above, with a simple L1 -> L2 -> L1 sequence, with an empty L2 function. Patch 3 enhances the library functions by setting up L2 -> L1 stage-2 translation. Currently the translation is simple, with start level 0, 4 levels, 4KB granules, normal cachable, 48-bit IA, 40-bit OA. [1]: https://lore.kernel.org/kvmarm/20260306142656.2775185-1-joey.gouly@arm.com/ Wei-Lin Chang (3): KVM: arm64: selftests: Add library functions for NV KVM: arm64: sefltests: Add basic NV selftest KVM: arm64: selftests: Enable stage-2 in NV preparation functions tools/testing/selftests/kvm/Makefile.kvm | 3 + .../selftests/kvm/arm64/hello_nested.c | 65 ++++++++ .../selftests/kvm/include/arm64/nested.h | 25 +++ .../selftests/kvm/include/arm64/processor.h | 9 + .../testing/selftests/kvm/lib/arm64/nested.c | 154 ++++++++++++++++++ .../selftests/kvm/lib/arm64/nested_asm.S | 35 ++++ 6 files changed, 291 insertions(+) create mode 100644 tools/testing/selftests/kvm/arm64/hello_nested.c create mode 100644 tools/testing/selftests/kvm/include/arm64/nested.h create mode 100644 tools/testing/selftests/kvm/lib/arm64/nested.c create mode 100644 tools/testing/selftests/kvm/lib/arm64/nested_asm.S -- 2.43.0