From mboxrd@z Thu Jan 1 00:00:00 1970 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 C2B1427FB1B; Wed, 6 Aug 2025 17:13:48 +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=1754500428; cv=none; b=GxhD1ES2+EI0gY4NQLrUJLURdrfRilMomWh3WsxYlsw1XcLlez2EVMqSrWElvu6/56aadQ4DeehyeAjXXBHSr9mbl7olzHf48q1Bt7pYiefOHPAiqMziESGcXfU7XcM6llVNNRAx20HbO0kaDEaKrXstc8pYZwyBoUjf308jF8A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754500428; c=relaxed/simple; bh=8Vggf2SHfGzqRxDTnJWCQ5dqoRdquclLk4o1w8m9LAY=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=nJ57ngARwpiPlGbBeo3yB1+/oT+IB0XqHQVGe9+fG4dj/nU9Trb1ttwa80IbFIH3WlYcbTiS7mlcmqsFEaHMecg9XSUWLWaika5721x4k+71mBMR3+zVjYiq/3K1H2zZjsBImtUMRLWRAsSmWDSCBGp9RQlPb8tOOg2wivxA76E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WrScxnv5; 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="WrScxnv5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C76EC4CEE7; Wed, 6 Aug 2025 17:13:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754500428; bh=8Vggf2SHfGzqRxDTnJWCQ5dqoRdquclLk4o1w8m9LAY=; h=From:To:Cc:Subject:Date:From; b=WrScxnv5OUixV5aL9DREM83KxjMw3FTOVgzNslxJDOEal41plYlUNIzbs8c6hmrHg yznHJAT9kF9YgzFC0ZfEj+YThXOuIUcjKoSGw8qWo2qAfZncP7xYgnMBA2qZ+2a09U 92YVK0IFtTWsCzJWyVyZFgleVkm/+vd74u7fEa8h1/CgB7++Pk/i3AN1TSE2nKhVjG XzIqI26Mu5uqfzrpACpDxNT3IaLo/ayyRnfhBjFxo2t7SRoAmNGJIzsey3ad9t46/8 /0QcorrKNt9r//Zjg9tPwRLOf8lZjo9YyU1wdGKPgs5WjcUJEPXkTOz5ljwZSi1tWf Lrq3PF8LE5NEQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1ujhhy-004Ztc-33; Wed, 06 Aug 2025 18:13:46 +0100 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , ajones@ventanamicro.com, Sebastian Ott Subject: [PATCH v2] KVM: arm64: selftest: Add standalone test checking for KVM's own UUID Date: Wed, 6 Aug 2025 18:13:41 +0100 Message-Id: <20250806171341.1521210-1-maz@kernel.org> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, ajones@ventanamicro.com, sebott@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Tinkering with UUIDs is a perilious task, and the KVM UUID gets broken at times. In order to spot this early enough, add a selftest that will shout if the expected value isn't found. Signed-off-by: Marc Zyngier Reviewed-by: Sebastian Ott Link: https://lore.kernel.org/r/20250721130558.50823-1-jackabt.amazon@gmail.com --- tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/arm64/kvm-uuid.c | 70 ++++++++++++++++++++ 2 files changed, 71 insertions(+) create mode 100644 tools/testing/selftests/kvm/arm64/kvm-uuid.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index ce817a975e50a..e1eb1ba238a2a 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -167,6 +167,7 @@ TEST_GEN_PROGS_arm64 += arm64/vgic_irq TEST_GEN_PROGS_arm64 += arm64/vgic_lpi_stress TEST_GEN_PROGS_arm64 += arm64/vpmu_counter_access TEST_GEN_PROGS_arm64 += arm64/no-vgic-v3 +TEST_GEN_PROGS_arm64 += arm64/kvm-uuid TEST_GEN_PROGS_arm64 += access_tracking_perf_test TEST_GEN_PROGS_arm64 += arch_timer TEST_GEN_PROGS_arm64 += coalesced_io_test diff --git a/tools/testing/selftests/kvm/arm64/kvm-uuid.c b/tools/testing/selftests/kvm/arm64/kvm-uuid.c new file mode 100644 index 0000000000000..af9581b860f14 --- /dev/null +++ b/tools/testing/selftests/kvm/arm64/kvm-uuid.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Check that nobody has tampered with KVM's UID + +#include +#include +#include +#include + +#include "processor.h" + +/* + * Do NOT redefine these constants, or try to replace them with some + * "common" version. They are hardcoded here to detect any potential + * breakage happening in the rest of the kernel. + * + * KVM UID value: 28b46fb6-2ec5-11e9-a9ca-4b564d003a74 + */ +#define ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 0xb66fb428U +#define ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 0xe911c52eU +#define ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 0x564bcaa9U +#define ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3 0x743a004dU + +static void guest_code(void) +{ + struct arm_smccc_res res = {}; + + smccc_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, 0, 0, 0, 0, 0, 0, 0, &res); + + __GUEST_ASSERT(res.a0 == ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 && + res.a1 == ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 && + res.a2 == ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 && + res.a3 == ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3, + "Unexpected KVM-specific UID %lx %lx %lx %lx\n", res.a0, res.a1, res.a2, res.a3); + GUEST_DONE(); +} + +int main (int argc, char *argv[]) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + bool guest_done = false; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + while (!guest_done) { + vcpu_run(vcpu); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_SYNC: + break; + case UCALL_DONE: + guest_done = true; + break; + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_PRINTF: + printf("%s", uc.buffer); + break; + default: + TEST_FAIL("Unexpected guest exit"); + } + } + + kvm_vm_free(vm); + + return 0; +} -- 2.39.2