From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EFE9606A31D for ; Mon, 26 Oct 2026 01:21:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=Y3DlwJY5; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=V1DqB3pb DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Unsubscribe-Post:List-Owner; bh=C5ioxP7uY30s85vV8DwHkSdiepRHIKFRzyzh0pLyvrQ=; b=Y3DlwJY5PdK/AjRGscJvsEE/+7 MTvrIANI9SN39UkXg0WDstrMXxCeo4sDPyTU6B4elcEKw1jvxR8wPq1CAR315TJqNahzko9HM+2h6 vOe7L5vMiDhfRWkjqAB0F3R+lJ2a7yStw69XYzrzkr6zm4djV4tRknkAxvwp9RHHod5cUIJoKwo1P 8Jh0nY85PJ1DGrPJCrvDaVVkzq7a5SQy8cnSTKOzyD5Nkmp+cl1qbwnsuFgj28Eb8jF+OBiuZSMEb rFsceRA9wuKgh8VfcPweX8MvpflnAgn1BvDjYGEiNObuahVwsE16+3AKwV3srrlyJZyUdY7oWMbgE cfvFGksg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xL9P2-00000001ZDs-3mwm; Mon, 26 Oct 2026 01:21:32 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xL9P2-00000001ZDm-1R8L for linux-arm-kernel@lists.infradead.org; Mon, 26 Oct 2026 01:21:32 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id ADE4D43C09; Mon, 26 Oct 2026 01:21:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6BEC1F01825; Mon, 26 Oct 2026 01:21:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792977691; bh=C5ioxP7uY30s85vV8DwHkSdiepRHIKFRzyzh0pLyvrQ=; h=From:To:Cc:Subject:Date; b=V1DqB3pbxP7rI9SN1R43pBQWTS3C67zUkKSoznsjQEqKyNtm8D6VseVMV4dlPp+Yj vUfWs8GRNk8VeYo1YsHqRQb/2GPMcudOZ/dSNZw7amrf+fH7BeRNCYHSmgbGXMfawP N2BBF1UKzjie0mK5a3YE7Wc1wUe3aLXW1ArWK9O4MAKNaqX4o3XUbCPiZ/6NVVainY 2ZqMA2i5RDZOCzcWFB6DhMgVp9FjqoQBzYu0jUuQYzuHEYDYGRcicx7C2vXRn8lpST 4RO/SjJB9dhvFteWGILoKpABngLxeW43OkAEphOc7N6fnhgx3l9heeD2DCL2ikPWsN q0ZeSD33q5Sdg== From: Sasha Levin To: Marc Zyngier , Oliver Upton Cc: Fuad Tabba , Mark Brown , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , Paolo Bonzini , Sean Christopherson , Shuah Khan , "Lorenzo Stoakes (ARM)" , Itaru Kitayama , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] KVM: arm64: selftests: Skip unwritable ID fields in the failed-run test Date: Sun, 25 Oct 2026 21:21:28 -0400 Message-ID: <20261026012128.2270251-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 test_idreg_frozen_after_failed_run() checks that changing a feature ID register after a failed first KVM_RUN is rejected with -EBUSY, and does so for every field of every register in test_regs. On a host without AArch32 support at EL0, KVM treats the AArch32 ID registers as RAZ/WI: aa32_id_visibility() returns REG_RAZ | REG_USER_WI, and kvm_sys_reg_set_user() ignores the write and returns 0 before set_id_reg() checks whether the ID registers are final. The test then fails on the first such register: arm64/set_id_regs.c:870: r < 0 && errno == EBUSY ID_DFR0_EL1_PerfMon write after failed first run: r=0 errno=16 KernelCI hits this on every run on an AArch64 only GB300 host. Only a field that userspace can change can be frozen, and KVM reports these registers as not writable in KVM_ARM_GET_REG_WRITABLE_MASKS. Skip the fields that the writable mask does not cover. test_vm_ftr_id_regs() already requires the mask to cover every other field in test_regs, so this only drops the fields KVM never lets userspace change. Whether KVM accepts writes to fields it reports as not writable is a separate question from finalization. Fixes: 00e309933879 ("KVM: arm64: selftests: Check ID regs are immutable after a failed run") Link: https://d.kernelci.org/test/maestro:6adcad0c55fda50760800a00 Signed-off-by: Sasha Levin --- Changes in v2: - Skip every field that KVM_ARM_GET_REG_WRITABLE_MASKS does not report as writable, instead of special casing the AArch32 ID registers (Mark Brown). v1: https://lore.kernel.org/all/20261024161118.1007472-1-sashal@kernel.org/ tools/testing/selftests/kvm/arm64/set_id_regs.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c index 10849d21c0dd2..1d2cc25cb3f4c 100644 --- a/tools/testing/selftests/kvm/arm64/set_id_regs.c +++ b/tools/testing/selftests/kvm/arm64/set_id_regs.c @@ -815,6 +815,10 @@ static void test_idreg_frozen_after_failed_run(void) SYS_REVIDR_EL1, SYS_AIDR_EL1, }; + u64 masks[KVM_ARM_FEATURE_ID_RANGE_SIZE]; + struct reg_mask_range range = { + .addr = (__u64)masks, + }; struct kvm_vcpu_init init; struct kvm_vcpu *vcpu; struct kvm_vm *vm; @@ -831,6 +835,7 @@ static void test_idreg_frozen_after_failed_run(void) vm = vm_create(1); vm_enable_cap(vm, KVM_CAP_ARM_WRITABLE_IMP_ID_REGS, 0); + vm_ioctl(vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range); kvm_get_default_vcpu_target(vm, &init); init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3); vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); @@ -852,7 +857,9 @@ static void test_idreg_frozen_after_failed_run(void) */ for (int i = 0; i < ARRAY_SIZE(test_regs); i++) { const struct reg_ftr_bits *ftr_bits = test_regs[i].ftr_bits; - u64 reg = KVM_ARM64_SYS_REG(test_regs[i].reg); + u32 reg_id = test_regs[i].reg; + u64 reg = KVM_ARM64_SYS_REG(reg_id); + u64 mask = masks[encoding_to_range_idx(reg_id)]; u64 val = vcpu_get_reg(vcpu, reg); for (int j = 0; ftr_bits[j].type != FTR_END; j++) { @@ -860,6 +867,10 @@ static void test_idreg_frozen_after_failed_run(void) u64 safe = get_safe_value(&ftr_bits[j], ftr); u64 new_val; + /* Only a field userspace could change can be frozen. */ + if ((mask & ftr_bits[j].mask) != ftr_bits[j].mask) + continue; + if (safe == ftr) continue; base-commit: 21a7f44fd0765fcc5194130b28767786eba1d1e7 -- 2.53.0