From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792977692; b=PwswJvr0NhJIeIn/vz/KranZoLwZZbuXsZjGSwvnSrGw7I7uFhMkapR1+ZuOvLzH3vab KKjcafat5HdC2vaZX4GWcYPFDNo57etrrH5ULxsEekJDBrpSGCA4f2Zt5XEwrzQfArr4v lzqz4bUWw2kD7bgNV1qSkuPfAPLvWsGrOHR+r/h93uVqsG6jpC6adh9A84y2UR8k7R54O qigoKNSw4FmeFyhte20ATmER+eefOZO89FNllsibAi04vsMfna1w1YvKtGTEsujMh7YK5 I2HQq3oszfooFVEGjA8N5l89ekle7uC/RPb5fp0idl0UdjrBu5jbch5OEAhHCWIkXEA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792977692; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Transfer-Encoding; bh=C5ioxP7uY30s85vV8DwHkSdiepRHIKFRzyzh0pLyvrQ=; b=xMaC5EGF1JkvdEufvnl86L8uj5WzFTyhsj/cDQE2NlRMiMNQjry/vzHnZWsPIzatHcX6 ph01Vj8eK/dq24mTqH5SKzFfVs0uChLrzyEfseQa/BHYMc2+Ck4PzXPzBC4Ql42taGLJ9 i3Ix346Gh+RWWxmvZzUe1ybOLvJJHq1R6bseaXGp6uL3YxpEIV1KKkQTwMJabxD+vOChS Vv5+hNAxCLb01afXfXtR2klEehOqOrR4bmRbqKc6Dsk7aq/g0BATZLKCmR3FSPTjGLZMx fzde7eXtwO2fyGCgzZdfEjdODab+TMpJBmU6/+xYeGMJk9vQeLNFQNOAkqSPog294vw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=V1DqB3pb; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1860D606A31A; Mon, 26 Oct 2026 01:21:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=V1DqB3pb 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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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