From nobody Sat Jul 12 05:32:58 2025 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail(p=none dis=none) header.from=arm.com Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 1624274330818848.1080604477974; Mon, 21 Jun 2021 04:18:50 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230076AbhFULVC (ORCPT ); Mon, 21 Jun 2021 07:21:02 -0400 Received: from foss.arm.com ([217.140.110.172]:32868 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229918AbhFULUx (ORCPT ); Mon, 21 Jun 2021 07:20:53 -0400 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 57D48D6E; Mon, 21 Jun 2021 04:18:39 -0700 (PDT) Received: from e112269-lin.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9ACAF3F718; Mon, 21 Jun 2021 04:18:36 -0700 (PDT) From: Steven Price To: Catalin Marinas , Marc Zyngier , Will Deacon Cc: Steven Price , James Morse , Julien Thierry , Suzuki K Poulose , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Dave Martin , Mark Rutland , Thomas Gleixner , qemu-devel@nongnu.org, Juan Quintela , "Dr. David Alan Gilbert" , Richard Henderson , Peter Maydell , Andrew Jones Subject: [PATCH v17 4/6] KVM: arm64: Expose KVM_ARM_CAP_MTE Date: Mon, 21 Jun 2021 12:17:14 +0100 Message-Id: <20210621111716.37157-5-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210621111716.37157-1-steven.price@arm.com> References: <20210621111716.37157-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" It's now safe for the VMM to enable MTE in a guest, so expose the capability to user space. Reviewed-by: Catalin Marinas Signed-off-by: Steven Price --- arch/arm64/kvm/arm.c | 9 +++++++++ arch/arm64/kvm/reset.c | 4 ++++ arch/arm64/kvm/sys_regs.c | 3 +++ 3 files changed, 16 insertions(+) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e720148232a0..28ce26a68f09 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -93,6 +93,12 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r =3D 0; kvm->arch.return_nisv_io_abort_to_user =3D true; break; + case KVM_CAP_ARM_MTE: + if (!system_supports_mte() || kvm->created_vcpus) + return -EINVAL; + r =3D 0; + kvm->arch.mte_enabled =3D true; + break; default: r =3D -EINVAL; break; @@ -237,6 +243,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long = ext) */ r =3D 1; break; + case KVM_CAP_ARM_MTE: + r =3D system_supports_mte(); + break; case KVM_CAP_STEAL_TIME: r =3D kvm_arm_pvtime_supported(); break; diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index d37ebee085cf..9e6922b9503a 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -244,6 +244,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) switch (vcpu->arch.target) { default: if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { + if (vcpu->kvm->arch.mte_enabled) { + ret =3D -EINVAL; + goto out; + } pstate =3D VCPU_RESET_PSTATE_SVC; } else { pstate =3D VCPU_RESET_PSTATE_EL1; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 5c75b24eae21..f6f126eb6ac1 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1312,6 +1312,9 @@ static bool access_ccsidr(struct kvm_vcpu *vcpu, stru= ct sys_reg_params *p, static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { + if (kvm_has_mte(vcpu->kvm)) + return 0; + return REG_HIDDEN; } =20 --=20 2.20.1