From patchwork Sun Nov 19 16:57:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13460584 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 913AA1FCC; Sun, 19 Nov 2023 08:59:51 -0800 (PST) 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 635671007; Sun, 19 Nov 2023 09:00:37 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 36E813F6C4; Sun, 19 Nov 2023 08:59:46 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v2 25/27] KVM: arm64: Disable MTE if tag storage is enabled Date: Sun, 19 Nov 2023 16:57:19 +0000 Message-Id: <20231119165721.9849-26-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com> References: <20231119165721.9849-1-alexandru.elisei@arm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 KVM allows MTE enabled VMs to be created when the backing VMA does not have MTE enabled. Without changes to how KVM allocates memory for a VM, it is impossible at the moment to discern when the corresponding tag storage needs to be reserved. For now, disable MTE in KVM if tag storage is enabled. Signed-off-by: Alexandru Elisei --- arch/arm64/kvm/arm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e5f75f1f1085..5b33c532c62a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -86,7 +87,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, break; case KVM_CAP_ARM_MTE: mutex_lock(&kvm->lock); - if (!system_supports_mte() || kvm->created_vcpus) { + if (!system_supports_mte() || tag_storage_enabled() || + kvm->created_vcpus) { r = -EINVAL; } else { r = 0; @@ -279,7 +281,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = 1; break; case KVM_CAP_ARM_MTE: - r = system_supports_mte(); + r = system_supports_mte() && !tag_storage_enabled(); break; case KVM_CAP_STEAL_TIME: r = kvm_arm_pvtime_supported();