From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 310DF10ED67C for ; Fri, 27 Mar 2026 14:03:47 +0000 (UTC) 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:References:In-Reply-To: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:List-Owner; bh=cfREr35L+cdrSYaBRsDM+BEeMMn+FytDIwrQitWVv/4=; b=Vb+NKn+mYurKhM40Izo2DqT39C YWhuu5qZLXyAWzo8RnJs+s4KVQkfDgeFTpFhCfaPSoIE+i8eSm90dfVKxjixrAgEmUBtfLdQCx9ac 4a0dppeiPFnsG73eXKbE8uJEPhiA3P3LgD2zQGqxvtSkWfECHlSX/q0G0cm3hg30w6eXe3fqSRjvi 5jSiDCCu+R39KHDeYXRgow/U+FT/vGOZiiboJkP6FfRnJcSIA+/06C0z+9BsOQ5GBD/o9crTU4PUI xtgieDWeOHia5IbYs8OlX8CKVkokX9ag5l7ckW+Wcv4Y8+pXMiD/HuSB0IOQofmJ4o6RIZcCMoPch hzb2oQXQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w67mm-00000007XUp-3Iqv; Fri, 27 Mar 2026 14:03:40 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w67li-00000007Wh8-2WQz for linux-arm-kernel@lists.infradead.org; Fri, 27 Mar 2026 14:02:34 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 60D5361334; Fri, 27 Mar 2026 14:02:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 491E7C2BC87; Fri, 27 Mar 2026 14:02:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774620153; bh=xP1AJM1pCnPyLFotqlriueEwwHJ5d4C3jycKF+LSR0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PTqKtb4I5dJjGwgx5dyVe+h1RjoRlXB7qXFiFKX+raCUHHv26mmGh5irCgzQpKoGT ihyTVoj/u9KWqRb47YkRQMB0sO6tCeBoXY/qgl9+fkFL7rIW5U8+fTGfX22/BaZTrW eXS98Qv1So1KpzzJs/J50jziVYncEp9C/V1IeLpAx7vXPBKgYxxrYVpkk4hNcF0m4y m9jw3SjepSzF6CGKgkdCYVAqhUwYLdxtOqkUkr7gMod3Ce/cnHX45mluER83fRxHD4 p6SJ2KObYcK0C5PUxiX+8k5IW8hpiSL3X3NnefatHP25585KKKrzQNrv9ydYkJCYQt wmN8rCpiALbIQ== From: Will Deacon To: kvmarm@lists.linux.dev Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Quentin Perret , Fuad Tabba , Vincent Donnefort , Mostafa Saleh , Alexandru Elisei Subject: [PATCH v4 31/38] KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled Date: Fri, 27 Mar 2026 14:00:30 +0000 Message-ID: <20260327140039.21228-32-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260327140039.21228-1-will@kernel.org> References: <20260327140039.21228-1-will@kernel.org> 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-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Introduce a new VM type for KVM/arm64 to allow userspace to request the creation of a "protected VM" when the host has booted with pKVM enabled. For now, this feature results in a taint on first use as many aspects of a protected VM are not yet protected! Tested-by: Fuad Tabba Tested-by: Mostafa Saleh Signed-off-by: Will Deacon --- arch/arm64/include/asm/kvm_pkvm.h | 2 +- arch/arm64/kvm/arm.c | 8 +++++++- arch/arm64/kvm/mmu.c | 3 --- arch/arm64/kvm/pkvm.c | 8 +++++++- include/uapi/linux/kvm.h | 5 +++++ 5 files changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 7041e398fb4c..2954b311128c 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -17,7 +17,7 @@ #define HYP_MEMBLOCK_REGIONS 128 -int pkvm_init_host_vm(struct kvm *kvm); +int pkvm_init_host_vm(struct kvm *kvm, unsigned long type); int pkvm_create_hyp_vm(struct kvm *kvm); bool pkvm_hyp_vm_is_created(struct kvm *kvm); void pkvm_destroy_hyp_vm(struct kvm *kvm); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3589fc08266c..c2b666a46893 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -203,6 +203,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) { int ret; + if (type & ~KVM_VM_TYPE_ARM_MASK) + return -EINVAL; + mutex_init(&kvm->arch.config_lock); #ifdef CONFIG_LOCKDEP @@ -234,9 +237,12 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) * If any failures occur after this is successful, make sure to * call __pkvm_unreserve_vm to unreserve the VM in hyp. */ - ret = pkvm_init_host_vm(kvm); + ret = pkvm_init_host_vm(kvm, type); if (ret) goto err_uninit_mmu; + } else if (type & KVM_VM_TYPE_ARM_PROTECTED) { + ret = -EINVAL; + goto err_uninit_mmu; } kvm_vgic_early_init(kvm); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 6a4151e3e4a3..45358ae8a300 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -881,9 +881,6 @@ static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type) u64 mmfr0, mmfr1; u32 phys_shift; - if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK) - return -EINVAL; - phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type); if (is_protected_kvm_enabled()) { phys_shift = kvm_ipa_limit; diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index da0a45dab203..632852648012 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -219,9 +219,10 @@ void pkvm_destroy_hyp_vm(struct kvm *kvm) mutex_unlock(&kvm->arch.config_lock); } -int pkvm_init_host_vm(struct kvm *kvm) +int pkvm_init_host_vm(struct kvm *kvm, unsigned long type) { int ret; + bool protected = type & KVM_VM_TYPE_ARM_PROTECTED; if (pkvm_hyp_vm_is_created(kvm)) return -EINVAL; @@ -236,6 +237,11 @@ int pkvm_init_host_vm(struct kvm *kvm) return ret; kvm->arch.pkvm.handle = ret; + kvm->arch.pkvm.is_protected = protected; + if (protected) { + pr_warn_once("kvm: protected VMs are experimental and for development only, tainting kernel\n"); + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + } return 0; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 80364d4dbebb..073b2bcaf560 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -703,6 +703,11 @@ struct kvm_enable_cap { #define KVM_VM_TYPE_ARM_IPA_SIZE_MASK 0xffULL #define KVM_VM_TYPE_ARM_IPA_SIZE(x) \ ((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK) + +#define KVM_VM_TYPE_ARM_PROTECTED (1UL << 31) +#define KVM_VM_TYPE_ARM_MASK (KVM_VM_TYPE_ARM_IPA_SIZE_MASK | \ + KVM_VM_TYPE_ARM_PROTECTED) + /* * ioctls for /dev/kvm fds: */ -- 2.53.0.1018.g2bb0e51243-goog