From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A691324B23 for ; Mon, 30 Mar 2026 14:49:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774882161; cv=none; b=RYw+gyX3x8kTKlYSQfn072GtOVbvS+/mjfpmVcV46XOyFCt4Q5PfJip+orhARalrMC8umGmg4dJlz81znxuXBnQeJR5j6CHAsv0ZFNuGt1F4+2KiBfm8PNCJVPOiwvIfZfGGZhn/4o4YGgAGjiMoB4dn9a0jlGfvf+gIa+vUUJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774882161; c=relaxed/simple; bh=7P+uzxldFf+9qg+nRD40JCugsSDrZRwu1jtKYArToK8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z8nZ3H0Or+2/tTy4q5nIrcyRr02fFhHOdxLUhBNAkfVk5pR3ksjaJcKfiqZEeIrXyQC4bBxL57L3tdtKyeQyhe1Oz2xHROq2U2GyDk5t9OTGaOk7amRIFCsoQUDZWFzJBkJfZCx9LroOGWN14GBcA7FMq0iVS1PM7CNbhfsyYSo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VMeOEdH2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VMeOEdH2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41056C2BCB1; Mon, 30 Mar 2026 14:49:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774882161; bh=7P+uzxldFf+9qg+nRD40JCugsSDrZRwu1jtKYArToK8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VMeOEdH2h+jUvGV7ydQh9oSm/Dj1t2ykqHJYdjyvymnP3dDB/nxB++AdjPzaWCHlq OXBDjpVwU4hKwy7zMgh8H8dMSRofvftFiAMVTexSWcEGMrvp1diz52/JiDZoLFevqe 3YAZhO/uUOy5bBbQN+6Peg+D5eZ6r9tDoogKbIcdTFA3bOJ3mZkNl0vhBt0+uSW2Cb FulM8Gy/h5nKWvwz0qdUqtHQLcxGD0PPtWokTLZLUj3oXo/vaTqc+mnbYXSkw4JzVz gm2qVysFx9KbOxomjdEMSujIh3gQNxai9mVJweAFIXxMi9yj6797dRyy9uv/yZdhW6 3TuEttyqW1h/w== 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 v5 09/38] KVM: arm64: Prevent unsupported memslot operations on protected VMs Date: Mon, 30 Mar 2026 15:48:10 +0100 Message-ID: <20260330144841.26181-10-will@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260330144841.26181-1-will@kernel.org> References: <20260330144841.26181-1-will@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Protected VMs do not support deleting or moving memslots after first run nor do they support read-only or dirty logging. Return -EPERM to userspace if such an operation is attempted. Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Tested-by: Mostafa Saleh Signed-off-by: Will Deacon --- arch/arm64/kvm/mmu.c | 13 +++++++++++++ arch/arm64/kvm/pkvm.c | 6 ++++++ 2 files changed, 19 insertions(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 5e7821fe0fc4..b3cc5dfe5723 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2414,6 +2414,19 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, hva_t hva, reg_end; int ret = 0; + if (kvm_vm_is_protected(kvm)) { + /* Cannot modify memslots once a pVM has run. */ + if (pkvm_hyp_vm_is_created(kvm) && + (change == KVM_MR_DELETE || change == KVM_MR_MOVE)) { + return -EPERM; + } + + if (new && + new->flags & (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY)) { + return -EPERM; + } + } + if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && change != KVM_MR_FLAGS_ONLY) return 0; diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index dd93dfdfe52d..94b70eb80aa8 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -192,10 +192,16 @@ int pkvm_create_hyp_vm(struct kvm *kvm) { int ret = 0; + /* + * Synchronise with kvm_arch_prepare_memory_region(), as we + * prevent memslot modifications on a pVM that has been run. + */ + mutex_lock(&kvm->slots_lock); mutex_lock(&kvm->arch.config_lock); if (!pkvm_hyp_vm_is_created(kvm)) ret = __pkvm_create_hyp_vm(kvm); mutex_unlock(&kvm->arch.config_lock); + mutex_unlock(&kvm->slots_lock); return ret; } -- 2.53.0.1018.g2bb0e51243-goog