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[139.178.88.99]) by mx.google.com with ESMTPS id h12-20020a170902f54c00b001d3c93f2363si776954plf.158.2023.12.18.06.00.37 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 06:00:37 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-3788-ouuuleilei=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20230601 header.b=Sgpe9Tkw; spf=pass (google.com: domain of linux-kernel+bounces-3788-ouuuleilei=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) smtp.mailfrom="linux-kernel+bounces-3788-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 4188E28370F for ; Mon, 18 Dec 2023 14:00:37 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 115793A1AF; Mon, 18 Dec 2023 13:59:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Sgpe9Tkw" X-Original-To: linux-kernel@vger.kernel.org Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F44937862 for ; Mon, 18 Dec 2023 13:59:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--sebastianene.bounces.google.com Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-5cf4696e202so38357887b3.2 for ; Mon, 18 Dec 2023 05:59:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702907991; x=1703512791; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=gY15YxDdKSZ0D8Iy0CW6yGr0u1mIBXiISHgw6mfVrxM=; b=Sgpe9Tkw1MxJx/Hj1mD6aOLDz9LRjH7ZfzWQJISlJitQgeQhjqtlvBhFSxK/XA/lZY iGqehjauOHgNbPdlXrfdtGmLTuECaSmcJSfoJlI6bwn5MxSYGBB5TtpfxiIeWSE5/EpF UTOhBkQUeNsZePUOdIPY0F9pELqsmoTyRhkKrgcw5YEpaX3TlmubJVZThV4yokhxRF4s 24LutZASDVRqJcXX2c5lOx+6MlMc++Z54FnvBnw9zZo94h9fKg8a0C3zet2CUrUe/Z4r KOLCPryjsZKXkERoIjc8NNxahVIcLP68sF338B7hnn5sWLrOA56bMv1s7hRFfOgnOhyc 45ZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702907991; x=1703512791; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=gY15YxDdKSZ0D8Iy0CW6yGr0u1mIBXiISHgw6mfVrxM=; b=haBEdiu3wYz7J1o4lcmu88aaO6t/wVuMIHt1EoyJNKsWC/nUQpkz1G5oNxAPd8Mjq+ OcJ83HNCSDU2XwuCtkN8oDcjk5RrjEAig2G5MqjtTvVuj1SU5fIjjqaqLK/+crzsEoAO NYa9QyUpQ1geINBZs/INlIvsysJxErLvSwyHa1g6zYp5CLmRXATCR2BEu8zVmZcyAnlG F8VTF1mxSnynKnkoJa7hw+zNsvZxPkf5QzhhYi4qwXKRcznguzJw3tmHZdmMVHp34j3S OS7HpGijhK+ivUCtRJ8WP3wT7Y0URQu9cPCYOCXgacO81vlnNQ9iG29gTch7KTgVkur2 i9Gw== X-Gm-Message-State: AOJu0Yz1vxkycVHP7IoGHBFmDYzh9i6eGwom5XzvqslST7MA1ZaxNxBm d3NG1XP9klAF4q5KiUJmNDQoLU8LLzsng6AEyy8= X-Received: from sebkvm.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:cd5]) (user=sebastianene job=sendgmr) by 2002:a05:690c:385:b0:5d3:a348:b0c0 with SMTP id bh5-20020a05690c038500b005d3a348b0c0mr2399920ywb.5.1702907991281; Mon, 18 Dec 2023 05:59:51 -0800 (PST) Date: Mon, 18 Dec 2023 13:58:52 +0000 In-Reply-To: <20231218135859.2513568-2-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231218135859.2513568-2-sebastianene@google.com> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20231218135859.2513568-4-sebastianene@google.com> Subject: [PATCH v4 02/10] KVM: arm64: Add ptdump registration with debugfs for the stage-2 pagetables From: Sebastian Ene To: will@kernel.org, Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , catalin.marinas@arm.com, mark.rutland@arm.com, akpm@linux-foundation.org, maz@kernel.org Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com, vdonnefort@google.com, qperret@google.com, smostafa@google.com, Sebastian Ene X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1785628498176440465 X-GMAIL-MSGID: 1785628498176440465 While arch/*/mem/ptdump handles the kernel pagetable dumping code, introduce KVM/ptdump which deals with the stage-2 pagetables. The separation is necessary because most of the definitions from the stage-2 pagetable reside in the KVM path and we will be invoking functionality **specific** to KVM. This registers a wrapper on top of debugfs_create_file which allows us to hook callbacks on the debugfs open/show/close. The callbacks are used to prepare the display portion of the pagetable dumping code. Guard this functionality under the newly introduced PTDUMP_STAGE2_DEBUGFS. Signed-off-by: Sebastian Ene --- arch/arm64/kvm/Kconfig | 13 +++++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/arm.c | 2 + arch/arm64/kvm/kvm_ptdump.h | 18 +++++++ arch/arm64/kvm/ptdump.c | 96 +++++++++++++++++++++++++++++++++++++ 5 files changed, 130 insertions(+) create mode 100644 arch/arm64/kvm/kvm_ptdump.h create mode 100644 arch/arm64/kvm/ptdump.c diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 83c1e09be..0014e55e2 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -71,4 +71,17 @@ config PROTECTED_NVHE_STACKTRACE If unsure, or not using protected nVHE (pKVM), say N. +config PTDUMP_STAGE2_DEBUGFS + bool "Present the stage-2 pagetables to debugfs" + depends on PTDUMP_DEBUGFS && KVM + default n + help + Say Y here if you want to show the stage-2 kernel pagetables + layout in a debugfs file. This information is only useful for kernel developers + who are working in architecture specific areas of the kernel. + It is probably not a good idea to enable this feature in a production + kernel. + + If in doubt, say N. + endif # VIRTUALIZATION diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index c0c050e53..190eac175 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -23,6 +23,7 @@ kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ vgic/vgic-its.o vgic/vgic-debug.o kvm-$(CONFIG_HW_PERF_EVENTS) += pmu-emul.o pmu.o +kvm-$(CONFIG_PTDUMP_STAGE2_DEBUGFS) += ptdump.o always-y := hyp_constants.h hyp-constants.s diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e5f75f1f1..ee8d7cb67 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include @@ -2592,6 +2593,7 @@ static __init int kvm_arm_init(void) if (err) goto out_subs; + kvm_ptdump_register_host(); kvm_arm_initialised = true; return 0; diff --git a/arch/arm64/kvm/kvm_ptdump.h b/arch/arm64/kvm/kvm_ptdump.h new file mode 100644 index 000000000..98b595ce8 --- /dev/null +++ b/arch/arm64/kvm/kvm_ptdump.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +// +// Copyright (C) Google, 2023 +// Author: Sebastian Ene + +#ifndef __KVM_PTDUMP_H +#define __KVM_PTDUMP_H + +#include + + +#ifdef CONFIG_PTDUMP_STAGE2_DEBUGFS +void kvm_ptdump_register_host(void); +#else +static inline void kvm_ptdump_register_host(void) { } +#endif /* CONFIG_PTDUMP_STAGE2_DEBUGFS */ + +#endif /* __KVM_PTDUMP_H */ diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c new file mode 100644 index 000000000..5816fc632 --- /dev/null +++ b/arch/arm64/kvm/ptdump.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Debug helper used to dump the stage-2 pagetables of the system and their +// associated permissions. +// +// Copyright (C) Google, 2023 +// Author: Sebastian Ene + +#include +#include +#include + +#include +#include + + +struct kvm_ptdump_register { + void *(*get_ptdump_info)(struct kvm_ptdump_register *reg); + void (*put_ptdump_info)(void *priv); + int (*show_ptdump_info)(struct seq_file *m, void *v); + void *priv; +}; + +static int kvm_ptdump_open(struct inode *inode, struct file *file); +static int kvm_ptdump_release(struct inode *inode, struct file *file); +static int kvm_ptdump_show(struct seq_file *m, void *); + +static const struct file_operations kvm_ptdump_fops = { + .open = kvm_ptdump_open, + .read = seq_read, + .llseek = seq_lseek, + .release = kvm_ptdump_release, +}; + +static int kvm_ptdump_open(struct inode *inode, struct file *file) +{ + struct kvm_ptdump_register *reg = inode->i_private; + void *info = NULL; + int ret; + + if (reg->get_ptdump_info) { + info = reg->get_ptdump_info(reg); + if (!info) + return -ENOMEM; + } + + if (!reg->show_ptdump_info) + reg->show_ptdump_info = kvm_ptdump_show; + + ret = single_open(file, reg->show_ptdump_info, info); + if (ret && reg->put_ptdump_info) + reg->put_ptdump_info(info); + + return ret; +} + +static int kvm_ptdump_release(struct inode *inode, struct file *file) +{ + struct kvm_ptdump_register *reg = inode->i_private; + struct seq_file *seq_file = file->private_data; + + if (reg->put_ptdump_info) + reg->put_ptdump_info(seq_file->private); + + return 0; +} + +static int kvm_ptdump_show(struct seq_file *m, void *) +{ + return -EINVAL; +} + +static void kvm_ptdump_debugfs_register(struct kvm_ptdump_register *reg, + const char *name, struct dentry *parent) +{ + debugfs_create_file(name, 0400, parent, reg, &kvm_ptdump_fops); +} + +static struct kvm_ptdump_register host_reg; + +void kvm_ptdump_register_host(void) +{ + if (!is_protected_kvm_enabled()) + return; + + kvm_ptdump_debugfs_register(&host_reg, "host_page_tables", + kvm_debugfs_dir); +} + +static int __init kvm_host_ptdump_init(void) +{ + host_reg.priv = (void *)host_s2_pgtable_pages(); + return 0; +} + +device_initcall(kvm_host_ptdump_init);