From patchwork Fri Jun 21 12:32:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Ene X-Patchwork-Id: 13707533 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 E5BB7C2BBCA for ; Fri, 21 Jun 2024 12:32:58 +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-Type:Cc:To:From: Subject:Message-ID:Mime-Version:Date:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=PMXX+jk8CoyrGDajp1NmkklStgSxsIyqK7BV0cb2dR4=; b=0pN0qRzMM3QcaebdjCOcbRXmqA 0XwBumRL8c7PJd8wtc1ax7z3GK/Via5+xGTEj8hZLqDxV+RQkslDZyDcfTa2unugrQRhTq863SRKT 5KxZ/sPi/KFGuP2qo8LbrLggRbCQNIgC/YkYX3jH+lQY/G2witegLTtfK8uf1ZSZvGFHI1s0sVMk7 nZLU/ggQPzX2t30VxpTS0sF/IgQSzLZSnClFs5M1ngUJBqEgCO0B1CbJW9Z/5gfMwxws+M4USfKYh il86FSNgIYyICoIlNYWza7YXOnlfkw0meFWqbwJfmBrHpxpcW1Da96IFAVLyUSR5fhYVQ5WfeF0PT 8QQGJTDA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKdRb-0000000997I-0qat; Fri, 21 Jun 2024 12:32:43 +0000 Received: from mail-wm1-x349.google.com ([2a00:1450:4864:20::349]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sKdRX-0000000995U-2Cxj for linux-arm-kernel@lists.infradead.org; Fri, 21 Jun 2024 12:32:41 +0000 Received: by mail-wm1-x349.google.com with SMTP id 5b1f17b1804b1-421759c3556so15831925e9.1 for ; Fri, 21 Jun 2024 05:32:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1718973157; x=1719577957; darn=lists.infradead.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=PMXX+jk8CoyrGDajp1NmkklStgSxsIyqK7BV0cb2dR4=; b=EEEpuH6vW6L4DiXgwQkwHVAOWVXpEAvLgvF6iUKau9IL8dIcYJ2xvRxC53HmPY0bXq OjIG58BKEgFoYlerk5WRNwx+DaRspVNYl+89Ipihl5E7G7kt4mx8hJ7goSrnXXcWMo5l UeWmZHREBDOclch20mmTz1Q7KcxeXA5a7VOkD/bio/9lFbuF+T/jIRNFN5rOArtUWV3x P5JTIQsCnkFpHUR+M7j/tTmM+GgXE9fDMqcOyf8gf3s0pEhRgRS33RMTgeykxfRUdVeH pbf4jFMdBAgbNpejSn3tFCHpj/hmFbj3hCzD3Nsyz1uJTz+5Ooh7NIb8j/GXZwKFpiwg gU+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718973157; x=1719577957; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=PMXX+jk8CoyrGDajp1NmkklStgSxsIyqK7BV0cb2dR4=; b=FZ/0/lkQkZlU1ec7xxuaWa2tqCCHvBAkiUYBLGgQ5xIeBUoOLf3SmF9KbhWkaB0oMa jP9S15uYMRfO8xnJZcBntUdxqRmc+2DxM06lgLTBl1QHqnjmuYqeBXSOQSTuEPsvKf4w PNebP2xhG3E+ENFmiTuAPyisKx8RzH7k9242lquSwOpNbyuqeiPYm0Tv2Y3BoB0rSvZ4 tOVXn7czo3zsE+qQZ92COB8/9iNXFeKnpW7f4LcHeNLAxK2El35KS/XCGvClPdgCphfI 9b6+QEmyOC40cnr/DVFHK0qIXz1HpbXlCImnk+86rYPio5PnnO8+azEVagnXDbv+fdAz 8rXw== X-Forwarded-Encrypted: i=1; AJvYcCUjFPQUn8fhxp9+5fQalQ9GOcKLJxjdKX1tOtUxRnhZsOAt0KucnUmutTp5u7kb0PUaDIJD2qyCUK90erKgP+7k4+/BbmCxitUHc4hb/8SdjnXogOA= X-Gm-Message-State: AOJu0YzA23AZ/m3ZlZ9uVxq0N31inLRjTNfJkWkhiwKkmDQJLIVIiBte 4kUeLQB9tQfcFqSd5EfEUQv/cLSLl37Dtd4Q7PRFRKj1pPUcisu/do/H+epcqL1GGO9Y0b5lo3Q jFz3Jezir/m3WJ4gzH5Kf3vPM4g== X-Google-Smtp-Source: AGHT+IEF1VDRkJcqgGZr7F6pw8YsXYfWulpGqWDu9ViK9xi/OKgbp+BBhdGW5TbYitbNz0PnBDObFBUGJcfUzlV7l5c= X-Received: from sebkvm.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:cd5]) (user=sebastianene job=sendgmr) by 2002:a05:600c:511d:b0:421:de31:7b with SMTP id 5b1f17b1804b1-42474ca44c6mr1852195e9.0.1718973157245; Fri, 21 Jun 2024 05:32:37 -0700 (PDT) Date: Fri, 21 Jun 2024 12:32:24 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.45.2.741.gdbec12cfda-goog Message-ID: <20240621123230.1085265-1-sebastianene@google.com> Subject: [PATCH v7 0/6] arm64: ptdump: View the second stage page-tables From: Sebastian Ene To: akpm@linux-foundation.org, alexghiti@rivosinc.com, ankita@nvidia.com, ardb@kernel.org, catalin.marinas@arm.com, christophe.leroy@csgroup.eu, james.morse@arm.com, vdonnefort@google.com, mark.rutland@arm.com, maz@kernel.org, oliver.upton@linux.dev, rananta@google.com, ryan.roberts@arm.com, sebastianene@google.com, shahuang@redhat.com, suzuki.poulose@arm.com, will@kernel.org, yuzenghui@huawei.com Cc: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-team@android.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240621_053239_626917_72695F90 X-CRM114-Status: GOOD ( 24.15 ) 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 Hi, This series extends the ptdump support to allow dumping the guest stage-2 pagetables. When CONFIG_PTDUMP_STAGE2_DEBUGFS is enabled, ptdump registers '/sys/debug/kvm//stage2_page_tables' entry with debugfs upon guest creation. This allows userspace tools (eg. cat) to dump the stage-2 pagetables by reading the registered file. Reading the debugfs file shows stage-2 memory ranges in following format: Below is the output of a guest stage-2 pagetable dump running under Qemu: ---[ IPA bits 33 start lvl 2 ]--- 0x0000000000000000-0x0000000080000000 2G PGD 0x0000000080000000-0x0000000080c00000 12M PGD R W AF BLK 0x0000000080c00000-0x0000000080e00000 2M PGD XN R W AF BLK 0x0000000080e00000-0x0000000081000000 2M PGD R W AF BLK 0x0000000081000000-0x0000000081400000 4M PGD XN R W AF BLK 0x0000000081400000-0x000000008fe00000 234M PGD 0x000000008fe00000-0x0000000090000000 2M PGD XN R W AF BLK 0x0000000090000000-0x00000000fa000000 1696M PGD 0x00000000fa000000-0x00000000fe000000 64M PGD XN R W AF BLK 0x00000000fe000000-0x0000000100000000 32M PGD 0x0000000100000000-0x0000000101c00000 28M PGD XN R W AF BLK 0x0000000101c00000-0x0000000102000000 4M PGD 0x0000000102000000-0x0000000102200000 2M PGD XN R W AF BLK 0x0000000102200000-0x000000017b000000 1934M PGD 0x000000017b000000-0x0000000180000000 80M PGD XN R W AF BLK Link to v6: https://lore.kernel.org/all/20240220151035.327199-1-sebastianene@google.com/ Link to v5: https://lore.kernel.org/all/20240207144832.1017815-2-sebastianene@google.com/ Link to v4: https://lore.kernel.org/all/20231218135859.2513568-2-sebastianene@google.com/ Link to v3: https://lore.kernel.org/all/20231115171639.2852644-2-sebastianene@google.com/ Changelog: v6 -> v7: * Reworded commit for this patch : [PATCH v6 2/6] arm64: ptdump: Expose the attribute parsing functionality * fixed minor conflicts in the struct pg_state definition * moved the kvm_ptdump_guest_registration in the * kvm_arch_create_vm_debugfs * reset the parse state before walking the pagetables * copy the level name to the pg_level buffer v5 -> v6: * don't return an error if the kvm_arch_create_vm_debugfs fails to initialize (ref. https://lore.kernel.org/all/20240216155941.2029458-1-oliver.upton@linux.dev/) * fix use-after-free suggested by getting a reference to the KVM struct while manipulating the debugfs files and put the reference on the file close. * do all the allocations at once for the ptdump parser state tracking and simplify the initialization. * move the ptdump parser state initialization as part of the file_open * create separate files for printing the guest stage-2 pagetable configuration such as: the start level of the pagetable walk and the number of bits used for the IPA space representation. * fixed the wrong header format for the newly added file * include missing patch which hasn't been posted on the v5: "KVM-arm64-Move-pagetable-definitions-to-common-heade.patch" v4 -> v5: * refactorization: split the series into two parts as per the feedback received from Oliver. Introduce the base support which allows dumping of the guest stage-2 pagetables. * removed the *ops* struct wrapper built on top of the file_ops and simplify the ptdump interface access. * keep the page table walker away from the ptdump specific code v3 -> current_version: * refactorization: moved all the **KVM** specific components under kvm/ as suggested by Oliver. Introduced a new file arm64/kvm/ptdump.c which handled the second stage translation. re-used only the display portion from mm/ptdump.c * pagetable snapshot creation now uses memory donated from the host. The memory is no longer shared with the host as this can pose a security risk if the host has access to manipulate the pagetable copy while the hypervisor iterates it. * fixed a memory leak: while memory was used from the memcache for building the snapshot pagetable, it was no longer giving back the pages to the host for freeing. A separate array was introduced to keep track of the pages allocated from the memcache. v2 -> v3: * register the stage-2 debugfs entry for the host under /sys/debug/kvm/host_stage2_page_tables and in /sys/debug/kvm//stage2_page_tables for guests. * don't use a static array for parsing the attributes description, generate it dynamically based on the number of pagetable levels * remove the lock that was guarding the seq_file private inode data, and keep the data private to the open file session. * minor fixes & renaming of CONFIG_NVHE_EL2_PTDUMP_DEBUGFS to CONFIG_PTDUMP_STAGE2_DEBUGFS v1 -> v2: * use the stage-2 pagetable walker for dumping descriptors instead of the one provided by ptdump. * support for guests pagetables dumping under VHE/nVHE non-protected Thanks, Sebastian Ene (6): KVM: arm64: Move pagetable definitions to common header arm64: ptdump: Expose the attribute parsing functionality arm64: ptdump: Use the mask from the state structure KVM: arm64: Register ptdump with debugfs on guest creation KVM: arm64: Initialize the ptdump parser with stage-2 attributes KVM: arm64: Expose guest stage-2 pagetable config to debugfs arch/arm64/include/asm/kvm_pgtable.h | 42 +++++ arch/arm64/include/asm/ptdump.h | 42 ++++- arch/arm64/kvm/Kconfig | 14 ++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/arm.c | 2 + arch/arm64/kvm/hyp/pgtable.c | 42 ----- arch/arm64/kvm/kvm_ptdump.h | 20 ++ arch/arm64/kvm/ptdump.c | 272 +++++++++++++++++++++++++++ arch/arm64/mm/ptdump.c | 50 +---- 9 files changed, 402 insertions(+), 83 deletions(-) create mode 100644 arch/arm64/kvm/kvm_ptdump.h create mode 100644 arch/arm64/kvm/ptdump.c