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 B0EEEC43458 for ; Tue, 30 Jun 2026 12:12:00 +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=66lti4rc67S1MgW6C9Fx0qKsel1IWwwp0ZGwruFCjuE=; b=EiPpa+3cCUAYu7wNal02eQs+tq La2rKfWX6E1WG1WOz7d7MsmfR6TjqdqKnLXPscoerVVwTYfF+nvozd1kST4MfPQfmfxwzNLtGIWR/ xS9cddwfcF/4d7DQE6BzfKHD3CCRY+u8ESvj9M3QiKQ5bPZRj8EfiWwBEYH1YtrhDQDe3KXlVBn9g sIIK0Ik89E3/P+vbivi1CJ8MA9qeQIoSw5ykoeV8L68oxP6XEEEOewpWFd2S+Y7MZ72JQ+baYxzTZ Batb+OU8NdcAewMJb2/Lie4yBocg/qka8hxZKGGFGN5nKaumuEryidz/nKUk3cVcDhkeYunxeqar4 39LfSb3w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1weXJh-0000000GwXD-16oC; Tue, 30 Jun 2026 12:11:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1weXJS-0000000GwMs-3T07 for linux-arm-kernel@lists.infradead.org; Tue, 30 Jun 2026 12:11:40 +0000 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 341F32C46; Tue, 30 Jun 2026 05:11:33 -0700 (PDT) Received: from workstation-e142269.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7BFA43F905; Tue, 30 Jun 2026 05:11:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782821497; bh=N46ez0DDf1cDWzY7fWrdPqdcU1IQG980oeawrFJDpIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vaXLvhl7Tp04uLTI3rg7VSfVqsqMC/4Sqwwj8/ShCwzmZj84LwmWFcz2BPWBN1Eby x8/3xD18EtcB2AyMQ0UiM3M/zPGJN8cIQJg47sjGnAY8C6Uuf0NaHiFMniwP/DF3mZ mrn0LaPQ4CPz0PZsGANef0Wrk5R43RQqf9bDG+3s= From: Wei-Lin Chang To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Marc Zyngier , Oliver Upton , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Itaru Kitayama , Sebastian Ene , Wei-Lin Chang Subject: [PATCH v2 6/6] KVM: arm64: ptdump: Introduce the shadow ptdump file Date: Tue, 30 Jun 2026 13:10:05 +0100 Message-ID: <20260630121005.1130996-7-weilin.chang@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260630121005.1130996-1-weilin.chang@arm.com> References: <20260630121005.1130996-1-weilin.chang@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260630_051139_080387_C71D6943 X-CRM114-Status: GOOD ( 17.31 ) 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 Create a ptdump file for all shadow page tables. It will dump out all valid shadow page tables at the time of request, with the mmu's index, guest VTCR_EL2, VTTBR_EL2, and whether the guest stage-2 is enabled or not. Also detach the nested mmu array under the mmu_lock in kvm_arch_flush_shadow_all() so readers cannot race with the array being removed, then free the old array after dropping the lock. Signed-off-by: Wei-Lin Chang --- arch/arm64/kvm/nested.c | 12 ++++++-- arch/arm64/kvm/ptdump.c | 61 ++++++++++++++++++++++++++++++++++++++++- 2 files changed, 69 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 6435efd65cb5..17a180ddf6ca 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -1283,6 +1283,7 @@ void kvm_nested_s2_flush(struct kvm *kvm) void kvm_arch_flush_shadow_all(struct kvm *kvm) { + struct kvm_s2_mmu *mmus; int i; for (i = 0; i < kvm->arch.nested_mmus_size; i++) { @@ -1291,9 +1292,14 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm) if (!WARN_ON(atomic_read(&mmu->refcnt))) kvm_free_stage2_pgd(mmu); } - kvfree(kvm->arch.nested_mmus); - kvm->arch.nested_mmus = NULL; - kvm->arch.nested_mmus_size = 0; + + scoped_guard(write_lock, &kvm->mmu_lock) { + mmus = kvm->arch.nested_mmus; + kvm->arch.nested_mmus = NULL; + kvm->arch.nested_mmus_size = 0; + } + + kvfree(mmus); kvm_uninit_stage2_mmu(kvm); } diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c index 40f93b7c7ad9..1649eaa75798 100644 --- a/arch/arm64/kvm/ptdump.c +++ b/arch/arm64/kvm/ptdump.c @@ -181,6 +181,50 @@ static int kvm_ptdump_guest_canonical_show(struct seq_file *m, void *unused) return 0; } +static int kvm_ptdump_guest_nested_show(struct seq_file *m, void *unused) +{ + int ret = 0, i; + struct kvm_ptdump_guest_state *st = m->private; + struct kvm *kvm = st->kvm; + struct kvm_pgtable_walker walker = (struct kvm_pgtable_walker) { + .cb = kvm_ptdump_visitor, + .arg = &st->parser_state, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + + guard(write_lock)(&kvm->mmu_lock); + + if (!kvm->arch.nested_mmus) + return 0; + + for (i = 0; i < kvm->arch.nested_mmus_size; i++) { + struct kvm_s2_mmu *mmu = &kvm->arch.nested_mmus[i]; + + if (!mmu->pgt) + continue; + + if (kvm_s2_mmu_valid(mmu)) { + memset(st, 0, sizeof(*st)); + ret = kvm_ptdump_parser_init(st, kvm, mmu->pgt); + if (ret) + return ret; + st->parser_state = (struct ptdump_pg_state) { + .marker = &st->ipa_marker[0], + .level = -1, + .pg_level = &st->level[0], + .seq = m, + }; + seq_printf(m, "nested mmu %d VTCR: 0x%016llx VTTBR: 0x%016llx s2: %s\n", + i, mmu->tlb_vtcr, mmu->tlb_vttbr, + mmu->nested_stage2_enabled ? "enabled" : "disabled"); + ret = kvm_pgtable_walk(mmu->pgt, 0, BIT(mmu->pgt->ia_bits), &walker); + if (ret) + return ret; + } + } + return ret; +} + static int kvm_ptdump_guest_open(struct inode *m, struct file *file, int (*show)(struct seq_file *, void *)) { @@ -212,6 +256,11 @@ static int kvm_ptdump_guest_canonical_open(struct inode *m, struct file *file) return kvm_ptdump_guest_open(m, file, kvm_ptdump_guest_canonical_show); } +static int kvm_ptdump_guest_nested_open(struct inode *m, struct file *file) +{ + return kvm_ptdump_guest_open(m, file, kvm_ptdump_guest_nested_show); +} + static int kvm_ptdump_guest_close(struct inode *m, struct file *file) { struct kvm *kvm = m->i_private; @@ -230,6 +279,13 @@ static const struct file_operations kvm_ptdump_guest_canonical_fops = { .release = kvm_ptdump_guest_close, }; +static const struct file_operations kvm_ptdump_guest_nested_fops = { + .open = kvm_ptdump_guest_nested_open, + .read = seq_read, + .llseek = seq_lseek, + .release = kvm_ptdump_guest_close, +}; + static int kvm_pgtable_range_show(struct seq_file *m, void *unused) { struct kvm *kvm = m->private; @@ -307,6 +363,9 @@ void kvm_s2_ptdump_create_debugfs(struct kvm *kvm) kvm, &kvm_pgtable_range_fops); debugfs_create_file("stage2_levels", 0400, kvm->debugfs_dentry, kvm, &kvm_pgtable_levels_fops); - if (cpus_have_final_cap(ARM64_HAS_NESTED_VIRT)) + if (cpus_have_final_cap(ARM64_HAS_NESTED_VIRT)) { kvm->arch.debugfs_nv_dentry = debugfs_create_dir("nested", kvm->debugfs_dentry); + debugfs_create_file("shadow_page_tables", 0400, kvm->arch.debugfs_nv_dentry, + kvm, &kvm_ptdump_guest_nested_fops); + } } -- 2.43.0