From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) (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 7B95824677B for ; Sat, 28 Mar 2026 05:32:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.185 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774675937; cv=none; b=ivyeBnPzRdGbHWVcM1/yx/c+KdNrqMG/TajavbqvmeSFRuwgWjyY9ATq0JH6HK1pCPVr4Q8GtdOaPy8lc1SsWyrd8y0z6yVUyWRHVRi6d1UmENNV0kTPFoNXA+qv6uZLXm9uTGm8W2whr7JlOs/uBKY8kmYZDk2LvRm+JzHVDFY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774675937; c=relaxed/simple; bh=p6lz8//QcBPyGWeIMhackmvndYzCYQ4x4eCh5/dmWP8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SI9TGdtcHbZasNyU75sHUb0Mjzxad8+Xqj42QIpZY4USg79g8+S5aAYyj8UQDCyjaAxjgOCutN8tqy2hatDtq2CtpdAmRRGoCzLJzW1snuNApJuN8+STPMvn6dq1LLKYGA1sUwEnAuszPZChAh3K//QmtzpS2LsntuhgFggtqJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=LiNvA6Gv; arc=none smtp.client-ip=91.218.175.185 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="LiNvA6Gv" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1774675932; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=zOJ9iIsuZvHL5cyLqdAmY9/F0c2z+tYW7wmPGa32F7A=; b=LiNvA6Gv9B9EL4M01WVY9OIl4HG+G7cPdHPvRKnlGleR/TB3rZQ3i3HILU6oWbDiumeg2q LFs98nuOGnPNP8afIRjenAYkQQAagYf8kpOdxwbTk1NJZk3oNlYk5VzL+iBneaoCBJ1Dj0 iyFmCK/OGLBW5mqJVrYyqbFVZF2oazI= From: Zenghui Yu To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, "Zenghui Yu (Huawei)" Subject: [PATCH] KVM: arm64: ptdump: Initialize parser_state before pgtable walk Date: Sat, 28 Mar 2026 13:31:55 +0800 Message-ID: <20260328053155.12219-1-zenghui.yu@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: "Zenghui Yu (Huawei)" If we go through the "need a bigger buffer" path in seq_read_iter(), which is likely to happen as we're dumping page tables, we will pass the populated-by-last-run st::parser_state to kvm_pgtable_walk()/kvm_ptdump_visitor(). As a result, the output of stage2_page_tables on my box looks like 0x0000000240000000-0x0000000000000000 17179869175G 1 0x0000000000000000-0x0000000000200000 2M 2 R px ux AF BLK 0x0000000000200000-0x0000000040000000 1022M 2 0x0000000040000000-0x0000000040200000 2M 2 R W PXNUXN AF BLK [...] Fix it by always initializing st::parser_state before starting a new pgtable walk. Besides, remove st::range as it's not used by note_page(); remove the explicit initialization of parser_state::start_address as it will be initialized in note_page() anyway. Signed-off-by: Zenghui Yu (Huawei) --- arch/arm64/kvm/ptdump.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c index 6a8836207a79..5dfd526c6dc9 100644 --- a/arch/arm64/kvm/ptdump.c +++ b/arch/arm64/kvm/ptdump.c @@ -22,7 +22,6 @@ struct kvm_ptdump_guest_state { struct ptdump_pg_state parser_state; struct addr_marker ipa_marker[MARKERS_LEN]; struct ptdump_pg_level level[KVM_PGTABLE_MAX_LEVELS]; - struct ptdump_range range[MARKERS_LEN]; }; static const struct ptdump_prot_bits stage2_pte_bits[] = { @@ -131,16 +130,7 @@ static struct kvm_ptdump_guest_state *kvm_ptdump_parser_create(struct kvm *kvm) st->ipa_marker[0].name = "Guest IPA"; st->ipa_marker[1].start_address = BIT(pgtable->ia_bits); - st->range[0].end = BIT(pgtable->ia_bits); - st->kvm = kvm; - st->parser_state = (struct ptdump_pg_state) { - .marker = &st->ipa_marker[0], - .level = -1, - .pg_level = &st->level[0], - .ptdump.range = &st->range[0], - .start_address = 0, - }; return st; } @@ -151,14 +141,18 @@ static int kvm_ptdump_guest_show(struct seq_file *m, void *unused) struct kvm_ptdump_guest_state *st = m->private; struct kvm *kvm = st->kvm; struct kvm_s2_mmu *mmu = &kvm->arch.mmu; - struct ptdump_pg_state *parser_state = &st->parser_state; struct kvm_pgtable_walker walker = (struct kvm_pgtable_walker) { .cb = kvm_ptdump_visitor, - .arg = parser_state, + .arg = &st->parser_state, .flags = KVM_PGTABLE_WALK_LEAF, }; - parser_state->seq = m; + st->parser_state = (struct ptdump_pg_state) { + .marker = &st->ipa_marker[0], + .level = -1, + .pg_level = &st->level[0], + .seq = m, + }; write_lock(&kvm->mmu_lock); ret = kvm_pgtable_walk(mmu->pgt, 0, BIT(mmu->pgt->ia_bits), &walker); -- 2.53.0