From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DB5C428BAB9 for ; Mon, 20 Jul 2026 08:53:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784537619; cv=none; b=VMfHzT/Le04YHqQif8+7nZ1qIZg6QjREcbmiTv0X9XBLhODveeZsc62ipswvlf5mzVi7yxa2gAk0QdgsGDPGkAFRrukfsTtYANZM7T67bxfCI5GRyT3624w8Z25CepHZz/pjCVj2NHCbf5FZ44iLv91/UuO4uVlT6pshJq/Rmw4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784537619; c=relaxed/simple; bh=GPcoRiOabqZcrKhtCc+010r/lyLlvM0NRgvjbYmd7Ls=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mFIxz9rEnLa8eRf4NHFsvOHquaDFBRY184iq8wakQTulJXTZ84aQgaxyOabO2X472judUoBkZwBPvjgD+v1JAF7mn0L8ZQrPgxwKtmVzuVHe1NX53W1kbULtUdsXLOZoykD9zJOoEApC3wn1O+t14Pg3Lwbxpbbwl0H4PI0+V8I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=a3p+arOH; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="a3p+arOH" 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 BC9C42B; Mon, 20 Jul 2026 01:53:31 -0700 (PDT) Received: from [10.164.19.57] (unknown [10.164.19.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D49D03FB82; Mon, 20 Jul 2026 01:53:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784537615; bh=GPcoRiOabqZcrKhtCc+010r/lyLlvM0NRgvjbYmd7Ls=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=a3p+arOH4IgRk1UdjlpkNlL7fdOacQQheCQ+AEjtvgt29y2yTQ+2P3ZI+RRoC88+z 2+C/Ph2/U6oUkMdI01CqAqixS5bJMyrn5sMtdEGWCGqEQ62x6ZOeL5haE9cSZKnn1q dzBpzHaZ2684ZHWnVMEbh9AcXc8LV6TcaGy/jANI= Message-ID: Date: Mon, 20 Jul 2026 14:23:29 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] KVM: arm64: ptdump: Flush the last region To: Wei-Lin Chang , 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 , Ryan Roberts , Sebastian Ene , Vincent Donnefort References: <20260717231233.2299068-1-weilin.chang@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20260717231233.2299068-1-weilin.chang@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 18/07/26 4:42 am, Wei-Lin Chang wrote: > Currently the stage-2 ptdump calls note_page() at each leaf entry visit. > This simply misses the output of the last region, because note_page() > only dumps output when it detects a change in level/prot, or when the > walk enters a next marker section. The last region in the guest IPA > space with the same level/prot is not dumped since there is no change > after it. > > To dump the final region, manually issue a note_page() call with address > BIT(ia_bits) (end of guest IPA space) and level == -1 to trigger a level > change after the last region. Additionally treat level == -1 as a last > flushing note_page() call and avoid dumping the name of the next marker > for this case. > > Fixes: 7c4f73548ed1 ("KVM: arm64: Register ptdump with debugfs on guest creation") > Reported-by: Sashiko AI > Closes: https://lore.kernel.org/kvmarm/20260630122758.891011F00A3A@smtp.kernel.org/ > Signed-off-by: Wei-Lin Chang > --- > arch/arm64/kvm/ptdump.c | 8 +++++--- > arch/arm64/mm/ptdump.c | 5 +++-- > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c > index c9140e22abcf..4096e4a92fae 100644 > --- a/arch/arm64/kvm/ptdump.c > +++ b/arch/arm64/kvm/ptdump.c > @@ -155,11 +155,13 @@ static int kvm_ptdump_guest_show(struct seq_file *m, void *unused) > .seq = m, > }; > > - write_lock(&kvm->mmu_lock); > + guard(write_lock)(&kvm->mmu_lock); The guard clause change has nothing to do with the fix I think? Although the change is small and the fix is for a recent commit so maybe we don't care having this in the same patch - not sure how strict kvm reviewers are about this : ) > ret = kvm_pgtable_walk(mmu->pgt, 0, BIT(mmu->pgt->ia_bits), &walker); > - write_unlock(&kvm->mmu_lock); > + if (ret) > + return ret; > + note_page(&st->parser_state.ptdump, BIT(mmu->pgt->ia_bits), -1, 0); > > - return ret; > + return 0; > } > > static int kvm_ptdump_guest_open(struct inode *m, struct file *file) > diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c > index ab9899ca1e5f..fed4e4407e0e 100644 > --- a/arch/arm64/mm/ptdump.c > +++ b/arch/arm64/mm/ptdump.c > @@ -194,6 +194,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, > struct ptdump_pg_state *st = container_of(pt_st, struct ptdump_pg_state, ptdump); > struct ptdump_pg_level *pg_level = st->pg_level; > static const char units[] = "KMGTPE"; > + bool flush = level == -1; Can we do something similar to what S1 ptdump does (note_page_flush in ptdump_walk_pgd). > ptdesc_t prot = 0; > > /* check if the current level has been folded dynamically */ > @@ -234,7 +235,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, > pg_level[st->level].num); > pt_dump_seq_puts(st->seq, "\n"); > > - if (addr >= st->marker[1].start_address) { > + if (addr >= st->marker[1].start_address && !flush) { > st->marker++; > pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > } > @@ -244,7 +245,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, > st->level = level; > } > > - if (addr >= st->marker[1].start_address) { > + if (addr >= st->marker[1].start_address && !flush) { > st->marker++; > pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > }