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 E083A3A257A for ; Sat, 25 Jul 2026 17:17:02 +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=1784999826; cv=none; b=XOnIO99sx1JmBy+RR1fBVT3ZN+YGIWyLrKASBaXJ7k73eSnqTbujevV8a20U7nTSCIi1745SA6zgd+nlIMlD3UVeP8dLuOAzjfor4xEnmzdy+7HV7GQlWEcLHBuah+7+noP1F1Zbz35Atj79fmU5jnf0ywW/vtCZj5mLwyX6diM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784999826; c=relaxed/simple; bh=+omX/Tl/a3q8wWs0/af+Q2F7EKuxKZ0L0Z4YWQFCw5I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=B6cR0ytEkukhl8DGZJd1yIFlEDBUX7UROFRZ42MyBbllY8CYKkmmzch1HECzT6xAU7/sE/2bhsBYrYowqZ063SamE5/ylPsgwXbRqRHRFz+2CMcYFn3QRDjIy4KnJPwJeebVKQFtmXHIKh8NW6hHnZB1nnamv5zTFS2FCEqohJs= 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=Rd95tlal; 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="Rd95tlal" 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 E8C131476; Sat, 25 Jul 2026 10:16:51 -0700 (PDT) Received: from [10.163.131.227] (unknown [10.163.131.227]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 48FBB3F9AB; Sat, 25 Jul 2026 10:16:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784999816; bh=+omX/Tl/a3q8wWs0/af+Q2F7EKuxKZ0L0Z4YWQFCw5I=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Rd95tlalpS7RDjQuSTC6ghjgE6h3pX1mN7C+5aPsmZ4bZifOdScIeoMZiD9sHma90 keWMVLOOFKrEZc+uUI088msUtDYJF1x0Sjx6+elNJ03fT1HsPVyzUUoif0bUqhrF7D RVDiUTMJpkKHCE5zFohv/PFXn1SwYUK0ndD8yNik= Message-ID: Date: Sat, 25 Jul 2026 22:46:37 +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 v2 2/2] 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 , Anshuman Khandual , Ryan Roberts , "David Hildenbrand (Arm)" , Matt Fleming , Ard Biesheuvel , Mark Rutland , Sebastian Ene , Vincent Donnefort , Sashiko AI References: <20260724185431.2990395-1-weilin.chang@arm.com> <20260724185431.2990395-3-weilin.chang@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20260724185431.2990395-3-weilin.chang@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 25/07/26 12:24 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. > > Call note_page_flush() to dump the final region. note_page_flush() > expects ptdump_state.range[] to be initialized to the range of the > address space, so also do that. > > Also change the second marker's start address to ULONG_MAX so we never > cross it. This avoids dumping redundant marker names (which are NULL), > and advancing beyond the end of the marker array. > > 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 | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c > index c9140e22abcf..222577163d2b 100644 > --- a/arch/arm64/kvm/ptdump.c > +++ b/arch/arm64/kvm/ptdump.c > @@ -130,7 +130,7 @@ static struct kvm_ptdump_guest_state *kvm_ptdump_parser_create(struct kvm_s2_mmu > } > > st->ipa_marker[0].name = "Guest IPA"; > - st->ipa_marker[1].start_address = BIT(pgtable->ia_bits); > + st->ipa_marker[1].start_address = ULONG_MAX; > > st->mmu = mmu; > return st; > @@ -148,18 +148,26 @@ static int kvm_ptdump_guest_show(struct seq_file *m, void *unused) > .flags = KVM_PGTABLE_WALK_LEAF, > }; > > + guard(write_lock)(&kvm->mmu_lock); > st->parser_state = (struct ptdump_pg_state) { > .marker = &st->ipa_marker[0], > .level = -1, > .pg_level = &st->level[0], > .seq = m, > + .ptdump = { > + .range = (struct ptdump_range[]){ > + {0, BIT(mmu->pgt->ia_bits)}, > + {0, 0} > + } I am having a real hard time reading that indentation :) you could make it look like what we have currently in ptdump_walk(). The code looks sensible to me. I have also tested by booting a Linux VM inside a Linux VM on a Mac, and I see the stage2 ptdump prints the last range upto the ia_bits correctly. So with the nit addressed above: Reviewed-by: Dev Jain Tested-by: Dev Jain > + } > }; > > - write_lock(&kvm->mmu_lock); > ret = kvm_pgtable_walk(mmu->pgt, 0, BIT(mmu->pgt->ia_bits), &walker); > - write_unlock(&kvm->mmu_lock); > + if (ret) > + return ret; > + note_page_flush(&st->parser_state.ptdump); > > - return ret; > + return 0; > } > > static int kvm_ptdump_guest_open(struct inode *m, struct file *file)