From beca1b97a21d81eae9cbd267ecc44b5d2193e60a Mon Sep 17 00:00:00 2001 From: Wei-Lin Chang Date: Fri, 14 Aug 2026 23:24:58 +0100 Subject: [PATCH] KVM: arm64: ptdump: Flush the last region 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() uses ptdump_pg_state.end_address to call the final note_page(), so also provide the end address. 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/ Reviewed-by: Dev Jain Tested-by: Dev Jain Signed-off-by: Wei-Lin Chang Reviewed-by: Marc Zyngier Signed-off-by: Will Deacon --- arch/arm64/kvm/ptdump.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c index c9140e22abcf..69899797dbad 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 +148,21 @@ 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], + .end_address = BIT(mmu->pgt->ia_bits), .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); - 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)