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KVM: arm64: ptdump: Flush the last region

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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: 7c4f73548e ("KVM: arm64: Register ptdump with debugfs on guest creation")
Reported-by: Sashiko AI <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/kvmarm/20260630122758.891011F00A3A@smtp.kernel.org/
Reviewed-by: Dev Jain <dev.jain@arm.com>
Tested-by: Dev Jain <dev.jain@arm.com>
Signed-off-by: Wei-Lin Chang <weilin.chang@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Wei-Lin Chang 2026-08-14 23:24:58 +01:00 committed by Will Deacon
parent 902caade3c
commit beca1b97a2
1 changed files with 7 additions and 4 deletions
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11
arch/arm64/kvm/ptdump.c
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@ -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)