On Tue, Aug 20, 2024 at 03:25:13PM +0100, Marc Zyngier wrote:

On Tue, 20 Aug 2024 15:13:27 +0100,
Sebastian Ene [off-list ref] wrote:

quoted

On Tue, Aug 20, 2024 at 02:49:04PM +0100, Marc Zyngier wrote:

quoted

On Fri, 16 Aug 2024 13:39:03 +0100,
Sebastian Ene [off-list ref] wrote:

quoted

Printing the descriptor attributes requires accessing a mask which has a
different set of attributes for stage-2. In preparation for adding support
for the stage-2 pagetables dumping, use the mask from the local context
and not from the globally defined pg_level array. Store a pointer to
the pg_level array in the ptdump state structure. This will allow us to
extract the mask which is wrapped in the pg_level array and use it for
descriptor parsing in the note_page.

Signed-off-by: Sebastian Ene <redacted>
---
 arch/arm64/include/asm/ptdump.h |  1 +
 arch/arm64/mm/ptdump.c          | 13 ++++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index bd5d3ee3e8dc..71a7ed01153a 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h

@@ -44,6 +44,7 @@ struct ptdump_pg_level {
  */
 struct ptdump_pg_state {
 	struct ptdump_state ptdump;
+	struct ptdump_pg_level *pg_level;
 	struct seq_file *seq;
 	const struct addr_marker *marker;
 	const struct mm_struct *mm;

diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
index 404751fd30fe..ca53ef274a8b 100644
--- a/arch/arm64/mm/ptdump.c
+++ b/arch/arm64/mm/ptdump.c

@@ -117,7 +117,7 @@ static const struct ptdump_prot_bits pte_bits[] = {
 	}
 };
 
-static struct ptdump_pg_level pg_level[] __ro_after_init = {
+static struct ptdump_pg_level kernel_pg_levels[] __ro_after_init = {

Hi Marc,

 

quoted

Do you actually need this sort of renaming? Given that it is static,
this looks like some slightly abusive repainting which isn't warranted
here.

I applied Will's suggestion from
https://lore.kernel.org/all/20240705111229.GB9231@willie-the-truck/ (local)

quoted

I also didn't understand the commit message: you're not tracking any
mask here, but a page table level. You are also not using it for
anything yet, see below.

and I missed updating the commit message.

quoted

quoted

 	{ /* pgd */
 		.name	= "PGD",
 		.bits	= pte_bits,

@@ -192,6 +192,7 @@ void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 	       u64 val)
 {
 	struct ptdump_pg_state *st = container_of(pt_st, struct ptdump_pg_state, ptdump);
+	struct ptdump_pg_level *pg_level = st->pg_level;

This is what I mean. What is this pg_level used for?

I make use of it to extract the name based on the level. The suggestion
that Will made allowed me to keep the code with less changes.

Err, I see that now. It'd be good if you described what actually
happens, because it is almost impossible to understand it from reading
the patch.

Yes, let me re-write the commit message in the next version,

Thanks,
Seb

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.