[PATCH v3 2/2] lib/test_kho: use kho_preserve_vmalloc instead of storing addresses in fdt

Mike Rapoport
2025-09-08T10:35:50Z

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

KHO test stores physical addresses of the preserved folios directly in
fdt.
Use kho_preserve_vmalloc() instead of it and kho_restore_vmalloc() to
retrieve the addresses after kexec.

This makes the test more scalable from one side and adds tests coverage
for kho_preserve_vmalloc() from the other.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
lib/test_kho.c | 41 +++++++++++++++++++++++++++++------------
1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/lib/test_kho.c b/lib/test_kho.c
index fe8504e3407b..c46f577b6aee 100644
--- a/lib/test_kho.c
+++ b/lib/test_kho.c
@@ -32,6 +32,7 @@ module_param(max_mem, long, 0644);
struct kho_test_state {
unsigned int nr_folios;
struct folio **folios;
+ phys_addr_t *folios_info;
struct folio *fdt;
__wsum csum;
};
@@ -67,18 +68,15 @@ static struct notifier_block kho_test_nb = {

static int kho_test_save_data(struct kho_test_state *state, void *fdt)
{
- phys_addr_t *folios_info;
+ phys_addr_t *folios_info __free(kvfree) = NULL;
+ phys_addr_t folios_info_phys;
int err = 0;

- err |= fdt_begin_node(fdt, "data");
- err |= fdt_property(fdt, "nr_folios", &state->nr_folios,
- sizeof(state->nr_folios));
- err |= fdt_property_placeholder(fdt, "folios_info",
- state->nr_folios * sizeof(*folios_info),
- (void **)&folios_info);
- err |= fdt_property(fdt, "csum", &state->csum, sizeof(state->csum));
- err |= fdt_end_node(fdt);
+ folios_info = vmalloc_array(state->nr_folios, sizeof(*folios_info));
+ if (!folios_info)
+ return -ENOMEM;

+ err = kho_preserve_vmalloc(folios_info, &folios_info_phys);
if (err)
return err;

@@ -93,6 +91,17 @@ static int kho_test_save_data(struct kho_test_state *state, void *fdt)
break;
}

+ err |= fdt_begin_node(fdt, "data");
+ err |= fdt_property(fdt, "nr_folios", &state->nr_folios,
+ sizeof(state->nr_folios));
+ err |= fdt_property(fdt, "folios_info", &folios_info_phys,
+ sizeof(folios_info_phys));
+ err |= fdt_property(fdt, "csum", &state->csum, sizeof(state->csum));
+ err |= fdt_end_node(fdt);
+
+ if (!err)
+ state->folios_info = no_free_ptr(folios_info);
+
return err;
}

@@ -210,7 +219,8 @@ static int kho_test_save(void)
static int kho_test_restore_data(const void *fdt, int node)
{
const unsigned int *nr_folios;
- const phys_addr_t *folios_info;
+ const phys_addr_t *folios_info_phys;
+ phys_addr_t *folios_info;
const __wsum *old_csum;
__wsum csum = 0;
int len;
@@ -225,8 +235,12 @@ static int kho_test_restore_data(const void *fdt, int node)
if (!old_csum || len != sizeof(*old_csum))
return -EINVAL;

- folios_info = fdt_getprop(fdt, node, "folios_info", &len);
- if (!folios_info || len != sizeof(*folios_info) * *nr_folios)
+ folios_info_phys = fdt_getprop(fdt, node, "folios_info", &len);
+ if (!folios_info_phys || len != sizeof(*folios_info_phys))
+ return -EINVAL;
+
+ folios_info = kho_restore_vmalloc(*folios_info_phys);
+ if (!folios_info)
return -EINVAL;

for (int i = 0; i < *nr_folios; i++) {
@@ -246,6 +260,8 @@ static int kho_test_restore_data(const void *fdt, int node)
folio_put(folio);
}

+ vfree(folios_info);
+
if (csum != *old_csum)
return -EINVAL;

@@ -304,6 +320,7 @@ static void kho_test_cleanup(void)
folio_put(kho_test_state.folios[i]);

kvfree(kho_test_state.folios);
+ vfree(kho_test_state.folios_info);
folio_put(kho_test_state.fdt);
}

--
2.50.1