This is a note to let you know that I've just added the patch titled
s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-mm-add-missing-arch_set_page_dat-call-to-vmem_crst_alloc.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 09cda0a400519b1541591c506e54c9c48e3101bf Mon Sep 17 00:00:00 2001
From: Heiko Carstens <hca@xxxxxxxxxxxxx>
Date: Tue, 17 Oct 2023 21:07:04 +0200
Subject: s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc()
From: Heiko Carstens <hca@xxxxxxxxxxxxx>
commit 09cda0a400519b1541591c506e54c9c48e3101bf upstream.
If the cmma no-dat feature is available all pages that are not used for
dynamic address translation are marked as "no-dat" with the ESSA
instruction. This information is visible to the hypervisor, so that the
hypervisor can optimize purging of guest TLB entries. This also means that
pages which are used for dynamic address translation must not be marked as
"no-dat", since the hypervisor may then incorrectly not purge guest TLB
entries.
Region and segment tables allocated via vmem_crst_alloc() are incorrectly
marked as "no-dat", as soon as slab_is_available() returns true.
Such tables are allocated e.g. when kernel page tables are split, memory is
hotplugged, or a DCSS segment is loaded.
Fix this by adding the missing arch_set_page_dat() call.
Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/mm/vmem.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -12,6 +12,7 @@
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/sort.h>
+#include <asm/page-states.h>
#include <asm/cacheflush.h>
#include <asm/nospec-branch.h>
#include <asm/pgalloc.h>
@@ -45,8 +46,11 @@ void *vmem_crst_alloc(unsigned long val)
unsigned long *table;
table = vmem_alloc_pages(CRST_ALLOC_ORDER);
- if (table)
- crst_table_init(table, val);
+ if (!table)
+ return NULL;
+ crst_table_init(table, val);
+ if (slab_is_available())
+ arch_set_page_dat(virt_to_page(table), CRST_ALLOC_ORDER);
return table;
}
Patches currently in stable-queue which might be from hca@xxxxxxxxxxxxx are
queue-6.6/s390-mm-add-missing-arch_set_page_dat-call-to-vmem_crst_alloc.patch
queue-6.6/s390-cmma-fix-initial-kernel-address-space-page-table-walk.patch
queue-6.6/s390-cmma-fix-handling-of-swapper_pg_dir-and-invalid_pg_dir.patch
queue-6.6/s390-cmma-fix-detection-of-dat-pages.patch
queue-6.6/s390-mm-add-missing-arch_set_page_dat-call-to-gmap-allocations.patch
