This is a note to let you know that I've just added the patch titled
x86/xen, pat: Remove PAT table init code from Xen
to the 4.6-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:
x86-xen-pat-remove-pat-table-init-code-from-xen.patch
and it can be found in the queue-4.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 88ba281108ed0c25c9d292b48bd3f272fcb90dd0 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani@xxxxxxx>
Date: Wed, 23 Mar 2016 15:42:02 -0600
Subject: x86/xen, pat: Remove PAT table init code from Xen
From: Toshi Kani <toshi.kani@xxxxxxx>
commit 88ba281108ed0c25c9d292b48bd3f272fcb90dd0 upstream.
Xen supports PAT without MTRRs for its guests. In order to
enable WC attribute, it was necessary for xen_start_kernel()
to call pat_init_cache_modes() to update PAT table before
starting guest kernel.
Now that the kernel initializes PAT table to the BIOS handoff
state when MTRR is disabled, this Xen-specific PAT init code
is no longer necessary. Delete it from xen_start_kernel().
Also change __init_cache_modes() to a static function since
PAT table should not be tweaked by other modules.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Juergen Gross <jgross@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxx>
Cc: elliott@xxxxxxx
Cc: paul.gortmaker@xxxxxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1458769323-24491-7-git-send-email-toshi.kani@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/pat.h | 1 -
arch/x86/mm/pat.c | 2 +-
arch/x86/xen/enlighten.c | 9 ---------
3 files changed, 1 insertion(+), 11 deletions(-)
--- a/arch/x86/include/asm/pat.h
+++ b/arch/x86/include/asm/pat.h
@@ -7,7 +7,6 @@
bool pat_enabled(void);
void pat_disable(const char *reason);
extern void pat_init(void);
-void __init_cache_modes(u64);
extern int reserve_memtype(u64 start, u64 end,
enum page_cache_mode req_pcm, enum page_cache_mode *ret_pcm);
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -192,7 +192,7 @@ static enum page_cache_mode pat_get_cach
* configuration.
* Using lower indices is preferred, so we start with highest index.
*/
-void __init_cache_modes(u64 pat)
+static void __init_cache_modes(u64 pat)
{
enum page_cache_mode cache;
char pat_msg[33];
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -75,7 +75,6 @@
#include <asm/mach_traps.h>
#include <asm/mwait.h>
#include <asm/pci_x86.h>
-#include <asm/pat.h>
#include <asm/cpu.h>
#ifdef CONFIG_ACPI
@@ -1511,7 +1510,6 @@ asmlinkage __visible void __init xen_sta
{
struct physdev_set_iopl set_iopl;
unsigned long initrd_start = 0;
- u64 pat;
int rc;
if (!xen_start_info)
@@ -1618,13 +1616,6 @@ asmlinkage __visible void __init xen_sta
xen_start_info->nr_pages);
xen_reserve_special_pages();
- /*
- * Modify the cache mode translation tables to match Xen's PAT
- * configuration.
- */
- rdmsrl(MSR_IA32_CR_PAT, pat);
- __init_cache_modes(pat);
-
/* keep using Xen gdt for now; no urgent need to change it */
#ifdef CONFIG_X86_32
Patches currently in stable-queue which might be from toshi.kani@xxxxxxx are
queue-4.6/x86-mm-pat-replace-cpu_has_pat-with-boot_cpu_has.patch
queue-4.6/x86-mtrr-fix-xorg-crashes-in-qemu-sessions.patch
queue-4.6/libnvdimm-pfn-dax-fix-initialization-vs-autodetect-for-mode-alignment.patch
queue-4.6/x86-mm-pat-add-support-of-non-default-pat-msr-setting.patch
queue-4.6/x86-xen-pat-remove-pat-table-init-code-from-xen.patch
queue-4.6/x86-mtrr-fix-pat-init-handling-when-mtrr-is-disabled.patch
queue-4.6/x86-mm-pat-add-pat_disable-interface.patch
queue-4.6/x86-mm-pat-fix-bug_on-in-mmap_mem-on-qemu-i386.patch
queue-4.6/x86-pat-document-the-pat-initialization-sequence.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html