From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:43422 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932177AbcHNQBK (ORCPT ); Sun, 14 Aug 2016 12:01:10 -0400 Subject: Patch "x86/mm/pat: Add pat_disable() interface" has been added to the 4.6-stable tree To: toshi.kani@hpe.com, akpm@linux-foundation.org, bp@alien8.de, bp@suse.de, brgerst@gmail.com, dvlasenk@redhat.com, elliott@hpe.com, gregkh@linuxfoundation.org, hpa@zytor.com, jgross@suse.com, luto@amacapital.net, mcgrof@suse.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, toshi.kani@hp.com Cc: , From: Date: Sun, 14 Aug 2016 18:00:42 +0200 Message-ID: <14711904427656@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/mm/pat: Add pat_disable() interface 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-mm-pat-add-pat_disable-interface.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 know about it. >>From 224bb1e5d67ba0f2872c98002d6a6f991ac6fd4a Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Wed, 23 Mar 2016 15:41:58 -0600 Subject: x86/mm/pat: Add pat_disable() interface From: Toshi Kani commit 224bb1e5d67ba0f2872c98002d6a6f991ac6fd4a upstream. In preparation for fixing a regression caused by: 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it is disabled") ... PAT needs to provide an interface that prevents the OS from initializing the PAT MSR. PAT MSR initialization must be done on all CPUs using the specific sequence of operations defined in the Intel SDM. This requires MTRRs to be enabled since pat_init() is called as part of MTRR init from mtrr_rendezvous_handler(). Make pat_disable() as the interface that prevents the OS from initializing the PAT MSR. MTRR will call this interface when it cannot provide the SDM-defined sequence to initialize PAT. This also assures that pat_disable() called from pat_bsp_init() will set the PAT table properly when CPU does not support PAT. Signed-off-by: Toshi Kani Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Juergen Gross Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Robert Elliott Cc: Toshi Kani Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-3-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/pat.h | 1 + arch/x86/mm/pat.c | 13 ++++++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/pat.h +++ b/arch/x86/include/asm/pat.h @@ -5,6 +5,7 @@ #include bool pat_enabled(void); +void pat_disable(const char *reason); extern void pat_init(void); void __init_cache_modes(u64); --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -40,11 +40,22 @@ static bool boot_cpu_done; static int __read_mostly __pat_enabled = IS_ENABLED(CONFIG_X86_PAT); +static void init_cache_modes(void); -static inline void pat_disable(const char *reason) +void pat_disable(const char *reason) { + if (!__pat_enabled) + return; + + if (boot_cpu_done) { + WARN_ONCE(1, "x86/PAT: PAT cannot be disabled after initialization\n"); + return; + } + __pat_enabled = 0; pr_info("x86/PAT: %s\n", reason); + + init_cache_modes(); } static int __init nopat(char *str) Patches currently in stable-queue which might be from toshi.kani@hpe.com 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