From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50100 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753118AbeDJOFO (ORCPT ); Tue, 10 Apr 2018 10:05:14 -0400 Subject: Patch "x86/CPU: Check CPU feature bits after microcode upgrade" has been added to the 4.14-stable tree To: bp@suse.de, arjan@linux.intel.com, ashok.raj@intel.com, bp@alien8.de, dan.j.williams@intel.com, dave.hansen@linux.intel.com, dwmw2@infradead.org, gregkh@linuxfoundation.org, jpoimboe@redhat.com, luto@kernel.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Tue, 10 Apr 2018 16:05:05 +0200 Message-ID: <152336910563150@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/CPU: Check CPU feature bits after microcode upgrade to the 4.14-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-cpu-check-cpu-feature-bits-after-microcode-upgrade.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 42ca8082e260dcfd8afa2afa6ec1940b9d41724c Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 16 Feb 2018 12:26:40 +0100 Subject: x86/CPU: Check CPU feature bits after microcode upgrade From: Borislav Petkov commit 42ca8082e260dcfd8afa2afa6ec1940b9d41724c upstream. With some microcode upgrades, new CPUID features can become visible on the CPU. Check what the kernel has mirrored now and issue a warning hinting at possible things the user/admin can do to make use of the newly visible features. Originally-by: Ashok Raj Tested-by: Ashok Raj Signed-off-by: Borislav Petkov Reviewed-by: Ashok Raj Cc: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180216112640.11554-4-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/common.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1732,5 +1732,25 @@ core_initcall(init_cpu_syscore); */ void microcode_check(void) { + struct cpuinfo_x86 info; + perf_check_microcode(); + + /* Reload CPUID max function as it might've changed. */ + info.cpuid_level = cpuid_eax(0); + + /* + * Copy all capability leafs to pick up the synthetic ones so that + * memcmp() below doesn't fail on that. The ones coming from CPUID will + * get overwritten in get_cpu_cap(). + */ + memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)); + + get_cpu_cap(&info); + + if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability))) + return; + + pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n"); + pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n"); } Patches currently in stable-queue which might be from bp@suse.de are queue-4.14/x86-microcode-intel-check-microcode-revision-before-updating-sibling-threads.patch queue-4.14/x86-microcode-attempt-late-loading-only-when-new-microcode-is-present.patch queue-4.14/x86-microcode-propagate-return-value-from-updating-functions.patch queue-4.14/x86-cpu-check-cpu-feature-bits-after-microcode-upgrade.patch queue-4.14/x86-microcode-intel-writeback-and-invalidate-caches-before-updating-microcode.patch queue-4.14/x86-microcode-intel-look-into-the-patch-cache-first.patch queue-4.14/edac-mv64x60-fix-an-error-handling-path.patch queue-4.14/x86-microcode-request-microcode-on-the-bsp.patch queue-4.14/x86-microcode-get-rid-of-struct-apply_microcode_ctx.patch queue-4.14/x86-microcode-fix-cpu-synchronization-routine.patch queue-4.14/x86-microcode-synchronize-late-microcode-loading.patch queue-4.14/x86-microcode-do-not-upload-microcode-if-cpus-are-offline.patch queue-4.14/x86-cpu-add-a-microcode-loader-callback.patch