From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED4F6C433DF for ; Fri, 22 May 2020 09:33:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D549F206C3 for ; Fri, 22 May 2020 09:33:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729822AbgEVJdN (ORCPT ); Fri, 22 May 2020 05:33:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729591AbgEVJdC (ORCPT ); Fri, 22 May 2020 05:33:02 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A7AAC08C5C0; Fri, 22 May 2020 02:33:01 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jc42z-0001QC-Iy; Fri, 22 May 2020 11:32:57 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 46FFA1C0095; Fri, 22 May 2020 11:32:57 +0200 (CEST) Date: Fri, 22 May 2020 09:32:57 -0000 From: "tip-bot2 for Balbir Singh" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/mm] x86/kvm: Refactor L1D flush page management Cc: Balbir Singh , Thomas Gleixner , Kees Cook , x86 , LKML In-Reply-To: <20200510014803.12190-2-sblbir@amazon.com> References: <20200510014803.12190-2-sblbir@amazon.com> MIME-Version: 1.0 Message-ID: <159013997717.17951.6819922422442729397.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/mm branch of tip: Commit-ID: b9b3bc1c30be1f056c1c0564bc7268820ea8bf70 Gitweb: https://git.kernel.org/tip/b9b3bc1c30be1f056c1c0564bc7268820ea8bf70 Author: Balbir Singh AuthorDate: Sun, 10 May 2020 11:47:58 +10:00 Committer: Thomas Gleixner CommitterDate: Wed, 13 May 2020 18:12:18 +02:00 x86/kvm: Refactor L1D flush page management Split out the allocation and free routines and move them into builtin code so they can be reused for the upcoming paranoid L1D flush on context switch mitigation. [ tglx: Add missing SPDX identifier and massage subject and changelog ] Signed-off-by: Balbir Singh Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20200510014803.12190-2-sblbir@amazon.com --- arch/x86/include/asm/cacheflush.h | 3 ++- arch/x86/kernel/Makefile | 1 +- arch/x86/kernel/l1d_flush.c | 39 ++++++++++++++++++++++++++++++- arch/x86/kvm/vmx/vmx.c | 25 ++----------------- 4 files changed, 46 insertions(+), 22 deletions(-) create mode 100644 arch/x86/kernel/l1d_flush.c diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index 63feaf2..bac56fc 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -6,6 +6,9 @@ #include #include +#define L1D_CACHE_ORDER 4 void clflush_cache_range(void *addr, unsigned int size); +void *l1d_flush_alloc_pages(void); +void l1d_flush_cleanup_pages(void *l1d_flush_pages); #endif /* _ASM_X86_CACHEFLUSH_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index ba89cab..c04d218 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -156,3 +156,4 @@ ifeq ($(CONFIG_X86_64),y) endif obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_arch.o +obj-y += l1d_flush.o diff --git a/arch/x86/kernel/l1d_flush.c b/arch/x86/kernel/l1d_flush.c new file mode 100644 index 0000000..4f298b7 --- /dev/null +++ b/arch/x86/kernel/l1d_flush.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +#include + +void *l1d_flush_alloc_pages(void) +{ + struct page *page; + void *l1d_flush_pages = NULL; + int i; + + /* + * This allocation for l1d_flush_pages is not tied to a VM/task's + * lifetime and so should not be charged to a memcg. + */ + page = alloc_pages(GFP_KERNEL, L1D_CACHE_ORDER); + if (!page) + return NULL; + l1d_flush_pages = page_address(page); + + /* + * Initialize each page with a different pattern in + * order to protect against KSM in the nested + * virtualization case. + */ + for (i = 0; i < 1u << L1D_CACHE_ORDER; ++i) { + memset(l1d_flush_pages + i * PAGE_SIZE, i + 1, + PAGE_SIZE); + } + return l1d_flush_pages; +} +EXPORT_SYMBOL_GPL(l1d_flush_alloc_pages); + +void l1d_flush_cleanup_pages(void *l1d_flush_pages) +{ + free_pages((unsigned long)l1d_flush_pages, L1D_CACHE_ORDER); +} +EXPORT_SYMBOL_GPL(l1d_flush_cleanup_pages); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 8305097..225aa82 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -203,14 +203,10 @@ static const struct { [VMENTER_L1D_FLUSH_NOT_REQUIRED] = {"not required", false}, }; -#define L1D_CACHE_ORDER 4 static void *vmx_l1d_flush_pages; static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf) { - struct page *page; - unsigned int i; - if (!boot_cpu_has_bug(X86_BUG_L1TF)) { l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_NOT_REQUIRED; return 0; @@ -253,24 +249,9 @@ static int vmx_setup_l1d_flush(enum vmx_l1d_flush_state l1tf) if (l1tf != VMENTER_L1D_FLUSH_NEVER && !vmx_l1d_flush_pages && !boot_cpu_has(X86_FEATURE_FLUSH_L1D)) { - /* - * This allocation for vmx_l1d_flush_pages is not tied to a VM - * lifetime and so should not be charged to a memcg. - */ - page = alloc_pages(GFP_KERNEL, L1D_CACHE_ORDER); - if (!page) + vmx_l1d_flush_pages = l1d_flush_alloc_pages(); + if (!vmx_l1d_flush_pages) return -ENOMEM; - vmx_l1d_flush_pages = page_address(page); - - /* - * Initialize each page with a different pattern in - * order to protect against KSM in the nested - * virtualization case. - */ - for (i = 0; i < 1u << L1D_CACHE_ORDER; ++i) { - memset(vmx_l1d_flush_pages + i * PAGE_SIZE, i + 1, - PAGE_SIZE); - } } l1tf_vmx_mitigation = l1tf; @@ -8026,7 +8007,7 @@ static struct kvm_x86_init_ops vmx_init_ops __initdata = { static void vmx_cleanup_l1d_flush(void) { if (vmx_l1d_flush_pages) { - free_pages((unsigned long)vmx_l1d_flush_pages, L1D_CACHE_ORDER); + l1d_flush_cleanup_pages(vmx_l1d_flush_pages); vmx_l1d_flush_pages = NULL; } /* Restore state so sysfs ignores VMX */