From patchwork Thu Jan 31 20:24:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KarimAllah Ahmed X-Patchwork-Id: 10791455 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8BD94922 for ; Thu, 31 Jan 2019 20:27:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8297C305C4 for ; Thu, 31 Jan 2019 20:27:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7304130B0B; Thu, 31 Jan 2019 20:27:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 10612305C4 for ; Thu, 31 Jan 2019 20:27:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728652AbfAaU1R (ORCPT ); Thu, 31 Jan 2019 15:27:17 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:18358 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728614AbfAaU1Q (ORCPT ); Thu, 31 Jan 2019 15:27:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1548966435; x=1580502435; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=jfyjGv9g5xU0ZRTdgZ3MlRsZNZ0NVJf/Pg95NKC1DMg=; b=G+xk3fTsc6iZ+i6U2/Wt0bhBQRt5+el4rvQiXLdK4aMvvl0l3CHYG6k6 Hd/rOLiyg/syfQ0Ntrej0C9Q4n/A9Q4qO7il3JdTpJ15lfcGoevOMHiWP zKostfn9D7n18ZtW/Fi+eoiWuZSjtXt73Zy6n0WZd4uZ46RXgAkHczwCr U=; X-IronPort-AV: E=Sophos;i="5.56,545,1539648000"; d="scan'208";a="756877149" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2c-c6afef2e.us-west-2.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 31 Jan 2019 20:27:12 +0000 Received: from u54e1ad5160425a4b64ea.ant.amazon.com (pdx2-ws-svc-lb17-vlan3.amazon.com [10.247.140.70]) by email-inbound-relay-2c-c6afef2e.us-west-2.amazon.com (Postfix) with ESMTPS id 85212A20F1; Thu, 31 Jan 2019 20:27:11 +0000 (UTC) Received: from u54e1ad5160425a4b64ea.ant.amazon.com (localhost [127.0.0.1]) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Debian-3) with ESMTP id x0VKR97w029041; Thu, 31 Jan 2019 21:27:09 +0100 Received: (from karahmed@localhost) by u54e1ad5160425a4b64ea.ant.amazon.com (8.15.2/8.15.2/Submit) id x0VKR8rL029036; Thu, 31 Jan 2019 21:27:08 +0100 From: KarimAllah Ahmed To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Paolo Bonzini Cc: KarimAllah Ahmed Subject: [PATCH v6 14/14] kvm, x86: Properly check whether a pfn is an MMIO or not Date: Thu, 31 Jan 2019 21:24:44 +0100 Message-Id: <1548966284-28642-15-git-send-email-karahmed@amazon.de> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1548966284-28642-1-git-send-email-karahmed@amazon.de> References: <1548966284-28642-1-git-send-email-karahmed@amazon.de> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pfn_valid check is not sufficient because it only checks if a page has a struct page or not, if "mem=" was passed to the kernel some valid pages won't have a struct page. This means that if guests were assigned valid memory that lies after the mem= boundary it will be passed uncached to the guest no matter what the guest caching attributes are for this memory. Introduce a new function e820__mapped_raw_any which is equivalent to e820__mapped_any but uses the original e820 unmodified and use it to identify real *RAM*. Signed-off-by: KarimAllah Ahmed --- v1 -> v2: - Introduce e820__mapped_raw_any --- arch/x86/include/asm/e820/api.h | 1 + arch/x86/kernel/e820.c | 18 +++++++++++++++--- arch/x86/kvm/mmu.c | 5 ++++- 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h index 4562062..b3f6e89 100644 --- a/arch/x86/include/asm/e820/api.h +++ b/arch/x86/include/asm/e820/api.h @@ -12,6 +12,7 @@ extern unsigned long e820_saved_max_low_pfn; extern unsigned long pci_mem_start; +extern bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type); extern bool e820__mapped_any(u64 start, u64 end, enum e820_type type); extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type); diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index ef914d0..3039659 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -75,12 +75,13 @@ EXPORT_SYMBOL(pci_mem_start); * This function checks if any part of the range is mapped * with type. */ -bool e820__mapped_any(u64 start, u64 end, enum e820_type type) +static bool _e820__mapped_any(struct e820_table *table, + u64 start, u64 end, enum e820_type type) { int i; - for (i = 0; i < e820_table->nr_entries; i++) { - struct e820_entry *entry = &e820_table->entries[i]; + for (i = 0; i < table->nr_entries; i++) { + struct e820_entry *entry = &table->entries[i]; if (type && entry->type != type) continue; @@ -90,6 +91,17 @@ bool e820__mapped_any(u64 start, u64 end, enum e820_type type) } return 0; } + +bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table_firmware, start, end, type); +} +EXPORT_SYMBOL_GPL(e820__mapped_raw_any); + +bool e820__mapped_any(u64 start, u64 end, enum e820_type type) +{ + return _e820__mapped_any(e820_table, start, end, type); +} EXPORT_SYMBOL_GPL(e820__mapped_any); /* diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index da9c423..abf6a0d 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -44,6 +44,7 @@ #include #include #include +#include #include #include #include @@ -2875,7 +2876,9 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) */ (!pat_enabled() || pat_pfn_immune_to_uc_mtrr(pfn)); - return true; + return !e820__mapped_raw_any(pfn_to_hpa(pfn), + pfn_to_hpa(pfn + 1) - 1, + E820_TYPE_RAM); } /* Bits which may be returned by set_spte() */