From patchwork Wed Jan 8 20:24:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11324609 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3611A1871 for ; Wed, 8 Jan 2020 20:27:19 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1ECE420643 for ; Wed, 8 Jan 2020 20:27:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1ECE420643 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 128CD10097DB9; Wed, 8 Jan 2020 12:30:31 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=134.134.136.20; helo=mga02.intel.com; envelope-from=sean.j.christopherson@intel.com; receiver= Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 0FE2310097DEE for ; Wed, 8 Jan 2020 12:30:26 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 12:27:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,411,1571727600"; d="scan'208";a="211658380" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga007.jf.intel.com with ESMTP; 08 Jan 2020 12:27:06 -0800 From: Sean Christopherson To: Paolo Bonzini Subject: [PATCH 08/14] KVM: x86/mmu: Drop level optimization from fast_page_fault() Date: Wed, 8 Jan 2020 12:24:42 -0800 Message-Id: <20200108202448.9669-9-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200108202448.9669-1-sean.j.christopherson@intel.com> References: <20200108202448.9669-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Message-ID-Hash: ZW6P7JE3CCUQCNOI3Q6PFBJELM6BAS2K X-Message-ID-Hash: ZW6P7JE3CCUQCNOI3Q6PFBJELM6BAS2K X-MailFrom: sean.j.christopherson@intel.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Paul Mackerras , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Andrew Morton , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com, Andrea Arcangeli , Barret Rhoden , David Hildenbrand , Jason Zeng , Liran Alon , linux-nvdimm X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Remove fast_page_fault()'s optimization to stop the shadow walk if the iterator level drops below the intended map level. The intended map level is only acccurate for HugeTLB mappings (THP mappings are detected after fast_page_fault()), i.e. it's not required for correctness, and a future patch will also move HugeTLB mapping detection to after fast_page_fault(). Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4bd7f745b56d..7d78d1d996ed 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3593,7 +3593,7 @@ static bool is_access_allowed(u32 fault_err_code, u64 spte) * - true: let the vcpu to access on the same address again. * - false: let the real page fault path to fix it. */ -static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, int level, +static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u32 error_code) { struct kvm_shadow_walk_iterator iterator; @@ -3611,8 +3611,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, int level, u64 new_spte; for_each_shadow_entry_lockless(vcpu, cr2_or_gpa, iterator, spte) - if (!is_shadow_present_pte(spte) || - iterator.level < level) + if (!is_shadow_present_pte(spte)) break; sp = page_header(__pa(iterator.sptep)); @@ -4223,7 +4222,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, if (level > PT_PAGE_TABLE_LEVEL) gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); - if (fast_page_fault(vcpu, gpa, level, error_code)) + if (fast_page_fault(vcpu, gpa, error_code)) return RET_PF_RETRY; mmu_seq = vcpu->kvm->mmu_notifier_seq;