From patchwork Fri Apr 22 21:05:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Matlack X-Patchwork-Id: 12824146 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B871DC433EF for ; Fri, 22 Apr 2022 22:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232469AbiDVWPi (ORCPT ); Fri, 22 Apr 2022 18:15:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232155AbiDVWPZ (ORCPT ); Fri, 22 Apr 2022 18:15:25 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92D2C318301 for ; Fri, 22 Apr 2022 14:05:55 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id bj12-20020a056a02018c00b003a9eebaad34so5645591pgb.10 for ; Fri, 22 Apr 2022 14:05:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=qj35gLZCMYjMIw6N9BxxV9K4UpqK4GN2xsPfew8h1po=; b=LTYqvOe8H4iYkeYGOiGGp+LDxFbJSGMgHCPdJvbGalGaPgV3owbywuxQA0M8i8kMli t/WctQkFGEtSGNyrmrWxpv5mmqWyVa4wrq1adnpyg3vwj+FKN/VPw3KcEn3QJa2ZaGHy amM1QtGztXc2MDapK4PoKtaSTSm70EXfzTBk3Csg2naDWW9xYIpxsvf8WYA8+v7loTUu NnIHT0jtnMCxnU6HycnCKiBJrjPG2aerN3qK3rpmiu76/NwCsJBxh2JDyki3YE13TFHW 3RLMUsQr0W5n6/yb7Ukb8NM/9EncuYcYny9iID3dOJgijVtv6WEuioZKjMYNbf1nRhCf hf3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=qj35gLZCMYjMIw6N9BxxV9K4UpqK4GN2xsPfew8h1po=; b=X0DPK1l0TPUaV7pwvRvU/1jt6QRSYiJxAdHNJjoDPS5HdIcXig9ST9hF2ZmsP7YCb2 kG6xiHblWM6++wwVTmWiyLBVImp3oaezkYjerBIFC7Krw7GhcRmF/Or5sOR+8O0W0Pup mpHMFb2j0Zvqs1aSpOD5ViVQEGbQLpA1HRcSn+7H1wA5dTQqqfjQ5j/AyuRQbwmLyPy+ 6i4Hl6cD8PwosqLiz2gM9FitqXjUGUIh4CtSITpBA1hTHXAP47VEWF9NlFRIqDsdBUaf f/IY3OksxADc64GOAc4K/WkDawRqGRYa9IR8qFNB8S8j83nelq+DIiP+XCNdf0iSD4OG tx+Q== X-Gm-Message-State: AOAM531vskfU+UqXcF1UOFNfUqRp5NjjOF9HoO6+cwa4o8owVu2rDYYI S1oXi0fV7nrG/I/cmobYVqVpN0R7muKKgA== X-Google-Smtp-Source: ABdhPJz9+I2RcqkgbBc37x1EPNWRxfFKvB0IAHvRY78mXJGJY+nNWbIdU+DbOHi9vy5UgEQ9XRpwIo7McSbuHQ== X-Received: from dmatlack-heavy.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:19cd]) (user=dmatlack job=sendgmr) by 2002:a17:902:aa4b:b0:15a:44e6:4efb with SMTP id c11-20020a170902aa4b00b0015a44e64efbmr6443542plr.64.1650661555076; Fri, 22 Apr 2022 14:05:55 -0700 (PDT) Date: Fri, 22 Apr 2022 21:05:30 +0000 In-Reply-To: <20220422210546.458943-1-dmatlack@google.com> Message-Id: <20220422210546.458943-5-dmatlack@google.com> Mime-Version: 1.0 References: <20220422210546.458943-1-dmatlack@google.com> X-Mailer: git-send-email 2.36.0.rc2.479.g8af0fa9b8e-goog Subject: [PATCH v4 04/20] KVM: x86/mmu: Decompose kvm_mmu_get_page() into separate functions From: David Matlack To: Paolo Bonzini Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Sean Christopherson , Andrew Jones , Ben Gardon , Peter Xu , maciej.szmigiero@oracle.com, "moderated list:KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)" , "open list:KERNEL VIRTUAL MACHINE FOR MIPS (KVM/mips)" , "open list:KERNEL VIRTUAL MACHINE FOR MIPS (KVM/mips)" , "open list:KERNEL VIRTUAL MACHINE FOR RISC-V (KVM/riscv)" , Peter Feiner , David Matlack Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Decompose kvm_mmu_get_page() into separate helper functions to increase readability and prepare for allocating shadow pages without a vcpu pointer. Specifically, pull the guts of kvm_mmu_get_page() into 2 helper functions: kvm_mmu_find_shadow_page() - Walks the page hash checking for any existing mmu pages that match the given gfn and role. kvm_mmu_alloc_shadow_page() Allocates and initializes an entirely new kvm_mmu_page. This currently requries a vcpu pointer for allocation and looking up the memslot but that will be removed in a future commit. No functional change intended. Signed-off-by: David Matlack Reviewed-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 52 +++++++++++++++++++++++++++++++----------- 1 file changed, 39 insertions(+), 13 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 4249a771818b..5582badf4947 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -2021,16 +2021,16 @@ static void clear_sp_write_flooding_count(u64 *spte) __clear_sp_write_flooding_count(sptep_to_sp(spte)); } -static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, - union kvm_mmu_page_role role) +static struct kvm_mmu_page *kvm_mmu_find_shadow_page(struct kvm_vcpu *vcpu, + gfn_t gfn, + struct hlist_head *sp_list, + union kvm_mmu_page_role role) { - struct hlist_head *sp_list; struct kvm_mmu_page *sp; int ret; int collisions = 0; LIST_HEAD(invalid_list); - sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; for_each_valid_sp(vcpu->kvm, sp, sp_list) { if (sp->gfn != gfn) { collisions++; @@ -2055,7 +2055,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, /* unsync and write-flooding only apply to indirect SPs. */ if (sp->role.direct) - goto trace_get_page; + goto out; if (sp->unsync) { /* @@ -2081,14 +2081,26 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, __clear_sp_write_flooding_count(sp); -trace_get_page: - trace_kvm_mmu_get_page(sp, false); goto out; } + sp = NULL; ++vcpu->kvm->stat.mmu_cache_miss; - sp = kvm_mmu_alloc_page(vcpu, role.direct); +out: + kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); + + if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) + vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; + return sp; +} + +static struct kvm_mmu_page *kvm_mmu_alloc_shadow_page(struct kvm_vcpu *vcpu, + gfn_t gfn, + struct hlist_head *sp_list, + union kvm_mmu_page_role role) +{ + struct kvm_mmu_page *sp = kvm_mmu_alloc_page(vcpu, role.direct); sp->gfn = gfn; sp->role = role; @@ -2098,12 +2110,26 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, if (role.level == PG_LEVEL_4K && kvm_vcpu_write_protect_gfn(vcpu, gfn)) kvm_flush_remote_tlbs_with_address(vcpu->kvm, gfn, 1); } - trace_kvm_mmu_get_page(sp, true); -out: - kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); - if (collisions > vcpu->kvm->stat.max_mmu_page_hash_collisions) - vcpu->kvm->stat.max_mmu_page_hash_collisions = collisions; + return sp; +} + +static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, + union kvm_mmu_page_role role) +{ + struct hlist_head *sp_list; + struct kvm_mmu_page *sp; + bool created = false; + + sp_list = &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]; + + sp = kvm_mmu_find_shadow_page(vcpu, gfn, sp_list, role); + if (!sp) { + created = true; + sp = kvm_mmu_alloc_shadow_page(vcpu, gfn, sp_list, role); + } + + trace_kvm_mmu_get_page(sp, created); return sp; }