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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 AAA3DC4320E for ; Mon, 2 Aug 2021 18:33:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91A1B610A2 for ; Mon, 2 Aug 2021 18:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231232AbhHBSd4 (ORCPT ); Mon, 2 Aug 2021 14:33:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40393 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230442AbhHBSdz (ORCPT ); Mon, 2 Aug 2021 14:33:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627929225; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PkDhCDhsOamlo5EjAL2H44dG3irxXE0SxvQCRWziXwI=; b=CiuKz8h7ubgYCEQlLGwogH63ZTmLj93+1rymP6bMdVh/EHNQGpjIqTFMZZLmd0F1B1bpmF fNCCzmTWJPUFmkDXut+HvuWHRe7hwzWXWrnNB/MU7nofgQyByZI9LereigPPGnkAqryRjm I9io9t4uTrubSrJpDObqTojZJ2GJCK8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-398-k0zjZcpmMiq4gMe972eiYg-1; Mon, 02 Aug 2021 14:33:43 -0400 X-MC-Unique: k0zjZcpmMiq4gMe972eiYg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2E17A10066E5; Mon, 2 Aug 2021 18:33:42 +0000 (UTC) Received: from localhost.localdomain (unknown [10.35.206.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id A44DD3AE1; Mon, 2 Aug 2021 18:33:38 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Cc: Wanpeng Li , Thomas Gleixner , Joerg Roedel , Borislav Petkov , Sean Christopherson , Jim Mattson , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), Suravee Suthikulpanit , Vitaly Kuznetsov , Ingo Molnar , "H. Peter Anvin" , Paolo Bonzini , Maxim Levitsky Subject: [PATCH v3 02/12] KVM: x86/mmu: bump mmu notifier count in kvm_zap_gfn_range Date: Mon, 2 Aug 2021 21:33:19 +0300 Message-Id: <20210802183329.2309921-3-mlevitsk@redhat.com> In-Reply-To: <20210802183329.2309921-1-mlevitsk@redhat.com> References: <20210802183329.2309921-1-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This together with previous patch, ensures that kvm_zap_gfn_range doesn't race with page fault running on another vcpu, and will make this page fault code retry instead. This is based on a patch suggested by Sean Christopherson: https://lkml.org/lkml/2021/7/22/1025 Suggested-by: Sean Christopherson Signed-off-by: Maxim Levitsky --- arch/x86/kvm/mmu/mmu.c | 4 ++++ include/linux/kvm_host.h | 5 +++++ virt/kvm/kvm_main.c | 7 +++++-- 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 9d78cb1c0f35..9da635e383c2 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5640,6 +5640,8 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) write_lock(&kvm->mmu_lock); + kvm_inc_notifier_count(kvm, gfn_start, gfn_end); + if (kvm_memslots_have_rmaps(kvm)) { for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { slots = __kvm_memslots(kvm, i); @@ -5671,6 +5673,8 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) if (flush) kvm_flush_remote_tlbs_with_address(kvm, gfn_start, gfn_end); + kvm_dec_notifier_count(kvm, gfn_start, gfn_end); + write_unlock(&kvm->mmu_lock); } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9d6b4ad407b8..962e11a73e8e 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -985,6 +985,11 @@ void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc); void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc); #endif +void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start, + unsigned long end); +void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start, + unsigned long end); + long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg); long kvm_arch_vcpu_ioctl(struct file *filp, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a96cbe24c688..71042cd807b3 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -608,7 +608,7 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn, kvm_handle_hva_range(mn, address, address + 1, pte, kvm_set_spte_gfn); } -static void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start, +void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start, unsigned long end) { /* @@ -636,6 +636,7 @@ static void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start, max(kvm->mmu_notifier_range_end, end); } } +EXPORT_SYMBOL_GPL(kvm_inc_notifier_count); static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, const struct mmu_notifier_range *range) @@ -670,7 +671,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, return 0; } -static void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start, +void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start, unsigned long end) { /* @@ -687,6 +688,8 @@ static void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start, */ kvm->mmu_notifier_count--; } +EXPORT_SYMBOL_GPL(kvm_dec_notifier_count); + static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, const struct mmu_notifier_range *range) -- 2.26.3