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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07C9FC433EF for ; Sat, 26 Feb 2022 00:16:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240597AbiBZART (ORCPT ); Fri, 25 Feb 2022 19:17:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240463AbiBZAQy (ORCPT ); Fri, 25 Feb 2022 19:16:54 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCB972255BF for ; Fri, 25 Feb 2022 16:16:15 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id g31-20020a63521f000000b003783582a261so1439648pgb.5 for ; Fri, 25 Feb 2022 16:16:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=G398P7RcaSAEnVDGuXyKG1MtPaHrsCLmNhGjwb/vYpg=; b=R8L3GXb2iyMDkg0JQmqrX2X7ARQEO+Z7DOJsS5/5XHBLGcLkRCgSn+ANc7wRoFYg99 ziYt2seRoQuDB2HvG+EaZ9MHLF2GdsHB4o6qqxE6aBd5DNyFAXDZVzz1EYDnRcxhC2r4 S2geRnlh62kLBJUVLBy6yVJwLY3RQyPv7AMJNmGocuZKnW1uRQsNZwh94q4Q4XbXlmKL foeaFq/xbag68suV0gOwJO0JXHPCBFEy+Mo35Qyr75jDB+S25pbbpHqdxicOZ+5rd6Op QPt3fLxyXF2hsSO7/EYM6J+XV840P5D+ooewjyfq+2Hyw3hak7qvX8oJmmD6hR5m0xAC 2U/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=G398P7RcaSAEnVDGuXyKG1MtPaHrsCLmNhGjwb/vYpg=; b=0RcgO3YIiVSG0Me6rBvnTFfZp2LnWR3kMcd87rMrZ9YGNu1LAIq/tvN0MUujwM4lSL gWZxGyLuEwYeCSCpzhU7Ngq1s0Hgxb6cy65ZmEM+DtPWH/ATNI6ux//VHsov4EIJPGKf jZzv80c/74GVXqQNr4zfQ6tKOR3i67RO/PEie6hJuNoH9m76v6UQ1Etu8gHkXCUtLWTI KkuiJ+IJ0qzK/bHHBNeqSEGIEGctkGmGwtT9uRXeiK90Qih2qcp06SY8K/P33mKaavHb hmm7KfKApXw7lT9GQBeFiYnTocf3B4V/khCEUqhAOB84ph8SRQHrkQwmDCZtIgt9Bwht Ew3A== X-Gm-Message-State: AOAM530XHMQDH8+XSKNRTQddJOAcnfitRr3tuJgs0zSYktQoyAYlX1Zj mejX3de7+egyDOxCJrKW2p56Kr7JNNE= X-Google-Smtp-Source: ABdhPJy7lHJWDyxwAWHN4q2rpPYcO/QcoMfFh0Asba4foDlLtm+DAdHJ17610fWaI/B/snIanvtPDxy+PBc= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a17:90b:4b52:b0:1bc:b208:dc5c with SMTP id mi18-20020a17090b4b5200b001bcb208dc5cmr761907pjb.1.1645834574884; Fri, 25 Feb 2022 16:16:14 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 26 Feb 2022 00:15:26 +0000 In-Reply-To: <20220226001546.360188-1-seanjc@google.com> Message-Id: <20220226001546.360188-9-seanjc@google.com> Mime-Version: 1.0 References: <20220226001546.360188-1-seanjc@google.com> X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog Subject: [PATCH v3 08/28] KVM: x86/mmu: Batch TLB flushes from TDP MMU for MMU notifier change_spte From: Sean Christopherson To: Paolo Bonzini , Christian Borntraeger , Janosch Frank , Claudio Imbrenda Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Hildenbrand , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , Ben Gardon , Mingwei Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Batch TLB flushes (with other MMUs) when handling ->change_spte() notifications in the TDP MMU. The MMU notifier path in question doesn't allow yielding and correcty flushes before dropping mmu_lock. Signed-off-by: Sean Christopherson Reviewed-by: Ben Gardon --- arch/x86/kvm/mmu/tdp_mmu.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 848448b65703..634a2838e117 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1203,13 +1203,12 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, */ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { - bool flush = kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); - - /* FIXME: return 'flush' instead of flushing here. */ - if (flush) - kvm_flush_remote_tlbs_with_address(kvm, range->start, 1); - - return false; + /* + * No need to handle the remote TLB flush under RCU protection, the + * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a + * shadow page. See the WARN on pfn_changed in __handle_changed_spte(). + */ + return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); } /* -- 2.35.1.574.g5d30c73bfb-goog