From patchwork Wed Oct 13 10:33:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12555433 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 66F9DC433F5 for ; Wed, 13 Oct 2021 10:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EF4260F4A for ; Wed, 13 Oct 2021 10:35:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232486AbhJMKhD (ORCPT ); Wed, 13 Oct 2021 06:37:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49297 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230460AbhJMKhC (ORCPT ); Wed, 13 Oct 2021 06:37:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634121299; 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=cHf2ZqC5DC9zioFkkyjMYiEOu523mJCDOZFO8VfZXy8=; b=a8+EKECW4PqHC/7NpsKrljdEvrtBQjiZDZjzeRD2JkoePy4s+IaVvQVve+9V7yqEK05D2e VGsTAfD/7a+RR7UXBn++vkUGY/dnhQ7/8nkOTBeXAyW87J3ZclXNZZcj2R9QQPB8xHw/54 jfo3vgpELvJJu/0ZZCZkBOv0vEtrwWI= 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-281-NI4MhWvBNF6bRyWFtjjMtw-1; Wed, 13 Oct 2021 06:34:56 -0400 X-MC-Unique: NI4MhWvBNF6bRyWFtjjMtw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4F84C100CCC2; Wed, 13 Oct 2021 10:34:55 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.194.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4110D5D9D5; Wed, 13 Oct 2021 10:34:49 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: David Hildenbrand , Paolo Bonzini , Eduardo Habkost , Marcel Apfelbaum , "Michael S. Tsirkin" , Igor Mammedov , Ani Sinha , Peter Xu , "Dr . David Alan Gilbert" , Stefan Hajnoczi , Richard Henderson , =?utf-8?q?Philippe_Mathie?= =?utf-8?q?u-Daud=C3=A9?= , kvm@vger.kernel.org Subject: [PATCH RFC 05/15] vhost: Don't merge unmergeable memory sections Date: Wed, 13 Oct 2021 12:33:20 +0200 Message-Id: <20211013103330.26869-6-david@redhat.com> In-Reply-To: <20211013103330.26869-1-david@redhat.com> References: <20211013103330.26869-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Memory sections that are marked unmergeable should not be merged, to allow for atomic removal later. Signed-off-by: David Hildenbrand --- hw/virtio/vhost.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 2707972870..49a1074097 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -620,7 +620,7 @@ static void vhost_region_add_section(struct vhost_dev *dev, mrs_size, mrs_host); } - if (dev->n_tmp_sections) { + if (dev->n_tmp_sections && !section->unmergeable) { /* Since we already have at least one section, lets see if * this extends it; since we're scanning in order, we only * have to look at the last one, and the FlatView that calls @@ -653,7 +653,7 @@ static void vhost_region_add_section(struct vhost_dev *dev, size_t offset = mrs_gpa - prev_gpa_start; if (prev_host_start + offset == mrs_host && - section->mr == prev_sec->mr && + section->mr == prev_sec->mr && !prev_sec->unmergeable && (!dev->vhost_ops->vhost_backend_can_merge || dev->vhost_ops->vhost_backend_can_merge(dev, mrs_host, mrs_size,