From patchwork Wed Aug 23 15:30:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 13362764 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 4109FEE4993 for ; Wed, 23 Aug 2023 15:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237232AbjHWPbc (ORCPT ); Wed, 23 Aug 2023 11:31:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233497AbjHWPbb (ORCPT ); Wed, 23 Aug 2023 11:31:31 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BE6CCEF for ; Wed, 23 Aug 2023 08:30:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692804644; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=BiPg1CR7QhpEos1y8wjGxBQSx510OyL+G2I/cKhPLW8=; b=iHxolWmF+UtVDlyY+iqY2RXRHaoQ+oScrFUJBRqwyHByNy2gUlUX47Y2cTpqZXFR/aRFT+ 7cR8dWFa+ZEzfuQfNQB420RzeogspNFwF5iPUUqYpe7r8WfkxaAjIHqxKLUhxnfOjl4dJY So44IvyjVPJfIZWuNSceunjo93zmpW8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-473-8NWu1HKwP7-2Q0-vJASG5Q-1; Wed, 23 Aug 2023 11:30:40 -0400 X-MC-Unique: 8NWu1HKwP7-2Q0-vJASG5Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 25F0B85D083; Wed, 23 Aug 2023 15:30:38 +0000 (UTC) Received: from laptop.redhat.com (unknown [10.39.193.143]) by smtp.corp.redhat.com (Postfix) with ESMTP id 15181C15BAE; Wed, 23 Aug 2023 15:30:35 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, elic@nvidia.com, mail@anirudhrb.com, jasowang@redhat.com, mst@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH] vhost: Allow null msg.size on VHOST_IOTLB_INVALIDATE Date: Wed, 23 Aug 2023 17:30:32 +0200 Message-ID: <20230823153032.239304-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") Forbade vhost iotlb msg with null size to prevent entries with size = start = 0 and last = ULONG_MAX to end up in the iotlb. Then commit 95932ab2ea07 ("vhost: allow batching hint without size") only applied the check for VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE message types to fix a regression observed with batching hit. Still, the introduction of that check introduced a regression for some users attempting to invalidate the whole ULONG_MAX range by setting the size to 0. This is the case with qemu/smmuv3/vhost integration which does not work anymore. It Looks safe to partially revert the original commit and allow VHOST_IOTLB_INVALIDATE messages with null size. vhost_iotlb_del_range() will compute a correct end iova. Same for vhost_vdpa_iotlb_unmap(). Signed-off-by: Eric Auger Fixes: e2ae38cf3d91 ("vhost: fix hung thread due to erroneous iotlb entries") Acked-by: Jason Wang --- drivers/vhost/vhost.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c71d573f1c94..e0c181ad17e3 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1458,9 +1458,7 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev, goto done; } - if ((msg.type == VHOST_IOTLB_UPDATE || - msg.type == VHOST_IOTLB_INVALIDATE) && - msg.size == 0) { + if (msg.type == VHOST_IOTLB_UPDATE && msg.size == 0) { ret = -EINVAL; goto done; }