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=-9.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 E89D4C433E7 for ; Thu, 8 Oct 2020 21:24:47 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 270AD2223F for ; Thu, 8 Oct 2020 21:24:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FN0S6se1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 270AD2223F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54162 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kQdP3-0004js-V3 for qemu-devel@archiver.kernel.org; Thu, 08 Oct 2020 17:24:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53740) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kQdMu-0003xK-Be for qemu-devel@nongnu.org; Thu, 08 Oct 2020 17:22:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49331) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kQdMr-0004nq-K9 for qemu-devel@nongnu.org; Thu, 08 Oct 2020 17:22:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602192148; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=foe8IvXTZgjpuNZ07X2ksFCt/nw0A/GnkEBbWA83SbU=; b=FN0S6se12RWfkEASOU9loHzY7XRHYnLlSFkD2ZsPbfNCXJITfnT/ITU+vtLX3X716Q+j+P AzEicyY8hejzd4/VLeT52Dq6E4rNEhOFItOLvkdFYZRmCYtpSoyzZpT5AJddN8/s/1y+tm mII9hg59dfFofb3fawA/6yXLZwjVkGI= 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-427-YFt3FEODNzeHlAFjzzGRuw-1; Thu, 08 Oct 2020 17:22:24 -0400 X-MC-Unique: YFt3FEODNzeHlAFjzzGRuw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 69F5C1019625; Thu, 8 Oct 2020 21:22:23 +0000 (UTC) Received: from w520.home (ovpn-113-244.phx2.redhat.com [10.3.113.244]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0F0A355797; Thu, 8 Oct 2020 21:22:15 +0000 (UTC) Date: Thu, 8 Oct 2020 15:22:14 -0600 From: Alex Williamson To: Jean-Philippe Brucker Subject: Re: [PATCH v10 10/10] vfio: Don't issue full 2^64 unmap Message-ID: <20201008152214.3cb1425b@w520.home> In-Reply-To: <20201008171558.410886-11-jean-philippe@linaro.org> References: <20201008171558.410886-1-jean-philippe@linaro.org> <20201008171558.410886-11-jean-philippe@linaro.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=alex.williamson@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=alex.williamson@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/08 02:56:27 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mst@redhat.com, qemu-devel@nongnu.org, peterx@redhat.com, eric.auger@redhat.com, pbonzini@redhat.com, bbhushan2@marvell.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 8 Oct 2020 19:15:58 +0200 Jean-Philippe Brucker wrote: > IOMMUs may declare memory regions spanning from 0 to UINT64_MAX. When > attempting to deal with such region, vfio_listener_region_del() passes a > size of 2^64 to int128_get64() which throws an assertion failure. Even > ignoring this, the VFIO_IOMMU_DMA_MAP ioctl cannot handle this size > since the size field is 64-bit. Split the request in two. > > Signed-off-by: Jean-Philippe Brucker > --- > For me this happens when memory_region_iommu_set_page_size_mask() > returns an error because a hotplugged endpoint uses an incompatible page > mask. vfio_connect_container() releases the memory listener which calls > region_del() with the 2^64 IOMMU region. There are probably other ways > to reach this. > --- > hw/vfio/common.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index e66054b02a7..e90a89c389e 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -797,6 +797,17 @@ static void vfio_listener_region_del(MemoryListener *listener, > } > > if (try_unmap) { > + if (llsize == int128_2_64()) { > + /* The unmap ioctl doesn't accept a full 64-bit span. */ > + llsize = int128_rshift(llsize, 1); > + ret = vfio_dma_unmap(container, iova, int128_get64(llsize)); > + if (ret) { > + error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " > + "0x%"HWADDR_PRIx") = %d (%m)", > + container, iova, int128_get64(llsize), ret); > + } > + iova += int128_get64(llsize); > + } > ret = vfio_dma_unmap(container, iova, int128_get64(llsize)); > if (ret) { > error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " We're still susceptible that splitting the range in two could result in unmap calls that attempt to bisect a mapping that spans both ranges. Both unmap calls would fail in that case. I think we could solve this more completely with a high water marker, but this probably good enough for now. Acked-by: Alex Williamson