From nobody Thu Nov 6 06:39:19 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1539071514647798.8286566676555; Tue, 9 Oct 2018 00:51:54 -0700 (PDT) Received: from localhost ([::1]:50077 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9mo5-0003lM-M4 for importer@patchew.org; Tue, 09 Oct 2018 03:51:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52723) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g9mj4-000132-Mj for qemu-devel@nongnu.org; Tue, 09 Oct 2018 03:46:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g9mj0-0000P2-44 for qemu-devel@nongnu.org; Tue, 09 Oct 2018 03:46:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39726) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g9miz-0000NV-Tv for qemu-devel@nongnu.org; Tue, 09 Oct 2018 03:46:38 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 296A38A004 for ; Tue, 9 Oct 2018 07:46:35 +0000 (UTC) Received: from xz-x1.nay.redhat.com (dhcp-14-128.nay.redhat.com [10.66.14.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5ECA959448; Tue, 9 Oct 2018 07:46:32 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Tue, 9 Oct 2018 15:45:43 +0800 Message-Id: <20181009074543.6013-3-peterx@redhat.com> In-Reply-To: <20181009074543.6013-1-peterx@redhat.com> References: <20181009074543.6013-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 09 Oct 2018 07:46:35 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 2/2] intel_iommu: handle invalid ce for shadow sync X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Michael S . Tsirkin" , Jason Wang , Alex Williamson , peterx@redhat.com, Eric Auger , Maxime Coquelin , Pei Zhang Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" We should handle VTD_FR_CONTEXT_ENTRY_P properly when synchronizing shadow page tables. Having invalid context entry there is perfectly valid when we move a device out of an existing domain. When that happens, instead of posting an error we invalidate the whole region. Without this patch, QEMU will crash if we do these steps: (1) start QEMU with VT-d IOMMU and two 10G NICs (ixgbe) (2) bind the NICs with vfio-pci in the guest (3) start testpmd with the NICs applied (4) stop testpmd (5) rebind the NIC back to ixgbe kernel driver The patch should fix it. Reported-by: Pei Zhang Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=3D1627272 Signed-off-by: Peter Xu Reviewed-by: Eric Auger --- hw/i386/intel_iommu.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index d6b4f8705d..6072f9a4e0 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -37,6 +37,8 @@ #include "kvm_i386.h" #include "trace.h" =20 +static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n); + static void vtd_define_quad(IntelIOMMUState *s, hwaddr addr, uint64_t val, uint64_t wmask, uint64_t w1cmask) { @@ -1056,11 +1058,27 @@ static int vtd_sync_shadow_page_table(VTDAddressSpa= ce *vtd_as) { int ret; VTDContextEntry ce; + IOMMUNotifier *n; =20 ret =3D vtd_dev_to_context_entry(vtd_as->iommu_state, pci_bus_num(vtd_as->bus), vtd_as->devfn, &ce); if (ret) { + if (ret =3D=3D -VTD_FR_CONTEXT_ENTRY_P) { + /* + * It's a valid scenario to have a context entry that is + * not present. For example, when a device is removed + * from an existing domain then the context entry will be + * zeroed by the guest before it was put into another + * domain. When this happens, instead of synchronizing + * the shadow pages we should invalidate all existing + * mappings and notify the backends. + */ + IOMMU_NOTIFIER_FOREACH(n, &vtd_as->iommu) { + vtd_address_space_unmap(vtd_as, n); + } + ret =3D 0; + } return ret; } =20 --=20 2.17.1