From nobody Thu Nov 6 10:32:12 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 1540429055012701.2417398425225; Wed, 24 Oct 2018 17:57:35 -0700 (PDT) Received: from localhost ([::1]:51456 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gFTxt-0005x5-Nn for importer@patchew.org; Wed, 24 Oct 2018 20:57:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57885) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gFTtZ-0002fR-AJ for qemu-devel@nongnu.org; Wed, 24 Oct 2018 20:53:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gFTtW-0004Xc-4e for qemu-devel@nongnu.org; Wed, 24 Oct 2018 20:53:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47200) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gFTtV-0004XL-Pc for qemu-devel@nongnu.org; Wed, 24 Oct 2018 20:53:02 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B1A46C05B02A; Thu, 25 Oct 2018 00:53:00 +0000 (UTC) Received: from redhat.com (ovpn-120-69.rdu2.redhat.com [10.10.120.69]) by smtp.corp.redhat.com (Postfix) with SMTP id D7D4166D4C; Thu, 25 Oct 2018 00:52:52 +0000 (UTC) Date: Wed, 24 Oct 2018 20:52:51 -0400 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20181025005110.249256-6-mst@redhat.com> References: <20181025005110.249256-1-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181025005110.249256-1-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 25 Oct 2018 00:53:00 +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] [PULL v2 05/28] 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: Peter Maydell , Eduardo Habkost , Peter Xu , Eric Auger , Maxime Coquelin , Pei Zhang , Paolo Bonzini , Richard Henderson 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 Content-Type: text/plain; charset="utf-8" From: Peter Xu 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 Reviewed-by: Maxime Coquelin Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/intel_iommu.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 25e54671f4..f24ebfca1c 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -38,6 +38,7 @@ #include "trace.h" =20 static void vtd_address_space_refresh_all(IntelIOMMUState *s); +static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n); =20 static void vtd_define_quad(IntelIOMMUState *s, hwaddr addr, uint64_t val, uint64_t wmask, uint64_t w1cmask) @@ -1066,11 +1067,27 @@ 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 MST