From nobody Sat Apr 12 16:49:34 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 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 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1694418686750601.0592664031592; Mon, 11 Sep 2023 00:51:26 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qfbh3-0004Em-5D; Mon, 11 Sep 2023 03:50:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qfbgx-00047X-Bl for qemu-devel@nongnu.org; Mon, 11 Sep 2023 03:50:43 -0400 Received: from gandalf.ozlabs.org ([150.107.74.76]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qfbgu-0008Cl-2W for qemu-devel@nongnu.org; Mon, 11 Sep 2023 03:50:43 -0400 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4Rkf5p2kbdz4xMC; Mon, 11 Sep 2023 17:50:38 +1000 (AEST) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4Rkf5m2XPPz4xM5; Mon, 11 Sep 2023 17:50:36 +1000 (AEST) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-devel@nongnu.org Cc: Alex Williamson , Avihai Horon , Yanghang Liu , Peter Xu , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PULL 11/13] vfio/migration: Block VFIO migration with postcopy migration Date: Mon, 11 Sep 2023 09:50:06 +0200 Message-ID: <20230911075008.462712-12-clg@redhat.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230911075008.462712-1-clg@redhat.com> References: <20230911075008.462712-1-clg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=150.107.74.76; envelope-from=SRS0=GLJ6=E3=redhat.com=clg@ozlabs.org; helo=gandalf.ozlabs.org X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1694418688298100007 From: Avihai Horon VFIO migration is not compatible with postcopy migration. A VFIO device in the destination can't handle page faults for pages that have not been sent yet. Doing such migration will cause the VM to crash in the destination: qemu-system-x86_64: VFIO_MAP_DMA failed: Bad address qemu-system-x86_64: vfio_dma_map(0x55a28c7659d0, 0xc0000, 0xb000, 0x7f1b11a= 00000) =3D -14 (Bad address) qemu: hardware error: vfio: DMA mapping failed, unable to continue To prevent this, block VFIO migration with postcopy migration. Reported-by: Yanghang Liu Signed-off-by: Avihai Horon Tested-by: Yanghang Liu Reviewed-by: Peter Xu Signed-off-by: C=C3=A9dric Le Goater --- hw/vfio/migration.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 71855468fe985291e2d009b81c6efd29abcbe755..20994dc1d60b1606728415fec17= c19cfd00c4dee 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -335,6 +335,27 @@ static bool vfio_precopy_supported(VFIODevice *vbasede= v) =20 /* ---------------------------------------------------------------------- = */ =20 +static int vfio_save_prepare(void *opaque, Error **errp) +{ + VFIODevice *vbasedev =3D opaque; + + /* + * Snapshot doesn't use postcopy, so allow snapshot even if postcopy i= s on. + */ + if (runstate_check(RUN_STATE_SAVE_VM)) { + return 0; + } + + if (migrate_postcopy_ram()) { + error_setg( + errp, "%s: VFIO migration is not supported with postcopy migra= tion", + vbasedev->name); + return -EOPNOTSUPP; + } + + return 0; +} + static int vfio_save_setup(QEMUFile *f, void *opaque) { VFIODevice *vbasedev =3D opaque; @@ -640,6 +661,7 @@ static bool vfio_switchover_ack_needed(void *opaque) } =20 static const SaveVMHandlers savevm_vfio_handlers =3D { + .save_prepare =3D vfio_save_prepare, .save_setup =3D vfio_save_setup, .save_cleanup =3D vfio_save_cleanup, .state_pending_estimate =3D vfio_state_pending_estimate, --=20 2.41.0