From patchwork Thu Feb 6 13:14:33 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 13963028 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 10654C02194 for ; Thu, 6 Feb 2025 13:15:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tg1iw-0007Rc-EM; Thu, 06 Feb 2025 08:15:20 -0500 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 1tg1ic-00078Z-JG for qemu-devel@nongnu.org; Thu, 06 Feb 2025 08:14:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tg1ib-0000CS-0e for qemu-devel@nongnu.org; Thu, 06 Feb 2025 08:14:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738847695; 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=FgtGN4QsOF8XaCWgrj+kwMaZMtpQDiettMvYvUpXuRc=; b=EmFaYhTya/sNPaVspNYPPOkSQjv3m3fBuslngx4ndKWCdmpfKwtoifgp66TXA1RMsceHs7 Gb8czs4ejER+JeDsC5EdvmsH+3IF4ID9fkkFuX4jaT/3XzzBLpAYiRYyLn8Pi3cvbLaP5y M9ubPuZ10lmENNdmMzP3khFPj00Br9g= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-454-XEtgE_wYOWSqTepMQL5upA-1; Thu, 06 Feb 2025 08:14:54 -0500 X-MC-Unique: XEtgE_wYOWSqTepMQL5upA-1 X-Mimecast-MFC-AGG-ID: XEtgE_wYOWSqTepMQL5upA Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7AE2B1800874 for ; Thu, 6 Feb 2025 13:14:53 +0000 (UTC) Received: from corto.redhat.com (unknown [10.39.192.15]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3D1D830001AB; Thu, 6 Feb 2025 13:14:51 +0000 (UTC) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: qemu-devel@nongnu.org Cc: Alex Williamson , =?utf-8?q?C=C3=A9dric_Le_G?= =?utf-8?q?oater?= Subject: [PATCH v3 5/7] vfio: Improve error reporting when MMIO region mapping fails Date: Thu, 6 Feb 2025 14:14:33 +0100 Message-ID: <20250206131438.1505542-6-clg@redhat.com> In-Reply-To: <20250206131438.1505542-1-clg@redhat.com> References: <20250206131438.1505542-1-clg@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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_H2=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org When the IOMMU address space width is smaller than the physical address width, a MMIO region of a device can fail to map because the region is outside the supported IOVA ranges of the VM. In this case, PCI peer-to-peer transactions on BARs are not supported. This can occur with the 39-bit IOMMU address space width, as can be the case on some Intel consumer processors, or when using a vIOMMU device with default settings. The current error message is unclear, improve it and also change the error report to a warning because it is a non fatal condition for the VM. To prevent excessive log messages, restrict these recurring DMA mapping errors to a single warning at runtime. Signed-off-by: Cédric Le Goater --- hw/vfio/common.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 62af1216fc5a9089fc718c2afe3a405d9381db32..4fca4c6166f761acceb7b57b52e379603ea53876 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -555,6 +555,18 @@ static bool vfio_get_section_iova_range(VFIOContainerBase *bcontainer, return true; } +static void vfio_device_error_append(VFIODevice *vbasedev, Error **errp) +{ + /* + * MMIO region mapping failures are not fatal but in this case PCI + * peer-to-peer transactions are broken. + */ + if (vbasedev && vbasedev->type == VFIO_DEVICE_TYPE_PCI) { + error_append_hint(errp, "%s: PCI peer-to-peer transactions " + "on BARs are not supported.\n", vbasedev->name); + } +} + static void vfio_listener_region_add(MemoryListener *listener, MemoryRegionSection *section) { @@ -670,7 +682,10 @@ static void vfio_listener_region_add(MemoryListener *listener, strerror(-ret)); if (memory_region_is_ram_device(section->mr)) { /* Allow unexpected mappings not to be fatal for RAM devices */ - error_report_err(err); + VFIODevice *vbasedev = + vfio_get_vfio_device(memory_region_owner(section->mr)); + vfio_device_error_append(vbasedev, &err); + warn_report_err_once(err); return; } goto fail;