From patchwork Mon Apr 18 09:58:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 611639 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qpNtd2Y54z9t3f for ; Mon, 18 Apr 2016 20:00:25 +1000 (AEST) Received: from localhost ([::1]:34366 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1as5yh-0002VO-Fz for incoming@patchwork.ozlabs.org; Mon, 18 Apr 2016 06:00:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49391) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1as5wz-00075b-SY for qemu-devel@nongnu.org; Mon, 18 Apr 2016 05:58:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1as5wy-0006ZB-Ip for qemu-devel@nongnu.org; Mon, 18 Apr 2016 05:58:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51629) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1as5wy-0006YB-C3 for qemu-devel@nongnu.org; Mon, 18 Apr 2016 05:58:36 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C629885547; Mon, 18 Apr 2016 09:58:35 +0000 (UTC) Received: from redhat.com (ovpn-116-32.ams2.redhat.com [10.36.116.32]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u3I9wTdb001238; Mon, 18 Apr 2016 05:58:29 -0400 Date: Mon, 18 Apr 2016 12:58:28 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Message-ID: <1460973374-32719-4-git-send-email-mst@redhat.com> References: <1460973374-32719-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1460973374-32719-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 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 RFC 3/3] vfio: add virtio pci quirk 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: Wei Liu , kvm@vger.kernel.org, Julia Lawall , Jason Wang , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, Christian Borntraeger , Alex Williamson , Andy Lutomirski , Paolo Bonzini , Cornelia Huck , Feng Wu , David Woodhouse , Dan Carpenter Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Modern virtio pci devices can set VIRTIO_F_IOMMU_PLATFORM to signal they are safe to use with an IOMMU. Without this bit, exposing the device to userspace is unsafe, so probe and fail VFIO initialization unless noiommu is enabled. Signed-off-by: Michael S. Tsirkin --- drivers/vfio/pci/vfio_pci_private.h | 1 + drivers/vfio/pci/vfio_pci.c | 11 +++ drivers/vfio/pci/vfio_pci_virtio.c | 135 ++++++++++++++++++++++++++++++++++++ drivers/vfio/pci/Makefile | 1 + 4 files changed, 148 insertions(+) create mode 100644 drivers/vfio/pci/vfio_pci_virtio.c diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 8a7d546..604d445 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -130,4 +130,5 @@ static inline int vfio_pci_igd_init(struct vfio_pci_device *vdev) return -ENODEV; } #endif +extern int vfio_pci_virtio_quirk(struct vfio_pci_device *vdev, int noiommu); #endif /* VFIO_PCI_PRIVATE_H */ diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index d622a41..2bb8c76 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1125,6 +1125,17 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) return ret; } + if (pdev->vendor == PCI_VENDOR_ID_REDHAT_QUMRANET && + ((ret = vfio_pci_virtio_quirk(vdev, ret)))) { + dev_warn(&vdev->pdev->dev, + "Failed to setup Virtio for VFIO\n"); + vfio_del_group_dev(&pdev->dev); + vfio_iommu_group_put(group, &pdev->dev); + kfree(vdev); + return ret; + } + + if (vfio_pci_is_vga(pdev)) { vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode); vga_set_legacy_decoding(pdev, diff --git a/drivers/vfio/pci/vfio_pci_virtio.c b/drivers/vfio/pci/vfio_pci_virtio.c new file mode 100644 index 0000000..1a32064 --- /dev/null +++ b/drivers/vfio/pci/vfio_pci_virtio.c @@ -0,0 +1,135 @@ +/* + * VFIO PCI Intel Graphics support + * + * Copyright (C) 2016 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Register a device specific region through which to provide read-only + * access to the Intel IGD opregion. The register defining the opregion + * address is also virtualized to prevent user modification. + */ + +#include +#include +#include +#include +#include +#include + +#include "vfio_pci_private.h" + +/** + * virtio_pci_find_capability - walk capabilities to find device info. + * @dev: the pci device + * @cfg_type: the VIRTIO_PCI_CAP_* value we seek + * + * Returns offset of the capability, or 0. + */ +static inline int virtio_pci_find_capability(struct pci_dev *dev, u8 cfg_type) +{ + int pos; + + for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); + pos > 0; + pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) { + u8 type; + pci_read_config_byte(dev, pos + offsetof(struct virtio_pci_cap, + cfg_type), + &type); + + if (type != cfg_type) + continue; + + /* Ignore structures with reserved BAR values */ + if (type != VIRTIO_PCI_CAP_PCI_CFG) { + u8 bar; + + pci_read_config_byte(dev, pos + + offsetof(struct virtio_pci_cap, + bar), + &bar); + if (bar > 0x5) + continue; + } + + return pos; + } + return 0; +} + + +int vfio_pci_virtio_quirk(struct vfio_pci_device *vdev, int noiommu) +{ + struct pci_dev *dev = vdev->pdev; + int common, cfg; + u32 features; + u32 offset; + u8 bar; + + /* Without an IOMMU, we don't care */ + if (noiommu) + return 0; + /* Check whether device enforces the IOMMU correctly */ + + /* + * All modern devices must have common and cfg capabilities. We use cfg + * capability for access so that we don't need to worry about resource + * availability. Slow but sure. + * Note that all vendor-specific fields we access are little-endian + * which matches what pci config accessors expect, so they do byteswap + * for us if appropriate. + */ + common = virtio_pci_find_capability(dev, VIRTIO_PCI_CAP_COMMON_CFG); + cfg = virtio_pci_find_capability(dev, VIRTIO_PCI_CAP_PCI_CFG); + if (!cfg || !common) { + dev_warn(&dev->dev, + "Virtio device lacks common or pci cfg.\n"); + return -ENODEV; + } + + pci_read_config_byte(dev, common + offsetof(struct virtio_pci_cap, + bar), + &bar); + pci_read_config_dword(dev, common + offsetof(struct virtio_pci_cap, + offset), + &offset); + + /* Program cfg capability for dword access into common cfg. */ + pci_write_config_byte(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + cap.bar), + bar); + pci_write_config_dword(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + cap.length), + 0x4); + + /* Select features dword that has VIRTIO_F_IOMMU_PLATFORM. */ + pci_write_config_dword(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + cap.offset), + offset + offsetof(struct virtio_pci_common_cfg, + device_feature_select)); + pci_write_config_dword(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + pci_cfg_data), + VIRTIO_F_IOMMU_PLATFORM / 32); + + /* Get the features dword. */ + pci_write_config_dword(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + cap.offset), + offset + offsetof(struct virtio_pci_common_cfg, + device_feature)); + pci_read_config_dword(dev, cfg + offsetof(struct virtio_pci_cfg_cap, + pci_cfg_data), + &features); + + /* Does this device obey the platform's IOMMU? If not it's an error. */ + if (!(features & (0x1 << (VIRTIO_F_IOMMU_PLATFORM % 32)))) { + dev_warn(&dev->dev, + "Virtio device lacks VIRTIO_F_IOMMU_PLATFORM.\n"); + return -ENODEV; + } + + return 0; +} diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile index 76d8ec0..e9b20e7 100644 --- a/drivers/vfio/pci/Makefile +++ b/drivers/vfio/pci/Makefile @@ -1,5 +1,6 @@ vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o +vfio-pci-y += vfio_pci_virtio.o vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o obj-$(CONFIG_VFIO_PCI) += vfio-pci.o