From patchwork Thu Mar 12 09:37:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 5992261 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 79CF2BF90F for ; Thu, 12 Mar 2015 09:38:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8C079203A0 for ; Thu, 12 Mar 2015 09:38:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 993C720375 for ; Thu, 12 Mar 2015 09:38:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751833AbbCLJhu (ORCPT ); Thu, 12 Mar 2015 05:37:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39590 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750973AbbCLJht (ORCPT ); Thu, 12 Mar 2015 05:37:49 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2C9bgMj018468 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 12 Mar 2015 05:37:42 -0400 Received: from redhat.com (ovpn-116-109.ams2.redhat.com [10.36.116.109]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id t2C9bd3T010949; Thu, 12 Mar 2015 05:37:40 -0400 Date: Thu, 12 Mar 2015 10:37:39 +0100 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Rusty Russell , virtualization@lists.linux-foundation.org, Pawel Moll , kvm@vger.kernel.org Subject: [PATCH v2 log fixed] virtio_mmio: fix endian-ness for mmio Message-ID: <20150312093739.GA4655@redhat.com> MIME-Version: 1.0 Content-Disposition: inline X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Subject: [PATCH] virtio_mmio: fix access width for mmio Going over the virtio mmio code, I noticed that it doesn't correctly access modern device config values using "natural" accessors: it uses readb to get/set them byte by byte, while the virtio 1.0 spec explicitly states: 4.2.2.2 Driver Requirements: MMIO Device Register Layout ... The driver MUST only use 32 bit wide and aligned reads and writes to access the control registers described in table 4.1. For the device-specific configuration space, the driver MUST use 8 bit wide accesses for 8 bit wide fields, 16 bit wide and aligned accesses for 16 bit wide fields and 32 bit wide and aligned accesses for 32 and 64 bit wide fields. Borrow code from virtio_pci_modern to do this correctly. Signed-off-by: Michael S. Tsirkin --- This is exactly the same as PATCH virtio_mmio: fix endian-ness for mmio but with corrected subject and commit log, to make it easier to apply. Note: untested: QEMU doesn't support virtio 1.0 for virtio-mmio, but seems pretty obvious. Let's apply ASAP so we don't ship incompliant drivers for virtio 1.0? drivers/virtio/virtio_mmio.c | 79 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 71 insertions(+), 8 deletions(-) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index cad5698..0375456 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -156,22 +156,85 @@ static void vm_get(struct virtio_device *vdev, unsigned offset, void *buf, unsigned len) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); - u8 *ptr = buf; - int i; + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; + u8 b; + __le16 w; + __le32 l; - for (i = 0; i < len; i++) - ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); + if (vm_dev->version == 1) { + u8 *ptr = buf; + int i; + + for (i = 0; i < len; i++) + ptr[i] = readb(base + offset + i); + return; + } + + switch (len) { + case 1: + b = readb(base + offset); + memcpy(buf, &b, sizeof b); + break; + case 2: + w = cpu_to_le16(readw(base + offset)); + memcpy(buf, &w, sizeof w); + break; + case 4: + l = cpu_to_le32(readl(base + offset)); + memcpy(buf, &l, sizeof l); + break; + case 8: + l = cpu_to_le32(readl(base + offset)); + memcpy(buf, &l, sizeof l); + l = cpu_to_le32(ioread32(base + offset + sizeof l)); + memcpy(buf + sizeof l, &l, sizeof l); + break; + default: + BUG(); + } } static void vm_set(struct virtio_device *vdev, unsigned offset, const void *buf, unsigned len) { struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); - const u8 *ptr = buf; - int i; + void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; + u8 b; + __le16 w; + __le32 l; - for (i = 0; i < len; i++) - writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i); + if (vm_dev->version == 1) { + const u8 *ptr = buf; + int i; + + for (i = 0; i < len; i++) + writeb(ptr[i], base + offset + i); + + return; + } + + switch (len) { + case 1: + memcpy(&b, buf, sizeof b); + writeb(b, base + offset); + break; + case 2: + memcpy(&w, buf, sizeof w); + writew(le16_to_cpu(w), base + offset); + break; + case 4: + memcpy(&l, buf, sizeof l); + writel(le32_to_cpu(l), base + offset); + break; + case 8: + memcpy(&l, buf, sizeof l); + writel(le32_to_cpu(l), base + offset); + memcpy(&l, buf + sizeof l, sizeof l); + writel(le32_to_cpu(l), base + offset + sizeof l); + break; + default: + BUG(); + } } static u8 vm_get_status(struct virtio_device *vdev)