Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932678AbaD1Pyf (ORCPT ); Mon, 28 Apr 2014 11:54:35 -0400 Received: from mail-wi0-f171.google.com ([209.85.212.171]:37439 "EHLO mail-wi0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932442AbaD1Py1 (ORCPT ); Mon, 28 Apr 2014 11:54:27 -0400 From: Antonios Motakis To: alex.williamson@redhat.com, kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org Cc: tech@virtualopensystems.com, a.rigo@virtualopensystems.com, kvm@vger.kernel.org, christoffer.dall@linaro.org, will.deacon@arm.com, kim.phillips@freescale.com, stuart.yoder@freescale.com, Antonios Motakis , linux-kernel@vger.kernel.org (open list) Subject: [RFC PATCH v5 07/11] VFIO_PLATFORM: Read and write support for the device fd Date: Mon, 28 Apr 2014 17:52:47 +0200 Message-Id: <1398700371-20096-8-git-send-email-a.motakis@virtualopensystems.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1398700371-20096-1-git-send-email-a.motakis@virtualopensystems.com> References: <1398700371-20096-1-git-send-email-a.motakis@virtualopensystems.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org VFIO returns a file descriptor which we can use to manipulate the memory regions of the device. Since some memory regions we cannot mmap due to security concerns, we also allow to read and write to this file descriptor directly. Signed-off-by: Antonios Motakis --- drivers/vfio/platform/vfio_platform.c | 110 +++++++++++++++++++++++++++++++++- 1 file changed, 107 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index 5430cbe..7c01ced 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -55,7 +55,8 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev) region.addr = res->start; region.size = resource_size(res); - region.flags = 0; + region.flags = VFIO_REGION_INFO_FLAG_READ + | VFIO_REGION_INFO_FLAG_WRITE; vdev->region[i] = region; } @@ -153,13 +154,116 @@ static long vfio_platform_ioctl(void *device_data, static ssize_t vfio_platform_read(void *device_data, char __user *buf, size_t count, loff_t *ppos) { - return 0; + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + unsigned int done = 0; + void __iomem *io; + + if (index >= vdev->num_regions) + return -EINVAL; + + io = ioremap_nocache(vdev->region[index].addr, + vdev->region[index].size); + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + val = ioread32(io + off); + if (copy_to_user(buf, &val, 4)) + goto err; + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + val = ioread16(io + off); + if (copy_to_user(buf, &val, 2)) + goto err; + + filled = 2; + } else { + u8 val; + + val = ioread8(io + off); + if (copy_to_user(buf, &val, 1)) + goto err; + + filled = 1; + } + + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + iounmap(io); + return done; +err: + iounmap(io); + return -EFAULT; } static ssize_t vfio_platform_write(void *device_data, const char __user *buf, size_t count, loff_t *ppos) { - return 0; + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + unsigned int done = 0; + void __iomem *io; + + if (index >= vdev->num_regions) + return -EINVAL; + + io = ioremap_nocache(vdev->region[index].addr, + vdev->region[index].size); + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + if (copy_from_user(&val, buf, 4)) + goto err; + iowrite32(val, io + off); + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + if (copy_from_user(&val, buf, 2)) + goto err; + iowrite16(val, io + off); + + filled = 2; + } else { + u8 val; + + if (copy_from_user(&val, buf, 1)) + goto err; + iowrite8(val, io + off); + + filled = 1; + } + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + iounmap(io); + return done; +err: + iounmap(io); + return -EFAULT; } static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/