Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752839AbaJ0SJa (ORCPT ); Mon, 27 Oct 2014 14:09:30 -0400 Received: from mail-wg0-f43.google.com ([74.125.82.43]:44740 "EHLO mail-wg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752103AbaJ0SJ0 (ORCPT ); Mon, 27 Oct 2014 14:09:26 -0400 From: Antonios Motakis To: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, alex.williamson@redhat.com Cc: will.deacon@arm.com, tech@virtualopensystems.com, christoffer.dall@linaro.org, eric.auger@linaro.org, kim.phillips@freescale.com, marc.zyngier@arm.com, Antonios Motakis , kvm@vger.kernel.org (open list:VFIO DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v9 08/19] vfio/platform: read and write support for the device fd Date: Mon, 27 Oct 2014 19:07:53 +0100 Message-Id: <1414433284-31719-9-git-send-email-a.motakis@virtualopensystems.com> X-Mailer: git-send-email 2.1.1 In-Reply-To: <1414433284-31719-1-git-send-email-a.motakis@virtualopensystems.com> References: <1414433284-31719-1-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. Usually, the user will mmap memory regions that are addressable on page boundaries, however for memory regions where this is not the case we cannot provide mmap functionality due to security concerns. For this reason we also need allow to read and write to the memory regions via the file descriptor. Implement this funcionality only for MMIO regions of platform devices; PIO regions are not being handled at this point. Signed-off-by: Antonios Motakis --- drivers/vfio/platform/vfio_platform_common.c | 150 ++++++++++++++++++++++++++ drivers/vfio/platform/vfio_platform_private.h | 1 + 2 files changed, 151 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 82de752..e10a8d0 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -55,6 +55,10 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev) switch (resource_type(res)) { case IORESOURCE_MEM: vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO; + vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ; + if (!(res->flags & IORESOURCE_READONLY)) + vdev->regions[i].flags |= + VFIO_REGION_INFO_FLAG_WRITE; break; case IORESOURCE_IO: vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; @@ -74,6 +78,11 @@ err: static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) { + int i; + + for (i = 0; i < vdev->num_regions; i++) + iounmap(vdev->regions[i].ioaddr); + vdev->num_regions = 0; kfree(vdev->regions); } @@ -176,15 +185,156 @@ static long vfio_platform_ioctl(void *device_data, return -ENOTTY; } +static ssize_t vfio_platform_read_mmio(struct vfio_platform_region reg, + char __user *buf, size_t count, + loff_t off) +{ + unsigned int done = 0; + + if (!reg.ioaddr) { + reg.ioaddr = + ioremap_nocache(reg.addr, reg.size); + + if (!reg.ioaddr) + return -ENOMEM; + } + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + val = ioread32(reg.ioaddr + off); + if (copy_to_user(buf, &val, 4)) + goto err; + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + val = ioread16(reg.ioaddr + off); + if (copy_to_user(buf, &val, 2)) + goto err; + + filled = 2; + } else { + u8 val; + + val = ioread8(reg.ioaddr + off); + if (copy_to_user(buf, &val, 1)) + goto err; + + filled = 1; + } + + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + return done; +err: + return -EFAULT; +} + static ssize_t vfio_platform_read(void *device_data, char __user *buf, size_t count, loff_t *ppos) { + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + + if (index >= vdev->num_regions) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)) + return -EINVAL; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_read_mmio(vdev->regions[index], + buf, count, off); + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + return -EINVAL; } +static ssize_t vfio_platform_write_mmio(struct vfio_platform_region reg, + const char __user *buf, size_t count, + loff_t off) +{ + unsigned int done = 0; + + if (!reg.ioaddr) { + reg.ioaddr = + ioremap_nocache(reg.addr, reg.size); + + if (!reg.ioaddr) + return -ENOMEM; + } + + while (count) { + size_t filled; + + if (count >= 4 && !(off % 4)) { + u32 val; + + if (copy_from_user(&val, buf, 4)) + goto err; + iowrite32(val, reg.ioaddr + off); + + filled = 4; + } else if (count >= 2 && !(off % 2)) { + u16 val; + + if (copy_from_user(&val, buf, 2)) + goto err; + iowrite16(val, reg.ioaddr + off); + + filled = 2; + } else { + u8 val; + + if (copy_from_user(&val, buf, 1)) + goto err; + iowrite8(val, reg.ioaddr + off); + + filled = 1; + } + + count -= filled; + done += filled; + off += filled; + buf += filled; + } + + return done; +err: + return -EFAULT; +} + static ssize_t vfio_platform_write(void *device_data, const char __user *buf, size_t count, loff_t *ppos) { + struct vfio_platform_device *vdev = device_data; + unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos); + loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK; + + if (index >= vdev->num_regions) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)) + return -EINVAL; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_write_mmio(vdev->regions[index], + buf, count, off); + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + return -EINVAL; } diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h index b24729f..1f251b2 100644 --- a/drivers/vfio/platform/vfio_platform_private.h +++ b/drivers/vfio/platform/vfio_platform_private.h @@ -31,6 +31,7 @@ struct vfio_platform_region { u32 type; #define VFIO_PLATFORM_REGION_TYPE_MMIO 1 #define VFIO_PLATFORM_REGION_TYPE_PIO 2 + void __iomem *ioaddr; }; struct vfio_platform_device { -- 2.1.1 -- 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/