On 10/27/2014 07:07 PM, Antonios Motakis wrote:
> 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
some rewording needed here
> via the file descriptor. Implement this funcionality
typo
Regards
Eric
only for MMIO regions
> of platform devices; PIO regions are not being handled at this point.
>
> Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
> ---
> 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 {
>
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