On Wed, Nov 12, 2014 at 4:46 PM, Eric Auger <eric.auger@xxxxxxxxxx> wrote:
> 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
>
Ack!
> 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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