Re: [Qemu-devel] [PATCH v7 08/13] vfio/ccw: get io region info

[Alex Williamson <alex.williamson@redhat.com>]

On Fri,  5 May 2017 04:03:47 +0200
Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> wrote:

> vfio-ccw provides an MMIO region for I/O operations. We fetch its
> information via ioctls here, then we can use it performing I/O
> instructions and retrieving I/O results later on.
> 
> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
> ---


Acked-by: Alex Williamson <alex.williamson@redhat.com>


>  hw/vfio/ccw.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
> 
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index 7d2497c..7ddcfd7 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -12,6 +12,7 @@
>   */
>  
>  #include <linux/vfio.h>
> +#include <linux/vfio_ccw.h>
>  #include <sys/ioctl.h>
>  
>  #include "qemu/osdep.h"
> @@ -26,6 +27,9 @@
>  typedef struct VFIOCCWDevice {
>      S390CCWDevice cdev;
>      VFIODevice vdev;
> +    uint64_t io_region_size;
> +    uint64_t io_region_offset;
> +    struct ccw_io_region *io_region;
>  } VFIOCCWDevice;
>  
>  static void vfio_ccw_compute_needs_reset(VFIODevice *vdev)
> @@ -50,6 +54,48 @@ static void vfio_ccw_reset(DeviceState *dev)
>      ioctl(vcdev->vdev.fd, VFIO_DEVICE_RESET);
>  }
>  
> +static void vfio_ccw_get_region(VFIOCCWDevice *vcdev, Error **errp)
> +{
> +    VFIODevice *vdev = &vcdev->vdev;
> +    struct vfio_region_info *info;
> +    int ret;
> +
> +    /* Sanity check device */
> +    if (!(vdev->flags & VFIO_DEVICE_FLAGS_CCW)) {
> +        error_setg(errp, "vfio: Um, this isn't a vfio-ccw device");
> +        return;
> +    }
> +
> +    if (vdev->num_regions < VFIO_CCW_CONFIG_REGION_INDEX + 1) {
> +        error_setg(errp, "vfio: Unexpected number of the I/O region %u",
> +                   vdev->num_regions);
> +        return;
> +    }
> +
> +    ret = vfio_get_region_info(vdev, VFIO_CCW_CONFIG_REGION_INDEX, &info);
> +    if (ret) {
> +        error_setg_errno(errp, -ret, "vfio: Error getting config info");
> +        return;
> +    }
> +
> +    vcdev->io_region_size = info->size;
> +    if (sizeof(*vcdev->io_region) != vcdev->io_region_size) {
> +        error_setg(errp, "vfio: Unexpected size of the I/O region");
> +        g_free(info);
> +        return;
> +    }
> +
> +    vcdev->io_region_offset = info->offset;
> +    vcdev->io_region = g_malloc0(info->size);
> +
> +    g_free(info);
> +}
> +
> +static void vfio_ccw_put_region(VFIOCCWDevice *vcdev)
> +{
> +    g_free(vcdev->io_region);
> +}
> +
>  static void vfio_put_device(VFIOCCWDevice *vcdev)
>  {
>      g_free(vcdev->vdev.name);
> @@ -122,8 +168,15 @@ static void vfio_ccw_realize(DeviceState *dev, Error **errp)
>          goto out_device_err;
>      }
>  
> +    vfio_ccw_get_region(vcdev, &err);
> +    if (err) {
> +        goto out_region_err;
> +    }
> +
>      return;
>  
> +out_region_err:
> +    vfio_put_device(vcdev);
>  out_device_err:
>      vfio_put_group(group);
>  out_group_err:
> @@ -142,6 +195,7 @@ static void vfio_ccw_unrealize(DeviceState *dev, Error **errp)
>      S390CCWDeviceClass *cdc = S390_CCW_DEVICE_GET_CLASS(cdev);
>      VFIOGroup *group = vcdev->vdev.group;
>  
> +    vfio_ccw_put_region(vcdev);
>      vfio_put_device(vcdev);
>      vfio_put_group(group);
>