Re: [Qemu-ppc] [PATCH v7 2/4] vfio: Add vfio_container_spapr_get_info()

[Alex Williamson]

On Thu, 2014-06-05 at 15:49 +1000, Alexey Kardashevskiy wrote:
> To perform DMA mapping via TCE table correctly, the guest must
> know where DMA window is located on the PCI bus. A hypervisor is
> expected to provide such information. Since QEMU has no control
> over this setting, we need a way to obtain a start address and size
> from the host VFIO driver.
> 
> This adds a helper which returns the default DMA window properties
> for the specific IOMMU group. The upstream kernel implements this ioctl
> already.

Couldn't this be done with Gavin's vfio_pci_container_ioctl()?  Thanks,

Alex


> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
> Changes:
> v7:
> * do not return a group fd from the helper
> 
> v6:
> * added dup() to protect group_fd from accidental disposal
> 
> v5:
> * reworked to reflect change in vfio_get_group() from one
> of previous patches change
> 
> v4:
> * fixed possible leaks on error paths
> ---
>  hw/misc/vfio.c         | 36 ++++++++++++++++++++++++++++++++++++
>  include/hw/misc/vfio.h | 11 +++++++++++
>  2 files changed, 47 insertions(+)
>  create mode 100644 include/hw/misc/vfio.h
> 
> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
> index 7437c2e..99141f3 100644
> --- a/hw/misc/vfio.c
> +++ b/hw/misc/vfio.c
> @@ -39,6 +39,7 @@
>  #include "qemu/range.h"
>  #include "sysemu/kvm.h"
>  #include "sysemu/sysemu.h"
> +#include "hw/misc/vfio.h"
>  
>  /* #define DEBUG_VFIO */
>  #ifdef DEBUG_VFIO
> @@ -4318,3 +4319,38 @@ static void register_vfio_pci_dev_type(void)
>  }
>  
>  type_init(register_vfio_pci_dev_type)
> +
> +int vfio_container_spapr_get_info(AddressSpace *as,
> +                                  int32_t groupid,
> +                                  struct vfio_iommu_spapr_tce_info *info)
> +{
> +    VFIOGroup *group;
> +    VFIOContainer *container;
> +    int ret, fd;
> +
> +    group = vfio_get_group(groupid, as);
> +    if (!group) {
> +        return -1;
> +    }
> +    container = group->container;
> +    if (!group->container) {
> +        goto put_group_exit;
> +    }
> +    fd = container->fd;
> +    if (!ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_SPAPR_TCE_IOMMU)) {
> +        goto put_group_exit;
> +    }
> +    ret = ioctl(fd, VFIO_IOMMU_SPAPR_TCE_GET_INFO, info);
> +    if (ret) {
> +        error_report("vfio: failed to get iommu info for container: %s",
> +                     strerror(errno));
> +        goto put_group_exit;
> +    }
> +
> +    return 0;
> +
> +put_group_exit:
> +    vfio_put_group(group);
> +
> +    return -1;
> +}
> diff --git a/include/hw/misc/vfio.h b/include/hw/misc/vfio.h
> new file mode 100644
> index 0000000..e82f5a3
> --- /dev/null
> +++ b/include/hw/misc/vfio.h
> @@ -0,0 +1,11 @@
> +#ifndef VFIO_API_H
> +#define VFIO_API_H
> +
> +#include "qemu/typedefs.h"
> +#include <linux/vfio.h>
> +
> +extern int vfio_container_spapr_get_info(AddressSpace *as,
> +                                         int32_t groupid,
> +                                         struct vfio_iommu_spapr_tce_info 
> *info);
> +
> +#endif