On Wed, 2014-08-20 at 17:49 +1000, Alexey Kardashevskiy wrote:
> On 08/19/2014 03:42 AM, Alex Williamson wrote:
> > On Fri, 2014-08-15 at 20:12 +1000, Alexey Kardashevskiy wrote:
> >> Since the changes are not in upstream yet, no tag or branch is specified
> >> here.
> >>
> >> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> >> ---
> >> linux-headers/linux/vfio.h | 37 ++++++++++++++++++++++++++++++++++++-
> >> 1 file changed, 36 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h
> >> index 26c218e..f0aa97d 100644
> >> --- a/linux-headers/linux/vfio.h
> >> +++ b/linux-headers/linux/vfio.h
> >> @@ -448,13 +448,48 @@ struct vfio_iommu_type1_dma_unmap {
> >> */
> >> struct vfio_iommu_spapr_tce_info {
> >> __u32 argsz;
> >> - __u32 flags; /* reserved for future use */
> >> + __u32 flags;
> >> +#define VFIO_IOMMU_SPAPR_TCE_FLAG_DDW 1 /* Support dynamic windows */
> >> __u32 dma32_window_start; /* 32 bit window start (bytes) */
> >> __u32 dma32_window_size; /* 32 bit window size (bytes) */
> >> };
> >>
> >> #define VFIO_IOMMU_SPAPR_TCE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
> >>
> >> +/*
> >> + * Dynamic DMA windows
> >> + */
> >> +struct vfio_iommu_spapr_tce_query {
> >> + __u32 argsz;
> >> + /* out */
> >> + __u32 windows_available;
> >> + __u32 page_size_mask;
> >> +};
> >
> > Why do we need a new ioctl for this vs extending tce_info to include it?
> > That's sort of the point of including argsz and flags in the ioctl.
>
>
> It is not actual now but I can imagine that these numbers may change
> depending on multiple calls of create()/remove().
Why does that matter?
> >> +#define VFIO_IOMMU_SPAPR_TCE_QUERY _IO(VFIO_TYPE, VFIO_BASE + 17)
> >> +
> >> +struct vfio_iommu_spapr_tce_create {
> >> + __u32 argsz;
> >> + /* in */
> >> + __u32 page_shift;
> >> + __u32 window_shift;
> >> + /* out */
> >> + __u64 start_addr;
> >> +
> >> +};
> >> +#define VFIO_IOMMU_SPAPR_TCE_CREATE _IO(VFIO_TYPE, VFIO_BASE + 18)
> >> +
> >> +struct vfio_iommu_spapr_tce_remove {
> >> + __u32 argsz;
> >> + /* in */
> >> + __u64 start_addr;
> >> +};
> >> +#define VFIO_IOMMU_SPAPR_TCE_REMOVE _IO(VFIO_TYPE, VFIO_BASE + 19)
> >> +
> >> +struct vfio_iommu_spapr_tce_reset {
> >> + __u32 argsz;
> >> +};
> >> +#define VFIO_IOMMU_SPAPR_TCE_RESET _IO(VFIO_TYPE, VFIO_BASE + 20)
> >> +
> >
> > argsz by itself seems rather pointless if we don't have a flags field to
> > augment the structure. Thanks,
>
>
> Add flags and check for zero or remove it? Cannot choose, please help :)
Do we really need to hash this out again? Almost every vfio ioctl
includes argsz and flags. Please continue to do this unless you have a
good reason otherwise. Thanks,
Alex
