[PATCH 1/3] drm/i915/gvt: Move mdev attribute groups into kvmgt module

[Jason Gunthorpe]

On Tue, May 11, 2021 at 04:33:30PM +0800, Zhenyu Wang wrote:
> As kvmgt module contains all handling for VFIO/mdev, leaving mdev attribute
> groups in gvt module caused dependency issue. Although it was there for possible
> other hypervisor usage, that turns out never to be true. So this moves all mdev
> handling into kvmgt module completely to resolve dependency issue.
> 
> Cc: Arnd Bergmann <arnd at kernel.org>
> Cc: Jason Gunthorpe <jgg at ziepe.ca>
> Cc: Alex Williamson <alex.williamson at redhat.com>
> Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/gvt.c       | 124 +------------------------
>  drivers/gpu/drm/i915/gvt/gvt.h       |   3 -
>  drivers/gpu/drm/i915/gvt/hypercall.h |   2 +-
>  drivers/gpu/drm/i915/gvt/kvmgt.c     | 129 +++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/gvt/mpt.h       |   4 +-
>  5 files changed, 126 insertions(+), 136 deletions(-)

There is no reason to make this into three patches, just make the one
line change to kconfig here.

> +static struct intel_vgpu_type *
> +intel_gvt_find_vgpu_type(struct intel_gvt *gvt, unsigned int type_group_id)
> +{
> +	if (WARN_ON(type_group_id >= gvt->num_types))
> +		return NULL;
> +	return &gvt->types[type_group_id];
> +}

The WARN_ON can't happen, all this error handling is code should be
deleted, just use the simple

struct intel_gvt *gvt = kdev_to_i915(mtype_get_parent_dev(mtype))->gvt;
struct intel_vgpu_type *type = &gvt->types[mtype_get_type_group_id(mtype)]

sequence like the other mdev drivers

> +static ssize_t available_instances_show(struct mdev_type *mtype,
> +					struct mdev_type_attribute *attr,
> +					char *buf)
> +{
> +	struct intel_vgpu_type *type;
> +	unsigned int num = 0;
> +	void *gvt = kdev_to_i915(mtype_get_parent_dev(mtype))->gvt;

Use proper types not 'void *'
> +
> +static int intel_gvt_init_vgpu_type_groups(struct intel_gvt *gvt)
> +{
> +	int i, j;
> +	struct intel_vgpu_type *type;
> +	struct attribute_group *group;
> +
> +	for (i = 0; i < gvt->num_types; i++) {
> +		type = &gvt->types[i];
> +
> +		group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
> +		if (WARN_ON(!group))
> +			goto unwind;

WARN_ON at allocation failure is not good

This need to go into the vfio tree in some way, either directly
through it, via rc or otherwise

Jason