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Commit 9bdb0734 authored by Zhenyu Wang's avatar Zhenyu Wang
Browse files

drm/i915/gvt: Change KVMGT as self load module 



This trys to make 'kvmgt' module as self loadable instead of loading
by i915/gvt device model. So hypervisor specific module could be
stand-alone, e.g only after loading hypervisor specific module, GVT
feature could be enabled via specific hypervisor interface, e.g VFIO/mdev.

So this trys to use hypervisor module register/unregister interface
for that. Hypervisor module needs to take care of module reference
itself when working for hypervisor interface, e.g for VFIO/mdev,
hypervisor module would reference counting mdev when open and release.

This makes 'kvmgt' module really split from GVT device model. User
needs to load 'kvmgt' to enable VFIO/mdev interface.

v6:
- remove unused variable

v5:
- put module reference in register error path

v4:
- fix checkpatch warning

v3:
- Fix module reference handling for device open and release. Unused
  mdev devices would be cleaned up in device unregister when module unload.

v2:
- Fix kvmgt order after i915 for built-in case

Cc: "Yuan, Hang" <hang.yuan@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: "He, Min" <min.he@intel.com>
Reviewed-by: default avatarYuan, Hang <hang.yuan@intel.com>
Acked-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: default avatarZhenyu Wang <zhenyuw@linux.intel.com>
parent a2b8419a

drivers/gpu/drm/i915/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -198,3 +198,4 @@ endif 
i915-y += intel_lpe_audio.o



obj-$(CONFIG_DRM_I915) += i915.o

obj-$(CONFIG_DRM_I915_GVT_KVMGT) += gvt/kvmgt.o

drivers/gpu/drm/i915/gvt/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -7,4 +7,3 @@ GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \ 


ccflags-y				+= -I$(src) -I$(src)/$(GVT_DIR)

i915-y					+= $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))
 
obj-$(CONFIG_DRM_I915_GVT_KVMGT)	+= $(GVT_DIR)/kvmgt.o

drivers/gpu/drm/i915/gvt/gvt.c

+44 −64
Original line number Diff line number Diff line
@@ -187,52 +187,6 @@ static const struct intel_gvt_ops intel_gvt_ops = { 
	.write_protect_handler = intel_vgpu_page_track_handler,

};



/**

 * intel_gvt_init_host - Load MPT modules and detect if we're running in host

 *

 * This function is called at the driver loading stage. If failed to find a

 * loadable MPT module or detect currently we're running in a VM, then GVT-g

 * will be disabled

 *

 * Returns:

 * Zero on success, negative error code if failed.

 *

 */

int intel_gvt_init_host(void)

{

	if (intel_gvt_host.initialized)

		return 0;



	/* Xen DOM U */

	if (xen_domain() && !xen_initial_domain())

		return -ENODEV;



	/* Try to load MPT modules for hypervisors */

	if (xen_initial_domain()) {

		/* In Xen dom0 */

		intel_gvt_host.mpt = try_then_request_module(

				symbol_get(xengt_mpt), "xengt");

		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_XEN;

	} else {

#if IS_ENABLED(CONFIG_DRM_I915_GVT_KVMGT)

		/* not in Xen. Try KVMGT */

		intel_gvt_host.mpt = try_then_request_module(

				symbol_get(kvmgt_mpt), "kvmgt");

		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_KVM;

#endif

	}



	/* Fail to load MPT modules - bail out */

	if (!intel_gvt_host.mpt)

		return -EINVAL;



	gvt_dbg_core("Running with hypervisor %s in host mode\n",

			supported_hypervisors[intel_gvt_host.hypervisor_type]);



	intel_gvt_host.initialized = true;

	return 0;

}



static void init_device_info(struct intel_gvt *gvt)

{

	struct intel_gvt_device_info *info = &gvt->device_info;
@@ -316,7 +270,6 @@ void intel_gvt_clean_device(struct drm_i915_private *dev_priv) 
		return;



	intel_gvt_destroy_idle_vgpu(gvt->idle_vgpu);

	intel_gvt_hypervisor_host_exit(&dev_priv->drm.pdev->dev);

	intel_gvt_cleanup_vgpu_type_groups(gvt);

	intel_gvt_clean_vgpu_types(gvt);
@@ -352,13 +305,6 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv) 
	struct intel_vgpu *vgpu;

	int ret;



	/*

	 * Cannot initialize GVT device without intel_gvt_host gets

	 * initialized first.

	 */

	if (WARN_ON(!intel_gvt_host.initialized))

		return -EINVAL;



	if (WARN_ON(dev_priv->gvt))

		return -EEXIST;
@@ -420,13 +366,6 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv) 
		goto out_clean_types;

	}



	ret = intel_gvt_hypervisor_host_init(&dev_priv->drm.pdev->dev, gvt,

				&intel_gvt_ops);

	if (ret) {

		gvt_err("failed to register gvt-g host device: %d\n", ret);

		goto out_clean_types;

	}



	vgpu = intel_gvt_create_idle_vgpu(gvt);

	if (IS_ERR(vgpu)) {

		ret = PTR_ERR(vgpu);
@@ -441,6 +380,8 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv) 


	gvt_dbg_core("gvt device initialization is done\n");

	dev_priv->gvt = gvt;

	intel_gvt_host.dev = &dev_priv->drm.pdev->dev;

	intel_gvt_host.initialized = true;

	return 0;



out_clean_types:
@@ -467,6 +408,45 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv) 
	return ret;

}



#if IS_ENABLED(CONFIG_DRM_I915_GVT_KVMGT)

MODULE_SOFTDEP("pre: kvmgt");

#endif
 
int

intel_gvt_register_hypervisor(struct intel_gvt_mpt *m)

{

	int ret;

	void *gvt;



	if (!intel_gvt_host.initialized)

		return -ENODEV;



	if (m->type != INTEL_GVT_HYPERVISOR_KVM &&

	    m->type != INTEL_GVT_HYPERVISOR_XEN)

		return -EINVAL;



	/* Get a reference for device model module */

	if (!try_module_get(THIS_MODULE))

		return -ENODEV;



	intel_gvt_host.mpt = m;

	intel_gvt_host.hypervisor_type = m->type;

	gvt = (void *)kdev_to_i915(intel_gvt_host.dev)->gvt;



	ret = intel_gvt_hypervisor_host_init(intel_gvt_host.dev, gvt,

					     &intel_gvt_ops);

	if (ret < 0) {

		gvt_err("Failed to init %s hypervisor module\n",

			supported_hypervisors[intel_gvt_host.hypervisor_type]);

		module_put(THIS_MODULE);

		return -ENODEV;

	}

	gvt_dbg_core("Running with hypervisor %s in host mode\n",

		     supported_hypervisors[intel_gvt_host.hypervisor_type]);

	return 0;

}

EXPORT_SYMBOL_GPL(intel_gvt_register_hypervisor);



void

intel_gvt_unregister_hypervisor(void)

{

	intel_gvt_hypervisor_host_exit(intel_gvt_host.dev);

	module_put(THIS_MODULE);

}

EXPORT_SYMBOL_GPL(intel_gvt_unregister_hypervisor);

drivers/gpu/drm/i915/gvt/gvt.h

+1 −5
Original line number Diff line number Diff line
@@ -52,12 +52,8 @@ 


#define GVT_MAX_VGPU 8



enum {

	INTEL_GVT_HYPERVISOR_XEN = 0,

	INTEL_GVT_HYPERVISOR_KVM,

};



struct intel_gvt_host {

	struct device *dev;

	bool initialized;

	int hypervisor_type;

	struct intel_gvt_mpt *mpt;

drivers/gpu/drm/i915/gvt/hypercall.h

+6 −1
Original line number Diff line number Diff line
@@ -33,11 +33,17 @@ 
#ifndef _GVT_HYPERCALL_H_

#define _GVT_HYPERCALL_H_



enum hypervisor_type {

	INTEL_GVT_HYPERVISOR_XEN = 0,

	INTEL_GVT_HYPERVISOR_KVM,

};



/*

 * Specific GVT-g MPT modules function collections. Currently GVT-g supports

 * both Xen and KVM by providing dedicated hypervisor-related MPT modules.

 */

struct intel_gvt_mpt {

	enum hypervisor_type type;

	int (*host_init)(struct device *dev, void *gvt, const void *ops);

	void (*host_exit)(struct device *dev);

	int (*attach_vgpu)(void *vgpu, unsigned long *handle);
@@ -67,6 +73,5 @@ struct intel_gvt_mpt { 
};



extern struct intel_gvt_mpt xengt_mpt;

extern struct intel_gvt_mpt kvmgt_mpt;



#endif /* _GVT_HYPERCALL_H_ */