[PATCH v4] drm/i915/gvt: Change KVMGT as self load module
Zhenyu Wang
zhenyuw at linux.intel.com
Tue Dec 4 02:40:28 UTC 2018
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.
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: Alex Williamson <alex.williamson at redhat.com>
Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/gvt/Makefile | 1 -
drivers/gpu/drm/i915/gvt/gvt.c | 107 +++++++++++----------------
drivers/gpu/drm/i915/gvt/gvt.h | 6 +-
drivers/gpu/drm/i915/gvt/hypercall.h | 7 +-
drivers/gpu/drm/i915/gvt/kvmgt.c | 21 +++++-
drivers/gpu/drm/i915/gvt/mpt.h | 3 +
drivers/gpu/drm/i915/intel_gvt.c | 9 ---
8 files changed, 72 insertions(+), 83 deletions(-)
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 0ff878c994e2..ae0d975a6f34 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -195,3 +195,4 @@ endif
i915-y += intel_lpe_audio.o
obj-$(CONFIG_DRM_I915) += i915.o
+obj-$(CONFIG_DRM_I915_GVT_KVMGT) += gvt/kvmgt.o
diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile
index b016dc753db9..271fb46d4dd0 100644
--- a/drivers/gpu/drm/i915/gvt/Makefile
+++ b/drivers/gpu/drm/i915/gvt/Makefile
@@ -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
diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
index a5b760b7bc10..e1c9c20918af 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.c
+++ b/drivers/gpu/drm/i915/gvt/gvt.c
@@ -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 +408,44 @@ 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]);
+ 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);
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index b4ab1dad0143..8a4cf995d755 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -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;
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index e49a9247ed78..50798868ab15 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -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_ */
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 1bbd04d30c42..ef248d577e49 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -50,6 +50,7 @@
#include "gvt.h"
static const struct intel_gvt_ops *intel_gvt_ops;
+static struct intel_gvt *intel_gvt;
/* helper macros copied from vfio-pci */
#define VFIO_PCI_OFFSET_SHIFT 40
@@ -627,6 +628,12 @@ static int intel_vgpu_open(struct mdev_device *mdev)
goto undo_iommu;
}
+ /* Take a module reference as mdev core doesn't take
+ * a reference for vendor driver.
+ */
+ if (!try_module_get(THIS_MODULE))
+ goto undo_group;
+
ret = kvmgt_guest_init(mdev);
if (ret)
goto undo_group;
@@ -679,6 +686,9 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
&vgpu->vdev.group_notifier);
WARN(ret, "vfio_unregister_notifier for group failed: %d\n", ret);
+ /* dereference module reference taken at open */
+ module_put(THIS_MODULE);
+
info = (struct kvmgt_guest_info *)vgpu->handle;
kvmgt_guest_exit(info);
@@ -1459,8 +1469,10 @@ static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
struct attribute_group **kvm_vgpu_type_groups;
intel_gvt_ops = ops;
+ intel_gvt = (struct intel_gvt *)gvt;
+
if (!intel_gvt_ops->get_gvt_attrs(&kvm_type_attrs,
- &kvm_vgpu_type_groups))
+ &kvm_vgpu_type_groups))
return -EFAULT;
intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
@@ -1849,7 +1861,8 @@ static bool kvmgt_is_valid_gfn(unsigned long handle, unsigned long gfn)
return ret;
}
-struct intel_gvt_mpt kvmgt_mpt = {
+static struct intel_gvt_mpt kvmgt_mpt = {
+ .type = INTEL_GVT_HYPERVISOR_KVM,
.host_init = kvmgt_host_init,
.host_exit = kvmgt_host_exit,
.attach_vgpu = kvmgt_attach_vgpu,
@@ -1868,15 +1881,17 @@ struct intel_gvt_mpt kvmgt_mpt = {
.put_vfio_device = kvmgt_put_vfio_device,
.is_valid_gfn = kvmgt_is_valid_gfn,
};
-EXPORT_SYMBOL_GPL(kvmgt_mpt);
static int __init kvmgt_init(void)
{
+ if (intel_gvt_register_hypervisor(&kvmgt_mpt) < 0)
+ return -ENODEV;
return 0;
}
static void __exit kvmgt_exit(void)
{
+ intel_gvt_unregister_hypervisor();
}
module_init(kvmgt_init);
diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index c95ef77da62c..9b4225d44243 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -360,4 +360,7 @@ static inline bool intel_gvt_hypervisor_is_valid_gfn(
return intel_gvt_host.mpt->is_valid_gfn(vgpu->handle, gfn);
}
+int intel_gvt_register_hypervisor(struct intel_gvt_mpt *);
+void intel_gvt_unregister_hypervisor(void);
+
#endif /* _GVT_MPT_H_ */
diff --git a/drivers/gpu/drm/i915/intel_gvt.c b/drivers/gpu/drm/i915/intel_gvt.c
index c22b3e18a0f5..d74e59e22c9d 100644
--- a/drivers/gpu/drm/i915/intel_gvt.c
+++ b/drivers/gpu/drm/i915/intel_gvt.c
@@ -105,15 +105,6 @@ int intel_gvt_init(struct drm_i915_private *dev_priv)
return -EIO;
}
- /*
- * We're not in host or fail to find a MPT module, disable GVT-g
- */
- ret = intel_gvt_init_host();
- if (ret) {
- DRM_DEBUG_DRIVER("Not in host or MPT modules not found\n");
- goto bail;
- }
-
ret = intel_gvt_init_device(dev_priv);
if (ret) {
DRM_DEBUG_DRIVER("Fail to init GVT device\n");
--
2.19.1
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