drm/i915/gvt: Activate/de-activate vGPU in mdev ops.
This patch introduces two functions for activating/de-activating vGPU in
mdev ops.
A racing condition was found between virtual vblank emulation and KVGMT
mdev release path. V-blank emulation will emulate and inject V-blank
interrupt for every active vGPU with holding gvt->lock, while in mdev
release path, it will directly release hypervisor handle without changing
vGPU status or taking gvt->lock, so a kernel oops is encountered when
vblank emulation is injecting a interrupt with a invalid hypervisor
handle. (Reported by Terrence)
To solve this problem, we factor out vGPU activation/de-activation from
vGPU creation/destruction path and let KVMGT mdev release ops de-activate
the vGPU before release hypervisor handle. Once a vGPU is de-activated,
GVT-g will not emulate v-blank for it or touch the hypervisor handle.
Fixes: 659643f ("drm/i915/gvt/kvmgt: add vfio/mdev support to KVMGT")
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
index 3b9d59e..ef3baa0 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.c
+++ b/drivers/gpu/drm/i915/gvt/gvt.c
@@ -52,6 +52,8 @@ static const struct intel_gvt_ops intel_gvt_ops = {
.vgpu_create = intel_gvt_create_vgpu,
.vgpu_destroy = intel_gvt_destroy_vgpu,
.vgpu_reset = intel_gvt_reset_vgpu,
+ .vgpu_activate = intel_gvt_activate_vgpu,
+ .vgpu_deactivate = intel_gvt_deactivate_vgpu,
};
/**
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 2379192..2387eac 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -382,7 +382,8 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu);
void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
unsigned int engine_mask);
void intel_gvt_reset_vgpu(struct intel_vgpu *vgpu);
-
+void intel_gvt_activate_vgpu(struct intel_vgpu *vgpu);
+void intel_gvt_deactivate_vgpu(struct intel_vgpu *vgpu);
/* validating GM functions */
#define vgpu_gmadr_is_aperture(vgpu, gmadr) \
@@ -449,6 +450,8 @@ struct intel_gvt_ops {
struct intel_vgpu_type *);
void (*vgpu_destroy)(struct intel_vgpu *);
void (*vgpu_reset)(struct intel_vgpu *);
+ void (*vgpu_activate)(struct intel_vgpu *);
+ void (*vgpu_deactivate)(struct intel_vgpu *);
};
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index d641214..9843d74 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -544,6 +544,8 @@ static int intel_vgpu_open(struct mdev_device *mdev)
if (ret)
goto undo_group;
+ intel_gvt_ops->vgpu_activate(vgpu);
+
atomic_set(&vgpu->vdev.released, 0);
return ret;
@@ -569,6 +571,8 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
if (atomic_cmpxchg(&vgpu->vdev.released, 0, 1))
return;
+ intel_gvt_ops->vgpu_deactivate(vgpu);
+
ret = vfio_unregister_notifier(mdev_dev(vgpu->vdev.mdev), VFIO_IOMMU_NOTIFY,
&vgpu->vdev.iommu_notifier);
WARN(ret, "vfio_unregister_notifier for iommu failed: %d\n", ret);
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 41cfa5c..2f5792a 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -179,6 +179,47 @@ static void intel_gvt_update_vgpu_types(struct intel_gvt *gvt)
}
/**
+ * intel_gvt_active_vgpu - activate a virtual GPU
+ * @vgpu: virtual GPU
+ *
+ * This function is called when user wants to activate a virtual GPU.
+ *
+ */
+void intel_gvt_activate_vgpu(struct intel_vgpu *vgpu)
+{
+ mutex_lock(&vgpu->gvt->lock);
+ vgpu->active = true;
+ mutex_unlock(&vgpu->gvt->lock);
+}
+
+/**
+ * intel_gvt_deactive_vgpu - deactivate a virtual GPU
+ * @vgpu: virtual GPU
+ *
+ * This function is called when user wants to deactivate a virtual GPU.
+ * All virtual GPU runtime information will be destroyed.
+ *
+ */
+void intel_gvt_deactivate_vgpu(struct intel_vgpu *vgpu)
+{
+ struct intel_gvt *gvt = vgpu->gvt;
+
+ mutex_lock(&gvt->lock);
+
+ vgpu->active = false;
+
+ if (atomic_read(&vgpu->running_workload_num)) {
+ mutex_unlock(&gvt->lock);
+ intel_gvt_wait_vgpu_idle(vgpu);
+ mutex_lock(&gvt->lock);
+ }
+
+ intel_vgpu_stop_schedule(vgpu);
+
+ mutex_unlock(&gvt->lock);
+}
+
+/**
* intel_gvt_destroy_vgpu - destroy a virtual GPU
* @vgpu: virtual GPU
*
@@ -191,16 +232,9 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu)
mutex_lock(&gvt->lock);
- vgpu->active = false;
+ WARN(vgpu->active, "vGPU is still active!\n");
+
idr_remove(&gvt->vgpu_idr, vgpu->id);
-
- if (atomic_read(&vgpu->running_workload_num)) {
- mutex_unlock(&gvt->lock);
- intel_gvt_wait_vgpu_idle(vgpu);
- mutex_lock(&gvt->lock);
- }
-
- intel_vgpu_stop_schedule(vgpu);
intel_vgpu_clean_sched_policy(vgpu);
intel_vgpu_clean_gvt_context(vgpu);
intel_vgpu_clean_execlist(vgpu);
@@ -277,7 +311,6 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
if (ret)
goto out_clean_shadow_ctx;
- vgpu->active = true;
mutex_unlock(&gvt->lock);
return vgpu;