[14/29] drm/i915/gvt: devirtualize ->{get, put}_vfio_device

Commit Message

Christoph Hellwig Nov. 2, 2021, 7:05 a.m. UTC

Just open code the calls to the VFIO APIs.

Signed-off-by: Christoph Hellwig <[e-mail]>
---
 drivers/gpu/drm/i915/gvt/dmabuf.c    | 12 ++++++-----
 drivers/gpu/drm/i915/gvt/hypercall.h |  2 --
 drivers/gpu/drm/i915/gvt/kvmgt.c     | 22 --------------------
 drivers/gpu/drm/i915/gvt/mpt.h       | 30 ----------------------------
 4 files changed, 7 insertions(+), 59 deletions(-)

Comments

Jason Gunthorpe Nov. 2, 2021, 4:12 p.m. UTC | #1

On Tue, Nov 02, 2021 at 08:05:46AM +0100, Christoph Hellwig wrote:
> Just open code the calls to the VFIO APIs.
> 
> Signed-off-by: Christoph Hellwig <[e-mail]>
>  drivers/gpu/drm/i915/gvt/dmabuf.c    | 12 ++++++-----
>  drivers/gpu/drm/i915/gvt/hypercall.h |  2 --
>  drivers/gpu/drm/i915/gvt/kvmgt.c     | 22 --------------------
>  drivers/gpu/drm/i915/gvt/mpt.h       | 30 ----------------------------
>  4 files changed, 7 insertions(+), 59 deletions(-)

I suspect the use of get/put here is very questionable

It only prevents the vfio_device from becoming unregistered, but the
main thing a mdev should care about is if it is still beween
opne_device() / close_device() - ie the FD is open, there is a SW
IOMMU available, and memory pins can be made.

Still, not for this patch

Reviewed-by: Jason Gunthorpe <[e-mail]>

Jason

Patch

diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
index 8e65cd8258b97..bc53a0c60b444 100644
--- a/drivers/gpu/drm/i915/gvt/dmabuf.c
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
@@ -29,7 +29,7 @@ 
  */
 
 #include <linux/dma-buf.h>
-#include <linux/vfio.h>
+#include <linux/mdev.h>
 
 #include "i915_drv.h"
 #include "gvt.h"
@@ -152,7 +152,7 @@  static void dmabuf_gem_object_free(struct kref *kref)
 					struct intel_vgpu_dmabuf_obj, list);
 			if (dmabuf_obj == obj) {
 				list_del(pos);
-				intel_gvt_hypervisor_put_vfio_device(vgpu);
+				vfio_device_put(vgpu->vfio_device);
 				idr_remove(&vgpu->object_idr,
 					   dmabuf_obj->dmabuf_id);
 				kfree(dmabuf_obj->info);
@@ -493,9 +493,11 @@  int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args)
 	kref_init(&dmabuf_obj->kref);
 
 	mutex_lock(&vgpu->dmabuf_lock);
-	if (intel_gvt_hypervisor_get_vfio_device(vgpu)) {
-		gvt_vgpu_err("get vfio device failed\n");
+	vgpu->vfio_device = vfio_device_get_from_dev(mdev_dev(vgpu->mdev));
+	if (!vgpu->vfio_device) {
+		gvt_vgpu_err("failed to get vfio device\n");
 		mutex_unlock(&vgpu->dmabuf_lock);
+		ret = -ENODEV;
 		goto out_free_info;
 	}
 	mutex_unlock(&vgpu->dmabuf_lock);
@@ -605,7 +607,7 @@  void intel_vgpu_dmabuf_cleanup(struct intel_vgpu *vgpu)
 		dmabuf_obj->vgpu = NULL;
 
 		idr_remove(&vgpu->object_idr, dmabuf_obj->dmabuf_id);
-		intel_gvt_hypervisor_put_vfio_device(vgpu);
+		vfio_device_put(vgpu->vfio_device);
 		list_del(pos);
 
 		/* dmabuf_obj might be freed in dmabuf_obj_put */
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index 61e493e2de852..fd903d52f4314 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -60,8 +60,6 @@  struct intel_gvt_mpt {
 
 	int (*set_opregion)(struct intel_vgpu *vgpu);
 	int (*set_edid)(struct intel_vgpu *vgpu, int port_num);
-	int (*get_vfio_device)(struct intel_vgpu *vgpu);
-	void (*put_vfio_device)(struct intel_vgpu *vgpu);
 	bool (*is_valid_gfn)(struct intel_vgpu *vgpu, unsigned long gfn);
 };
 
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 002d43b02adde..87dcfce3d532b 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -644,18 +644,6 @@  static int intel_vgpu_register_reg(struct intel_vgpu *vgpu,
 	return 0;
 }
 
-static int kvmgt_get_vfio_device(struct intel_vgpu *vgpu)
-{
-	vgpu->vfio_device = vfio_device_get_from_dev(
-		mdev_dev(vgpu->mdev));
-	if (!vgpu->vfio_device) {
-		gvt_vgpu_err("failed to get vfio device\n");
-		return -ENODEV;
-	}
-	return 0;
-}
-
-
 static int kvmgt_set_opregion(struct intel_vgpu *vgpu)
 {
 	void *base;
@@ -712,14 +700,6 @@  static int kvmgt_set_edid(struct intel_vgpu *vgpu, int port_num)
 	return ret;
 }
 
-static void kvmgt_put_vfio_device(struct intel_vgpu *vgpu)
-{
-	if (WARN_ON(!vgpu->vfio_device))
-		return;
-
-	vfio_device_put(vgpu->vfio_device);
-}
-
 static int intel_vgpu_create(struct mdev_device *mdev)
 {
 	struct intel_vgpu *vgpu = NULL;
@@ -2034,8 +2014,6 @@  static const struct intel_gvt_mpt kvmgt_mpt = {
 	.dma_pin_guest_page = kvmgt_dma_pin_guest_page,
 	.set_opregion = kvmgt_set_opregion,
 	.set_edid = kvmgt_set_edid,
-	.get_vfio_device = kvmgt_get_vfio_device,
-	.put_vfio_device = kvmgt_put_vfio_device,
 	.is_valid_gfn = kvmgt_is_valid_gfn,
 };
 
diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index 72388ceec5966..2196187203af1 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -242,36 +242,6 @@  static inline int intel_gvt_hypervisor_set_edid(struct intel_vgpu *vgpu,
 	return intel_gvt_host.mpt->set_edid(vgpu, port_num);
 }
 
-/**
- * intel_gvt_hypervisor_get_vfio_device - increase vfio device ref count
- * @vgpu: a vGPU
- *
- * Returns:
- * Zero on success, negative error code if failed.
- */
-static inline int intel_gvt_hypervisor_get_vfio_device(struct intel_vgpu *vgpu)
-{
-	if (!intel_gvt_host.mpt->get_vfio_device)
-		return 0;
-
-	return intel_gvt_host.mpt->get_vfio_device(vgpu);
-}
-
-/**
- * intel_gvt_hypervisor_put_vfio_device - decrease vfio device ref count
- * @vgpu: a vGPU
- *
- * Returns:
- * Zero on success, negative error code if failed.
- */
-static inline void intel_gvt_hypervisor_put_vfio_device(struct intel_vgpu *vgpu)
-{
-	if (!intel_gvt_host.mpt->put_vfio_device)
-		return;
-
-	intel_gvt_host.mpt->put_vfio_device(vgpu);
-}
-
 /**
  * intel_gvt_hypervisor_is_valid_gfn - check if a visible gfn
  * @vgpu: a vGPU