From 3da1a26319612f8150f1a1c695a80f68bbc04d73 Mon Sep 17 00:00:00 2001
From: Gurchetan Singh <gurchetansingh@chromium.org>
Date: Tue, 21 Sep 2021 16:20:22 -0700
Subject: drm/virtio: implement context init: handle
 VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK
Git-commit: 8d6b006e1f51c99016aa39ca9e03947cbdd024e3
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

For the Sommelier guest Wayland proxy, it's desirable for the
DRM fd to be pollable in response to an host compositor event.
This can also be used by the 3D driver to poll events on a CPU
timeline.

This enables the DRM fd associated with a particular 3D context
to be polled independent of KMS events.  The parameter
VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK specifies the pollable
rings.

Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Acked-by: Nicholas Verne <nverne@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20210921232024.817-11-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/virtio/virtgpu_drv.h   |  1 +
 drivers/gpu/drm/virtio/virtgpu_ioctl.c | 22 +++++++++++++++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index cca9ab505deb..cb60d52c2bd1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -266,6 +266,7 @@ struct virtio_gpu_fpriv {
 	bool context_created;
 	uint32_t num_rings;
 	uint64_t base_fence_ctx;
+	uint64_t ring_idx_mask;
 	struct mutex context_lock;
 };
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 262f79210283..be7b22a03884 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -694,6 +694,7 @@ static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
 {
 	int ret = 0;
 	uint32_t num_params, i, param, value;
+	uint64_t valid_ring_mask;
 	size_t len;
 	struct drm_virtgpu_context_set_param *ctx_set_params = NULL;
 	struct virtio_gpu_device *vgdev = dev->dev_private;
@@ -707,7 +708,7 @@ static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
 		return -EINVAL;
 
 	/* Number of unique parameters supported at this time. */
-	if (num_params > 2)
+	if (num_params > 3)
 		return -EINVAL;
 
 	ctx_set_params = memdup_user(u64_to_user_ptr(args->ctx_set_params),
@@ -761,12 +762,31 @@ static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
 			vfpriv->base_fence_ctx = dma_fence_context_alloc(value);
 			vfpriv->num_rings = value;
 			break;
+		case VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK:
+			if (vfpriv->ring_idx_mask) {
+				ret = -EINVAL;
+				goto out_unlock;
+			}
+
+			vfpriv->ring_idx_mask = value;
+			break;
 		default:
 			ret = -EINVAL;
 			goto out_unlock;
 		}
 	}
 
+	if (vfpriv->ring_idx_mask) {
+		valid_ring_mask = 0;
+		for (i = 0; i < vfpriv->num_rings; i++)
+			valid_ring_mask |= 1 << i;
+
+		if (~valid_ring_mask & vfpriv->ring_idx_mask) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+	}
+
 	virtio_gpu_create_context_locked(vgdev, vfpriv);
 	virtio_gpu_notify(vgdev);
 
-- 
2.38.1