Message-Id: <1495874332-2851-6-git-send-email-xiaoguang.chen@intel.com>
Date:   Sat, 27 May 2017 16:38:51 +0800
From:   Xiaoguang Chen <xiaoguang.chen@...el.com>
To:     alex.williamson@...hat.com, kraxel@...hat.com,
        chris@...is-wilson.co.uk, intel-gfx@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, zhenyuw@...ux.intel.com,
        zhiyuan.lv@...el.com, intel-gvt-dev@...ts.freedesktop.org,
        zhi.a.wang@...el.com, kevin.tian@...el.com
Cc:     Xiaoguang Chen <xiaoguang.chen@...el.com>
Subject: [PATCH v6 5/6] drm/i915/gvt: Dmabuf support for GVT-g

dmabuf for GVT-g can be exported to users who can use the dmabuf to show
the desktop of vm which use intel vgpu.

Currently we provide query and create new dmabuf operations.

Users of dmabuf can cache some created dmabufs and related information
such as the framebuffer's address, size, tiling mode, width, height etc.
When refresh the screen first query the currnet vgpu's frambuffer and
compare with the cached ones(address, size, tiling, width, height etc)
if found one then reuse the found dmabuf to gain performance improvment.

If there is no dmabuf created yet or not found in the cached dmabufs then
need to create a new dmabuf. To create a dmabuf first a gem object will
be created and the backing storage of this gem object is the vgpu's
framebuffer(primary/cursor).
Set caching mode, change tiling mode and set domains of this gem object
is not supported.
Then associate this gem object to a dmabuf and export this dmabuf.
A file descriptor will be generated for this dmabuf and this file
descriptor can be sent to user space to do display.

Signed-off-by: Xiaoguang Chen <xiaoguang.chen@...el.com>
---
 drivers/gpu/drm/i915/gvt/Makefile      |   2 +-
 drivers/gpu/drm/i915/gvt/dmabuf.c      | 269 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/gvt/dmabuf.h      |  37 +++++
 drivers/gpu/drm/i915/gvt/gvt.h         |   1 +
 drivers/gpu/drm/i915/i915_gem.c        |  26 +++-
 drivers/gpu/drm/i915/i915_gem_object.h |   9 ++
 6 files changed, 342 insertions(+), 2 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/gvt/dmabuf.c
 create mode 100644 drivers/gpu/drm/i915/gvt/dmabuf.h

diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile
index 192ca26..e480f7d 100644
--- a/drivers/gpu/drm/i915/gvt/Makefile
+++ b/drivers/gpu/drm/i915/gvt/Makefile
@@ -2,7 +2,7 @@ GVT_DIR := gvt
 GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
 	interrupt.o gtt.o cfg_space.o opregion.o mmio.o display.o edid.o \
 	execlist.o scheduler.o sched_policy.o render.o cmd_parser.o \
-	fb_decoder.o
+	fb_decoder.o dmabuf.o
 
 ccflags-y				+= -I$(src) -I$(src)/$(GVT_DIR) -Wall
 i915-y					+= $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))
diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
new file mode 100644
index 0000000..c831e91
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
@@ -0,0 +1,269 @@
+/*
+ * Copyright 2017 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Zhiyuan Lv <zhiyuan.lv@...el.com>
+ *
+ * Contributors:
+ *    Xiaoguang Chen <xiaoguang.chen@...el.com>
+ */
+
+#include <linux/dma-buf.h>
+#include <drm/drmP.h>
+#include <linux/vfio.h>
+
+#include "i915_drv.h"
+#include "gvt.h"
+
+#define GEN8_DECODE_PTE(pte) (pte & GENMASK_ULL(63, 12))
+
+static struct sg_table *intel_vgpu_gem_get_pages(
+		struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
+	struct sg_table *st;
+	struct scatterlist *sg;
+	int i, ret;
+	gen8_pte_t __iomem *gtt_entries;
+	struct intel_vgpu_fb_info *fb_info;
+
+	fb_info = (struct intel_vgpu_fb_info *)obj->gvt_info;
+	if (WARN_ON(!fb_info))
+		return ERR_PTR(-ENODEV);
+
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st) {
+		ret = -ENOMEM;
+		return ERR_PTR(ret);
+	}
+
+	ret = sg_alloc_table(st, fb_info->fb_size, GFP_KERNEL);
+	if (ret) {
+		kfree(st);
+		return ERR_PTR(ret);
+	}
+	gtt_entries = (gen8_pte_t __iomem *)dev_priv->ggtt.gsm +
+		(fb_info->fb_addr >> PAGE_SHIFT);
+	for_each_sg(st->sgl, sg, fb_info->fb_size, i) {
+		sg->offset = 0;
+		sg->length = PAGE_SIZE;
+		sg_dma_address(sg) =
+			GEN8_DECODE_PTE(readq(&gtt_entries[i]));
+		sg_dma_len(sg) = PAGE_SIZE;
+	}
+
+	return st;
+}
+
+static void intel_vgpu_gem_put_pages(struct drm_i915_gem_object *obj,
+		struct sg_table *pages)
+{
+	sg_free_table(pages);
+	kfree(pages);
+}
+
+static const struct drm_i915_gem_object_ops intel_vgpu_gem_ops = {
+	.flags = I915_GEM_OBJECT_IS_PROXY,
+	.get_pages = intel_vgpu_gem_get_pages,
+	.put_pages = intel_vgpu_gem_put_pages,
+};
+
+static struct drm_i915_gem_object *intel_vgpu_create_gem(struct drm_device *dev,
+		struct vfio_vgpu_plane_info *info)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_gem_object *obj;
+
+	obj = i915_gem_object_alloc(dev_priv);
+	if (obj == NULL)
+		return NULL;
+
+	drm_gem_private_object_init(dev, &obj->base,
+		info->size << PAGE_SHIFT);
+	i915_gem_object_init(obj, &intel_vgpu_gem_ops);
+
+	obj->base.read_domains = I915_GEM_DOMAIN_GTT;
+	obj->base.write_domain = 0;
+	/* Change tiling mode from user space is not supported to a GVT-g's
+	 * dma-buf gem object.
+	 * We increase the obj's framebuffer_references to disable this kind
+	 * of operation.
+	 */
+	obj->framebuffer_references++;
+	if (IS_SKYLAKE(dev_priv)) {
+		unsigned int tiling_mode = 0;
+		unsigned int stride = 0;
+
+		switch (info->drm_format_mod << 10) {
+		case PLANE_CTL_TILED_LINEAR:
+			tiling_mode = I915_TILING_NONE;
+			break;
+		case PLANE_CTL_TILED_X:
+			tiling_mode = I915_TILING_X;
+			stride = info->stride;
+			break;
+		case PLANE_CTL_TILED_Y:
+			tiling_mode = I915_TILING_Y;
+			stride = info->stride;
+			break;
+		default:
+			gvt_dbg_core("not supported tiling mode\n");
+		}
+		obj->tiling_and_stride = tiling_mode | stride;
+	} else {
+		obj->tiling_and_stride = info->drm_format_mod ?
+					I915_TILING_X : 0;
+	}
+
+	return obj;
+}
+
+static int intel_vgpu_get_plane_info(struct drm_device *dev,
+		struct intel_vgpu *vgpu, struct vfio_vgpu_plane_info *info)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct intel_vgpu_primary_plane_format *p;
+	struct intel_vgpu_cursor_plane_format *c;
+	struct intel_vgpu_pipe_format *pipe;
+	int plane_id = info->plane_id;
+
+	pipe = intel_vgpu_decode_plane(dev, vgpu);
+	if (pipe == NULL)
+		return -ENODEV;
+
+	if (plane_id == PLANE_PRIMARY) {
+		p = &pipe->primary;
+		if (p != NULL) {
+			info->start = p->base;
+			info->width = p->width;
+			info->height = p->height;
+			info->stride = p->stride;
+			info->drm_format = p->drm_format;
+			info->drm_format_mod = p->tiled;
+			info->size = (((p->stride * p->height * p->bpp) / 8) +
+					(PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		} else {
+			gvt_vgpu_err("invalid primary plane\n");
+			return -EINVAL;
+		}
+	} else if (plane_id == PLANE_CURSOR) {
+		c = &pipe->cursor;
+		if (c != NULL) {
+			info->start = c->base;
+			info->width = c->width;
+			info->height = c->height;
+			info->stride = c->width * (c->bpp / 8);
+			info->drm_format = c->drm_format;
+			info->drm_format_mod = 0;
+			info->x_pos = c->x_pos;
+			info->y_pos = c->y_pos;
+			info->size = (((info->stride * c->height * c->bpp) / 8)
+					+ (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		} else {
+			gvt_vgpu_err("invalid cursor plane\n");
+			return -EINVAL;
+		}
+	} else {
+		gvt_vgpu_err("invalid plane id:%d\n", plane_id);
+		return -EINVAL;
+	}
+
+	if (info->size == 0) {
+		gvt_vgpu_err("fb size is zero\n");
+		return -EINVAL;
+	}
+
+	if (info->start & (PAGE_SIZE - 1)) {
+		gvt_vgpu_err("Not aligned fb address:0x%x\n", info->start);
+		return -EFAULT;
+	}
+	if (((info->start >> PAGE_SHIFT) + info->size) >
+		ggtt_total_entries(&dev_priv->ggtt)) {
+		gvt_vgpu_err("Invalid GTT offset or size\n");
+		return -EFAULT;
+	}
+
+	if (!intel_gvt_ggtt_validate_range(vgpu, info->start, info->size)) {
+		gvt_vgpu_err("invalid gma addr\n");
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args)
+{
+	struct drm_device *dev = &vgpu->gvt->dev_priv->drm;
+	struct vfio_vgpu_plane_info *info = args;
+
+	return intel_vgpu_get_plane_info(dev, vgpu, info);
+}
+
+int intel_vgpu_create_dmabuf(struct intel_vgpu *vgpu, void *args)
+{
+	struct dma_buf *dmabuf;
+	struct drm_i915_gem_object *obj;
+	struct drm_device *dev = &vgpu->gvt->dev_priv->drm;
+	struct vfio_vgpu_dmabuf_info *gvt_dmabuf = args;
+	struct intel_vgpu_fb_info *fb_info;
+	int ret;
+
+	ret = intel_vgpu_get_plane_info(dev, vgpu, &gvt_dmabuf->plane_info);
+	if (ret != 0)
+		return ret;
+
+	obj = intel_vgpu_create_gem(dev, &gvt_dmabuf->plane_info);
+	if (obj == NULL) {
+		gvt_vgpu_err("create gvt gem obj failed:%d\n", vgpu->id);
+		return -ENOMEM;
+	}
+	fb_info = kmalloc(sizeof(*fb_info), GFP_KERNEL);
+	if (!fb_info) {
+		i915_gem_object_put(obj);
+		gvt_vgpu_err("allocate intel vgpu fb info failed\n");
+		return -ENOMEM;
+	}
+	fb_info->fb_addr = gvt_dmabuf->plane_info.start;
+	fb_info->fb_size = gvt_dmabuf->plane_info.size;
+	fb_info->vgpu = vgpu;
+	obj->gvt_info = fb_info;
+
+	dmabuf = i915_gem_prime_export(dev, &obj->base, DRM_CLOEXEC | DRM_RDWR);
+
+	if (IS_ERR(dmabuf)) {
+		kfree(fb_info);
+		i915_gem_object_free(obj);
+		gvt_vgpu_err("export dma-buf failed\n");
+		return PTR_ERR(dmabuf);
+	}
+
+	ret = dma_buf_fd(dmabuf, DRM_CLOEXEC | DRM_RDWR);
+	if (ret < 0) {
+		kfree(fb_info);
+		i915_gem_object_free(obj);
+		gvt_vgpu_err("create dma-buf fd failed ret:%d\n", ret);
+		return ret;
+	}
+	gvt_dmabuf->fd = ret;
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.h b/drivers/gpu/drm/i915/gvt/dmabuf.h
new file mode 100644
index 0000000..8be9979
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/dmabuf.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#ifndef _GVT_DMABUF_H_
+#define _GVT_DMABUF_H_
+
+struct intel_vgpu_fb_info {
+	struct intel_vgpu *vgpu;
+	uint32_t fb_addr;
+	uint32_t fb_size;
+};
+
+int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args);
+int intel_vgpu_create_dmabuf(struct intel_vgpu *vgpu, void *args);
+
+#endif
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index c42266c..763a8c5 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -47,6 +47,7 @@
 #include "render.h"
 #include "cmd_parser.h"
 #include "fb_decoder.h"
+#include "dmabuf.h"
 
 #define GVT_MAX_VGPU 8
 
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0c1cbe9..14be3b0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1609,6 +1609,12 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	if (!obj)
 		return -ENOENT;
 
+	/* proxy gem object does not support setting domain */
+	if (i915_gem_object_is_proxy(obj)) {
+		i915_gem_object_put(obj);
+		return -EPERM;
+	}
+
 	/* Try to flush the object off the GPU without holding the lock.
 	 * We will repeat the flush holding the lock in the normal manner
 	 * to catch cases where we are gazumped.
@@ -1677,6 +1683,12 @@ i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data,
 	if (!obj)
 		return -ENOENT;
 
+	/* proxy gem obj does not support this operation */
+	if (i915_gem_object_is_proxy(obj)) {
+		i915_gem_object_put(obj);
+		return -EPERM;
+	}
+
 	/* Pinned buffers may be scanout, so flush the cache */
 	i915_gem_object_flush_if_display(obj);
 	i915_gem_object_put(obj);
@@ -1727,7 +1739,7 @@ i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
 	 */
 	if (!obj->base.filp) {
 		i915_gem_object_put(obj);
-		return -EINVAL;
+		return -EPERM;
 	}
 
 	addr = vm_mmap(obj->base.filp, 0, args->size,
@@ -3717,6 +3729,12 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
 	if (!obj)
 		return -ENOENT;
 
+	/* proxy gem obj does not support setting caching mode */
+	if (i915_gem_object_is_proxy(obj)) {
+		i915_gem_object_put(obj);
+		return -EPERM;
+	}
+
 	if (obj->cache_level == level)
 		goto out;
 
@@ -4168,6 +4186,12 @@ i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
 	if (!obj)
 		return -ENOENT;
 
+	/* proxy gem obj does not support changing backding storage */
+	if (i915_gem_object_is_proxy(obj)) {
+		i915_gem_object_put(obj);
+		return -EPERM;
+	}
+
 	err = mutex_lock_interruptible(&obj->mm.lock);
 	if (err)
 		goto out;
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h
index 174cf92..be18a43 100644
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -39,6 +39,7 @@ struct drm_i915_gem_object_ops {
 	unsigned int flags;
 #define I915_GEM_OBJECT_HAS_STRUCT_PAGE 0x1
 #define I915_GEM_OBJECT_IS_SHRINKABLE   0x2
+#define I915_GEM_OBJECT_IS_PROXY	0x4
 
 	/* Interface between the GEM object and its backing storage.
 	 * get_pages() is called once prior to the use of the associated set
@@ -184,6 +185,8 @@ struct drm_i915_gem_object {
 		} userptr;
 
 		unsigned long scratch;
+
+		void *gvt_info;
 	};
 
 	/** for phys allocated objects */
@@ -286,6 +289,12 @@ i915_gem_object_is_shrinkable(const struct drm_i915_gem_object *obj)
 }
 
 static inline bool
+i915_gem_object_is_proxy(const struct drm_i915_gem_object *obj)
+{
+	return obj->ops->flags & I915_GEM_OBJECT_IS_PROXY;
+}
+
+static inline bool
 i915_gem_object_is_active(const struct drm_i915_gem_object *obj)
 {
 	return obj->active_count;
-- 
2.7.4

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