1 /*
2  * Virtio GPU Device
3  *
4  * Copyright Red Hat, Inc. 2013-2014
5  *
6  * Authors:
7  *     Dave Airlie <airlied@redhat.com>
8  *     Gerd Hoffmann <kraxel@redhat.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/units.h"
16 #include "qemu-common.h"
17 #include "qemu/iov.h"
18 #include "ui/console.h"
19 #include "hw/virtio/virtio-gpu.h"
20 #include "hw/virtio/virtio-gpu-pixman.h"
21 #include "trace.h"
22 #include "exec/ramblock.h"
23 #include "sysemu/hostmem.h"
24 #include <sys/ioctl.h>
25 #include <fcntl.h>
26 #include <linux/memfd.h>
27 #include "qemu/memfd.h"
28 #include "standard-headers/linux/udmabuf.h"
29 
30 static void virtio_gpu_create_udmabuf(struct virtio_gpu_simple_resource *res)
31 {
32     struct udmabuf_create_list *list;
33     RAMBlock *rb;
34     ram_addr_t offset;
35     int udmabuf, i;
36 
37     udmabuf = udmabuf_fd();
38     if (udmabuf < 0) {
39         return;
40     }
41 
42     list = g_malloc0(sizeof(struct udmabuf_create_list) +
43                      sizeof(struct udmabuf_create_item) * res->iov_cnt);
44 
45     for (i = 0; i < res->iov_cnt; i++) {
46         rcu_read_lock();
47         rb = qemu_ram_block_from_host(res->iov[i].iov_base, false, &offset);
48         rcu_read_unlock();
49 
50         if (!rb || rb->fd < 0) {
51             g_free(list);
52             return;
53         }
54 
55         list->list[i].memfd  = rb->fd;
56         list->list[i].offset = offset;
57         list->list[i].size   = res->iov[i].iov_len;
58     }
59 
60     list->count = res->iov_cnt;
61     list->flags = UDMABUF_FLAGS_CLOEXEC;
62 
63     res->dmabuf_fd = ioctl(udmabuf, UDMABUF_CREATE_LIST, list);
64     if (res->dmabuf_fd < 0) {
65         warn_report("%s: UDMABUF_CREATE_LIST: %s", __func__,
66                     strerror(errno));
67     }
68     g_free(list);
69 }
70 
71 static void virtio_gpu_remap_udmabuf(struct virtio_gpu_simple_resource *res)
72 {
73     res->remapped = mmap(NULL, res->blob_size, PROT_READ,
74                          MAP_SHARED, res->dmabuf_fd, 0);
75     if (res->remapped == MAP_FAILED) {
76         warn_report("%s: dmabuf mmap failed: %s", __func__,
77                     strerror(errno));
78         res->remapped = NULL;
79     }
80 }
81 
82 static void virtio_gpu_destroy_udmabuf(struct virtio_gpu_simple_resource *res)
83 {
84     if (res->remapped) {
85         munmap(res->remapped, res->blob_size);
86         res->remapped = NULL;
87     }
88     if (res->dmabuf_fd >= 0) {
89         close(res->dmabuf_fd);
90         res->dmabuf_fd = -1;
91     }
92 }
93 
94 static int find_memory_backend_type(Object *obj, void *opaque)
95 {
96     bool *memfd_backend = opaque;
97     int ret;
98 
99     if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
100         HostMemoryBackend *backend = MEMORY_BACKEND(obj);
101         RAMBlock *rb = backend->mr.ram_block;
102 
103         if (rb && rb->fd > 0) {
104             ret = fcntl(rb->fd, F_GET_SEALS);
105             if (ret > 0) {
106                 *memfd_backend = true;
107             }
108         }
109     }
110 
111     return 0;
112 }
113 
114 bool virtio_gpu_have_udmabuf(void)
115 {
116     Object *memdev_root;
117     int udmabuf;
118     bool memfd_backend = false;
119 
120     udmabuf = udmabuf_fd();
121     if (udmabuf < 0) {
122         return false;
123     }
124 
125     memdev_root = object_resolve_path("/objects", NULL);
126     object_child_foreach(memdev_root, find_memory_backend_type, &memfd_backend);
127 
128     return memfd_backend;
129 }
130 
131 void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res)
132 {
133     void *pdata = NULL;
134 
135     res->dmabuf_fd = -1;
136     if (res->iov_cnt == 1) {
137         pdata = res->iov[0].iov_base;
138     } else {
139         virtio_gpu_create_udmabuf(res);
140         if (res->dmabuf_fd < 0) {
141             return;
142         }
143         virtio_gpu_remap_udmabuf(res);
144         if (!res->remapped) {
145             return;
146         }
147         pdata = res->remapped;
148     }
149 
150     res->blob = pdata;
151 }
152 
153 void virtio_gpu_fini_udmabuf(struct virtio_gpu_simple_resource *res)
154 {
155     if (res->remapped) {
156         virtio_gpu_destroy_udmabuf(res);
157     }
158 }
159 
160 static void virtio_gpu_free_dmabuf(VirtIOGPU *g, VGPUDMABuf *dmabuf)
161 {
162     struct virtio_gpu_scanout *scanout;
163 
164     scanout = &g->parent_obj.scanout[dmabuf->scanout_id];
165     dpy_gl_release_dmabuf(scanout->con, &dmabuf->buf);
166     QTAILQ_REMOVE(&g->dmabuf.bufs, dmabuf, next);
167     g_free(dmabuf);
168 }
169 
170 static VGPUDMABuf
171 *virtio_gpu_create_dmabuf(VirtIOGPU *g,
172                           uint32_t scanout_id,
173                           struct virtio_gpu_simple_resource *res,
174                           struct virtio_gpu_framebuffer *fb)
175 {
176     VGPUDMABuf *dmabuf;
177 
178     if (res->dmabuf_fd < 0) {
179         return NULL;
180     }
181 
182     dmabuf = g_new0(VGPUDMABuf, 1);
183     dmabuf->buf.width = fb->width;
184     dmabuf->buf.height = fb->height;
185     dmabuf->buf.stride = fb->stride;
186     dmabuf->buf.fourcc = qemu_pixman_to_drm_format(fb->format);
187     dmabuf->buf.fd = res->dmabuf_fd;
188 
189     dmabuf->scanout_id = scanout_id;
190     QTAILQ_INSERT_HEAD(&g->dmabuf.bufs, dmabuf, next);
191 
192     return dmabuf;
193 }
194 
195 int virtio_gpu_update_dmabuf(VirtIOGPU *g,
196                              uint32_t scanout_id,
197                              struct virtio_gpu_simple_resource *res,
198                              struct virtio_gpu_framebuffer *fb)
199 {
200     struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
201     VGPUDMABuf *new_primary, *old_primary = NULL;
202 
203     new_primary = virtio_gpu_create_dmabuf(g, scanout_id, res, fb);
204     if (!new_primary) {
205         return -EINVAL;
206     }
207 
208     if (g->dmabuf.primary) {
209         old_primary = g->dmabuf.primary;
210     }
211 
212     g->dmabuf.primary = new_primary;
213     qemu_console_resize(scanout->con,
214                         new_primary->buf.width,
215                         new_primary->buf.height);
216     dpy_gl_scanout_dmabuf(scanout->con, &new_primary->buf);
217 
218     if (old_primary) {
219         virtio_gpu_free_dmabuf(g, old_primary);
220     }
221 
222     return 0;
223 }
224