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/error-report.h"
16 #include "qemu/units.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 <linux/memfd.h>
26 #include "qemu/memfd.h"
27 #include "standard-headers/linux/udmabuf.h"
28 
29 static void virtio_gpu_create_udmabuf(struct virtio_gpu_simple_resource *res)
30 {
31     struct udmabuf_create_list *list;
32     RAMBlock *rb;
33     ram_addr_t offset;
34     int udmabuf, i;
35 
36     udmabuf = udmabuf_fd();
37     if (udmabuf < 0) {
38         return;
39     }
40 
41     list = g_malloc0(sizeof(struct udmabuf_create_list) +
42                      sizeof(struct udmabuf_create_item) * res->iov_cnt);
43 
44     for (i = 0; i < res->iov_cnt; i++) {
45         rcu_read_lock();
46         rb = qemu_ram_block_from_host(res->iov[i].iov_base, false, &offset);
47         rcu_read_unlock();
48 
49         if (!rb || rb->fd < 0) {
50             g_free(list);
51             return;
52         }
53 
54         list->list[i].memfd  = rb->fd;
55         list->list[i].offset = offset;
56         list->list[i].size   = res->iov[i].iov_len;
57     }
58 
59     list->count = res->iov_cnt;
60     list->flags = UDMABUF_FLAGS_CLOEXEC;
61 
62     res->dmabuf_fd = ioctl(udmabuf, UDMABUF_CREATE_LIST, list);
63     if (res->dmabuf_fd < 0) {
64         warn_report("%s: UDMABUF_CREATE_LIST: %s", __func__,
65                     strerror(errno));
66     }
67     g_free(list);
68 }
69 
70 static void virtio_gpu_remap_udmabuf(struct virtio_gpu_simple_resource *res)
71 {
72     res->remapped = mmap(NULL, res->blob_size, PROT_READ,
73                          MAP_SHARED, res->dmabuf_fd, 0);
74     if (res->remapped == MAP_FAILED) {
75         warn_report("%s: dmabuf mmap failed: %s", __func__,
76                     strerror(errno));
77         res->remapped = NULL;
78     }
79 }
80 
81 static void virtio_gpu_destroy_udmabuf(struct virtio_gpu_simple_resource *res)
82 {
83     if (res->remapped) {
84         munmap(res->remapped, res->blob_size);
85         res->remapped = NULL;
86     }
87     if (res->dmabuf_fd >= 0) {
88         close(res->dmabuf_fd);
89         res->dmabuf_fd = -1;
90     }
91 }
92 
93 static int find_memory_backend_type(Object *obj, void *opaque)
94 {
95     bool *memfd_backend = opaque;
96     int ret;
97 
98     if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
99         HostMemoryBackend *backend = MEMORY_BACKEND(obj);
100         RAMBlock *rb = backend->mr.ram_block;
101 
102         if (rb && rb->fd > 0) {
103             ret = fcntl(rb->fd, F_GET_SEALS);
104             if (ret > 0) {
105                 *memfd_backend = true;
106             }
107         }
108     }
109 
110     return 0;
111 }
112 
113 bool virtio_gpu_have_udmabuf(void)
114 {
115     Object *memdev_root;
116     int udmabuf;
117     bool memfd_backend = false;
118 
119     udmabuf = udmabuf_fd();
120     if (udmabuf < 0) {
121         return false;
122     }
123 
124     memdev_root = object_resolve_path("/objects", NULL);
125     object_child_foreach(memdev_root, find_memory_backend_type, &memfd_backend);
126 
127     return memfd_backend;
128 }
129 
130 void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res)
131 {
132     void *pdata = NULL;
133 
134     res->dmabuf_fd = -1;
135     if (res->iov_cnt == 1 &&
136         res->iov[0].iov_len < 4096) {
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     g_clear_pointer(&dmabuf->buf, qemu_dmabuf_free);
167     QTAILQ_REMOVE(&g->dmabuf.bufs, dmabuf, next);
168     g_free(dmabuf);
169 }
170 
171 static VGPUDMABuf
172 *virtio_gpu_create_dmabuf(VirtIOGPU *g,
173                           uint32_t scanout_id,
174                           struct virtio_gpu_simple_resource *res,
175                           struct virtio_gpu_framebuffer *fb,
176                           struct virtio_gpu_rect *r)
177 {
178     VGPUDMABuf *dmabuf;
179 
180     if (res->dmabuf_fd < 0) {
181         return NULL;
182     }
183 
184     dmabuf = g_new0(VGPUDMABuf, 1);
185     dmabuf->buf = qemu_dmabuf_new(r->width, r->height, fb->stride,
186                                   r->x, r->y, fb->width, fb->height,
187                                   qemu_pixman_to_drm_format(fb->format),
188                                   0, res->dmabuf_fd, true, false);
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                              struct virtio_gpu_rect *r)
200 {
201     struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
202     VGPUDMABuf *new_primary, *old_primary = NULL;
203     uint32_t width, height;
204 
205     new_primary = virtio_gpu_create_dmabuf(g, scanout_id, res, fb, r);
206     if (!new_primary) {
207         return -EINVAL;
208     }
209 
210     if (g->dmabuf.primary[scanout_id]) {
211         old_primary = g->dmabuf.primary[scanout_id];
212     }
213 
214     width = qemu_dmabuf_get_width(new_primary->buf);
215     height = qemu_dmabuf_get_height(new_primary->buf);
216     g->dmabuf.primary[scanout_id] = new_primary;
217     qemu_console_resize(scanout->con, width, height);
218     dpy_gl_scanout_dmabuf(scanout->con, new_primary->buf);
219 
220     if (old_primary) {
221         virtio_gpu_free_dmabuf(g, old_primary);
222     }
223 
224     return 0;
225 }
226