hw/display/virtio-gpu-udmabuf.c

   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 }