Merge remote-tracking branch 'remotes/kraxel/tags/vga-20210527-pull-request' into staging

virtio-gpu: add blob resource support.
vhost-user-gpu: security fixes.

# gpg: Signature made Thu 27 May 2021 15:23:25 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vga-20210527-pull-request: (23 commits)
  virtio-gpu: Update cursor data using blob
  virtio-gpu: Add virtio_gpu_set_scanout_blob
  virtio-gpu: Factor out update scanout
  virtio-gpu: Add helpers to create and destroy dmabuf objects
  ui/pixman: Add qemu_pixman_to_drm_format()
  virtio-gpu: Add virtio_gpu_resource_create_blob
  virtio-gpu: Add initial definitions for blob resources
  virtio-gpu: Refactor virtio_gpu_create_mapping_iov
  virtio-gpu: Refactor virtio_gpu_set_scanout
  virtio-gpu: Add virtio_gpu_find_check_resource
  stubs: Add stubs for udmabuf helpers
  virtio-gpu: Add udmabuf helpers
  headers: Add udmabuf.h
  ui: Get the fd associated with udmabuf driver
  hw/display/qxl: Set pci rom address aligned with page size
  vhost-user-gpu: abstract vg_cleanup_mapping_iov
  vhost-user-gpu: fix OOB write in 'virgl_cmd_get_capset' (CVE-2021-3546)
  vhost-user-gpu: fix memory leak in 'virgl_resource_attach_backing' (CVE-2021-3544)
  vhost-user-gpu: fix memory leak in 'virgl_cmd_resource_unref' (CVE-2021-3544)
  vhost-user-gpu: fix memory leak while calling 'vg_resource_unref' (CVE-2021-3544)
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

7 files changed, 567 insertions, 98 deletions

diff --git a/hw/display/meson.build b/hw/display/meson.build
index aaf797c..e1f473c 100644
--- a/hw/display/meson.build
+++ b/hw/display/meson.build
@@ -56,6 +56,7 @@ if config_all_devices.has_key('CONFIG_VIRTIO_GPU')
   virtio_gpu_ss = ss.source_set()
   virtio_gpu_ss.add(when: 'CONFIG_VIRTIO_GPU',
                     if_true: [files('virtio-gpu-base.c', 'virtio-gpu.c'), pixman])
+  virtio_gpu_ss.add(when: 'CONFIG_LINUX', if_true: files('virtio-gpu-udmabuf.c'))
   virtio_gpu_ss.add(when: 'CONFIG_VHOST_USER_GPU', if_true: files('vhost-user-gpu.c'))
   hw_display_modules += {'virtio-gpu': virtio_gpu_ss}
 
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 2ba7563..6e1f8ff 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -321,7 +321,7 @@ static ram_addr_t qxl_rom_size(void)
 #define QXL_ROM_SZ 8192
 
     QEMU_BUILD_BUG_ON(QXL_REQUIRED_SZ > QXL_ROM_SZ);
-    return QXL_ROM_SZ;
+    return QEMU_ALIGN_UP(QXL_REQUIRED_SZ, qemu_real_host_page_size);
 }
 
 static void init_qxl_rom(PCIQXLDevice *d)
diff --git a/hw/display/trace-events b/hw/display/trace-events
index 9fccca1..e47264a 100644
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -30,8 +30,10 @@ virtio_gpu_features(bool virgl) "virgl %d"
 virtio_gpu_cmd_get_display_info(void) ""
 virtio_gpu_cmd_get_edid(uint32_t scanout) "scanout %d"
 virtio_gpu_cmd_set_scanout(uint32_t id, uint32_t res, uint32_t w, uint32_t h, uint32_t x, uint32_t y) "id %d, res 0x%x, w %d, h %d, x %d, y %d"
+virtio_gpu_cmd_set_scanout_blob(uint32_t id, uint32_t res, uint32_t w, uint32_t h, uint32_t x, uint32_t y) "id %d, res 0x%x, w %d, h %d, x %d, y %d"
 virtio_gpu_cmd_res_create_2d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h) "res 0x%x, fmt 0x%x, w %d, h %d"
 virtio_gpu_cmd_res_create_3d(uint32_t res, uint32_t fmt, uint32_t w, uint32_t h, uint32_t d) "res 0x%x, fmt 0x%x, w %d, h %d, d %d"
+virtio_gpu_cmd_res_create_blob(uint32_t res, uint64_t size) "res 0x%x, size %" PRId64
 virtio_gpu_cmd_res_unref(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_attach(uint32_t res) "res 0x%x"
 virtio_gpu_cmd_res_back_detach(uint32_t res) "res 0x%x"
diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
index afb3ee7..dd29427 100644
--- a/hw/display/virtio-gpu-base.c
+++ b/hw/display/virtio-gpu-base.c
@@ -208,6 +208,9 @@ virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t features,
     if (virtio_gpu_edid_enabled(g->conf)) {
         features |= (1 << VIRTIO_GPU_F_EDID);
     }
+    if (virtio_gpu_blob_enabled(g->conf)) {
+        features |= (1 << VIRTIO_GPU_F_RESOURCE_BLOB);
+    }
 
     return features;
 }
diff --git a/hw/display/virtio-gpu-udmabuf.c b/hw/display/virtio-gpu-udmabuf.c
new file mode 100644
index 0000000..3c01a41
--- /dev/null
+++ b/hw/display/virtio-gpu-udmabuf.c
@@ -0,0 +1,223 @@
+/*
+ * Virtio GPU Device
+ *
+ * Copyright Red Hat, Inc. 2013-2014
+ *
+ * Authors:
+ *     Dave Airlie <airlied@redhat.com>
+ *     Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "qemu-common.h"
+#include "qemu/iov.h"
+#include "ui/console.h"
+#include "hw/virtio/virtio-gpu.h"
+#include "hw/virtio/virtio-gpu-pixman.h"
+#include "trace.h"
+#include "exec/ramblock.h"
+#include "sysemu/hostmem.h"
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <linux/memfd.h>
+#include "qemu/memfd.h"
+#include "standard-headers/linux/udmabuf.h"
+
+static void virtio_gpu_create_udmabuf(struct virtio_gpu_simple_resource *res)
+{
+    struct udmabuf_create_list *list;
+    RAMBlock *rb;
+    ram_addr_t offset;
+    int udmabuf, i;
+
+    udmabuf = udmabuf_fd();
+    if (udmabuf < 0) {
+        return;
+    }
+
+    list = g_malloc0(sizeof(struct udmabuf_create_list) +
+                     sizeof(struct udmabuf_create_item) * res->iov_cnt);
+
+    for (i = 0; i < res->iov_cnt; i++) {
+        rcu_read_lock();
+        rb = qemu_ram_block_from_host(res->iov[i].iov_base, false, &offset);
+        rcu_read_unlock();
+
+        if (!rb || rb->fd < 0) {
+            g_free(list);
+            return;
+        }
+
+        list->list[i].memfd  = rb->fd;
+        list->list[i].offset = offset;
+        list->list[i].size   = res->iov[i].iov_len;
+    }
+
+    list->count = res->iov_cnt;
+    list->flags = UDMABUF_FLAGS_CLOEXEC;
+
+    res->dmabuf_fd = ioctl(udmabuf, UDMABUF_CREATE_LIST, list);
+    if (res->dmabuf_fd < 0) {
+        warn_report("%s: UDMABUF_CREATE_LIST: %s", __func__,
+                    strerror(errno));
+    }
+    g_free(list);
+}
+
+static void virtio_gpu_remap_udmabuf(struct virtio_gpu_simple_resource *res)
+{
+    res->remapped = mmap(NULL, res->blob_size, PROT_READ,
+                         MAP_SHARED, res->dmabuf_fd, 0);
+    if (res->remapped == MAP_FAILED) {
+        warn_report("%s: dmabuf mmap failed: %s", __func__,
+                    strerror(errno));
+        res->remapped = NULL;
+    }
+}
+
+static void virtio_gpu_destroy_udmabuf(struct virtio_gpu_simple_resource *res)
+{
+    if (res->remapped) {
+        munmap(res->remapped, res->blob_size);
+        res->remapped = NULL;
+    }
+    if (res->dmabuf_fd >= 0) {
+        close(res->dmabuf_fd);
+        res->dmabuf_fd = -1;
+    }
+}
+
+static int find_memory_backend_type(Object *obj, void *opaque)
+{
+    bool *memfd_backend = opaque;
+    int ret;
+
+    if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
+        HostMemoryBackend *backend = MEMORY_BACKEND(obj);
+        RAMBlock *rb = backend->mr.ram_block;
+
+        if (rb && rb->fd > 0) {
+            ret = fcntl(rb->fd, F_GET_SEALS);
+            if (ret > 0) {
+                *memfd_backend = true;
+            }
+        }
+    }
+
+    return 0;
+}
+
+bool virtio_gpu_have_udmabuf(void)
+{
+    Object *memdev_root;
+    int udmabuf;
+    bool memfd_backend = false;
+
+    udmabuf = udmabuf_fd();
+    if (udmabuf < 0) {
+        return false;
+    }
+
+    memdev_root = object_resolve_path("/objects", NULL);
+    object_child_foreach(memdev_root, find_memory_backend_type, &memfd_backend);
+
+    return memfd_backend;
+}
+
+void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res)
+{
+    void *pdata = NULL;
+
+    res->dmabuf_fd = -1;
+    if (res->iov_cnt == 1) {
+        pdata = res->iov[0].iov_base;
+    } else {
+        virtio_gpu_create_udmabuf(res);
+        if (res->dmabuf_fd < 0) {
+            return;
+        }
+        virtio_gpu_remap_udmabuf(res);
+        if (!res->remapped) {
+            return;
+        }
+        pdata = res->remapped;
+    }
+
+    res->blob = pdata;
+}
+
+void virtio_gpu_fini_udmabuf(struct virtio_gpu_simple_resource *res)
+{
+    if (res->remapped) {
+        virtio_gpu_destroy_udmabuf(res);
+    }
+}
+
+static void virtio_gpu_free_dmabuf(VirtIOGPU *g, VGPUDMABuf *dmabuf)
+{
+    struct virtio_gpu_scanout *scanout;
+
+    scanout = &g->parent_obj.scanout[dmabuf->scanout_id];
+    dpy_gl_release_dmabuf(scanout->con, &dmabuf->buf);
+    QTAILQ_REMOVE(&g->dmabuf.bufs, dmabuf, next);
+    g_free(dmabuf);
+}
+
+static VGPUDMABuf
+*virtio_gpu_create_dmabuf(VirtIOGPU *g,
+                          uint32_t scanout_id,
+                          struct virtio_gpu_simple_resource *res,
+                          struct virtio_gpu_framebuffer *fb)
+{
+    VGPUDMABuf *dmabuf;
+
+    if (res->dmabuf_fd < 0) {
+        return NULL;
+    }
+
+    dmabuf = g_new0(VGPUDMABuf, 1);
+    dmabuf->buf.width = fb->width;
+    dmabuf->buf.height = fb->height;
+    dmabuf->buf.stride = fb->stride;
+    dmabuf->buf.fourcc = qemu_pixman_to_drm_format(fb->format);
+    dmabuf->buf.fd = res->dmabuf_fd;
+
+    dmabuf->scanout_id = scanout_id;
+    QTAILQ_INSERT_HEAD(&g->dmabuf.bufs, dmabuf, next);
+
+    return dmabuf;
+}
+
+int virtio_gpu_update_dmabuf(VirtIOGPU *g,
+                             uint32_t scanout_id,
+                             struct virtio_gpu_simple_resource *res,
+                             struct virtio_gpu_framebuffer *fb)
+{
+    struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
+    VGPUDMABuf *new_primary, *old_primary = NULL;
+
+    new_primary = virtio_gpu_create_dmabuf(g, scanout_id, res, fb);
+    if (!new_primary) {
+        return -EINVAL;
+    }
+
+    if (g->dmabuf.primary) {
+        old_primary = g->dmabuf.primary;
+    }
+
+    g->dmabuf.primary = new_primary;
+    qemu_console_resize(scanout->con,
+                        new_primary->buf.width,
+                        new_primary->buf.height);
+    dpy_gl_scanout_dmabuf(scanout->con, &new_primary->buf);
+
+    if (old_primary) {
+        virtio_gpu_free_dmabuf(g, old_primary);
+    }
+
+    return 0;
+}
diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
index 72c14d9..092c6dc 100644
--- a/hw/display/virtio-gpu-virgl.c
+++ b/hw/display/virtio-gpu-virgl.c
@@ -289,7 +289,8 @@ static void virgl_resource_attach_backing(VirtIOGPU *g,
     VIRTIO_GPU_FILL_CMD(att_rb);
     trace_virtio_gpu_cmd_res_back_attach(att_rb.resource_id);
 
-    ret = virtio_gpu_create_mapping_iov(g, &att_rb, cmd, NULL, &res_iovs, &res_niov);
+    ret = virtio_gpu_create_mapping_iov(g, att_rb.nr_entries, sizeof(att_rb),
+                                        cmd, NULL, &res_iovs, &res_niov);
     if (ret != 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         return;
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index db56f04..4d54937 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -35,6 +35,10 @@
 
 static struct virtio_gpu_simple_resource*
 virtio_gpu_find_resource(VirtIOGPU *g, uint32_t resource_id);
+static struct virtio_gpu_simple_resource *
+virtio_gpu_find_check_resource(VirtIOGPU *g, uint32_t resource_id,
+                               bool require_backing,
+                               const char *caller, uint32_t *error);
 
 static void virtio_gpu_cleanup_mapping(VirtIOGPU *g,
                                        struct virtio_gpu_simple_resource *res);
@@ -45,20 +49,30 @@ void virtio_gpu_update_cursor_data(VirtIOGPU *g,
 {
     struct virtio_gpu_simple_resource *res;
     uint32_t pixels;
+    void *data;
 
-    res = virtio_gpu_find_resource(g, resource_id);
+    res = virtio_gpu_find_check_resource(g, resource_id, false,
+                                         __func__, NULL);
     if (!res) {
         return;
     }
 
-    if (pixman_image_get_width(res->image)  != s->current_cursor->width ||
-        pixman_image_get_height(res->image) != s->current_cursor->height) {
-        return;
+    if (res->blob_size) {
+        if (res->blob_size < (s->current_cursor->width *
+                              s->current_cursor->height * 4)) {
+            return;
+        }
+        data = res->blob;
+    } else {
+        if (pixman_image_get_width(res->image)  != s->current_cursor->width ||
+            pixman_image_get_height(res->image) != s->current_cursor->height) {
+            return;
+        }
+        data = pixman_image_get_data(res->image);
     }
 
     pixels = s->current_cursor->width * s->current_cursor->height;
-    memcpy(s->current_cursor->data,
-           pixman_image_get_data(res->image),
+    memcpy(s->current_cursor->data, data,
            pixels * sizeof(uint32_t));
 }
 
@@ -114,6 +128,37 @@ virtio_gpu_find_resource(VirtIOGPU *g, uint32_t resource_id)
     return NULL;
 }
 
+static struct virtio_gpu_simple_resource *
+virtio_gpu_find_check_resource(VirtIOGPU *g, uint32_t resource_id,
+                               bool require_backing,
+                               const char *caller, uint32_t *error)
+{
+    struct virtio_gpu_simple_resource *res;
+
+    res = virtio_gpu_find_resource(g, resource_id);
+    if (!res) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid resource specified %d\n",
+                      caller, resource_id);
+        if (error) {
+            *error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        }
+        return NULL;
+    }
+
+    if (require_backing) {
+        if (!res->iov || (!res->image && !res->blob)) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: no backing storage %d\n",
+                          caller, resource_id);
+            if (error) {
+                *error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+            }
+            return NULL;
+        }
+    }
+
+    return res;
+}
+
 void virtio_gpu_ctrl_response(VirtIOGPU *g,
                               struct virtio_gpu_ctrl_command *cmd,
                               struct virtio_gpu_ctrl_hdr *resp,
@@ -277,6 +322,62 @@ static void virtio_gpu_resource_create_2d(VirtIOGPU *g,
     g->hostmem += res->hostmem;
 }
 
+static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
+                                            struct virtio_gpu_ctrl_command *cmd)
+{
+    struct virtio_gpu_simple_resource *res;
+    struct virtio_gpu_resource_create_blob cblob;
+    int ret;
+
+    VIRTIO_GPU_FILL_CMD(cblob);
+    virtio_gpu_create_blob_bswap(&cblob);
+    trace_virtio_gpu_cmd_res_create_blob(cblob.resource_id, cblob.size);
+
+    if (cblob.resource_id == 0) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource id 0 is not allowed\n",
+                      __func__);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+
+    res = virtio_gpu_find_resource(g, cblob.resource_id);
+    if (res) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already exists %d\n",
+                      __func__, cblob.resource_id);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+        return;
+    }
+
+    res = g_new0(struct virtio_gpu_simple_resource, 1);
+    res->resource_id = cblob.resource_id;
+    res->blob_size = cblob.size;
+
+    if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_GUEST &&
+        cblob.blob_flags != VIRTIO_GPU_BLOB_FLAG_USE_SHAREABLE) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid memory type\n",
+                      __func__);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+        g_free(res);
+        return;
+    }
+
+    if (res->iov) {
+        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+        return;
+    }
+
+    ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
+                                        cmd, &res->addrs, &res->iov,
+                                        &res->iov_cnt);
+    if (ret != 0) {
+        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+        return;
+    }
+
+    virtio_gpu_init_udmabuf(res);
+    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
+}
+
 static void virtio_gpu_disable_scanout(VirtIOGPU *g, int scanout_id)
 {
     struct virtio_gpu_scanout *scanout = &g->parent_obj.scanout[scanout_id];
@@ -311,7 +412,7 @@ static void virtio_gpu_resource_destroy(VirtIOGPU *g,
         }
     }
 
-    pixman_image_unref(res->image);
+    qemu_pixman_image_unref(res->image);
     virtio_gpu_cleanup_mapping(g, res);
     QTAILQ_REMOVE(&g->reslist, res, next);
     g->hostmem -= res->hostmem;
@@ -352,11 +453,9 @@ static void virtio_gpu_transfer_to_host_2d(VirtIOGPU *g,
     virtio_gpu_t2d_bswap(&t2d);
     trace_virtio_gpu_cmd_res_xfer_toh_2d(t2d.resource_id);
 
-    res = virtio_gpu_find_resource(g, t2d.resource_id);
-    if (!res || !res->iov) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal resource specified %d\n",
-                      __func__, t2d.resource_id);
-        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+    res = virtio_gpu_find_check_resource(g, t2d.resource_id, true,
+                                         __func__, &cmd->error);
+    if (!res || res->blob) {
         return;
     }
 
@@ -402,6 +501,7 @@ static void virtio_gpu_resource_flush(VirtIOGPU *g,
 {
     struct virtio_gpu_simple_resource *res;
     struct virtio_gpu_resource_flush rf;
+    struct virtio_gpu_scanout *scanout;
     pixman_region16_t flush_region;
     int i;
 
@@ -410,20 +510,31 @@ static void virtio_gpu_resource_flush(VirtIOGPU *g,
     trace_virtio_gpu_cmd_res_flush(rf.resource_id,
                                    rf.r.width, rf.r.height, rf.r.x, rf.r.y);
 
-    res = virtio_gpu_find_resource(g, rf.resource_id);
+    res = virtio_gpu_find_check_resource(g, rf.resource_id, false,
+                                         __func__, &cmd->error);
     if (!res) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal resource specified %d\n",
-                      __func__, rf.resource_id);
-        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
         return;
     }
 
-    if (rf.r.x > res->width ||
+    if (res->blob) {
+        for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
+            scanout = &g->parent_obj.scanout[i];
+            if (scanout->resource_id == res->resource_id &&
+                console_has_gl(scanout->con)) {
+                dpy_gl_update(scanout->con, 0, 0, scanout->width,
+                              scanout->height);
+                return;
+            }
+        }
+    }
+
+    if (!res->blob &&
+        (rf.r.x > res->width ||
         rf.r.y > res->height ||
         rf.r.width > res->width ||
         rf.r.height > res->height ||
         rf.r.x + rf.r.width > res->width ||
-        rf.r.y + rf.r.height > res->height) {
+        rf.r.y + rf.r.height > res->height)) {
         qemu_log_mask(LOG_GUEST_ERROR, "%s: flush bounds outside resource"
                       " bounds for resource %d: %d %d %d %d vs %d %d\n",
                       __func__, rf.resource_id, rf.r.x, rf.r.y,
@@ -435,7 +546,6 @@ static void virtio_gpu_resource_flush(VirtIOGPU *g,
     pixman_region_init_rect(&flush_region,
                             rf.r.x, rf.r.y, rf.r.width, rf.r.height);
     for (i = 0; i < g->parent_obj.conf.max_outputs; i++) {
-        struct virtio_gpu_scanout *scanout;
         pixman_region16_t region, finalregion;
         pixman_box16_t *extents;
 
@@ -468,14 +578,115 @@ static void virtio_unref_resource(pixman_image_t *image, void *data)
     pixman_image_unref(data);
 }
 
+static void virtio_gpu_update_scanout(VirtIOGPU *g,
+                                      uint32_t scanout_id,
+                                      struct virtio_gpu_simple_resource *res,
+                                      struct virtio_gpu_rect *r)
+{
+    struct virtio_gpu_simple_resource *ores;
+    struct virtio_gpu_scanout *scanout;
+
+    scanout = &g->parent_obj.scanout[scanout_id];
+    ores = virtio_gpu_find_resource(g, scanout->resource_id);
+    if (ores) {
+        ores->scanout_bitmask &= ~(1 << scanout_id);
+    }
+
+    res->scanout_bitmask |= (1 << scanout_id);
+    scanout->resource_id = res->resource_id;
+    scanout->x = r->x;
+    scanout->y = r->y;
+    scanout->width = r->width;
+    scanout->height = r->height;
+}
+
+static void virtio_gpu_do_set_scanout(VirtIOGPU *g,
+                                      uint32_t scanout_id,
+                                      struct virtio_gpu_framebuffer *fb,
+                                      struct virtio_gpu_simple_resource *res,
+                                      struct virtio_gpu_rect *r,
+                                      uint32_t *error)
+{
+    struct virtio_gpu_scanout *scanout;
+    uint8_t *data;
+
+    if (scanout_id >= g->parent_obj.conf.max_outputs) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout id specified %d",
+                      __func__, scanout_id);
+        *error = VIRTIO_GPU_RESP_ERR_INVALID_SCANOUT_ID;
+        return;
+    }
+    scanout = &g->parent_obj.scanout[scanout_id];
+
+    if (r->x > fb->width ||
+        r->y > fb->height ||
+        r->width < 16 ||
+        r->height < 16 ||
+        r->width > fb->width ||
+        r->height > fb->height ||
+        r->x + r->width > fb->width ||
+        r->y + r->height > fb->height) {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout %d bounds for"
+                      " resource %d, rect (%d,%d)+%d,%d, fb %d %d\n",
+                      __func__, scanout_id, res->resource_id,
+                      r->x, r->y, r->width, r->height,
+                      fb->width, fb->height);
+        *error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+        return;
+    }
+
+    g->parent_obj.enable = 1;
+
+    if (res->blob) {
+        if (console_has_gl(scanout->con)) {
+            if (!virtio_gpu_update_dmabuf(g, scanout_id, res, fb)) {
+                virtio_gpu_update_scanout(g, scanout_id, res, r);
+                return;
+            }
+        }
+
+        data = res->blob;
+    } else {
+        data = (uint8_t *)pixman_image_get_data(res->image);
+    }
+
+    /* create a surface for this scanout */
+    if ((res->blob && !console_has_gl(scanout->con)) ||
+        !scanout->ds ||
+        surface_data(scanout->ds) != data + fb->offset ||
+        scanout->width != r->width ||
+        scanout->height != r->height) {
+        pixman_image_t *rect;
+        void *ptr = data + fb->offset;
+        rect = pixman_image_create_bits(fb->format, r->width, r->height,
+                                        ptr, fb->stride);
+
+        if (res->image) {
+            pixman_image_ref(res->image);
+            pixman_image_set_destroy_function(rect, virtio_unref_resource,
+                                              res->image);
+        }
+
+        /* realloc the surface ptr */
+        scanout->ds = qemu_create_displaysurface_pixman(rect);
+        if (!scanout->ds) {
+            *error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+            return;
+        }
+
+        pixman_image_unref(rect);
+        dpy_gfx_replace_surface(g->parent_obj.scanout[scanout_id].con,
+                                scanout->ds);
+    }
+
+    virtio_gpu_update_scanout(g, scanout_id, res, r);
+}
+
 static void virtio_gpu_set_scanout(VirtIOGPU *g,
                                    struct virtio_gpu_ctrl_command *cmd)
 {
-    struct virtio_gpu_simple_resource *res, *ores;
-    struct virtio_gpu_scanout *scanout;
-    pixman_format_code_t format;
-    uint32_t offset;
-    int bpp;
+    struct virtio_gpu_simple_resource *res;
+    struct virtio_gpu_framebuffer fb = { 0 };
     struct virtio_gpu_set_scanout ss;
 
     VIRTIO_GPU_FILL_CMD(ss);
@@ -483,86 +694,85 @@ static void virtio_gpu_set_scanout(VirtIOGPU *g,
     trace_virtio_gpu_cmd_set_scanout(ss.scanout_id, ss.resource_id,
                                      ss.r.width, ss.r.height, ss.r.x, ss.r.y);
 
-    if (ss.scanout_id >= g->parent_obj.conf.max_outputs) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout id specified %d",
-                      __func__, ss.scanout_id);
-        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_SCANOUT_ID;
+    if (ss.resource_id == 0) {
+        virtio_gpu_disable_scanout(g, ss.scanout_id);
         return;
     }
 
-    g->parent_obj.enable = 1;
+    res = virtio_gpu_find_check_resource(g, ss.resource_id, true,
+                                         __func__, &cmd->error);
+    if (!res) {
+        return;
+    }
+
+    fb.format = pixman_image_get_format(res->image);
+    fb.bytes_pp = DIV_ROUND_UP(PIXMAN_FORMAT_BPP(fb.format), 8);
+    fb.width  = pixman_image_get_width(res->image);
+    fb.height = pixman_image_get_height(res->image);
+    fb.stride = pixman_image_get_stride(res->image);
+    fb.offset = ss.r.x * fb.bytes_pp + ss.r.y * fb.stride;
+
+    virtio_gpu_do_set_scanout(g, ss.scanout_id,
+                              &fb, res, &ss.r, &cmd->error);
+}
+
+static void virtio_gpu_set_scanout_blob(VirtIOGPU *g,
+                                        struct virtio_gpu_ctrl_command *cmd)
+{
+    struct virtio_gpu_simple_resource *res;
+    struct virtio_gpu_framebuffer fb = { 0 };
+    struct virtio_gpu_set_scanout_blob ss;
+    uint64_t fbend;
+
+    VIRTIO_GPU_FILL_CMD(ss);
+    virtio_gpu_scanout_blob_bswap(&ss);
+    trace_virtio_gpu_cmd_set_scanout_blob(ss.scanout_id, ss.resource_id,
+                                          ss.r.width, ss.r.height, ss.r.x,
+                                          ss.r.y);
+
     if (ss.resource_id == 0) {
         virtio_gpu_disable_scanout(g, ss.scanout_id);
         return;
     }
 
-    /* create a surface for this scanout */
-    res = virtio_gpu_find_resource(g, ss.resource_id);
+    res = virtio_gpu_find_check_resource(g, ss.resource_id, true,
+                                         __func__, &cmd->error);
     if (!res) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal resource specified %d\n",
-                      __func__, ss.resource_id);
-        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
         return;
     }
 
-    if (ss.r.x > res->width ||
-        ss.r.y > res->height ||
-        ss.r.width < 16 ||
-        ss.r.height < 16 ||
-        ss.r.width > res->width ||
-        ss.r.height > res->height ||
-        ss.r.x + ss.r.width > res->width ||
-        ss.r.y + ss.r.height > res->height) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout %d bounds for"
-                      " resource %d, (%d,%d)+%d,%d vs %d %d\n",
-                      __func__, ss.scanout_id, ss.resource_id, ss.r.x, ss.r.y,
-                      ss.r.width, ss.r.height, res->width, res->height);
+    fb.format = virtio_gpu_get_pixman_format(ss.format);
+    if (!fb.format) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: host couldn't handle guest format %d\n",
+                      __func__, ss.format);
         cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
         return;
     }
 
-    scanout = &g->parent_obj.scanout[ss.scanout_id];
-
-    format = pixman_image_get_format(res->image);
-    bpp = DIV_ROUND_UP(PIXMAN_FORMAT_BPP(format), 8);
-    offset = (ss.r.x * bpp) + ss.r.y * pixman_image_get_stride(res->image);
-    if (!scanout->ds || surface_data(scanout->ds)
-        != ((uint8_t *)pixman_image_get_data(res->image) + offset) ||
-        scanout->width != ss.r.width ||
-        scanout->height != ss.r.height) {
-        pixman_image_t *rect;
-        void *ptr = (uint8_t *)pixman_image_get_data(res->image) + offset;
-        rect = pixman_image_create_bits(format, ss.r.width, ss.r.height, ptr,
-                                        pixman_image_get_stride(res->image));
-        pixman_image_ref(res->image);
-        pixman_image_set_destroy_function(rect, virtio_unref_resource,
-                                          res->image);
-        /* realloc the surface ptr */
-        scanout->ds = qemu_create_displaysurface_pixman(rect);
-        if (!scanout->ds) {
-            cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
-            return;
-        }
-        pixman_image_unref(rect);
-        dpy_gfx_replace_surface(g->parent_obj.scanout[ss.scanout_id].con,
-                                scanout->ds);
-    }
+    fb.bytes_pp = DIV_ROUND_UP(PIXMAN_FORMAT_BPP(fb.format), 8);
+    fb.width = ss.width;
+    fb.height = ss.height;
+    fb.stride = ss.strides[0];
+    fb.offset = ss.offsets[0] + ss.r.x * fb.bytes_pp + ss.r.y * fb.stride;
 
-    ores = virtio_gpu_find_resource(g, scanout->resource_id);
-    if (ores) {
-        ores->scanout_bitmask &= ~(1 << ss.scanout_id);
+    fbend = fb.offset;
+    fbend += fb.stride * (ss.r.height - 1);
+    fbend += fb.bytes_pp * ss.r.width;
+    if (fbend > res->blob_size) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: fb end out of range\n",
+                      __func__);
+        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+        return;
     }
 
-    res->scanout_bitmask |= (1 << ss.scanout_id);
-    scanout->resource_id = ss.resource_id;
-    scanout->x = ss.r.x;
-    scanout->y = ss.r.y;
-    scanout->width = ss.r.width;
-    scanout->height = ss.r.height;
+    virtio_gpu_do_set_scanout(g, ss.scanout_id,
+                              &fb, res, &ss.r, &cmd->error);
 }
 
 int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
-                                  struct virtio_gpu_resource_attach_backing *ab,
+                                  uint32_t nr_entries, uint32_t offset,
                                   struct virtio_gpu_ctrl_command *cmd,
                                   uint64_t **addr, struct iovec **iov,
                                   uint32_t *niov)
@@ -571,17 +781,17 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
     size_t esize, s;
     int e, v;
 
-    if (ab->nr_entries > 16384) {
+    if (nr_entries > 16384) {
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: nr_entries is too big (%d > 16384)\n",
-                      __func__, ab->nr_entries);
+                      __func__, nr_entries);
         return -1;
     }
 
-    esize = sizeof(*ents) * ab->nr_entries;
+    esize = sizeof(*ents) * nr_entries;
     ents = g_malloc(esize);
     s = iov_to_buf(cmd->elem.out_sg, cmd->elem.out_num,
-                   sizeof(*ab), ents, esize);
+                   offset, ents, esize);
     if (s != esize) {
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: command data size incorrect %zu vs %zu\n",
@@ -594,7 +804,7 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
     if (addr) {
         *addr = NULL;
     }
-    for (e = 0, v = 0; e < ab->nr_entries; e++) {
+    for (e = 0, v = 0; e < nr_entries; e++) {
         uint64_t a = le64_to_cpu(ents[e].addr);
         uint32_t l = le32_to_cpu(ents[e].length);
         hwaddr len;
@@ -606,8 +816,7 @@ int virtio_gpu_create_mapping_iov(VirtIOGPU *g,
                                  a, &len, DMA_DIRECTION_TO_DEVICE);
             if (!map) {
                 qemu_log_mask(LOG_GUEST_ERROR, "%s: failed to map MMIO memory for"
-                              " resource %d element %d\n",
-                              __func__, ab->resource_id, e);
+                              " element %d\n", __func__, e);
                 virtio_gpu_cleanup_mapping_iov(g, *iov, v);
                 g_free(ents);
                 *iov = NULL;
@@ -663,6 +872,10 @@ static void virtio_gpu_cleanup_mapping(VirtIOGPU *g,
     res->iov_cnt = 0;
     g_free(res->addrs);
     res->addrs = NULL;
+
+    if (res->blob) {
+        virtio_gpu_fini_udmabuf(res);
+    }
 }
 
 static void
@@ -690,8 +903,8 @@ virtio_gpu_resource_attach_backing(VirtIOGPU *g,
         return;
     }
 
-    ret = virtio_gpu_create_mapping_iov(g, &ab, cmd, &res->addrs,
-                                        &res->iov, &res->iov_cnt);
+    ret = virtio_gpu_create_mapping_iov(g, ab.nr_entries, sizeof(ab), cmd,
+                                        &res->addrs, &res->iov, &res->iov_cnt);
     if (ret != 0) {
         cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
         return;
@@ -709,11 +922,9 @@ virtio_gpu_resource_detach_backing(VirtIOGPU *g,
     virtio_gpu_bswap_32(&detach, sizeof(detach));
     trace_virtio_gpu_cmd_res_back_detach(detach.resource_id);
 
-    res = virtio_gpu_find_resource(g, detach.resource_id);
-    if (!res || !res->iov) {
-        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal resource specified %d\n",
-                      __func__, detach.resource_id);
-        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
+    res = virtio_gpu_find_check_resource(g, detach.resource_id, true,
+                                         __func__, &cmd->error);
+    if (!res) {
         return;
     }
     virtio_gpu_cleanup_mapping(g, res);
@@ -735,6 +946,13 @@ void virtio_gpu_simple_process_cmd(VirtIOGPU *g,
     case VIRTIO_GPU_CMD_RESOURCE_CREATE_2D:
         virtio_gpu_resource_create_2d(g, cmd);
         break;
+    case VIRTIO_GPU_CMD_RESOURCE_CREATE_BLOB:
+        if (!virtio_gpu_blob_enabled(g->parent_obj.conf)) {
+            cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+            break;
+        }
+        virtio_gpu_resource_create_blob(g, cmd);
+        break;
     case VIRTIO_GPU_CMD_RESOURCE_UNREF:
         virtio_gpu_resource_unref(g, cmd);
         break;
@@ -747,6 +965,13 @@ void virtio_gpu_simple_process_cmd(VirtIOGPU *g,
     case VIRTIO_GPU_CMD_SET_SCANOUT:
         virtio_gpu_set_scanout(g, cmd);
         break;
+    case VIRTIO_GPU_CMD_SET_SCANOUT_BLOB:
+        if (!virtio_gpu_blob_enabled(g->parent_obj.conf)) {
+            cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+            break;
+        }
+        virtio_gpu_set_scanout_blob(g, cmd);
+        break;
     case VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING:
         virtio_gpu_resource_attach_backing(g, cmd);
         break;
@@ -1058,6 +1283,18 @@ void virtio_gpu_device_realize(DeviceState *qdev, Error **errp)
     VirtIODevice *vdev = VIRTIO_DEVICE(qdev);
     VirtIOGPU *g = VIRTIO_GPU(qdev);
 
+    if (virtio_gpu_blob_enabled(g->parent_obj.conf)) {
+        if (!virtio_gpu_have_udmabuf()) {
+            error_setg(errp, "cannot enable blob resources without udmabuf");
+            return;
+        }
+
+        if (virtio_gpu_virgl_enabled(g->parent_obj.conf)) {
+            error_setg(errp, "blobs and virgl are not compatible (yet)");
+            return;
+        }
+    }
+
     if (!virtio_gpu_base_device_realize(qdev,
                                         virtio_gpu_handle_ctrl_cb,
                                         virtio_gpu_handle_cursor_cb,
@@ -1151,6 +1388,8 @@ static Property virtio_gpu_properties[] = {
     VIRTIO_GPU_BASE_PROPERTIES(VirtIOGPU, parent_obj.conf),
     DEFINE_PROP_SIZE("max_hostmem", VirtIOGPU, conf_max_hostmem,
                      256 * MiB),
+    DEFINE_PROP_BIT("blob", VirtIOGPU, parent_obj.conf.flags,
+                    VIRTIO_GPU_FLAG_BLOB_ENABLED, false),
     DEFINE_PROP_END_OF_LIST(),
 };