@@ -2140,6 +2140,13 @@ T: git https://gitlab.com/cohuck/qemu.git s390-next
T: git https://github.com/borntraeger/qemu.git s390-next
L: qemu-s390x@nongnu.org
+virtio-dmabuf
+M: Albert Esteve <aesteve@redhat.com>
+S: Supported
+F: hw/display/virtio-dmabuf.c
+F: include/hw/virtio/virtio-dmabuf.h
+F: tests/unit/test-virtio-dmabuf.c
+
virtiofs
M: Stefan Hajnoczi <stefanha@redhat.com>
S: Supported
@@ -37,6 +37,7 @@ softmmu_ss.add(when: 'CONFIG_MACFB', if_true: files('macfb.c'))
softmmu_ss.add(when: 'CONFIG_NEXTCUBE', if_true: files('next-fb.c'))
softmmu_ss.add(when: 'CONFIG_VGA', if_true: files('vga.c'))
+softmmu_ss.add(when: 'CONFIG_VIRTIO', if_true: files('virtio-dmabuf.c'))
if (config_all_devices.has_key('CONFIG_VGA_CIRRUS') or
config_all_devices.has_key('CONFIG_VGA_PCI') or
new file mode 100644
@@ -0,0 +1,82 @@
+/*
+ * Virtio Shared dma-buf
+ *
+ * Copyright Red Hat, Inc. 2023
+ *
+ * Authors:
+ * Albert Esteve <aesteve@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 "hw/virtio/virtio-dmabuf.h"
+
+
+static GMutex lock;
+static GHashTable *resource_uuids;
+
+
+static bool virtio_add_resource(QemuUUID *uuid, gpointer value)
+{
+ assert(resource_uuids != NULL);
+ if (g_hash_table_lookup(resource_uuids, uuid) != NULL) {
+ return false;
+ }
+
+ return g_hash_table_insert(resource_uuids, uuid, value);
+}
+
+static gpointer virtio_lookup_resource(const QemuUUID *uuid)
+{
+ if (resource_uuids == NULL) {
+ return NULL;
+ }
+
+ return g_hash_table_lookup(resource_uuids, uuid);
+}
+
+bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd)
+{
+ bool result;
+ if (udmabuf_fd < 0) {
+ return false;
+ }
+ g_mutex_lock(&lock);
+ if (resource_uuids == NULL) {
+ resource_uuids = g_hash_table_new(qemu_uuid_hash, qemu_uuid_equal);
+ }
+ result = virtio_add_resource(uuid, GINT_TO_POINTER(udmabuf_fd));
+ g_mutex_unlock(&lock);
+
+ return result;
+}
+
+bool virtio_remove_resource(const QemuUUID *uuid)
+{
+ bool result;
+ g_mutex_lock(&lock);
+ result = g_hash_table_remove(resource_uuids, uuid);
+ g_mutex_unlock(&lock);
+
+ return result;
+}
+
+int virtio_lookup_dmabuf(const QemuUUID *uuid)
+{
+ g_mutex_lock(&lock);
+ gpointer lookup_res = virtio_lookup_resource(uuid);
+ g_mutex_unlock(&lock);
+ if (lookup_res == NULL) {
+ return -1;
+ }
+
+ return GPOINTER_TO_INT(lookup_res);
+}
+
+void virtio_free_resources(void)
+{
+ g_hash_table_destroy(resource_uuids);
+ /* Reference count shall be 0 after the implicit unref on destroy */
+ resource_uuids = NULL;
+}
new file mode 100644
@@ -0,0 +1,59 @@
+/*
+ * Virtio Shared dma-buf
+ *
+ * Copyright Red Hat, Inc. 2023
+ *
+ * Authors:
+ * Albert Esteve <aesteve@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef VIRTIO_DMABUF_H
+#define VIRTIO_DMABUF_H
+
+#include "qemu/osdep.h"
+
+#include <glib.h>
+#include "qemu/uuid.h"
+
+/**
+ * virtio_add_dmabuf() - Add a new dma-buf resource to the lookup table
+ * @uuid: new resource's UUID
+ * @dmabuf_fd: the dma-buf descriptor that will be stored and shared with
+ * other virtio devices. The caller retains ownership over the
+ * descriptor and its lifecycle.
+ *
+ * Note: @dmabuf_fd must be a valid (non-negative) file descriptor.
+ *
+ * Return: true if the UUID did not exist and the resource has been added,
+ * false if another resource with the same UUID already existed.
+ * Note that if it finds a repeated UUID, the resource is not inserted in
+ * the lookup table.
+ */
+bool virtio_add_dmabuf(QemuUUID *uuid, int dmabuf_fd);
+
+/**
+ * virtio_remove_resource() - Removes a resource from the lookup table
+ * @uuid: resource's UUID
+ *
+ * Return: true if the UUID has been found and removed from the lookup table.
+ */
+bool virtio_remove_resource(const QemuUUID *uuid);
+
+/**
+ * virtio_lookup_dmabuf() - Looks for a dma-buf resource in the lookup table
+ * @uuid: resource's UUID
+ *
+ * Return: the dma-buf file descriptor integer, or -1 if the key is not found.
+ */
+int virtio_lookup_dmabuf(const QemuUUID *uuid);
+
+/**
+ * virtio_free_resources() - Destroys all keys and values of the shared
+ * resources lookup table, and frees them
+ */
+void virtio_free_resources(void);
+
+#endif /* VIRTIO_DMABUF_H */
@@ -50,6 +50,7 @@ tests = {
'test-qapi-util': [],
'test-interval-tree': [],
'test-xs-node': [qom],
+ 'test-virtio-dmabuf': [meson.project_source_root() / 'hw/display/virtio-dmabuf.c'],
}
if have_system or have_tools
new file mode 100644
@@ -0,0 +1,112 @@
+/*
+ * QEMU tests for shared dma-buf API
+ *
+ * Copyright (c) 2023 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "hw/virtio/virtio-dmabuf.h"
+
+
+static void test_add_remove_resources(void)
+{
+ QemuUUID uuid;
+ int i, dmabuf_fd;
+
+ for (i = 0; i < 100; ++i) {
+ qemu_uuid_generate(&uuid);
+ dmabuf_fd = g_random_int_range(3, 500);
+ /* Add a new resource */
+ g_assert(virtio_add_dmabuf(&uuid, dmabuf_fd));
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, dmabuf_fd);
+ /* Remove the resource */
+ g_assert(virtio_remove_resource(&uuid));
+ /* Resource is not found anymore */
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, -1);
+ }
+}
+
+static void test_remove_invalid_resource(void)
+{
+ QemuUUID uuid;
+ int i;
+
+ for (i = 0; i < 20; ++i) {
+ qemu_uuid_generate(&uuid);
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, -1);
+ /* Removing a resource that does not exist returns false */
+ g_assert_false(virtio_remove_resource(&uuid));
+ }
+}
+
+static void test_add_invalid_resource(void)
+{
+ QemuUUID uuid;
+ int i, dmabuf_fd = -2, alt_dmabuf = 2;
+
+ for (i = 0; i < 20; ++i) {
+ qemu_uuid_generate(&uuid);
+ /* Add a new resource with invalid (negative) resource fd */
+ g_assert_false(virtio_add_dmabuf(&uuid, dmabuf_fd));
+ /* Resource is not found */
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, -1);
+ }
+
+ for (i = 0; i < 20; ++i) {
+ /* Add a valid resource */
+ qemu_uuid_generate(&uuid);
+ dmabuf_fd = g_random_int_range(3, 500);
+ g_assert(virtio_add_dmabuf(&uuid, dmabuf_fd));
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, dmabuf_fd);
+ /* Add a new resource with repeated uuid returns false */
+ g_assert_false(virtio_add_dmabuf(&uuid, alt_dmabuf));
+ /* The value for the uuid key is not replaced */
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuid), ==, dmabuf_fd);
+ }
+}
+
+static void test_free_resources(void)
+{
+ QemuUUID uuids[20];
+ int i, dmabuf_fd;
+
+ for (i = 0; i < ARRAY_SIZE(uuids); ++i) {
+ qemu_uuid_generate(&uuids[i]);
+ dmabuf_fd = g_random_int_range(3, 500);
+ g_assert(virtio_add_dmabuf(&uuids[i], dmabuf_fd));
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuids[i]), ==, dmabuf_fd);
+ }
+ virtio_free_resources();
+ for (i = 0; i < ARRAY_SIZE(uuids); ++i) {
+ /* None of the resources is found after free'd */
+ g_assert_cmpint(virtio_lookup_dmabuf(&uuids[i]), ==, -1);
+ }
+
+}
+
+int main(int argc, char **argv)
+{
+ g_test_init(&argc, &argv, NULL);
+ g_test_add_func("/virtio-dmabuf/add_rm_res", test_add_remove_resources);
+ g_test_add_func("/virtio-dmabuf/rm_invalid_res",
+ test_remove_invalid_resource);
+ g_test_add_func("/virtio-dmabuf/add_invalid_res",
+ test_add_invalid_resource);
+ g_test_add_func("/virtio-dmabuf/free_res", test_free_resources);
+
+ return g_test_run();
+}
This API manages objects (in this iteration, dmabuf fds) that can be shared along different virtio devices. The API allows the different devices to add, remove and/or retrieve the objects by simply invoking the public functions that reside in the virtio-dmabuf file. Suggested-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Albert Esteve <aesteve@redhat.com> --- MAINTAINERS | 7 ++ hw/display/meson.build | 1 + hw/display/virtio-dmabuf.c | 82 ++++++++++++++++++++++ include/hw/virtio/virtio-dmabuf.h | 59 ++++++++++++++++ tests/unit/meson.build | 1 + tests/unit/test-virtio-dmabuf.c | 112 ++++++++++++++++++++++++++++++ 6 files changed, 262 insertions(+) create mode 100644 hw/display/virtio-dmabuf.c create mode 100644 include/hw/virtio/virtio-dmabuf.h create mode 100644 tests/unit/test-virtio-dmabuf.c