From faefdba8474fbc30427a64caa4dcd6df611f5b60 Mon Sep 17 00:00:00 2001 From: Albert Esteve Date: Mon, 2 Oct 2023 08:57:04 +0200 Subject: hw/display: introduce virtio-dmabuf MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This API manages objects (in this iteration, dmabuf fds) that can be shared along different virtio devices, associated to a UUID. 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. For vhost backends, the API stores the pointer to the backend holding the object. Suggested-by: Gerd Hoffmann Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Albert Esteve Message-Id: <20231002065706.94707-3-aesteve@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/display/meson.build | 1 + hw/display/virtio-dmabuf.c | 138 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 139 insertions(+) create mode 100644 hw/display/virtio-dmabuf.c (limited to 'hw') diff --git a/hw/display/meson.build b/hw/display/meson.build index 413ba4a..05619c6 100644 --- a/hw/display/meson.build +++ b/hw/display/meson.build @@ -37,6 +37,7 @@ system_ss.add(when: 'CONFIG_MACFB', if_true: files('macfb.c')) system_ss.add(when: 'CONFIG_NEXTCUBE', if_true: files('next-fb.c')) system_ss.add(when: 'CONFIG_VGA', if_true: files('vga.c')) +system_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 diff --git a/hw/display/virtio-dmabuf.c b/hw/display/virtio-dmabuf.c new file mode 100644 index 0000000..4a8e430 --- /dev/null +++ b/hw/display/virtio-dmabuf.c @@ -0,0 +1,138 @@ +/* + * Virtio Shared dma-buf + * + * Copyright Red Hat, Inc. 2023 + * + * Authors: + * Albert Esteve + * + * 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 "hw/virtio/virtio-dmabuf.h" + + +static GMutex lock; +static GHashTable *resource_uuids; + +/* + * uuid_equal_func: wrapper for UUID is_equal function to + * satisfy g_hash_table_new expected parameters signatures. + */ +static int uuid_equal_func(const void *lhv, const void *rhv) +{ + return qemu_uuid_is_equal(lhv, rhv); +} + +static bool virtio_add_resource(QemuUUID *uuid, VirtioSharedObject *value) +{ + bool result = false; + + g_mutex_lock(&lock); + if (resource_uuids == NULL) { + resource_uuids = g_hash_table_new_full(qemu_uuid_hash, + uuid_equal_func, + NULL, + g_free); + } + if (g_hash_table_lookup(resource_uuids, uuid) == NULL) { + result = g_hash_table_insert(resource_uuids, uuid, value); + } + g_mutex_unlock(&lock); + + return result; +} + +bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd) +{ + bool result; + VirtioSharedObject *vso; + if (udmabuf_fd < 0) { + return false; + } + vso = g_new(VirtioSharedObject, 1); + vso->type = TYPE_DMABUF; + vso->value = GINT_TO_POINTER(udmabuf_fd); + result = virtio_add_resource(uuid, vso); + + return result; +} + +bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev) +{ + bool result; + VirtioSharedObject *vso; + if (dev == NULL) { + return false; + } + vso = g_new(VirtioSharedObject, 1); + vso->type = TYPE_VHOST_DEV; + vso->value = dev; + result = virtio_add_resource(uuid, vso); + + 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; +} + +static VirtioSharedObject *get_shared_object(const QemuUUID *uuid) +{ + gpointer lookup_res = NULL; + + g_mutex_lock(&lock); + if (resource_uuids != NULL) { + lookup_res = g_hash_table_lookup(resource_uuids, uuid); + } + g_mutex_unlock(&lock); + + return (VirtioSharedObject *) lookup_res; +} + +int virtio_lookup_dmabuf(const QemuUUID *uuid) +{ + VirtioSharedObject *vso = get_shared_object(uuid); + if (vso == NULL) { + return -1; + } + assert(vso->type == TYPE_DMABUF); + return GPOINTER_TO_INT(vso->value); +} + +struct vhost_dev *virtio_lookup_vhost_device(const QemuUUID *uuid) +{ + VirtioSharedObject *vso = get_shared_object(uuid); + if (vso == NULL) { + return NULL; + } + assert(vso->type == TYPE_VHOST_DEV); + return (struct vhost_dev *) vso->value; +} + +SharedObjectType virtio_object_type(const QemuUUID *uuid) +{ + VirtioSharedObject *vso = get_shared_object(uuid); + if (vso == NULL) { + return TYPE_INVALID; + } + return vso->type; +} + +void virtio_free_resources(void) +{ + g_mutex_lock(&lock); + g_hash_table_destroy(resource_uuids); + /* Reference count shall be 0 after the implicit unref on destroy */ + resource_uuids = NULL; + g_mutex_unlock(&lock); +} -- cgit v1.1