On Wed, Sep 6, 2023 at 1:15 PM Albert Esteve <aest...@redhat.com> wrote:
> 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 <kra...@redhat.com> > Signed-off-by: Albert Esteve <aest...@redhat.com> > --- > MAINTAINERS | 7 ++ > hw/display/meson.build | 1 + > hw/display/virtio-dmabuf.c | 134 +++++++++++++++++++++++++++++ > include/hw/virtio/virtio-dmabuf.h | 103 ++++++++++++++++++++++ > tests/unit/meson.build | 1 + > tests/unit/test-virtio-dmabuf.c | 137 ++++++++++++++++++++++++++++++ > 6 files changed, 383 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 > > diff --git a/MAINTAINERS b/MAINTAINERS > index 3b29568ed4..fb0f7b823f 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2150,6 +2150,13 @@ T: git https://gitlab.com/cohuck/qemu.git s390-next > T: git https://github.com/borntraeger/qemu.git s390-next > L: qemu-s3...@nongnu.org > > +virtio-dmabuf > +M: Albert Esteve <aest...@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 <stefa...@redhat.com> > S: Supported > diff --git a/hw/display/meson.build b/hw/display/meson.build > index 413ba4ab24..05619c6968 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 0000000000..268ffe81ec > --- /dev/null > +++ b/hw/display/virtio-dmabuf.c > @@ -0,0 +1,134 @@ > +/* > + * Virtio Shared dma-buf > + * > + * Copyright Red Hat, Inc. 2023 > + * > + * Authors: > + * Albert Esteve <aest...@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; > + > +/* > + * 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; > + 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) { > + g_mutex_unlock(&lock); > + return false; > + } > + 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; > Just realized that the result variable is not required anymore with the last change. Not sure if it is worth sending a new review for this... I can take it into account for a follow-up refactor for the next update I make on the file. Or just send a separate trivial patch. > +} > + > +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) > +{ > + g_mutex_lock(&lock); > + if (resource_uuids == NULL) { > + g_mutex_unlock(&lock); > + return NULL; > + } > + gpointer 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); > +} > diff --git a/include/hw/virtio/virtio-dmabuf.h > b/include/hw/virtio/virtio-dmabuf.h > new file mode 100644 > index 0000000000..202eec5868 > --- /dev/null > +++ b/include/hw/virtio/virtio-dmabuf.h > @@ -0,0 +1,103 @@ > +/* > + * Virtio Shared dma-buf > + * > + * Copyright Red Hat, Inc. 2023 > + * > + * Authors: > + * Albert Esteve <aest...@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" > +#include "vhost.h" > + > +typedef enum SharedObjectType { > + TYPE_INVALID = 0, > + TYPE_DMABUF, > + TYPE_VHOST_DEV, > +} SharedObjectType; > + > +typedef struct VirtioSharedObject { > + SharedObjectType type; > + gpointer value; > +} VirtioSharedObject; > + > +/** > + * 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_add_vhost_device() - Add a new exporter vhost device that holds > the > + * resource with the associated UUID > + * @uuid: new resource's UUID > + * @dev: the pointer to the vhost device that holds the resource. The > caller > + * retains ownership over the device struct and its lifecycle. > + * > + * Return: true if the UUID did not exist and the device has been tracked, > + * 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_vhost_device(QemuUUID *uuid, struct vhost_dev *dev); > + > +/** > + * 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_lookup_vhost_device() - Looks for an exporter vhost device in > the > + * lookup table > + * @uuid: resource's UUID > + * > + * Return: pointer to the vhost_dev struct, or NULL if the key is not > found. > + */ > +struct vhost_dev *virtio_lookup_vhost_device(const QemuUUID *uuid); > + > +/** > + * virtio_object_type() - Looks for the type of resource in the lookup > table > + * @uuid: resource's UUID > + * > + * Return: the type of resource associated with the UUID, or TYPE_INVALID > if > + * the key is not found. > + */ > +SharedObjectType virtio_object_type(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 */ > diff --git a/tests/unit/meson.build b/tests/unit/meson.build > index 93977cc32d..425ecc30fb 100644 > --- a/tests/unit/meson.build > +++ b/tests/unit/meson.build > @@ -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 > diff --git a/tests/unit/test-virtio-dmabuf.c > b/tests/unit/test-virtio-dmabuf.c > new file mode 100644 > index 0000000000..40fe262538 > --- /dev/null > +++ b/tests/unit/test-virtio-dmabuf.c > @@ -0,0 +1,137 @@ > +/* > + * 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_add_remove_dev(void) > +{ > + QemuUUID uuid; > + struct vhost_dev *dev = g_new0(struct vhost_dev, 1); > + int i; > + > + for (i = 0; i < 100; ++i) { > + qemu_uuid_generate(&uuid); > + virtio_add_vhost_device(&uuid, dev); > + /* vhost device is found */ > + g_assert(virtio_lookup_vhost_device(&uuid) != NULL); > + /* Remove the vhost device */ > + g_assert(virtio_remove_resource(&uuid)); > + /* vhost device is not found anymore */ > + g_assert(virtio_lookup_vhost_device(&uuid) == NULL); > + } > + g_free(dev); > +} > + > +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; > + struct vhost_dev *dev = NULL; > + 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); > + /* Add a new vhost device with invalid (NULL) pointer */ > + g_assert_false(virtio_add_vhost_device(&uuid, dev)); > + /* vhost device is not found */ > + g_assert(virtio_lookup_vhost_device(&uuid) == NULL); > + } > + > + 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/add_rm_dev", test_add_remove_dev); > + 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(); > +} > -- > 2.41.0 > >
