| Message ID | 20230802090824.91688-3-aesteve@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Virtio shared dma-buf | expand |
Hi Albert, On 2/8/23 11:08, Albert Esteve 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 <kraxel@redhat.com> > Signed-off-by: Albert Esteve <aesteve@redhat.com> > --- > MAINTAINERS | 7 ++ > hw/display/meson.build | 1 + > hw/display/virtio-dmabuf.c | 136 +++++++++++++++++++++++++++++ > include/hw/virtio/virtio-dmabuf.h | 103 ++++++++++++++++++++++ > tests/unit/meson.build | 1 + > tests/unit/test-virtio-dmabuf.c | 137 ++++++++++++++++++++++++++++++ > 6 files changed, 385 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 12e59b6b27..cd8487785a 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2158,6 +2158,13 @@ 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 > 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..e852c71ba9 > --- /dev/null > +++ b/hw/display/virtio-dmabuf.c > @@ -0,0 +1,136 @@ > +/* > + * 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; > + > +/* > + * 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, struct VirtioSharedObject *value) Per QEMU coding style we use typedefs, so "VirtioSharedObject" here. > +{ > + 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) { > + return false; > + } > + > + return g_hash_table_insert(resource_uuids, uuid, value); Hmm shouldn't this function take the lock to access resource_uuids? > +} > + > +static gpointer virtio_lookup_resource(const QemuUUID *uuid) > +{ > + if (resource_uuids == NULL) { > + return NULL; > + } > + > + return g_hash_table_lookup(resource_uuids, uuid); Ditto. Here you can directly return the casted type (VirtioSharedObject *), since a plain gpointer isn't really used / useful. > +} > + > +bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd) > +{ > + bool result; > + struct VirtioSharedObject *vso; > + if (udmabuf_fd < 0) { > + return false; > + } > + vso = g_new0(struct VirtioSharedObject, 1); s/g_new0/g_new/ > + g_mutex_lock(&lock); > + vso->type = TYPE_DMABUF; > + vso->value = GINT_TO_POINTER(udmabuf_fd); > + result = virtio_add_resource(uuid, vso); > + g_mutex_unlock(&lock); > + > + return result; > +} > + > +bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev) > +{ > + bool result; > + struct VirtioSharedObject *vso; > + if (dev == NULL) { > + return false; > + } > + vso = g_new0(struct VirtioSharedObject, 1); > + g_mutex_lock(&lock); > + vso->type = TYPE_VHOST_DEV; > + vso->value = dev; > + result = virtio_add_resource(uuid, vso); Ah, you lock here... I'd rather do it in the callee. > + 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); virtio_remove_resource() correctly locks. For API parity, virtio_add_resource() should too. > + > + return result; > +} > + > +static struct VirtioSharedObject *get_shared_object(const QemuUUID *uuid) > +{ > + g_mutex_lock(&lock); > + gpointer lookup_res = virtio_lookup_resource(uuid); > + g_mutex_unlock(&lock); > + return (struct VirtioSharedObject*) lookup_res; See earlier, this function can be merged with virtio_lookup_resource(). > +} > + > +int virtio_lookup_dmabuf(const QemuUUID *uuid) > +{ > + struct 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) > +{ > + struct VirtioSharedObject *vso = get_shared_object(uuid); > + if (vso == NULL) { > + return NULL; > + } > + assert(vso->type == TYPE_VHOST_DEV); > + return (struct vhost_dev *) vso->value; > +} > + > +enum SharedObjectType virtio_object_type(const QemuUUID *uuid) > +{ > + struct VirtioSharedObject *vso = get_shared_object(uuid); > + if (vso == NULL) { > + return TYPE_INVALID; > + } > + return vso->type; > +} > + > +void virtio_free_resources(void) > +{ > + g_hash_table_destroy(resource_uuids); Lock? > + /* Reference count shall be 0 after the implicit unref on destroy */ > + resource_uuids = NULL; > +} > diff --git a/include/hw/virtio/virtio-dmabuf.h b/include/hw/virtio/virtio-dmabuf.h > new file mode 100644 > index 0000000000..536e622555 > --- /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 <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" > +#include "vhost.h" > + > +enum SharedObjectType { > + TYPE_INVALID = 0, > + TYPE_DMABUF, > + TYPE_VHOST_DEV, > +}; > + Please declare a typedef > +struct VirtioSharedObject { > + enum SharedObjectType type; > + gpointer value; > +}; VirtioSharedObject; and use it instead of 'struct VirtioSharedObject'. Regards, Phil.
On Wed, Sep 6, 2023 at 7:56 AM Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > Hi Albert, > > On 2/8/23 11:08, Albert Esteve 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 <kraxel@redhat.com> > > Signed-off-by: Albert Esteve <aesteve@redhat.com> > > --- > > MAINTAINERS | 7 ++ > > hw/display/meson.build | 1 + > > hw/display/virtio-dmabuf.c | 136 +++++++++++++++++++++++++++++ > > include/hw/virtio/virtio-dmabuf.h | 103 ++++++++++++++++++++++ > > tests/unit/meson.build | 1 + > > tests/unit/test-virtio-dmabuf.c | 137 ++++++++++++++++++++++++++++++ > > 6 files changed, 385 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 12e59b6b27..cd8487785a 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -2158,6 +2158,13 @@ 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 > > 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..e852c71ba9 > > --- /dev/null > > +++ b/hw/display/virtio-dmabuf.c > > @@ -0,0 +1,136 @@ > > +/* > > + * 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; > > + > > +/* > > + * 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, struct > VirtioSharedObject *value) > > Per QEMU coding style we use typedefs, so "VirtioSharedObject" here. > > > +{ > > + 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) { > > + return false; > > + } > > + > > + return g_hash_table_insert(resource_uuids, uuid, value); > > Hmm shouldn't this function take the lock to access resource_uuids? > > > +} > > + > > +static gpointer virtio_lookup_resource(const QemuUUID *uuid) > > +{ > > + if (resource_uuids == NULL) { > > + return NULL; > > + } > > + > > + return g_hash_table_lookup(resource_uuids, uuid); > > Ditto. > > Here you can directly return the casted type (VirtioSharedObject *), > since a plain gpointer isn't really used / useful. > > > +} > > + > > +bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd) > > +{ > > + bool result; > > + struct VirtioSharedObject *vso; > > + if (udmabuf_fd < 0) { > > + return false; > > + } > > + vso = g_new0(struct VirtioSharedObject, 1); > > s/g_new0/g_new/ > > > + g_mutex_lock(&lock); > > + vso->type = TYPE_DMABUF; > > + vso->value = GINT_TO_POINTER(udmabuf_fd); > > + result = virtio_add_resource(uuid, vso); > > + g_mutex_unlock(&lock); > > + > > + return result; > > +} > > + > > +bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev) > > +{ > > + bool result; > > + struct VirtioSharedObject *vso; > > + if (dev == NULL) { > > + return false; > > + } > > + vso = g_new0(struct VirtioSharedObject, 1); > > + g_mutex_lock(&lock); > > + vso->type = TYPE_VHOST_DEV; > > + vso->value = dev; > > + result = virtio_add_resource(uuid, vso); > > Ah, you lock here... I'd rather do it in the callee. > > > + 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); > > virtio_remove_resource() correctly locks. For API parity, > virtio_add_resource() should too. > > > + > > + return result; > > +} > > + > > +static struct VirtioSharedObject *get_shared_object(const QemuUUID > *uuid) > > +{ > > + g_mutex_lock(&lock); > > + gpointer lookup_res = virtio_lookup_resource(uuid); > > + g_mutex_unlock(&lock); > > + return (struct VirtioSharedObject*) lookup_res; > > See earlier, this function can be merged with virtio_lookup_resource(). > > > +} > > + > > +int virtio_lookup_dmabuf(const QemuUUID *uuid) > > +{ > > + struct 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) > > +{ > > + struct VirtioSharedObject *vso = get_shared_object(uuid); > > + if (vso == NULL) { > > + return NULL; > > + } > > + assert(vso->type == TYPE_VHOST_DEV); > > + return (struct vhost_dev *) vso->value; > > +} > > + > > +enum SharedObjectType virtio_object_type(const QemuUUID *uuid) > > +{ > > + struct VirtioSharedObject *vso = get_shared_object(uuid); > > + if (vso == NULL) { > > + return TYPE_INVALID; > > + } > > + return vso->type; > > +} > > + > > +void virtio_free_resources(void) > > +{ > > + g_hash_table_destroy(resource_uuids); > > Lock? > > > + /* Reference count shall be 0 after the implicit unref on destroy */ > > + resource_uuids = NULL; > > +} > > diff --git a/include/hw/virtio/virtio-dmabuf.h > b/include/hw/virtio/virtio-dmabuf.h > > new file mode 100644 > > index 0000000000..536e622555 > > --- /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 <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" > > +#include "vhost.h" > > + > > +enum SharedObjectType { > > + TYPE_INVALID = 0, > > + TYPE_DMABUF, > > + TYPE_VHOST_DEV, > > +}; > > + > > Please declare a > > typedef > > > +struct VirtioSharedObject { > > + enum SharedObjectType type; > > + gpointer value; > > +}; > > VirtioSharedObject; > > and use it instead of 'struct VirtioSharedObject'. > > You mean making the struct anonymous and typedefing? Should I do the same with the enum? In other files I see enums are typedef too, but not anonymous (e.g., block/qcow2.h). So I could do the same here. For the rest... Ack! > Regards, > > Phil. > >
On Wed, Sep 6, 2023 at 9:42 AM Albert Esteve <aesteve@redhat.com> wrote: > > > On Wed, Sep 6, 2023 at 7:56 AM Philippe Mathieu-Daudé <philmd@linaro.org> > wrote: > >> Hi Albert, >> >> On 2/8/23 11:08, Albert Esteve 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 <kraxel@redhat.com> >> > Signed-off-by: Albert Esteve <aesteve@redhat.com> >> > --- >> > MAINTAINERS | 7 ++ >> > hw/display/meson.build | 1 + >> > hw/display/virtio-dmabuf.c | 136 +++++++++++++++++++++++++++++ >> > include/hw/virtio/virtio-dmabuf.h | 103 ++++++++++++++++++++++ >> > tests/unit/meson.build | 1 + >> > tests/unit/test-virtio-dmabuf.c | 137 ++++++++++++++++++++++++++++++ >> > 6 files changed, 385 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 12e59b6b27..cd8487785a 100644 >> > --- a/MAINTAINERS >> > +++ b/MAINTAINERS >> > @@ -2158,6 +2158,13 @@ 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 >> > 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..e852c71ba9 >> > --- /dev/null >> > +++ b/hw/display/virtio-dmabuf.c >> > @@ -0,0 +1,136 @@ >> > +/* >> > + * 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; >> > + >> > +/* >> > + * 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, struct >> VirtioSharedObject *value) >> >> Per QEMU coding style we use typedefs, so "VirtioSharedObject" here. >> >> > +{ >> > + 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) { >> > + return false; >> > + } >> > + >> > + return g_hash_table_insert(resource_uuids, uuid, value); >> >> Hmm shouldn't this function take the lock to access resource_uuids? >> >> > +} >> > + >> > +static gpointer virtio_lookup_resource(const QemuUUID *uuid) >> > +{ >> > + if (resource_uuids == NULL) { >> > + return NULL; >> > + } >> > + >> > + return g_hash_table_lookup(resource_uuids, uuid); >> >> Ditto. >> >> Here you can directly return the casted type (VirtioSharedObject *), >> since a plain gpointer isn't really used / useful. >> >> > +} >> > + >> > +bool virtio_add_dmabuf(QemuUUID *uuid, int udmabuf_fd) >> > +{ >> > + bool result; >> > + struct VirtioSharedObject *vso; >> > + if (udmabuf_fd < 0) { >> > + return false; >> > + } >> > + vso = g_new0(struct VirtioSharedObject, 1); >> >> s/g_new0/g_new/ >> >> > + g_mutex_lock(&lock); >> > + vso->type = TYPE_DMABUF; >> > + vso->value = GINT_TO_POINTER(udmabuf_fd); >> > + result = virtio_add_resource(uuid, vso); >> > + g_mutex_unlock(&lock); >> > + >> > + return result; >> > +} >> > + >> > +bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev) >> > +{ >> > + bool result; >> > + struct VirtioSharedObject *vso; >> > + if (dev == NULL) { >> > + return false; >> > + } >> > + vso = g_new0(struct VirtioSharedObject, 1); >> > + g_mutex_lock(&lock); >> > + vso->type = TYPE_VHOST_DEV; >> > + vso->value = dev; >> > + result = virtio_add_resource(uuid, vso); >> >> Ah, you lock here... I'd rather do it in the callee. >> >> > + 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); >> >> virtio_remove_resource() correctly locks. For API parity, >> virtio_add_resource() should too. >> >> > + >> > + return result; >> > +} >> > + >> > +static struct VirtioSharedObject *get_shared_object(const QemuUUID >> *uuid) >> > +{ >> > + g_mutex_lock(&lock); >> > + gpointer lookup_res = virtio_lookup_resource(uuid); >> > + g_mutex_unlock(&lock); >> > + return (struct VirtioSharedObject*) lookup_res; >> >> See earlier, this function can be merged with virtio_lookup_resource(). >> >> > +} >> > + >> > +int virtio_lookup_dmabuf(const QemuUUID *uuid) >> > +{ >> > + struct 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) >> > +{ >> > + struct VirtioSharedObject *vso = get_shared_object(uuid); >> > + if (vso == NULL) { >> > + return NULL; >> > + } >> > + assert(vso->type == TYPE_VHOST_DEV); >> > + return (struct vhost_dev *) vso->value; >> > +} >> > + >> > +enum SharedObjectType virtio_object_type(const QemuUUID *uuid) >> > +{ >> > + struct VirtioSharedObject *vso = get_shared_object(uuid); >> > + if (vso == NULL) { >> > + return TYPE_INVALID; >> > + } >> > + return vso->type; >> > +} >> > + >> > +void virtio_free_resources(void) >> > +{ >> > + g_hash_table_destroy(resource_uuids); >> >> Lock? >> >> > + /* Reference count shall be 0 after the implicit unref on destroy >> */ >> > + resource_uuids = NULL; >> > +} >> > diff --git a/include/hw/virtio/virtio-dmabuf.h >> b/include/hw/virtio/virtio-dmabuf.h >> > new file mode 100644 >> > index 0000000000..536e622555 >> > --- /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 <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" >> > +#include "vhost.h" >> > + >> > +enum SharedObjectType { >> > + TYPE_INVALID = 0, >> > + TYPE_DMABUF, >> > + TYPE_VHOST_DEV, >> > +}; >> > + >> >> Please declare a >> >> typedef >> >> > +struct VirtioSharedObject { >> > + enum SharedObjectType type; >> > + gpointer value; >> > +}; >> >> VirtioSharedObject; >> >> and use it instead of 'struct VirtioSharedObject'. >> >> > You mean making the struct anonymous and typedefing? > So after re-reading your comment and looking for more examples in the codebase, I see it is not uncommon to have a named struct also typedef in the same declaration. So I will typedef, but not make it anonymous, same for the enum. > Should I do the same with the enum? In other files I see enums are typedef > too, but not anonymous (e.g., block/qcow2.h). > So I could do the same here. > > For the rest... Ack! > > >> Regards, >> >> Phil. >> >>
On 6/9/23 10:45, Albert Esteve wrote: > > diff --git a/include/hw/virtio/virtio-dmabuf.h > b/include/hw/virtio/virtio-dmabuf.h > > new file mode 100644 > > index 0000000000..536e622555 > > --- /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 <aesteve@redhat.com > <mailto: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" > > +#include "vhost.h" > > + > > +enum SharedObjectType { > > + TYPE_INVALID = 0, > > + TYPE_DMABUF, > > + TYPE_VHOST_DEV, > > +}; > > + > > Please declare a > > typedef > > > +struct VirtioSharedObject { > > + enum SharedObjectType type; > > + gpointer value; > > +}; > > VirtioSharedObject; > > and use it instead of 'struct VirtioSharedObject'. > > > You mean making the struct anonymous and typedefing? > > > So after re-reading your comment and looking for more examples in the > codebase, I see > it is not uncommon to have a named struct also typedef in the same > declaration. > So I will typedef, but not make it anonymous, same for the enum. Correct (see https://qemu-project.gitlab.io/qemu/devel/style.html#typedefs > Should I do the same with the enum? In other files I see enums are > typedef too, but not anonymous (e.g., block/qcow2.h). > So I could do the same here. > > For the rest... Ack! Thanks! Phil.
diff --git a/MAINTAINERS b/MAINTAINERS index 12e59b6b27..cd8487785a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2158,6 +2158,13 @@ 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 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..e852c71ba9 --- /dev/null +++ b/hw/display/virtio-dmabuf.c @@ -0,0 +1,136 @@ +/* + * 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; + +/* + * 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, struct VirtioSharedObject *value) +{ + 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) { + 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; + struct VirtioSharedObject *vso; + if (udmabuf_fd < 0) { + return false; + } + vso = g_new0(struct VirtioSharedObject, 1); + g_mutex_lock(&lock); + vso->type = TYPE_DMABUF; + vso->value = GINT_TO_POINTER(udmabuf_fd); + result = virtio_add_resource(uuid, vso); + g_mutex_unlock(&lock); + + return result; +} + +bool virtio_add_vhost_device(QemuUUID *uuid, struct vhost_dev *dev) +{ + bool result; + struct VirtioSharedObject *vso; + if (dev == NULL) { + return false; + } + vso = g_new0(struct VirtioSharedObject, 1); + g_mutex_lock(&lock); + vso->type = TYPE_VHOST_DEV; + vso->value = dev; + result = virtio_add_resource(uuid, vso); + 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; +} + +static struct VirtioSharedObject *get_shared_object(const QemuUUID *uuid) +{ + g_mutex_lock(&lock); + gpointer lookup_res = virtio_lookup_resource(uuid); + g_mutex_unlock(&lock); + return (struct VirtioSharedObject*) lookup_res; +} + +int virtio_lookup_dmabuf(const QemuUUID *uuid) +{ + struct 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) +{ + struct VirtioSharedObject *vso = get_shared_object(uuid); + if (vso == NULL) { + return NULL; + } + assert(vso->type == TYPE_VHOST_DEV); + return (struct vhost_dev *) vso->value; +} + +enum SharedObjectType virtio_object_type(const QemuUUID *uuid) +{ + struct VirtioSharedObject *vso = get_shared_object(uuid); + if (vso == NULL) { + return TYPE_INVALID; + } + return vso->type; +} + +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; +} diff --git a/include/hw/virtio/virtio-dmabuf.h b/include/hw/virtio/virtio-dmabuf.h new file mode 100644 index 0000000000..536e622555 --- /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 <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" +#include "vhost.h" + +enum SharedObjectType { + TYPE_INVALID = 0, + TYPE_DMABUF, + TYPE_VHOST_DEV, +}; + +struct VirtioSharedObject { + enum SharedObjectType type; + gpointer value; +}; + +/** + * 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. + */ +enum 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(); +}
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 <kraxel@redhat.com> Signed-off-by: Albert Esteve <aesteve@redhat.com> --- MAINTAINERS | 7 ++ hw/display/meson.build | 1 + hw/display/virtio-dmabuf.c | 136 +++++++++++++++++++++++++++++ include/hw/virtio/virtio-dmabuf.h | 103 ++++++++++++++++++++++ tests/unit/meson.build | 1 + tests/unit/test-virtio-dmabuf.c | 137 ++++++++++++++++++++++++++++++ 6 files changed, 385 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