On Thu, Feb 15, 2024 at 10:45 AM Albert Esteve wrote: > > > On Tue, Feb 6, 2024 at 12:11 AM Alex Bennée > wrote: > >> Albert Esteve writes: >> >> > Ensure that we cleanup all virtio shared >> > resources when the vhost devices is cleaned >> > up (after a hot unplug, or a crash). >> > >> > To do so, we add a new function to the virtio_dmabuf >> > API called `virtio_dmabuf_vhost_cleanup`, which >> > loop through the table and removes all >> > resources owned by the vhost device parameter. >> > >> > Also, add a test to verify that the new >> > function in the API behaves as expected. >> > >> > Signed-off-by: Albert Esteve >> > Acked-by: Stefan Hajnoczi >> > --- >> > hw/display/virtio-dmabuf.c | 22 +++++++++++++++++++++ >> > hw/virtio/vhost.c | 3 +++ >> > include/hw/virtio/virtio-dmabuf.h | 10 ++++++++++ >> > tests/unit/test-virtio-dmabuf.c | 33 +++++++++++++++++++++++++++++++ >> > 4 files changed, 68 insertions(+) >> > >> > diff --git a/hw/display/virtio-dmabuf.c b/hw/display/virtio-dmabuf.c >> > index 3dba4577ca..6688809777 100644 >> > --- a/hw/display/virtio-dmabuf.c >> > +++ b/hw/display/virtio-dmabuf.c >> > @@ -136,6 +136,28 @@ SharedObjectType virtio_object_type(const QemuUUID >> *uuid) >> > return vso->type; >> > } >> > >> > +static bool virtio_dmabuf_resource_is_owned(gpointer key, >> > + gpointer value, >> > + gpointer dev) >> > +{ >> > + VirtioSharedObject *vso; >> > + >> > + vso = (VirtioSharedObject *) value; >> > + return vso->type == TYPE_VHOST_DEV && vso->value == dev; >> >> It's a bit surprising to see vso->value being an anonymous gpointer >> rather than the proper type and a bit confusing between value and >> vso->value. >> >> > It is the signature required for this to be used with > `g_hash_table_foreach_remove`. > For the naming, the HashMap stores gpointers, that point to > `VirtioSharedObject`, and > these point to the underlying type (stored at `vso->value`). It may sound > a bit confusing, > but is a byproduct of the VirtioSharedObject indirection. Not sure which > names could be > more fit for this, but I'm open to change them. > > >> > +} >> > + >> > +int virtio_dmabuf_vhost_cleanup(struct vhost_dev *dev) >> > +{ >> > + int num_removed; >> > + >> > + g_mutex_lock(&lock); >> > + num_removed = g_hash_table_foreach_remove( >> > + resource_uuids, (GHRFunc) virtio_dmabuf_resource_is_owned, >> dev); >> > + g_mutex_unlock(&lock); >> >> I'll note if we used a QemuMutex for the lock we could: >> >> - use WITH_QEMU_LOCK_GUARD(&lock) { } >> - enable QSP porfiling for the lock >> >> > Was not aware of these QemuMutex's. I wouldn't mind changing the mutex in > this > file in a different commit. > The problem is that current lock is a global static, and `QemuMutex` needs to be initialised by doing `qemu_mutex_init(&lock);`. Maybe can be initialised at vhost-user.c by adding a public function? > > >> > + >> > + return num_removed; >> > +} >> > + >> > void virtio_free_resources(void) >> > { >> > g_mutex_lock(&lock); >> > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c >> > index 2c9ac79468..c5622eac14 100644 >> > --- a/hw/virtio/vhost.c >> > +++ b/hw/virtio/vhost.c >> > @@ -16,6 +16,7 @@ >> > #include "qemu/osdep.h" >> > #include "qapi/error.h" >> > #include "hw/virtio/vhost.h" >> > +#include "hw/virtio/virtio-dmabuf.h" >> > #include "qemu/atomic.h" >> > #include "qemu/range.h" >> > #include "qemu/error-report.h" >> > @@ -1599,6 +1600,8 @@ void vhost_dev_cleanup(struct vhost_dev *hdev) >> > migrate_del_blocker(&hdev->migration_blocker); >> > g_free(hdev->mem); >> > g_free(hdev->mem_sections); >> > + /* free virtio shared objects */ >> > + virtio_dmabuf_vhost_cleanup(hdev); >> > if (hdev->vhost_ops) { >> > hdev->vhost_ops->vhost_backend_cleanup(hdev); >> > } >> > diff --git a/include/hw/virtio/virtio-dmabuf.h >> b/include/hw/virtio/virtio-dmabuf.h >> > index 627c3b6db7..73f70fb482 100644 >> > --- a/include/hw/virtio/virtio-dmabuf.h >> > +++ b/include/hw/virtio/virtio-dmabuf.h >> > @@ -91,6 +91,16 @@ struct vhost_dev *virtio_lookup_vhost_device(const >> QemuUUID *uuid); >> > */ >> > SharedObjectType virtio_object_type(const QemuUUID *uuid); >> > >> > +/** >> > + * virtio_dmabuf_vhost_cleanup() - Destroys all entries of the shared >> > + * resources lookup table that are owned by the vhost backend >> > + * @dev: the pointer to the vhost device that owns the entries. Data >> is owned >> > + * by the called of the function. >> > + * >> > + * Return: the number of resource entries removed. >> > + */ >> > +int virtio_dmabuf_vhost_cleanup(struct vhost_dev *dev); >> > + >> > /** >> > * virtio_free_resources() - Destroys all keys and values of the shared >> > * resources lookup table, and frees them >> > diff --git a/tests/unit/test-virtio-dmabuf.c >> b/tests/unit/test-virtio-dmabuf.c >> > index a45ec52f42..1c8123c2d2 100644 >> > --- a/tests/unit/test-virtio-dmabuf.c >> > +++ b/tests/unit/test-virtio-dmabuf.c >> > @@ -103,6 +103,38 @@ static void test_add_invalid_resource(void) >> > } >> > } >> > >> > +static void test_cleanup_res(void) >> > +{ >> > + QemuUUID uuids[20], uuid_alt; >> > + struct vhost_dev *dev = g_new0(struct vhost_dev, 1); >> > + struct vhost_dev *dev_alt = g_new0(struct vhost_dev, 1); >> > + int i, num_removed; >> > + >> > + for (i = 0; i < ARRAY_SIZE(uuids); ++i) { >> > + qemu_uuid_generate(&uuids[i]); >> > + virtio_add_vhost_device(&uuids[i], dev); >> > + /* vhost device is found */ >> > + g_assert(virtio_lookup_vhost_device(&uuids[i]) != NULL); >> > + } >> > + qemu_uuid_generate(&uuid_alt); >> > + virtio_add_vhost_device(&uuid_alt, dev_alt); >> > + /* vhost device is found */ >> > + g_assert(virtio_lookup_vhost_device(&uuid_alt) != NULL); >> > + /* cleanup all dev resources */ >> > + num_removed = virtio_dmabuf_vhost_cleanup(dev); >> > + g_assert_cmpint(num_removed, ==, ARRAY_SIZE(uuids)); >> > + for (i = 0; i < ARRAY_SIZE(uuids); ++i) { >> > + /* None of the dev resources is found after free'd */ >> > + g_assert_cmpint(virtio_lookup_dmabuf(&uuids[i]), ==, -1); >> > + } >> > + /* uuid_alt is still in the hash table */ >> > + g_assert(virtio_lookup_vhost_device(&uuid_alt) != NULL); >> > + >> > + virtio_free_resources(); >> > + g_free(dev); >> > + g_free(dev_alt); >> > +} >> > + >> > static void test_free_resources(void) >> > { >> > QemuUUID uuids[20]; >> > @@ -131,6 +163,7 @@ int main(int argc, char **argv) >> > test_remove_invalid_resource); >> > g_test_add_func("/virtio-dmabuf/add_invalid_res", >> > test_add_invalid_resource); >> > + g_test_add_func("/virtio-dmabuf/cleanup_dev", test_cleanup_res); >> > g_test_add_func("/virtio-dmabuf/free_res", test_free_resources); >> > >> > return g_test_run(); >> >> -- >> Alex Bennée >> Virtualisation Tech Lead @ Linaro >> >>