| Message ID | 20250106155737.976977-1-jonah.palmer@oracle.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Move net backend cleanup to NIC cleanup | expand |
I tested this series of patches with virtio-net regression tests,everything works fine. Tested-by: Lei Yang <leiyang@redhat.com> On Mon, Jan 6, 2025 at 11:57 PM Jonah Palmer <jonah.palmer@oracle.com> wrote: > > Commit a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net > structures if peer nic is present") effectively delayed the backend > cleanup, allowing the frontend or the guest to access it resources as > long as the frontend NIC is still visible to the guest. > > However it does not clean up the resources until the qemu process is > over. This causes an effective leak if the device is deleted with > device_del, as there is no way to close the vdpa device. This makes > impossible to re-add that device to this or other QEMU instances until > the first instance of QEMU is finished. > > Move the cleanup from qemu_cleanup to the NIC deletion. > > v3: > Remove shadowed declaration of NetClientState nc variable in 2/2. > > v2: > Remove NIC peer also at net_cleanup. vhost-user trust all the > backends are clean before qemu removes char devices. > > This is not a requisite introduced by this commit as > system/runstate.c:qemu_cleanup shows. > > Eugenio Pérez (2): > net: parameterize the removing client from nc list > net: move backend cleanup to NIC cleanup > > net/net.c | 44 ++++++++++++++++++++++++++++++++++---------- > net/vhost-vdpa.c | 8 -------- > 2 files changed, 34 insertions(+), 18 deletions(-) > > -- > 2.43.5 >
On Mon, Jan 6, 2025 at 11:58 PM Jonah Palmer <jonah.palmer@oracle.com> wrote: > > Commit a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net > structures if peer nic is present") effectively delayed the backend > cleanup, allowing the frontend or the guest to access it resources as > long as the frontend NIC is still visible to the guest. > > However it does not clean up the resources until the qemu process is > over. This causes an effective leak if the device is deleted with > device_del, as there is no way to close the vdpa device. This makes > impossible to re-add that device to this or other QEMU instances until > the first instance of QEMU is finished. > > Move the cleanup from qemu_cleanup to the NIC deletion. > > v3: > Remove shadowed declaration of NetClientState nc variable in 2/2. > > v2: > Remove NIC peer also at net_cleanup. vhost-user trust all the > backends are clean before qemu removes char devices. > > This is not a requisite introduced by this commit as > system/runstate.c:qemu_cleanup shows. > > Eugenio Pérez (2): > net: parameterize the removing client from nc list > net: move backend cleanup to NIC cleanup > > net/net.c | 44 ++++++++++++++++++++++++++++++++++---------- > net/vhost-vdpa.c | 8 -------- > 2 files changed, 34 insertions(+), 18 deletions(-) > > -- > 2.43.5 > Queued. Thanks
Commit a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present") effectively delayed the backend cleanup, allowing the frontend or the guest to access it resources as long as the frontend NIC is still visible to the guest. However it does not clean up the resources until the qemu process is over. This causes an effective leak if the device is deleted with device_del, as there is no way to close the vdpa device. This makes impossible to re-add that device to this or other QEMU instances until the first instance of QEMU is finished. Move the cleanup from qemu_cleanup to the NIC deletion. v3: Remove shadowed declaration of NetClientState nc variable in 2/2. v2: Remove NIC peer also at net_cleanup. vhost-user trust all the backends are clean before qemu removes char devices. This is not a requisite introduced by this commit as system/runstate.c:qemu_cleanup shows. Eugenio Pérez (2): net: parameterize the removing client from nc list net: move backend cleanup to NIC cleanup net/net.c | 44 ++++++++++++++++++++++++++++++++++---------- net/vhost-vdpa.c | 8 -------- 2 files changed, 34 insertions(+), 18 deletions(-)