[libvirt] [PATCH 0/6] hostdev: handle usb detach/attach on node

Hi, all. This patch series aims to handle case when hostdev usb is detached and then attached back on node. Currently libvirtd does not track these events so that in the result hostdev usb is not usable. On the first glace it make sense to delete device from qemu when hostdev is detached on node and then add device back when hostdev is attached back. But these series adds a different behaviour. On detaching device is deleted from qemu and dummy (missing hostaddr and hostbus values) hostdev is inserted, then on attaching device on node dummy device is deleted and proper one is inserted. This way we have the same semantics of 'missing' flag for hostdev as in case of hostdev missing on startup/migration to different host. Also with such approach we additionally handle cases when hostdev is missing on startup but later is attached to node. Known issues: The last patch tries to handle case when hostdev attached/detached when libvirtd is down but if fails in one scenario. If hostdev is detached and thus dummy device in inserted in qemu then if libvirtd is down and hostdev is attached to node then qemu tries to bind appeared hostdev to the dummy device but fails as device is missing in qemu's mount namespace. Later when libvirtd is up and tries to replace dummy device with actual one the device_add fails because libusb the qemu uses tracks that deviced was missed ealier. For this reason I proposed to get rid of dummy device in RFC [1]. Alternatively libusb can be fixed. [1] https://www.redhat.com/archives/libvir-list/2019-August/msg01396.html Nikolay Shirokovskiy (6): qemu: track hostdev delete cause qemu: handle usb hostdev add/del udev events qemu: handle usb hostdev add/del on device DELETED_EVENT conf: parse hostdev missing flag qemu: handle libvirtd restarts during hostdev reattaching qemu: handle hostdev add/del when libvirtd is down src/conf/domain_conf.c | 32 ++++ src/conf/domain_conf.h | 10 ++ src/qemu/Makefile.inc.am | 2 + src/qemu/qemu_conf.h | 3 + src/qemu/qemu_domain.c | 2 + src/qemu/qemu_domain.h | 2 + src/qemu/qemu_driver.c | 376 +++++++++++++++++++++++++++++++++++++-- src/qemu/qemu_hotplug.c | 94 ++++++++-- src/qemu/qemu_hotplug.h | 7 +- src/qemu/qemu_process.c | 55 +++++- src/util/virhostdev.c | 6 +- tests/qemuhotplugtest.c | 2 +- 12 files changed, 558 insertions(+), 33 deletions(-) -- 2.23.0