* src/qemu/qemu_hostdev.c (qemuDomainReAttachHostdevDevices): pciDeviceListFree(pcidevs) at the end free()s the device even if it's in use by other domain, this is complete wrong, and will cause race. E.g. # sh test1.sh Device pci_0000_00_19_0 dettached Domain test started Device attached successfully error: Failed to start domain test2 error: Requested operation is not valid: PCI device 0000:00:19.0 is in use by domain test [ -- 1th time --] Device pci_0000_00_19_0 re-attached [ -- 2th time --] Device pci_0000_00_19_0 re-attached [ -- 3th time --] Device pci_0000_00_19_0 re-attached [ -- 4th time --] Device pci_0000_00_19_0 re-attached [ -- 5th time --] Device pci_0000_00_19_0 re-attached clean up Domain test destroyed Device pci_0000_00_19_0 re-attached [root@Osier libvirt]# sh test1.sh Device pci_0000_00_19_0 dettached Domain test started Device attached successfully error: Failed to start domain test2 error: Requested operation is not valid: PCI device 0000:00:19.0 is in use by domain test [ -- 1th time --] Device pci_0000_00_19_0 re-attached [ -- 2th time --] Device pci_0000_00_19_0 re-attached [ -- 3th time --] Device pci_0000_00_19_0 re-attached [ -- 4th time --] Device pci_0000_00_19_0 re-attached [ -- 5th time --] Device pci_0000_00_19_0 re-attached clean up Domain test destroyed Device pci_0000_00_19_0 re-attached [root@Osier libvirt]# sh test1.sh Device pci_0000_00_19_0 dettached Domain test started Device attached successfully error: Failed to start domain test2 error: Requested operation is not valid: PCI device 0000:00:19.0 is in use by domain test [ -- 1th time --] Device pci_0000_00_19_0 re-attached [ -- 2th time --] Device pci_0000_00_19_0 re-attached [ -- 3th time --] Device pci_0000_00_19_0 re-attached [ -- 4th time --] Device pci_0000_00_19_0 re-attached [ -- 5th time --] Device pci_0000_00_19_0 re-attached clean up Domain test destroyed Device pci_0000_00_19_0 re-attached [root@Osier libvirt]# sh test1.sh Device pci_0000_00_19_0 dettached Domain test started Device attached successfully error: Failed to start domain test2 error: Requested operation is not valid: PCI device 0000:00:19.0 is in use by domain test [ -- 1th time --] error: Failed to re-attach device pci_0000_00_19_0 error: internal error Not reattaching active device 0000:00:19.0 [ -- 2th time --] Device pci_0000_00_19_0 re-attached [ -- 3th time --] Device pci_0000_00_19_0 re-attached [ -- 4th time --] Device pci_0000_00_19_0 re-attached [ -- 5th time --] Device pci_0000_00_19_0 re-attached clean up Domain test destroyed Device pci_0000_00_19_0 re-attached The patch also fixes another problem alongside, there won't be error like "qemuDomainReAttachHostdevDevices: Not reattaching active device 0000:00:19.0" in daemon log if some device is in active. As pciResetDevice and pciReattachDevice won't be called for the device anymore. This is sensiable as we already reported error when preparing the device if it's active. Blindly trying to pciResetDevice & pciReattachDevice on the device and getting an error is just redundant. --- src/qemu/qemu_hostdev.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_hostdev.c b/src/qemu/qemu_hostdev.c index 1fb373e..7efbab0 100644 --- a/src/qemu/qemu_hostdev.c +++ b/src/qemu/qemu_hostdev.c @@ -369,8 +369,10 @@ void qemuDomainReAttachHostdevDevices(struct qemud_driver *driver, */ activeDev = pciDeviceListFind(driver->activePciHostdevs, dev); if (activeDev && - STRNEQ_NULLABLE(name, pciDeviceGetUsedBy(activeDev))) + STRNEQ_NULLABLE(name, pciDeviceGetUsedBy(activeDev))) { + pciDeviceListSteal(pcidevs, dev); continue; + } /* pciDeviceListFree() will take care of freeing the dev. */ pciDeviceListSteal(driver->activePciHostdevs, dev); -- 1.7.6