On 29.08.22 17:15, Jason Andryuk wrote:
An HVM guest with linux stubdom and 2 PCI devices failed to start as libxl timed out waiting for the PCI devices to be added. It happens intermittently but with some regularity. libxl wrote the two xenstore entries for the devices, but then timed out waiting for backend state 4 (Connected) - the state stayed at 7 (Reconfiguring). (PCI passthrough to an HVM with stubdomain is PV passthrough to the stubdomain and then HVM passthrough with the QEMU inside the stubdomain.) The stubdom kernel never printed "pcifront pci-0: Installing PCI frontend", so it seems to have missed state 4 which would have called pcifront_try_connect -> pcifront_connect_and_init_dma Have pcifront_detach_devices special-case state Initialised and call pcifront_connect_and_init_dma. Don't use pcifront_try_connect because that sets the xenbus state which may throw off the backend. After connecting, skip the remainder of detach_devices since none have been initialized yet. When the backend switches to Reconfigured, pcifront_attach_devices will pick them up again. Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx> The modifications of the commit message requested by Bjorn can be done while committing. Juergen
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