On Fri, 17 Jul 2026 15:16:14 +0100 Daniel P. Berrangé <[email protected]> wrote:
> On Fri, Jul 17, 2026 at 04:05:42PM +0200, Christian Schoenebeck wrote: > > On Monday, 13 July 2026 09:49:35 CEST Igor Mammedov wrote: > > > On Fri, 10 Jul 2026 15:40:04 +0100 > > > > > > Daniel P. Berrangé <[email protected]> wrote: > > > > On Fri, Jul 10, 2026 at 04:31:51PM +0200, Christian Schoenebeck wrote: > > > > > On Friday, 10 July 2026 14:51:49 CEST Igor Mammedov wrote: > > > > > > On Fri, 10 Jul 2026 12:49:06 +0200 > > > > > > > > > > > > Christian Schoenebeck <[email protected]> wrote: > > > > > > > On Friday, 10 July 2026 12:23:45 CEST Igor Mammedov wrote: > > > > > [...] > > > > > > > > > > > note: I'm looking from pov of hotpluggable PCI device and generic > > > > > > hotplug > > > > > > infra, only. > > > > > > > > > > That's okay, but so far I don't see the relevance for this particular > > > > > 9p > > > > > device. > > > > > > > > > > > it's not guest users directly, it's how hotplug flow works for > > > > > > various > > > > > > guest OSes: > > > > > > > > > > > > 1. host plugs device in (-device or device_add) > > > > > > 2. guest OS get's notified one way or another and does what ever > > > > > > guest > > > > > > side > > > > > > > > > > > > init needed (incl. mounting share in 9pfs case) > > > > > > > > > > That's not affected by this patch, right? > > > > > > > > > > > opposite flow: > > > > > > 1. host does device_del (basically notify guest to remove device) > > > > > > 2. guest OS frees resources and tells qemu to delete device > > > > > > 3. qemu process remove event (which incl. unrealize as part of > > > > > > destroying > > > > > > device) > > > > > > > > > > And that's not affected by this patch either, right? > > > > > > the patch would break unplug flow by effectively removing 'eject' knob > > > from guest side, which is part of unplug flow. > > > > These are two different things: device_del would not be affected by this. > > > > 1. Ejecting the device from host side e.g. via QMP would still work. > > > > vs. > > > > 2. Ejecting from guest side OTOH would be disabled. > > > > It is also different from regular block devices where you have convenient > > ways > > to eject a block device on guest OSes. For a virtio-9p device it is not that > > easy. > > Igor can correct me if I'm wrong, but IIUC there's no distinction > to those 2 scenarios from the guest POV. > > A "device_del" in QMP does not actually delete a device from the > QEMU POV. Rather it triggers an ACPI notification to the geust > OS, that the operator wants to unplug the device. The guest OS > then honours (or not) that by initiating a guest side "eject". > IOW disabling guest initiated eject would break device_del too > AFAIK. That's how it works. Sorry if I wasn't able to convey the message in my previous replies. > > With regards, > Daniel
