Re: [Qemu-devel] [PATCH v2 5/6] s390x/pci: Drop release timer and replace it with a flag

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 30 Jan 2019 16:57:32 +0100
David Hildenbrand <david@redhat.com> wrote:

> Let's handle it similar to x86 ACPI PCI code and don't use a timer.
> Instead, remember if an unplug request is pending and keep it pending
> for eternity. (a follow up patch will process the request on
> reboot).
> 
> We expect that a guest that is up and running, will process the unplug
> request and trigger the unplug. This is normal operation, no timer needed.
> 
> If the guest does not react, this usually means something in the guest
> is going wrong. Simply removing the device after 30 seconds does not
> really sound like a good idea. It might sometimes be wanted, but I
> consider this rather an "opt-in" decision as it might harm a guest not
> prepared for it.
> 
> If we ever actually want a "forced/surprise removal", we will have to
> implement something on top of the existing "device_del" framework. E.g.
> also x86 might want to do a forced/surprise removal of PCI devices under
> some conditions. "device_del X, forced=true" could be an option and will
> require changes to the hotplug handler infrastructure.
> 
> This will then move the responsibility on when to do a forced removal
> to a higher level. Doing a forced removal right now overcomplicates
> things and doesn't really.
> 
> Let's allow to send multiple requests.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/s390x/s390-pci-bus.c | 38 +++++++-------------------------------
>  hw/s390x/s390-pci-bus.h |  3 +--
>  2 files changed, 8 insertions(+), 33 deletions(-)

Thanks, applied.