Re: [Qemu-devel] [PATCH 0/2] acpi: robust notifications

[Gleb Natapov]

On Sun, Mar 18, 2012 at 07:06:23PM +0200, Michael S. Tsirkin wrote:
> acpi currently clears up/down registers on each hotplug
> request. This loses events if they are done quickly.
> It's easy to clear down on ej write.
> To detect that guest was notified of device addition,
> we track configuration accesses since system reset.
> 
This is hack. This is not how real HW works, why do we needed it?
If up/down thing is so broken that this is required lets move to how
cpu hot-plug works and maintain slot status bit map instead. BTW
we discussed that with Alex last week. Have you followed that thread.

> Michael S. Tsirkin (2):
>   pci: track function accesses
>   acpi: don't clear up/down on each host change
> 
>  hw/acpi_piix4.c |   32 +++++++++++++++++++++++++++-----
>  hw/pci.c        |   26 ++++++++++++++++++++++++++
>  hw/pci.h        |    3 +++
>  hw/pci_host.c   |    2 ++
>  4 files changed, 58 insertions(+), 5 deletions(-)
> 
> -- 
> 1.7.9.111.gf3fb0

--
                        Gleb.