Re: [PATCH] hw/i386/acpi-build: adjust q35 IO addr range for acpi pci hotplug

[Igor Mammedov]

On Wed,  8 Sep 2021 09:41:39 +0530
Ani Sinha <ani@anisinha.ca> wrote:

> Change caf108bc58790 ("hw/i386/acpi-build: Add ACPI PCI hot-plug methods to 
> Q35")
> selects an IO address range for acpi based PCI hotplug for q35 arbitrarily. It
> starts at address 0x0cc4 and ends at 0x0cdb. It was assumed that this address
> range was free and available. However, upon more testing, it seems this 
> address
> range to be not available for some latest versions of windows. 

The range is something assigned by QEMU, and guest has no say where it should 
be.
but perhaps we failed to describe it properly or something similar, so one gets
'no resource' error.
We need a find out a reason why Windows doesn't like it. You might get more
detailed error running Windows debug build with ACPI debugger attached.

> Hence, this
> change modifies the IO address range so that windows can allocate the address
> range without any conflict. The new address range would start at 0x0dd4 and 
> end
> at address 0x0deb.
> 
> This change has been tested using a Windows Server 2019 guest VM.
> 
> Fixes: caf108bc58790 ("hw/i386/acpi-build: Add ACPI PCI hot-plug methods to 
> Q35")
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/561
> 
> Signed-off-by: Ani Sinha <ani@anisinha.ca>
> ---
>  include/hw/acpi/ich9.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
> index a329ce43ab..b68c5a2174 100644
> --- a/include/hw/acpi/ich9.h
> +++ b/include/hw/acpi/ich9.h
> @@ -29,7 +29,7 @@
>  #include "hw/acpi/acpi_dev_interface.h"
>  #include "hw/acpi/tco.h"
>  
> -#define ACPI_PCIHP_ADDR_ICH9 0x0cc4
> +#define ACPI_PCIHP_ADDR_ICH9 0x0dd4

that's ABI change, it must be versioned 

>  
>  typedef struct ICH9LPCPMRegs {
>      /*