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Re: [Qemu-devel] Re: [PATCH V6 17/32] pci: 64bit bar support.

From: Avi Kivity
Subject: Re: [Qemu-devel] Re: [PATCH V6 17/32] pci: 64bit bar support.
Date: Tue, 03 Nov 2009 14:22:07 +0200
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Thunderbird/3.0b4

On 11/03/2009 01:47 PM, Michael S. Tsirkin wrote:

If qemu is compiled with target phys address size 32 bit, emulated
devices can not support a 64 bit BAR.  Therefore, according to PCI spec,
such devices should declare all BARs as 32 bit.

What happens if you take a PCI card that supports 64-bit BARs and stick it into a machine that has a 32-bit physical address space?

The firmware/OS will configure the BARs to below 4G.

I think you are right that guests on such systems really do not have a
way to address PCI devices if BAR is set beyond 4G. But pci emulation is
better off not relying on this, IMO. Makes sense?

No.  Device emulation shouldn't change with the machine type.

error compiling committee.c: too many arguments to function

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