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[Xen-devel] disable qemu PCI devices in HVM domains

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Subject: [Xen-devel] disable qemu PCI devices in HVM domains
From: "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
Date: Thu, 11 Dec 2008 14:10:50 +1100
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Thread-topic: disable qemu PCI devices in HVM domains
I would like to implement a mechanism to disable PCI devices by writing
to a certain IO port to prevent the problem of duplication where PV on
HVM drivers are used.

Disabling drivers in the GPLPV drivers is quite troublesome and while I
think 3.3 has eliminated the corruption problem (no caching appears to
make windows understand that it is the same underlying device) I'd still
rather that the qemu PCI devices weren't there at all.

So if the PV drivers loaded early in the boot process, they would write
to a designated IO port and qemu would then tell the PCI devices to not
work anymore. Because I would do it at the driver level rather than at
the device level, it should happen even before windows has loaded the
pci.sys driver and started probing the PCI space.

Does that sound acceptable?



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