Jeremy Fitzhardinge wrote:
> In a virtual environment, device drivers such as legacy IDE will waste
> quite a lot of time probing for their devices which will never appear.
> This helper function allows a paravirt implementation to lay claim to
> the whole iomem and ioport space, thereby disabling all device drivers
> trying to claim IO resources.
>
> Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
> Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
>
> diff -r 83c67f9402b5 arch/i386/kernel/paravirt.c
> --- a/arch/i386/kernel/paravirt.c Tue Jun 05 17:41:04 2007 -0700
> +++ b/arch/i386/kernel/paravirt.c Tue Jun 05 18:17:29 2007 -0700
> @@ -227,6 +227,39 @@ static int __init print_banner(void)
> return 0;
> }
> core_initcall(print_banner);
> +
> +static struct resource reserve_ioports = {
> + .start = 0,
> + .end = IO_SPACE_LIMIT,
> + .name = "paravirt-ioport",
> + .flags = IORESOURCE_IO | IORESOURCE_BUSY,
> +};
> +
> +static struct resource reserve_iomem = {
> + .start = 0,
> + .end = -1,
> + .name = "paravirt-iomem",
> + .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
> +};
> +
> +/*
> + * Reserve the whole legacy IO space to prevent any legacy drivers
> + * from wasting time probing for their hardware. This is a fairly
> + * brute-force approach to disabling all non-virtual drivers.
> + *
> + * Note that this must be called very early to have any effect.
> + */
> +int paravirt_disable_iospace(void)
> +{
> + int ret = 0;
> +
> + ret = request_resource(&ioport_resource, &reserve_ioports);
> + if (ret == 0)
> + ret = request_resource(&iomem_resource, &reserve_iomem);
> +
> + return ret;
> +}
> +
>
> struct paravirt_ops paravirt_ops = {
> .name = "bare hardware",
> diff -r 83c67f9402b5 arch/i386/xen/setup.c
> --- a/arch/i386/xen/setup.c Tue Jun 05 17:41:04 2007 -0700
> +++ b/arch/i386/xen/setup.c Tue Jun 05 18:17:29 2007 -0700
>
Oops. This was supposed to be in the corresponding Xen patch.
J
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