Re: [PATCH 1/2 RESEND v10] x86/mm, resource: add a new I/O resource descriptor 'IORES_DESC_RESERVED'

From: Borislav Petkov
Date: Tue Apr 02 2019 - 05:07:01 EST


On Fri, Mar 29, 2019 at 08:39:13PM +0800, Lianbo Jiang wrote:
> -static int __ioremap_check_desc_other(struct resource *res)
> +/*
> + * Originally, these areas described as IORES_DESC_NONE are not mapped
> + * as encrypted when using ioremap(), for example, E820_TYPE_{RESERVED,
> + * RESERVED_KERN,RAM,UNUSABLE}, etc. It checks for a resource that is
> + * not described as IORES_DESC_NONE, which can make sure the reserved
> + * areas are not mapped as encrypted when using ioremap().
> + *
> + * Now IORES_DESC_RESERVED has been created for the reserved areas so
> + * the check needs to be expanded so that these areas are not mapped
> + * encrypted when using ioremap().
> + */
> +static int __ioremap_check_desc_none_and_reserved(struct resource *res)
> {
> - return (res->desc != IORES_DESC_NONE);
> + return ((res->desc != IORES_DESC_NONE) &&

Why is this still checking IORES_DESC_NONE when the idea is to have this
specific IORES_DESC_RESERVED for all marked as *reserved* regions in
e820 which should not be mapped encrypted?

IOW, which regions are still marked as IORES_DESC_NONE and should not be
mapped encrypted?

--
Regards/Gruss,
Boris.

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