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

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Message-ID: <20190402090652.GD6826@zn.tnic>
Date:   Tue, 2 Apr 2019 11:06:52 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Lianbo Jiang <lijiang@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kexec@...ts.infradead.org,
        tglx@...utronix.de, mingo@...hat.com, akpm@...ux-foundation.org,
        dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org,
        x86@...nel.org, hpa@...or.com, dyoung@...hat.com, bhe@...hat.com,
        Thomas.Lendacky@....com
Subject: Re: [PATCH 1/2 RESEND v10] x86/mm, resource: add a new I/O resource
 descriptor 'IORES_DESC_RESERVED'

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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