linux-kernel - Re: [PATCH] x86/efi: Always map boot service regions into new EFI page tables

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Message-ID: <1457912678.10465.4.camel@talk21.com>
Date:	Sun, 13 Mar 2016 23:44:38 +0000
From:	Scott Ashcroft <scott.ashcroft@...k21.com>
To:	Matt Fleming <matt@...eblueprint.co.uk>
Cc:	Ingo Molnar <mingo@...nel.org>, "H . Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ard Biesheuvel <ard.biesheuvel@...aro.org>,
	linux-kernel@...r.kernel.org, linux-efi@...r.kernel.org,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	Borislav Petkov <bp@...en8.de>,
	Ben Hutchings <ben@...adent.org.uk>,
	Raphael Hertzog <hertzog@...ian.org>,
	Roger Shimizu <rogershimizu@...il.com>,
	Alexis Murzeau <amurzeau@...il.com>
Subject: Re: [PATCH] x86/efi: Always map boot service regions into new EFI
 page tables

On Sun, 2016-03-13 at 23:07 +0000, Matt Fleming wrote:
> On Sun, 13 Mar, at 09:58:47PM, Matt Fleming wrote:
> > Does $(grep pdpe1gb /proc/cpuinfo) show any output on your machine?
> Assuming the answer to this question is "no", can you try out this
> patch?

The answer is no. Attached is the dmesg with CONFIG_EFI_PGT_DUMP.

> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
> index 8fee5b6f8f66..af74849e8c0f 100644
> --- a/arch/x86/mm/pageattr.c
> +++ b/arch/x86/mm/pageattr.c
> @@ -1055,7 +1055,7 @@ static int populate_pud(struct cpa_data *cpa,
> unsigned long start, pgd_t *pgd,
>  	/*
>  	 * Map everything starting from the Gb boundary, possibly
> with 1G pages
>  	 */
> -	while (end - start >= PUD_SIZE) {
> +	while (cpu_has_gbpages && end - start >= PUD_SIZE) {
>  		set_pud(pud, __pud(cpa->pfn << PAGE_SHIFT |
> _PAGE_PSE |
>  				   massage_pgprot(pud_pgprot)));

OK. I'll give that a go.


Cheers,
Scott
View attachment "dmesg_pgt_dump.txt" of type "text/plain" (75106 bytes)