Re: [PATCH v4 3/3] xen/arm: acpi: Allow Xen to boot with ACPI 5.1

From: Bertrand Marquis <Bertrand.Marquis@arm.com>
To: Julien Grall <julien@xen.org>
Cc: "open list:X86" <xen-devel@lists.xenproject.org>,
	"alex.bennee@linaro.org" <alex.bennee@linaro.org>,
	Andre Przywara <Andre.Przywara@arm.com>,
	Rahul Singh <Rahul.Singh@arm.com>,
	Julien Grall <Julien.Grall@arm.com>,
	Julien Grall <jgrall@amazon.com>,
	Stefano Stabellini <sstabellini@kernel.org>
Subject: Re: [PATCH v4 3/3] xen/arm: acpi: Allow Xen to boot with ACPI 5.1
Date: Thu, 19 Nov 2020 18:16:31 +0000	[thread overview]
Message-ID: <24299314-EDE1-451C-89E5-CDEEB5A6614F@arm.com> (raw)
In-Reply-To: <20201119170829.9923-4-julien@xen.org>

Hi,

> On 19 Nov 2020, at 17:08, Julien Grall <julien@xen.org> wrote:
> 
> From: Julien Grall <julien.grall@arm.com>
> 
> At the moment Xen requires the FADT ACPI table to be at least version
> 6.0, apparently because of some reliance on other ACPI v6.0 features.
> 
> But actually this is overzealous, and Xen works now fine with ACPI v5.1.
> 
> Let's relax the version check for the FADT table to allow QEMU to
> run the hypervisor with ACPI.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
> Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>

Cheers
Bertrand

> 
> ---
>    Changes in v3:
>        - Add Stefano's acked-by
> 
>    Changes in v2:
>        - Patch added
> ---
> xen/arch/arm/acpi/boot.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
> index 55c3e5cbc834..7ea2990cb82c 100644
> --- a/xen/arch/arm/acpi/boot.c
> +++ b/xen/arch/arm/acpi/boot.c
> @@ -181,8 +181,8 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
>      * we only deal with ACPI 6.0 or newer revision to get GIC and SMP
>      * boot protocol configuration data, or we will disable ACPI.
>      */
> -    if ( table->revision > 6
> -         || (table->revision == 6 && fadt->minor_revision >= 0) )
> +    if ( table->revision > 5
> +         || (table->revision == 5 && fadt->minor_revision >= 1) )
>         return 0;
> 
>     printk("Unsupported FADT revision %d.%d, should be 6.0+, will disable ACPI\n",
> -- 
> 2.17.1
>