Message-ID: <68195c77-e645-ebd5-3067-489536e7ace9@suse.com>
Date:   Thu, 16 Mar 2023 12:15:08 +0100
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Subject: Re: [PATCH v3] acpi/processor: fix evaluating _PDC method when
 running as Xen dom0
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To:     =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= <roger.pau@citrix.com>
Cc:     xen-devel@lists.xenproject.org, josef@oderland.se,
        Juergen Gross <jgross@suse.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
        Alex Chiang <achiang@hp.com>, linux-acpi@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230316103236.37102-1-roger.pau@citrix.com>
 <ba2d10ed-a1c0-2f35-3ffc-13637c83ed93@suse.com>
 <ZBL2yosC4LWGdjsn@Air-de-Roger>
From:   Jan Beulich <jbeulich@suse.com>
In-Reply-To: <ZBL2yosC4LWGdjsn@Air-de-Roger>
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On 16.03.2023 12:00, Roger Pau Monné wrote:
> On Thu, Mar 16, 2023 at 11:45:47AM +0100, Jan Beulich wrote:
>> On 16.03.2023 11:32, Roger Pau Monne wrote:
>>> --- a/arch/x86/include/asm/xen/hypervisor.h
>>> +++ b/arch/x86/include/asm/xen/hypervisor.h
>>> @@ -63,4 +63,14 @@ void __init xen_pvh_init(struct boot_params *boot_params);
>>>  void __init mem_map_via_hcall(struct boot_params *boot_params_p);
>>>  #endif
>>>  
>>> +#ifdef CONFIG_XEN_DOM0
>>
>> Shouldn't you also check CONFIG_X86 here, seeing the condition for when
>> pcpu.c would be built?
> 
> It's in a x86 specific header, so that's enough I think? (note the
> path of the header)

Oh, of course I should have paid attention - I'm sorry. (Then again it's
not really logical to live in an arch-dependent header, as the same would
be needed elsewhere with ACPI.)

>> Additionally CONFIG_ACPI may want checking, which
>> - taken together - would amount to checking CONFIG_XEN_ACPI. (For which
>> in turn I find odd that it will also be engaged when !DOM0.)
> 
> Hm, is it worth making the acpi_id field in struct pcpu or helper
> conditional to CONFIG_ACPI? It's just data fetched from Xen so it
> doesn't depend on any of the ACPI functionality in Linux.
> 
> IMO I don't think it's worth the extra ifdefs.

I didn't mean to suggest #ifdef for the new struct field. But the helper
is of no use without ACPI.

Jan