Subject: Re: [PATCH v17 04/10] x86: kdump: move xen_pv_domain() check and
 insert_resource() to setup_arch()
From:   "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        <x86@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
        <linux-kernel@vger.kernel.org>, Dave Young <dyoung@redhat.com>,
        Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
        Eric Biederman <ebiederm@xmission.com>,
        <kexec@lists.infradead.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        "Will Deacon" <will@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        <devicetree@vger.kernel.org>, Jonathan Corbet <corbet@lwn.net>,
        <linux-doc@vger.kernel.org>
CC:     Randy Dunlap <rdunlap@infradead.org>,
        Feng Zhou <zhoufeng.zf@bytedance.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        "Chen Zhou" <dingguo.cz@antgroup.com>
References: <20211210065533.2023-1-thunder.leizhen@huawei.com>
 <20211210065533.2023-5-thunder.leizhen@huawei.com>
 <d328aede-1282-b4d5-f17a-aa9c3e9f6563@huawei.com>
Message-ID: <03bd43f3-14a1-dbd1-9fff-118c0885653c@huawei.com>
Date:   Wed, 15 Dec 2021 16:56:11 +0800
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On 2021/12/14 19:40, Leizhen (ThunderTown) wrote:
> 
> 
> On 2021/12/10 14:55, Zhen Lei wrote:
>> From: Chen Zhou <chenzhou10@huawei.com>
>>
>> We will make the functions reserve_crashkernel() as generic, the
>> xen_pv_domain() check in reserve_crashkernel() is relevant only to
>> x86, the same as insert_resource() in reserve_crashkernel[_low]().
>> So move xen_pv_domain() check and insert_resource() to setup_arch()
>> to keep them in x86.
>>
>> Suggested-by: Mike Rapoport <rppt@kernel.org>
>> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>> Tested-by: John Donnelly <John.p.donnelly@oracle.com>
>> Tested-by: Dave Kleikamp <dave.kleikamp@oracle.com>
>> Acked-by: Baoquan He <bhe@redhat.com>
>> ---
>>  arch/x86/kernel/setup.c | 19 +++++++++++--------
>>  1 file changed, 11 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>> index bb2a0973b98059e..7ae00716a208f82 100644
>> --- a/arch/x86/kernel/setup.c
>> +++ b/arch/x86/kernel/setup.c
>> @@ -456,7 +456,6 @@ static int __init reserve_crashkernel_low(void)
>>  
>>  	crashk_low_res.start = low_base;
>>  	crashk_low_res.end   = low_base + low_size - 1;
>> -	insert_resource(&iomem_resource, &crashk_low_res);
>>  #endif
>>  	return 0;
>>  }
>> @@ -480,11 +479,6 @@ static void __init reserve_crashkernel(void)
>>  		high = true;
>>  	}
>>  
>> -	if (xen_pv_domain()) {
>> -		pr_info("Ignoring crashkernel for a Xen PV domain\n");
>> -		return;
>> -	}
>> -
>>  	/* 0 means: find the address automatically */
>>  	if (!crash_base) {
>>  		/*
>> @@ -531,7 +525,6 @@ static void __init reserve_crashkernel(void)
>>  
>>  	crashk_res.start = crash_base;
>>  	crashk_res.end   = crash_base + crash_size - 1;
>> -	insert_resource(&iomem_resource, &crashk_res);
>>  }
>>  #else
>>  static void __init reserve_crashkernel(void)
>> @@ -1143,7 +1136,17 @@ void __init setup_arch(char **cmdline_p)
>>  	 * Reserve memory for crash kernel after SRAT is parsed so that it
>>  	 * won't consume hotpluggable memory.
>>  	 */
>> -	reserve_crashkernel();
> 
> Hi Baoquan:
>   How about move "#ifdef CONFIG_KEXEC_CORE" here, so that we can remove the
> empty reserve_crashkernel(). In fact, xen_pv_domain() is invoked only
> when CONFIG_KEXEC_CORE is enabled before.

Hi Baoquan:
  Did you miss this email? If no reply, I will keep it no change.

> 
>> +	if (xen_pv_domain())
>> +		pr_info("Ignoring crashkernel for a Xen PV domain\n");
>> +	else {
>> +		reserve_crashkernel();
>> +#ifdef CONFIG_KEXEC_CORE
>> +		if (crashk_res.end > crashk_res.start)
>> +			insert_resource(&iomem_resource, &crashk_res);
>> +		if (crashk_low_res.end > crashk_low_res.start)
>> +			insert_resource(&iomem_resource, &crashk_low_res);
>> +#endif
>> +	}
>>  
>>  	memblock_find_dma_reserve();
>>  
>>
> 
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