Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <9ef06123-b44f-b009-5bf5-60ad27bbede7@linux.ibm.com>
Date:   Mon, 20 Jun 2022 09:18:37 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.9.0
Subject: Re: [PATCH] s390/kvm: avoid hypfs error message
Content-Language: en-US
To:     Juergen Gross <jgross@suse.com>, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, Heiko Carstens <hca@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>
References: <20220607123314.10255-1-jgross@suse.com>
 <5431f626-9bd3-ed54-9889-aafbba9ca3e0@suse.com>
From:   Christian Borntraeger <borntraeger@linux.ibm.com>
In-Reply-To: <5431f626-9bd3-ed54-9889-aafbba9ca3e0@suse.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Am 20.06.22 um 08:03 schrieb Juergen Gross:
> Ping?
> 
> On 07.06.22 14:33, Juergen Gross wrote:
>> When booting under KVM the following error messages are issued:
>>
>> hypfs.7f5705: The hardware system does not support hypfs
>> hypfs.7a79f0: Initialization of hypfs failed with rc=-61
>>
>> While being documented, they can easily be avoided by bailing out of
>> hypfs_init() early in case of running as a KVM guest.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>>   arch/s390/hypfs/inode.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/s390/hypfs/inode.c b/arch/s390/hypfs/inode.c
>> index 5c97f48cea91..bdf078f3c641 100644
>> --- a/arch/s390/hypfs/inode.c
>> +++ b/arch/s390/hypfs/inode.c
>> @@ -464,6 +464,9 @@ static int __init hypfs_init(void)
>>   {
>>       int rc;
>> +    if (MACHINE_IS_KVM)
>> +        return -ENODATA;
>> +
>>       hypfs_dbfs_init();
>>       if (hypfs_diag_init()) {

In case KVM implements hypfs this check would then be wrong.
Question to people on CC/TO.
Would it be an option to still check with KVM but avoid the error message.
So basically changing hypfs_diag_init and fail_dbfs_exit to check
for KVM on error?
Or is this worse?