Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <7fe05c94-06ae-4e40-8894-95ad0b21a4a9@linux.ibm.com>
Date:   Fri, 27 Oct 2023 11:25:57 -0400
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 2/3] s390/vfio-ap: set status response code to 06 on
 gisc registration failure
Content-Language: en-US
To:     Halil Pasic <pasic@linux.ibm.com>
Cc:     linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, jjherne@linux.ibm.com,
        borntraeger@linux.ibm.com, frankja@linux.ibm.com,
        imbrenda@linux.ibm.com, david@redhat.com, mjrosato@linux.ibm.com
References: <20231026183250.254432-1-akrowiak@linux.ibm.com>
 <20231026183250.254432-3-akrowiak@linux.ibm.com>
 <20231027131904.165c7ad6.pasic@linux.ibm.com>
From:   Tony Krowiak <akrowiak@linux.ibm.com>
In-Reply-To: <20231027131904.165c7ad6.pasic@linux.ibm.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 10/27/23 07:19, Halil Pasic wrote:
> On Thu, 26 Oct 2023 14:32:44 -0400
> Tony Krowiak <akrowiak@linux.ibm.com> wrote:
> 
>> Since this scenario is very unlikely to happen and there is no status
>> response code to indicate an invalid ISC value, let's set the
> 
> Again invalid ISC won't happen except for hypervisor messes up.

Again, that is one of the checks performed by the kvm_s390_gisc_register
function; however, I get your point and will remove reference in the 
comment.

> 
>> response code to 06 indicating 'Invalid address of AP-queue notification
>> byte'. While this is not entirely accurate, it is better than indicating
>> that the ZONE/GISA designation is invalid which is something the guest
>> can do nothing about since those values are set by the hypervisor.
> 
> And more importantly AP_RESPONSE_INVALID_GISA is not valid for G2 in
> the given scenario, since G2 is not trying to set up interrupts on behalf
> of the G3 with a G3 GISA, but G2 is trying to set up interrupts for
> itself. And then AP_RESPONSE_INVALID_GISA is architecturally simply not
> a valid RC!

Got it.

> 
>>
>> Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
>> Suggested-by: Halil Pasic <pasic@linux.ibm.com>
> 
> Except for the explanation in the commit message, the patch is good. It
> is up to you if you want to fix the commit message or not.
> 

I'll fix the commit message.

> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>