Received-SPF: pass (google.com: domain of linux-kernel+bounces-22450-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Message-ID: <41baa1b2-4afd-9adb-2121-b14c8943d9b1@linux.ibm.com>
Date: Wed, 10 Jan 2024 10:44:40 -0500
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH v2 6/6] s390/vfio-ap: do not reset queue removed from host
 config
To: Tony Krowiak <akrowiak@linux.ibm.com>, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: borntraeger@de.ibm.com, pasic@linux.ibm.com, pbonzini@redhat.com,
        frankja@linux.ibm.com, imbrenda@linux.ibm.com,
        alex.williamson@redhat.com, kwankhede@nvidia.com,
        stable@vger.kernel.org
References: <20231212212522.307893-1-akrowiak@linux.ibm.com>
 <20231212212522.307893-7-akrowiak@linux.ibm.com>
Content-Language: en-US
From: "Jason J. Herne" <jjherne@linux.ibm.com>
In-Reply-To: <20231212212522.307893-7-akrowiak@linux.ibm.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit


On 12/12/23 4:25 PM, Tony Krowiak wrote:
> When a queue is unbound from the vfio_ap device driver, it is reset to
> ensure its crypto data is not leaked when it is bound to another device
> driver. If the queue is unbound due to the fact that the adapter or domain
> was removed from the host's AP configuration, then attempting to reset it
> will fail with response code 01 (APID not valid) getting returned from the
> reset command. Let's ensure that the queue is assigned to the host's
> configuration before resetting it.
> 
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Fixes: eeb386aeb5b7 ("s390/vfio-ap: handle config changed and scan complete notification")
> Cc: <stable@vger.kernel.org>
> ---
>   drivers/s390/crypto/vfio_ap_ops.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index e014108067dc..84decb0d5c97 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -2197,6 +2197,8 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
>   	q = dev_get_drvdata(&apdev->device);
>   	get_update_locks_for_queue(q);
>   	matrix_mdev = q->matrix_mdev;
> +	apid = AP_QID_CARD(q->apqn);
> +	apqi = AP_QID_QUEUE(q->apqn);
>   
>   	if (matrix_mdev) {
>   		/* If the queue is assigned to the guest's AP configuration */
> @@ -2214,8 +2216,16 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev)
>   		}
>   	}
>   
> -	vfio_ap_mdev_reset_queue(q);
> -	flush_work(&q->reset_work);
> +	/*
> +	 * If the queue is not in the host's AP configuration, then resetting
> +	 * it will fail with response code 01, (APQN not valid); so, let's make
> +	 * sure it is in the host's config.
> +	 */
> +	if (test_bit_inv(apid, (unsigned long *)matrix_dev->info.apm) &&
> +	    test_bit_inv(apqi, (unsigned long *)matrix_dev->info.aqm)) {
> +		vfio_ap_mdev_reset_queue(q);
> +		flush_work(&q->reset_work);
> +	}
>   
>   done:
>   	if (matrix_mdev)

Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>