From mboxrd@z Thu Jan 1 00:00:00 1970 From: Halil Pasic Subject: Re: [PATCH v6 13/21] s390: vfio-ap: sysfs interface to view matrix mdev matrix Date: Fri, 13 Jul 2018 18:38:52 +0200 Message-ID: <58a2b2c3-59a0-77d1-50d3-8fad5237d2d8@linux.ibm.com> References: <1530306683-7270-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1530306683-7270-14-git-send-email-akrowiak@linux.vnet.ibm.com> <2ebe297c-79e7-1cfd-05a9-1ab8943a0203@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <2ebe297c-79e7-1cfd-05a9-1ab8943a0203@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Tony Krowiak , pmorel@linux.ibm.com, Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com List-ID: On 07/13/2018 02:24 PM, Tony Krowiak wrote: > On 07/09/2018 04:38 PM, Pierre Morel wrote: >> On 09/07/2018 14:20, Pierre Morel wrote: >>> On 29/06/2018 23:11, Tony Krowiak wrote: >>>> Provides a sysfs interface to view the AP matrix configured for the >>>> mediated matrix device. >>>> >>>> The relevant sysfs structures are: >>>> >>>> /sys/devices/vfio_ap >>>> ... [matrix] >>>> ...... [mdev_supported_types] >>>> ......... [vfio_ap-passthrough] >>>> ............ [devices] >>>> ...............[$uuid] >>>> .................. matrix >>>> >>>> To view the matrix configured for the mediated matrix device, >>>> print the matrix file: >>>> >>>>     cat matrix >>>> >>>> Signed-off-by: Tony Krowiak >>>> --- >>>>   drivers/s390/crypto/vfio_ap_ops.c |   31 +++++++++++++++++++++++++++++++ >>>>   1 files changed, 31 insertions(+), 0 deletions(-) >>>> >>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c >>>> index c8f31f3..bc7398d 100644 >>>> --- a/drivers/s390/crypto/vfio_ap_ops.c >>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c >>>> @@ -697,6 +697,36 @@ static ssize_t control_domains_show(struct device *dev, >>>>   } >>>>   DEVICE_ATTR_RO(control_domains); >>>> >>>> +static ssize_t matrix_show(struct device *dev, struct device_attribute *attr, >>>> +               char *buf) >>>> +{ >>>> +    struct mdev_device *mdev = mdev_from_dev(dev); >>>> +    struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev); >>>> +    char *bufpos = buf; >>>> +    unsigned long apid; >>>> +    unsigned long apqi; >>>> +    unsigned long napm = matrix_mdev->matrix.apm_max + 1; >>>> +    unsigned long naqm = matrix_mdev->matrix.aqm_max + 1; >>>> +    int nchars = 0; >>>> +    int n; >>>> + >>>> +    for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm) { >>>> +        n = sprintf(bufpos, "%02lx\n", apid); >>>> +        bufpos += n; >>>> +        nchars += n; >>>> + >>>> +        for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, naqm) { >>>> +            n = sprintf(bufpos, "%02lx.%04lx\n", apid, apqi); >>>> +            bufpos += n; >>>> +            nchars += n; >>>> +        } >>>> +    } >>>> + >>>> +    return nchars; >>>> +} >>>> +DEVICE_ATTR_RO(matrix); >>>> + >>>> + >>>>   static struct attribute *vfio_ap_mdev_attrs[] = { >>>>       &dev_attr_assign_adapter.attr, >>>>       &dev_attr_unassign_adapter.attr, >>>> @@ -705,6 +735,7 @@ static ssize_t control_domains_show(struct device *dev, >>>>       &dev_attr_assign_control_domain.attr, >>>>       &dev_attr_unassign_control_domain.attr, >>>>       &dev_attr_control_domains.attr, >>>> +    &dev_attr_matrix.attr, >>>>       NULL, >>>>   }; >>>> >>> >>> I have still the same remark: what you show here is not what is currently >>> used by the SIE. >>> It is not irrelevant but what the guest really use may be more interesting >>> for the admin. >>> >>> >> OK, you implement the right view it in patch 16/21. >> >> Still, what is the purpose of showing this view? > > I find it to have great value when configuring the mdev. It provides a view of > what has been configured thus far. > IMHO we need to keep this view for the reason stated by Tony. Halil