From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v8 09/22] s390: vfio-ap: register matrix device with VFIO mdev framework Date: Thu, 9 Aug 2018 18:27:16 +0200 Message-ID: References: <1533739472-7172-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1533739472-7172-10-git-send-email-akrowiak@linux.vnet.ibm.com> <20180809130607.32781b72.cohuck@redhat.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.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, frankja@linux.ibm.com, Tony Krowiak To: Cornelia Huck , Tony Krowiak Return-path: In-Reply-To: <20180809130607.32781b72.cohuck@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 09/08/2018 13:06, Cornelia Huck wrote: > On Wed, 8 Aug 2018 10:44:19 -0400 > Tony Krowiak wrote: > >> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c >> index d7e39ad..6a827f3 100644 >> --- a/drivers/s390/crypto/vfio_ap_drv.c >> +++ b/drivers/s390/crypto/vfio_ap_drv.c >> @@ -12,6 +12,7 @@ >> #include >> #include >> #include >> +#include >> #include "vfio_ap_private.h" >> >> #define VFIO_AP_ROOT_NAME "vfio_ap" >> @@ -68,6 +69,18 @@ static int vfio_ap_matrix_dev_create(void) >> { >> int ret; >> >> + mutex_init(&matrix_dev.lock); >> + INIT_LIST_HEAD(&matrix_dev.mdev_list); >> + >> + /* Test if PQAP(QCI) instruction is available */ >> + if (test_facility(12)) { >> + ret = ap_qci(&matrix_dev.info); >> + if (ret) >> + return ret; >> + } >> + >> + atomic_set(&matrix_dev.available_instances, MAX_ZDEV_ENTRIES_EXT); >> + >> ret = misc_register(&matrix_dev.misc_dev); > OK, you are adding more stuff other than the miscdevice after all... > still, I don't think that this is a good idea. > > I think I had already asked this for a previous version: Why has this > been turned into a miscdevice? (I think my reaction to the answer was > 'meh'... but I think more and more that we should not do that.) Following our off-line conversation... I understand your concern, about the misc device and dynamically updating the misc device structure. For it is your main point of contention and we do not currently have a use case for the misc device I propose we just let it go and rebase on the device design we had in V6 and did not seem to make any trouble to any one. We will propose a v9 with the integration of all comment done so far soon as possible. Best regards, Pierre > >> if (ret) >> return ret; -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany