From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Date: Mon, 30 Jul 2018 12:46:23 +0000 Subject: Re: [PATCH v7 06/22] s390/zcrypt: Support for apmask and aqmask change on live system Message-Id: <20180730144623.254a076e.cohuck@redhat.com> In-Reply-To: <20180726195429.31960-7-borntraeger@de.ibm.com> References: <20180726195429.31960-7-borntraeger@de.ibm.com> To: linux-s390@vger.kernel.org, kvm@vger.kernel.org List-ID: On Thu, 26 Jul 2018 21:54:13 +0200 Christian Borntraeger wrote: > From: Harald Freudenberger > > This patch enables modifications of the apmask and aqmask on a live > system. Until now these both masks are read-only on a live system. The > only way to change these masks was via kernel command line parameter. > > This patch makes the sysfs attributes /sys/bus/ap/apmask and > /sys/bus/ap/aqmask writeable by root. With changing the mask(s) a > revision of the existing queue to driver bindings is done. So all > APQNs which are bound to the 'wrong' driver are reprobed via kernel > function device_reprobe() and thus the new correct driver will be > assigned with respect of the changed apmask and aqmask bits. The expected input for those attributes needs to be documented. IIRC the vfio-ap driver does not support device removal in the first shot. So, what happens if an APQN is added to the reserved set? BUG()? > > Signed-off-by: Harald Freudenberger > Signed-off-by: Christian Borntraeger > --- > drivers/s390/crypto/ap_bus.c | 153 ++++++++++++++++++++++++++++++++--- > 1 file changed, 143 insertions(+), 10 deletions(-)