lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 13 Mar 2019 11:15:20 +0100 From: Pierre Morel <pmorel@...ux.ibm.com> To: Tony Krowiak <akrowiak@...ux.ibm.com>, borntraeger@...ibm.com Cc: alex.williamson@...hat.com, cohuck@...hat.com, linux-kernel@...r.kernel.org, linux-s390@...r.kernel.org, kvm@...r.kernel.org, frankja@...ux.ibm.com, pasic@...ux.ibm.com, david@...hat.com, schwidefsky@...ibm.com, heiko.carstens@...ibm.com, freude@...ux.ibm.com, mimu@...ux.ibm.com Subject: Re: [PATCH v4 6/7] s390: ap: Cleanup on removing the AP device On 12/03/2019 22:53, Tony Krowiak wrote: > On 3/11/19 4:31 AM, Pierre Morel wrote: >> On 08/03/2019 23:43, Tony Krowiak wrote: >>> On 2/22/19 10:29 AM, Pierre Morel wrote: >>>> When the device is remove, we must make sure to >>>> clear the interruption and reset the AP device. >>>> >>>> We also need to clear the CRYCB of the guest. >>>> >>>> Signed-off-by: Pierre Morel <pmorel@...ux.ibm.com> >>>> --- >>>> drivers/s390/crypto/vfio_ap_drv.c | 35 >>>> +++++++++++++++++++++++++++++++++++ >>>> drivers/s390/crypto/vfio_ap_ops.c | 3 ++- >>>> drivers/s390/crypto/vfio_ap_private.h | 3 +++ >>>> 3 files changed, 40 insertions(+), 1 deletion(-) >>>> ...snip... >>>> + * vfio_ap_update_crycb >>>> + * @q: A pointer to the queue being removed >>>> + * >>>> + * We clear the APID of the queue, making this queue unusable for >>>> the guest. >>>> + * After this function we can reset the queue without to fear a >>>> race with >>>> + * the guest to access the queue again. >>>> + * We do not fear race with the host as we still get the devic >>>> + */ >>>> +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) >>>> +{ >>>> + struct ap_matrix_mdev *matrix_mdev = q->matrix_mdev; >>>> + >>>> + if (!matrix_mdev) >>>> + return; >>>> + > > You should probably check whether the APID has been cleared before > proceeding. Take the case where an AP with multiple queues is removed > from the configuration via the SE or SCLP. The AP bus is going to invoke > the vfio_ap_queue_dev_remove() function for each of the queues. The APID > will get cleared on the first remove, so it is not only unnecessary to > clear it on subsequent removes, it is kind of nasty to keep resetting > the masks in the guest's CRYCB (below) each time the remove callback is > invoked. This can not happen. The only way to clear the APM is when the matrix is not associated with KVM. This case is tested and the masks are not changed. > >>>> + clear_bit_inv(AP_QID_CARD(q->apqn), matrix_mdev->matrix.apm); >>>> + >>>> + if (!matrix_mdev->kvm) >>>> + return; >>>> + >>>> + kvm_arch_crypto_set_masks(matrix_mdev->kvm, >>>> + matrix_mdev->matrix.apm, >>>> + matrix_mdev->matrix.aqm, >>>> + matrix_mdev->matrix.adm); >>>> +} -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany
Powered by blists - more mailing lists