From mboxrd@z Thu Jan 1 00:00:00 1970 From: Halil Pasic Subject: Re: [PATCH v4 4/7] vfio: ap: register IOMMU VFIO notifier Date: Thu, 28 Feb 2019 17:55:13 +0100 Message-ID: <20190228175513.06504ae6@oc2783563651> References: <1550849400-27152-1-git-send-email-pmorel@linux.ibm.com> <1550849400-27152-5-git-send-email-pmorel@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Pierre Morel Cc: Christian Borntraeger , alex.williamson@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com List-ID: On Thu, 28 Feb 2019 09:48:39 +0100 Pierre Morel wrote: > On 28/02/2019 09:23, Christian Borntraeger wrote: > > On 22.02.2019 16:29, Pierre Morel wrote: > >> To be able to use the VFIO interface to facilitate the > >> mediated device memory pining/unpining we need to register > >> a notifier for IOMMU. > > > > You might want to add that while we start to pin one guest page for the > > interrupt indicator byte in the next patch, this is still ok with ballooning > > as this page will never be used by the guest virtio-balloon driver. So the > > pinned page will never be freed. And even a broken guest does so, that would > > not impact the host as the original page is still in control by vfio. > > > > Thanks, I ll do. > I recall a comment in qemu that says vfio-ap does not pin any pages. That one needs to be fixed up as well. Regards, Halil [..]