From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH 09/10] virtio/s390: use DMA memory for ccw I/O and classic notifiers From: Pierre Morel References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-10-pasic@linux.ibm.com> Date: Thu, 9 May 2019 15:30:08 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit Message-Id: Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Halil Pasic , kvm@vger.kernel.org, linux-s390@vger.kernel.org, Cornelia Huck , Martin Schwidefsky , Sebastian Ott Cc: virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman List-ID: On 08/05/2019 16:46, Pierre Morel wrote: > On 26/04/2019 20:32, Halil Pasic wrote: >> Before virtio-ccw could get away with not using DMA API for the pieces of >> memory it does ccw I/O with. With protected virtualization this has to >> change, since the hypervisor needs to read and sometimes also write these >> pieces of memory. >> >> The hypervisor is supposed to poke the classic notifiers, if these are >> used, out of band with regards to ccw I/O. So these need to be allocated >> as DMA memory (which is shared memory for protected virtualization >> guests). >> >> Let us factor out everything from struct virtio_ccw_device that needs to >> be DMA memory in a satellite that is allocated as such. >> ... >> +                       sizeof(indicators(vcdev))); > > should be sizeof(long) ? > > This is a recurrent error, but it is not an issue because the size of > the indicators is unsigned long as the size of the pointer. > > Regards, > Pierre > Here too, with the problem of the indicator size handled: Reviewed-by: Pierre Morel -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany