similar to: [RFC PATCH 02/12] virtio/s390: DMA support for virtio-ccw

Currently virtio-ccw devices do not work if the device has VIRTIO_F_IOMMU_PLATFORM. In future we do want to support DMA API with virtio-ccw. Let us do the plumbing, so the feature VIRTIO_F_IOMMU_PLATFORM works with virtio-ccw. Let us also switch from legacy avail/used accessors to the DMA aware ones (even if it isn't strictly necessary), and remove the legacy accessors (we were the last

The CCW_CMD_SET_VQ command has a different format for revision 1+ devices, allowing to specify a more complex virtqueue layout. For now, we stay however with the old layout and simply use the new command format for virtio-1 devices. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/s390/kvm/virtio_ccw.c | 54 ++++++++++++++++++++++++++++++++--------- 1 file changed,

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

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

On Fri, 5 Apr 2019 01:16:11 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > The commit 2a2d1382fe9d ("virtio: Add improved queue allocation API") > establishes a new way of allocating virtqueues (as a part of the effort > that taught DMA to virtio rings). > > In the future we will want virtio-ccw to use the DMA API as well. > > Let us switch from the

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

From: Halil Pasic <pasic at linux.ibm.com> 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

From: Halil Pasic <pasic at linux.ibm.com> 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

On Tue, 9 Apr 2019 13:29:27 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > On Tue, 9 Apr 2019 11:57:43 +0200 > Cornelia Huck <cohuck at redhat.com> wrote: > > > On Fri, 5 Apr 2019 01:16:12 +0200 > > Halil Pasic <pasic at linux.ibm.com> wrote: > > > > > Currently we have a problem if a virtio-ccw device has > > >

The commit 2a2d1382fe9d ("virtio: Add improved queue allocation API") establishes a new way of allocating virtqueues (as a part of the effort that taught DMA to virtio rings). In the future we will want virtio-ccw to use the DMA API as well. Let us switch from the legacy method of allocating virtqueues to vring_create_virtqueue() as the first step into that direction. Signed-off-by:

From: Alexander Gordeev <agordeev at linux.ibm.com> [ Upstream commit 5fc5b94a273655128159186c87662105db8afeb5 ] This does not fix a real bug, since virtual addresses are currently indentical to physical ones. Reviewed-by: Nico Boehr <nrb at linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev at linux.ibm.com> Signed-off-by: Janosch Frank <frankja at linux.ibm.com>

From: Alexander Gordeev <agordeev at linux.ibm.com> [ Upstream commit 5fc5b94a273655128159186c87662105db8afeb5 ] This does not fix a real bug, since virtual addresses are currently indentical to physical ones. Reviewed-by: Nico Boehr <nrb at linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev at linux.ibm.com> Signed-off-by: Janosch Frank <frankja at linux.ibm.com>

On Tue, 9 Apr 2019 15:23:13 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > On Tue, 9 Apr 2019 15:01:20 +0200 > Cornelia Huck <cohuck at redhat.com> wrote: > > > On Tue, 9 Apr 2019 13:29:27 +0200 > > Halil Pasic <pasic at linux.ibm.com> wrote: > > > > > On Tue, 9 Apr 2019 11:57:43 +0200 > > > Cornelia Huck <cohuck at

On Mon, 13 May 2019 11:41:36 +0200 Cornelia Huck <cohuck at redhat.com> wrote: > On Fri, 26 Apr 2019 20:32:41 +0200 > Halil Pasic <pasic at linux.ibm.com> wrote: > > > As virtio-ccw devices are channel devices, we need to use the dma area > > for any communication with the hypervisor. > > > > This patch addresses the most basic stuff (mostly what is

On Wed, 15 May 2019 22:51:58 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > On Mon, 13 May 2019 11:41:36 +0200 > Cornelia Huck <cohuck at redhat.com> wrote: > > > On Fri, 26 Apr 2019 20:32:41 +0200 > > Halil Pasic <pasic at linux.ibm.com> wrote: > > > > > As virtio-ccw devices are channel devices, we need to use the dma area > >

On Wed, 15 May 2019 22:51:58 +0200 Halil Pasic <pasic at linux.ibm.com> wrote: > On Mon, 13 May 2019 11:41:36 +0200 > Cornelia Huck <cohuck at redhat.com> wrote: > > > On Fri, 26 Apr 2019 20:32:41 +0200 > > Halil Pasic <pasic at linux.ibm.com> wrote: > > > > > As virtio-ccw devices are channel devices, we need to use the dma area > >

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

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

As virtio-ccw devices are channel devices, we need to use the dma area for any communication with the hypervisor. This patch addresses the most basic stuff (mostly what is required for virtio-ccw), and does take care of QDIO or any devices. An interesting side effect is that virtio structures are now going to get allocated in 31 bit addressable storage. Signed-off-by: Halil Pasic <pasic at

For virtio-1, we can theoretically have a more complex virtqueue layout with avail and used buffers not on a contiguous memory area with the descriptor table. For now, it's fine for a transport driver to stay with the old layout: It needs, however, a way to access the locations of the avail/used rings so it can register them with the host. Reviewed-by: David Hildenbrand <dahi at