On Fri, 26 Apr 2019 20:32:44 +0200 Halil Pasic <pa...@linux.ibm.com> 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. > > Note: The control blocks of I/O instructions do not need to be shared. > These are marshalled by the ultravisor. > > Signed-off-by: Halil Pasic <pa...@linux.ibm.com> > --- > drivers/s390/virtio/virtio_ccw.c | 177 > +++++++++++++++++++++------------------ > 1 file changed, 96 insertions(+), 81 deletions(-) > > @@ -176,6 +180,22 @@ static struct virtio_ccw_device *to_vc_device(struct > virtio_device *vdev) > return container_of(vdev, struct virtio_ccw_device, vdev); > } > > +static inline void *__vc_dma_alloc(struct virtio_device *vdev, size_t size) > +{ > + return ccw_device_dma_zalloc(to_vc_device(vdev)->cdev, size); > +} > + > +static inline void __vc_dma_free(struct virtio_device *vdev, size_t size, > + void *cpu_addr) > +{ > + return ccw_device_dma_free(to_vc_device(vdev)->cdev, cpu_addr, size); > +} Hm, why do these use leading underscores? Also, maybe make the _free function safe for NULL to simplify the cleanup paths? > + > +#define vc_dma_alloc_struct(vdev, ptr) \ > + ({ptr = __vc_dma_alloc(vdev, sizeof(*(ptr))); }) > +#define vc_dma_free_struct(vdev, ptr) \ > + __vc_dma_free(vdev, sizeof(*(ptr)), (ptr)) I find these a bit ugly... does adding a wrapper help that much? > + > static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info) > { > unsigned long i, flags; _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization