On Tue, 20 Oct 2020 09:18:48 +0300 "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> wrote: > VirtIO for KVM is a primary way to provide IO. All memory that used for > communication with the host has to be marked as shared. > > The easiest way to archive that is to use DMA API that already knows how > to deal with shared memory. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > --- > drivers/virtio/virtio_ring.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index becc77697960..ace733845d5d 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -12,6 +12,7 @@ > #include <linux/hrtimer.h> > #include <linux/dma-mapping.h> > #include <xen/xen.h> > +#include <asm/kvm_para.h> > > #ifdef DEBUG > /* For development, we want to crash whenever the ring is screwed. */ > @@ -255,6 +256,9 @@ static bool vring_use_dma_api(struct virtio_device *vdev) > if (xen_domain()) > return true; > > + if (kvm_mem_protected()) > + return true; > + I guess it does not matter because Christophs comment, but this breaks the build for s390, because there is no kvm_mem_protected() for s390. Regards, Halil > return false; > } >
