Fixing address of powerpc mailing list. Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> writes: > Hello, > > With Christoph's rework of the DMA API that recently landed, the patch > below is the only change needed in virtio to make it work in a POWER > secure guest under the ultravisor. > > The other change we need (making sure the device's dma_map_ops is NULL > so that the dma-direct/swiotlb code is used) can be made in > powerpc-specific code. > > Of course, I also have patches (soon to be posted as RFC) which hook up > <linux/mem_encrypt.h> to the powerpc secure guest support code. > > What do you think? > > From d0629a36a75c678b4a72b853f8f7f8c17eedd6b3 Mon Sep 17 00:00:00 2001 > From: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> > Date: Thu, 24 Jan 2019 22:08:02 -0200 > Subject: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted > > The host can't access the guest memory when it's encrypted, so using > regular memory pages for the ring isn't an option. Go through the DMA API. > > Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> > --- > drivers/virtio/virtio_ring.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index cd7e755484e3..321a27075380 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -259,8 +259,11 @@ static bool vring_use_dma_api(struct virtio_device *vdev) > * not work without an even larger kludge. Instead, enable > * the DMA API if we're a Xen guest, which at least allows > * all of the sensible Xen configurations to work correctly. > + * > + * Also, if guest memory is encrypted the host can't access > + * it directly. In this case, we'll need to use the DMA API. > */ > - if (xen_domain()) > + if (xen_domain() || sev_active()) > return true; > > return false; -- Thiago Jung Bauermann IBM Linux Technology Center _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
