On Wed, 25 Feb 2015 14:50:22 +1030 Rusty Russell <rusty@xxxxxxxxxxxxxxx> wrote: > OK, I am trying to experiment with virtio 1.0 support using the > latest kernel and MST's qemu tree: > > https://git.kernel.org/cgit/virt/kvm/mst/qemu.git/?h=virtio-1.0 > > The first issue is that the device config endian was wrong (see > attached patch). > > I'm now setting up a BE guest on my x86 laptop, and a BE and LE guest > on a BE powerpc machine, to check that all combinations work correctly. > If others test too, that would be appreciated! My virtio-1 work had been taking the back seat recently, but I plan to look into it again soon. > > Cheers, > Rusty. > > From 95ac91554ed602f856a2a5fcc25eaffcad1b1c8d Mon Sep 17 00:00:00 2001 > From: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Date: Tue, 24 Feb 2015 14:47:44 +1030 > Subject: [PATCH] virtio_config_write*/virtio_config_read*: Don't endian swap > for virtio 1.0. Ah, virtio-ccw doesn't use these config space accessors, that's why I did not look at them. > > Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 079944c..882a31b 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -662,7 +662,12 @@ uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr) > > k->get_config(vdev, vdev->config); > > - val = lduw_p(vdev->config + addr); > + /* Virtio 1.0 is always LE */ > + if (virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { > + val = lduw_le_p(vdev->config + addr); > + } else { > + val = lduw_p(vdev->config + addr); > + } Can't you use the virtio_* helpers for that? > return val; > } > <looks at the callers> It seems virtio-pci does some conditional swapping based on virtio-endianness already, which should account for virtio-1. virtio-mmio does not seem to do so. But: Device code accessing config space already does use the virtio accessors - or virtio-ccw would not work as it simply copies the whole config space. So it seems this change simply undos the endian swap in virtio-pci (while probably breaking virtio-mmio). Can we simply get rid of the endian swap in virtio-pci instead, or have I been throuroughly confused? _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
