On Thu, 19 Nov 2020 17:57:28 +0100 Eric Farman <[email protected]> wrote:
> If, for example, we boot off a virtio device and chreipl to a vfio-ccw > device, the space at lowcore will be non-zero. We build a Read IPL CCW > at address zero, but it will have leftover PSW data that will conflict > with the Format-0 CCW being generated: > > 0x0: 00080000 80010000 > ------ Ccw0.cda > -- Ccw0.chainData > -- Reserved bits > > The data address will be overwritten with the correct value (0x0), but > the apparent data chain bit will cause subsequent memory to be used as > the target of the data store, which may not be where we expect (0x0). > > Clear out this space when we boot from DASD, so that we know it exists > exactly as we expect. > > Signed-off-by: Eric Farman <[email protected]> > Reviewed-by: Jason J. Herne <[email protected]> > Acked-by: Christian Borntraeger <[email protected]> > --- > pc-bios/s390-ccw/dasd-ipl.c | 3 +++ > 1 file changed, 3 insertions(+) Acked-by: Cornelia Huck <[email protected]>
