Currently the pseries machine emulation does not support DMA for emulated
PCI devices, because the PAPR spec always requires a (guest visible,
paravirtualized) IOMMU which was not implemented. Now that we have
infrastructure for IOMMU emulation, we can correct this and allow PCI DMA
for pseries.
With the existing PAPR IOMMU code used for VIO devices, this is almost
trivial. We use a single DMAContext for each (virtual) PCI host bridge,
which is the usual configuration on real PAPR machines (which often have
_many_ PCI host bridges).
Cc: Alex Graf <agraf@suse.de>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Currently the pseries PCI code uses a somewhat strange scheme of PCI irq
allocation - one per slot up to a maximum that's greater than the usual 4.
This scheme more or less worked, because we were able to tell the guest the
irq mapping in the device tree, however it's a bit odd and may break
assumptions in the future. Worse, the array used to construct the dev
tree interrupt map was mis-sized, we got away with it only because it
happened that our SPAPR_PCI_NUM_LSI value was greater than 7.
This patch changes the pseries PCI code to use the same interrupt swizzling
scheme as is standardized for PCI to PCI bridges. This makes for better
consistency, deals better with any devices which use multiple interrupt
pins and will make life easier in the future when we add passthrough of
what may be either a host bridge or a PCI to PCI bridge. This won't break
existing guests, because they don't assume a particular mapping scheme for
host bridges, but just follow what we tell them in the device tree (also
updated to match, of course). This patch also fixes the allocation of the
irq map.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently, the function spapr_create_phb() uses its parameters to
initialize the correct memory windows for the new PCI Host Bridge
(PHB). This is not the way things are supposed to be done with qdevs,
and means you can't create extra PHBs easily using -device.
Since pSeries machines can and do have many PHBs with various
configurations, this is a real limitation, not just a theoretical.
This patch, therefore, alters the PHB initialization code to use qdev
properties to set these parameters of the new bridge, moving most of
the code from spapr_create_phb() to spapr_phb_init().
While we're at it, we change the naming of each PCI bus and its
associated memory regions to be less arbitrary and make it easier to
relate the guest and qemu views of memory to each other.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds a PCI bus to the pseries machine. This instantiates
the qemu generic PCI bus code, advertises a PCI host bridge in the
guest's device tree and implements the RTAS methods specified by PAPR
to access PCI config space. It also sets up the memory regions we
need to provide windows into the PCI memory and IO space, and
advertises those to the guest.
However, because qemu can't yet emulate an IOMMU, which is mandatory on
pseries, PCI devices which use DMA (i.e. most of them) will not work with
this code alone. Still, this is enough to support the virtio_pci device
(which probably _should_ use emulated PCI DMA, but is specced to use
direct hypervisor access to guest physical memory instead).
[agraf] remove typedef which could cause compile errors
Signed-off-by: Alexey Kardashevskiy <aik@au1.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
