On Wed, Sep 23, 2015 at 08:55:01PM +0200, Laurent Vivier wrote:
>
>
> On 17/09/2015 15:09, David Gibson wrote:
> > At present the PCI host bridge (PHB) for the pseries machine type has a
> > fixed DMA window from 0..1GB (in PCI address space) which is mapped to real
> > memory via the PAPR paravirtualized IOMMU.
> >
> > For better support of VFIO devices, we're going to want to allow for
> > different configurations of the DMA window.
> >
> > Eventually we'll want to allow the guest itself to reconfigure the window
> > via the PAPR dynamic DMA window interface, but as a preliminary this patch
> > allows the user to reconfigure the window with new properties on the PHB
> > device.
> >
> > Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> > ---
> > hw/ppc/spapr_pci.c | 7 +++++--
> > include/hw/pci-host/spapr.h | 3 +--
> > 2 files changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index b088491..622c4ac 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -1394,7 +1394,7 @@ static void spapr_phb_finish_realize(sPAPRPHBState
> > *sphb, Error **errp)
> > sPAPRTCETable *tcet;
> > uint32_t nb_table;
> >
> > - nb_table = SPAPR_PCI_DMA32_SIZE >> SPAPR_TCE_PAGE_SHIFT;
> > + nb_table = sphb->dma_win_size >> SPAPR_TCE_PAGE_SHIFT;
> > tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn,
> > 0, SPAPR_TCE_PAGE_SHIFT, nb_table, false);
> > if (!tcet) {
> > @@ -1404,7 +1404,7 @@ static void spapr_phb_finish_realize(sPAPRPHBState
> > *sphb, Error **errp)
> > }
> >
> > /* Register default 32bit DMA window */
> > - memory_region_add_subregion(&sphb->iommu_root, 0,
> > + memory_region_add_subregion(&sphb->iommu_root, sphb->dma_win_addr,
> > spapr_tce_get_iommu(tcet));
> > }
> >
> > @@ -1437,6 +1437,9 @@ static Property spapr_phb_properties[] = {
> > SPAPR_PCI_IO_WIN_SIZE),
> > DEFINE_PROP_BOOL("dynamic-reconfiguration", sPAPRPHBState, dr_enabled,
> > true),
> > + /* Default DMA window is 0..1GB */
> > + DEFINE_PROP_UINT64("dma_win_addr", sPAPRPHBState, dma_win_addr, 0),
> > + DEFINE_PROP_UINT64("dma_win_size", sPAPRPHBState, dma_win_size,
> > 0x40000000),
> > DEFINE_PROP_END_OF_LIST(),
> > };
>
> Add them too to the vmstate_spapr_pci ?
No. At least, not just now.
This is the sort of configuration information that typically isn't
migrated, instead requiring the far end to be set up matching. Which
is a problem, but not one within the scope of this patch series. In
any case just transferring the values wouldn't be enough - we'd need
post_load handlers to actually rewire the TCE table accordingly.
We will need to do this once we add dynamic DMA window support, but
again, not in scope just now.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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