On Wed, May 04, 2016 at 04:52:20PM +1000, Alexey Kardashevskiy wrote: > Currently TCE tables are created once at start and their sizes never > change. We are going to change that by introducing a Dynamic DMA windows > support where DMA configuration may change during the guest execution. > > This changes spapr_tce_new_table() to create an empty zero-size IOMMU > memory region (IOMMU MR). Only LIOBN is assigned by the time of creation. > It still will be called once at the owner object (VIO or PHB) creation. > > This introduces an "enabled" state for TCE table objects with two > helper functions - spapr_tce_table_enable()/spapr_tce_table_disable(). > - spapr_tce_table_enable() receives TCE table parameters, allocates > a guest view of the TCE table (in the user space or KVM) and > sets the correct size on the IOMMU MR. > - spapr_tce_table_disable() disposes the table and resets the IOMMU MR > size. > > This changes the PHB reset handler to do the default DMA initialization > instead of spapr_phb_realize(). This does not make differenct now but > later with more than just one DMA window, we will have to remove them all > and create the default one on a system reset. > > No visible change in behaviour is expected except the actual table > will be reallocated every reset. We might optimize this later. > > The other way to implement this would be dynamically create/remove > the TCE table QOM objects but this would make migration impossible > as the migration code expects all QOM objects to exist at the receiver > so we have to have TCE table objects created when migration begins. > > spapr_tce_table_do_enable() is separated from from spapr_tce_table_enable() > as later it will be called at the sPAPRTCETable post-migration stage when > it already has all the properties set after the migration; the same is > done for spapr_tce_table_disable(). > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> > --- > Changes: > v15: > * made adjustments after removing spapr_phb_dma_window_enable() > > v14: > * added spapr_tce_table_do_disable(), will make difference in following > patch with fully dynamic table migration > > # Conflicts: > # hw/ppc/spapr_pci.c > --- > hw/ppc/spapr_iommu.c | 86 > ++++++++++++++++++++++++++++++++++++-------------- > hw/ppc/spapr_pci.c | 8 +++-- > hw/ppc/spapr_vio.c | 8 ++--- > include/hw/ppc/spapr.h | 10 +++--- > 4 files changed, 75 insertions(+), 37 deletions(-) > > diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c > index 8132f64..9bcd3f6 100644 > --- a/hw/ppc/spapr_iommu.c > +++ b/hw/ppc/spapr_iommu.c > @@ -17,6 +17,7 @@ > * License along with this library; if not, see > <http://www.gnu.org/licenses/>. > */ > #include "qemu/osdep.h" > +#include "qemu/error-report.h" > #include "hw/hw.h" > #include "sysemu/kvm.h" > #include "hw/qdev.h" > @@ -174,15 +175,9 @@ static int spapr_tce_table_realize(DeviceState *dev) > sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev); > > tcet->fd = -1; > - tcet->table = spapr_tce_alloc_table(tcet->liobn, > - tcet->page_shift, > - tcet->nb_table, > - &tcet->fd, > - tcet->need_vfio); > - > + tcet->need_vfio = false; > memory_region_init_iommu(&tcet->iommu, OBJECT(dev), &spapr_iommu_ops, > - "iommu-spapr", > - (uint64_t)tcet->nb_table << tcet->page_shift); > + "iommu-spapr", 0); > > QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list); > > @@ -224,14 +219,10 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool > need_vfio) > tcet->table = newtable; > } > > -sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn, > - uint64_t bus_offset, > - uint32_t page_shift, > - uint32_t nb_table, > - bool need_vfio) > +sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn) > { > sPAPRTCETable *tcet; > - char tmp[64]; > + char tmp[32]; > > if (spapr_tce_find_by_liobn(liobn)) { > fprintf(stderr, "Attempted to create TCE table with duplicate" > @@ -239,16 +230,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, > uint32_t liobn, > return NULL; > } > > - if (!nb_table) { > - return NULL; > - } > - > tcet = SPAPR_TCE_TABLE(object_new(TYPE_SPAPR_TCE_TABLE)); > tcet->liobn = liobn; > - tcet->bus_offset = bus_offset; > - tcet->page_shift = page_shift; > - tcet->nb_table = nb_table; > - tcet->need_vfio = need_vfio; > > snprintf(tmp, sizeof(tmp), "tce-table-%x", liobn); > object_property_add_child(OBJECT(owner), tmp, OBJECT(tcet), NULL); > @@ -258,14 +241,69 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, > uint32_t liobn, > return tcet; > } > > +static void spapr_tce_table_do_enable(sPAPRTCETable *tcet) > +{ > + if (!tcet->nb_table) { > + return; > + } > + > + tcet->table = spapr_tce_alloc_table(tcet->liobn, > + tcet->page_shift, > + tcet->nb_table, > + &tcet->fd, > + tcet->need_vfio); > + > + memory_region_set_size(&tcet->iommu, > + (uint64_t)tcet->nb_table << tcet->page_shift); > + > + tcet->enabled = true; > +} > + > +void spapr_tce_table_enable(sPAPRTCETable *tcet, > + uint32_t page_shift, uint64_t bus_offset, > + uint32_t nb_table) > +{ > + if (tcet->enabled) { > + error_report("Warning: trying to enable already enabled TCE table"); > + return; > + } > + > + tcet->bus_offset = bus_offset; > + tcet->page_shift = page_shift; > + tcet->nb_table = nb_table; > + > + spapr_tce_table_do_enable(tcet); > +} > + > +static void spapr_tce_table_do_disable(sPAPRTCETable *tcet) > +{ > + memory_region_set_size(&tcet->iommu, 0); > + > + spapr_tce_free_table(tcet->table, tcet->fd, tcet->nb_table); > + tcet->fd = -1; > + tcet->table = NULL; > + tcet->enabled = false; > + tcet->bus_offset = 0; > + tcet->page_shift = 0; > + tcet->nb_table = 0; > +} > + > +static void spapr_tce_table_disable(sPAPRTCETable *tcet) > +{ > + if (!tcet->enabled) { > + error_report("Warning: trying to disable already disabled TCE > table"); > + return; > + } > + spapr_tce_table_do_disable(tcet); > +} > + > static void spapr_tce_table_unrealize(DeviceState *dev, Error **errp) > { > sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev); > > QLIST_REMOVE(tcet, list); > > - spapr_tce_free_table(tcet->table, tcet->fd, tcet->nb_table); > - tcet->fd = -1; > + spapr_tce_table_disable(tcet);
This should probably be do_disable(), or you'll get a spurious error
if you start and stop a VM but don't enable the table in between, or
if the guest disables all the tables before the shutdown.
> }
>
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet)
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 742d127..beeac06 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -1464,8 +1464,7 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> }
>
> 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);
> + tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn);
> if (!tcet) {
> error_setg(errp, "Unable to create TCE table for %s",
> sphb->dtbusname);
> @@ -1473,7 +1472,10 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
> }
>
> /* Register default 32bit DMA window */
> - memory_region_add_subregion(&sphb->iommu_root, sphb->dma_win_addr,
> + spapr_tce_table_enable(tcet, SPAPR_TCE_PAGE_SHIFT, sphb->dma_win_addr,
> + nb_table);
> +
> + memory_region_add_subregion(&sphb->iommu_root, tcet->bus_offset,
> spapr_tce_get_iommu(tcet));
>
> sphb->msi = g_hash_table_new_full(g_int_hash, g_int_equal, g_free,
> g_free);
> diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c
> index 8aa021f..a7d49a0 100644
> --- a/hw/ppc/spapr_vio.c
> +++ b/hw/ppc/spapr_vio.c
> @@ -482,11 +482,9 @@ static void spapr_vio_busdev_realize(DeviceState *qdev,
> Error **errp)
> memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass,
> 1);
> address_space_init(&dev->as, &dev->mrroot, qdev->id);
>
> - dev->tcet = spapr_tce_new_table(qdev, liobn,
> - 0,
> - SPAPR_TCE_PAGE_SHIFT,
> - pc->rtce_window_size >>
> - SPAPR_TCE_PAGE_SHIFT, false);
> + dev->tcet = spapr_tce_new_table(qdev, liobn);
> + spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
> + pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT);
> dev->tcet->vdev = dev;
> memory_region_add_subregion_overlap(&dev->mrroot, 0,
> spapr_tce_get_iommu(dev->tcet),
> 2);
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 815d5ee..0140810 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -534,6 +534,7 @@ typedef struct sPAPRTCETable sPAPRTCETable;
>
> struct sPAPRTCETable {
> DeviceState parent;
> + bool enabled;
> uint32_t liobn;
> uint32_t nb_table;
> uint64_t bus_offset;
> @@ -561,11 +562,10 @@ void spapr_events_fdt_skel(void *fdt, uint32_t
> epow_irq);
> int spapr_h_cas_compose_response(sPAPRMachineState *sm,
> target_ulong addr, target_ulong size,
> bool cpu_update, bool memory_update);
> -sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
> - uint64_t bus_offset,
> - uint32_t page_shift,
> - uint32_t nb_table,
> - bool need_vfio);
> +sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn);
> +void spapr_tce_table_enable(sPAPRTCETable *tcet,
> + uint32_t page_shift, uint64_t bus_offset,
> + uint32_t nb_table);
> void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool need_vfio);
>
> MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet);
--
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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