We are going to have multiple DMA windows at different offsets on
a PCI bus. For the sake of migration, we will have as many TCE table
objects pre-created as many windows supported.
So we need a way to map windows dynamically onto a PCI bus
when migration of a table is completed but at this stage a TCE table
object does not have access to a PHB to ask it to map a DMA window
backed by just migrated TCE table.
This adds a "root" memory region (UINT64_MAX long) to the TCE object.
This new region is mapped on a PCI bus with enabled overlapping as
there will be one root MR per TCE table, each of them mapped at 0.
The actual IOMMU memory region is a subregion of the root region and
a TCE table enables/disables this subregion and maps it at
the specific offset inside the root MR which is 1:1 mapping of
a PCI address space.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
hw/ppc/spapr_iommu.c | 9 ++++++++-
include/hw/ppc/spapr.h | 2 +-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index a015357..d880818 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -150,6 +150,8 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner,
uint32_t liobn)
tcet->liobn = liobn;
snprintf(tmp, sizeof(tmp), "tce-table-%x", liobn);
+ memory_region_init(&tcet->root, OBJECT(tcet), tmp, UINT64_MAX);
+
object_property_add_child(OBJECT(owner), tmp, OBJECT(tcet), NULL);
object_property_set_bool(OBJECT(tcet), true, "realized", NULL);
@@ -200,6 +202,8 @@ void spapr_tce_table_enable(sPAPRTCETable *tcet)
"iommu-spapr",
(uint64_t)tcet->nb_table << tcet->page_shift);
+ memory_region_add_subregion(&tcet->root, tcet->bus_offset, &tcet->iommu);
+
tcet->enabled = true;
}
@@ -209,6 +213,8 @@ void spapr_tce_table_disable(sPAPRTCETable *tcet)
return;
}
+ memory_region_del_subregion(&tcet->root, &tcet->iommu);
+
if (!kvm_enabled() ||
(kvmppc_remove_spapr_tce(tcet->table, tcet->fd,
tcet->nb_table) != 0)) {
@@ -216,6 +222,7 @@ void spapr_tce_table_disable(sPAPRTCETable *tcet)
g_free(tcet->table);
}
tcet->table = NULL;
+ object_unref(OBJECT(&tcet->iommu));
tcet->enabled = false;
spapr_tce_set_props(tcet, 0, 0, 0, false);
}
@@ -231,7 +238,7 @@ static void spapr_tce_table_unrealize(DeviceState *dev,
Error **errp)
MemoryRegion *spapr_tce_get_iommu(sPAPRTCETable *tcet)
{
- return &tcet->iommu;
+ return &tcet->root;
}
static void spapr_tce_reset(DeviceState *dev)
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 6e33b9b..5a45c3f 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -507,7 +507,7 @@ struct sPAPRTCETable {
bool bypass;
bool vfio_accel;
int fd;
- MemoryRegion iommu;
+ MemoryRegion root, iommu;
struct VIOsPAPRDevice *vdev; /* for @bypass migration compatibility only */
QLIST_ENTRY(sPAPRTCETable) list;
};
--
2.0.0
